Ghana - Sawmill residues utilization study (Vol. 1 of 2) : Technical report

Joint UNDP/World Bank Energy Sector Management Assistance Program Activity Completion Report No. 074A/87 Country: GHANA Activity: SAWMILL RESIDUES UTILIZATION STUDY (VOLUME I - TECHNICAL REPORT) OCTOBER 1988 Report of the Joint UNDP/Wdd Bank Energy Sector Management Assistance Program This document has a restricted distnbution. Its contents may not be disclosed without authorization from tne Government, the UNDP or the World Bank.  ENERGY SECTOR MANAGEMENT ASSISTANCE PROGRAM PURPOSE The Joint UNDP/World Bank Entrgy Sector Management Assistance Program (ESMAP) was started in 1983 as a companion to the Energy Assessment Program, established in 1980. The Assessment Program was designed to identify and analyee the most serious energy problems in developing countries. ESMAP was designed as a pre-invesetment facility, partly to assist in implementing the actions recommended in the Assessments. Today ESMAP carries out pre-investment activities in 45 countries and provides institutional and policy advice to developing country decision-makers. The Program aims to supplement, advance, and strengthen the impact of bilateral and multilateral resources already available for technical assistance in the energy sector. The reports produced under the ESMAP Program provide governments, donors, and potential investors with information needed to speed up project prepar- ation and implementation. ESMAP activities fall into two major groupings: - Energy Efficiency and Strategy, addressing the institutional, financial, and policy issues of the energy sector, including design of sector strategies, improving energy end-use, defining investment programs, and strengthening sector enterprises; and - Household, Rural, and Renewable Energy, addressing the tech- nical, economic, financial, institutional and policy issues affecting energy supply and demand, including energy from traditional and modern sources for use by rural and urban households and rural industries. FUNDING The Program is a major international effort supported by the UNDP, the World Bank, and bilateral agencies in a number of countries including the Netherlands, Canada, Switzerland, Norway, Sweden, Italy, Australia, Denmark, France, Finland, the United Kingdom, Ireland, Japan, New Zealand, Iceland, and the USA. INQUIRIES For further. information on the Program or to obtain copies Af the completed ESMAP reports listed at the end of this document, contact: Division for Global and OR Energy Strategy, Management Interregional Projects and Assessment Division United Nations Development Industry and Energy Department Programme World Bank One United Nations Plaza 1818 H Street, N.W. New York, N.Y. 10017 Washington, D.C. 20433  GHANA SAIWILL RESIDUES UTILIZATION STUDY VOLUME I - TECHNICAL REPORT OCTOBER 1988  AB8C - Architectural and Engineering Services ATP - African Timber and Plywood (Ghana) Ltd. BRRI - Building and Road Research Institute CIDA - Canadian International Development Agency eCw - Electricity Corporation of Ghana EEC - European Economic Community EBP - Export Rehabilitation Program FAO - Food and Agriculture Organization FD - Forestry Department FPIB - Forest Products Inspection Bureau FPRI - Forest Products Research Institute GIHOC - Ghana Industrial Holding Corporati"n COG - Government of Ghana CRC - Ghana Railway Commission CTMB - Ghana Timber Marketing Board CWA - Cliksten West Afica Ltd. IIED - Interna' nal Institute for Environment and Development MIN - 1lim Tim_r Co., Ltd. MLNR - Ministry of Lands and Natural Resource ODA - Overseas Development Administrition PNDC - Provisional National Defense Council SIPI. - Subri Industrial Plantations Ltd. STC - State Transport Corporation STP - Specialized Timber Products Ltd. TDRI - Tropical Development Research Institute TEDB - Timber Export Development Board TVLC - Takoradi Veneer and Lumber Co., Ltd. VRA - Volta River Authority ABBUEVITIE a - annum Abs - absclute ADO - Automotive Diesel Oil CIP - Cost, Insurance and Freight cm - centimeter C&E - Construction and Equipment DCF - Discounted Cash Flow DM - Deutsche Mark 1IRR - Economic Internal Rate of Return FAS - Free Aboard Ship PFl1 - Financial Internal Rate of Return FOB - Free on Board fUa - from and at CJ - gigajoule GWh - gigawatt-hour  h - hour ha - hectare Ha - Mercury HHV - Higher Heating Value hl - hectaliters HP - horsepower IDO - Industrial Diesel Oil IFO - Inland Fuel Oil Igal - Imperial gallon in - inch kg - kilogram kJ - kilojoule km - kilometer kPa - kilopascal kVA - kilovolt-ampere kV - kilowatt kWh - kilowatt-hour 1 - liter LHV - Lower Heating Value LRMC - Long Run Marginal Cost m - meter N - million MCaI - megacalorie mcdb - moisture content, dry basis icwb - moisture content, wet basis MD1 - Medium Density Fiberboard min - minute NJ - megajoule mm - millimeter Mo - month MW - megawatt M.T. - metric tonne NPV - Met Present Value OD - oven dry O&M - Operations and Maintenance RFO - Rosidual Fuel Oil RWE - Round Wood Equivalent SCF -S tandard Conversion Factor SWE - Sol8i Wood Equivalent t - metric tonne TC - turtogenerator toe - tonnes of oil equivalent tonne - metric tonne USD - U.S. Dollar WTP - Willingness-to-Pay yr - year  micY AND FURL BQUIVALES cumcY 1 VI$ - 150 Cedi COUVERSON FACTORS 1 MJ 948 Etu 239 Kcal * 0.278 kWh mcwb LHV HHV Fuel () (NJ/kg) (NJ/kg) Sawmill Residues 36 11.9 20.0 Fuelwood. air-tried 30 13.1 20.0 Sawdust Briquettes 5 18.9 20.0 Charcoal 5 29.0 30.2 Crude Oil -- 43.3 Gas Oil (ADO) 43.3 45.5 Industrial Diesel Oil (IDO) 42.1 44.6 Inland Fuel Oil (IFO) 40.1 42.8 Residual Fuel Oil (RPO) 39.8 42.5 Electricity - 3.6 a/ a/ NJ/kVh  Costs of Utiization.............................................. 46 Technical/Infrastructure Constraints to Residues Utilization ......... 47 Water Spray Lubricdtion of Saw Blades*................ 47 Outside Storage of Sawdust........................... 47 Boiler/Furnace Configuration......................... 47 Boiler Efficiency......e........................... * *7 V. POTENTIAL ON-SITE ALTERNATIVES FOR IMPROVING AND/OR INCREASING USE OF WOOD INDUSTRY RESIDUES AS FUEL........ 48 Summary ....................................................... 48 On-Site Utilization................................................ 50 Backgroun.................................................. 50 Sawmill Process ..................................... 50 Cogeneration at Grid Connected Mills................. 57 Cogeneration at Non Grid Connected Mills............. 64 Residue Handling and Combustion Efficiency Improvements ................................................... 83 ~~~~~~~~ ~~~~~~~83 Backgrounds ** **#*o ................e........................... 83 Saw Guide and Sawdust Storage Improvements*........... 84 Furnace Modifications for Sawdust Combustion .....0... 85 Boiler/Furnace Efficiency Improvements................ 85 VI. POTENTIAL OFF-SITE ALTERNATIVES FOR IMPROVING AND/OR INCREASING USE OF WOOD INDUSTRY RESIDUES AS FUEL ........ 86 Summary ....................................................... 86 Off-Site Utilization............................................... 88 Background ......................e.... ,****oo 88 Substitution of Sawdust for Oil Fuels Consumption.....*. 88 Financial and Economic Analysis...................... 88 Substitution of Sawdust for Fuelwood Consumption*....0.. 90 Financial and Economic Analysis...................... 91 Off-Site Conversion Alternatives e....................... 92 Background .................................................... 92 Improved Charcoal Production............................ 93 Present .e00 ............. 93 Improved Methods ......... 96 Financial and Economic Analysis of Improved Charcoal Options ................o *.. 106 Sawdust Briquetting ..... 109 Proposed Plants...................................... 117 Charcoal Briquettes ........... 124 Background....................................... ....... 124 Production Options/Economics......................... 125 VII. CONCLUSIONS AND REOOMENDATIONS FOR INCREASED AND,OR IMPROVED UTILIZATION OF WOOD INDUSTRY RESIDUES. ........ 128 Suuunary... ...*.*............................................ ~128 On-Site Direct Utilization.............................. 128  TABLE OF CONTS EXECUTIVE SMAY.......... ....... ............. ........ ........... i TM INTRODUCTION 1 Sackope o ....... ,............. ......... ......... ... ...... 3 Scope of Suy3 Organization of Report...B e p o rt.. ............000 e0e 4 II. TUE GHANAIAN WOOD PROCESSING INDDUSTRY ......oo........o.... 6 Sector Performance...................................... 6 Type, Capacity and Location of Wood Processing Facilitiest ieooooooeee*o..... .........o.o..o.... 10 Industrial Timber Production.ootucti...oo.o. oono... o.... 13 Wood Industry Trends Affecting Residues Disposition.... 15 Trend to Greater Value-Addedue-Atd..oeoo.oed.o. ooooo 15 Trend Toward Exploitation of Secondary Species.ooooos 16 III. SUPPLY OF WOOD INDUSTRY RESIDUESo.oo... ......o.o......o.o. 17 s.umry. ...... .... ............... ................... 1? Sources, Types and Characteristics of Residuestues.o.... 17 Location of Residues...... i d u es.... .................... 21 Forest Residueso......*.**..... ................... oo 21 Wood Processing Residuesi.dou esooo...oo.o.o.oo.o...o. 22 Quantities Producedod...... ...0.0.00.0... .0000 .0 0000..0 23 Existing Sto c k p i le.... 00.000.........................0. 25 Reliability of Supplies p p l ie.oo... o..... oo..o...o..o.... 26 Present and Projected Surplus r p lu..o.......o.o.os...... 27 Present Surpluso............ o ..............eo.o ..oo 27 Future Surplusr p l us.................................. 29 IV. DEMAND FOR WOOD PROCESSING INDUSTRY RESIDUES..*........ o 31 Summry .... ............. ................................ 31 On-site Energy Uses and Disposalo....oo.o.o.ooo...o..o 31 Steam and Process Heeatoooo...o....................... 31 Cogenerationo.oo*oooo*o,ooooo00 0 34 Charcoal Production..oood. u c t i on... ...... . ........ 36 D ispo sal..o..oooooooo. oo ... ooooooooo... o.... oo....oo 37 Off-site Energy Usesoosooooes...o.oos..o..ooooo..o..oooo 37 Industrial and Co_mercial Heat Raising sing**...o.oo.. 37 Domestic Cooking.ooki.n g .ooo.o.o...ooo . .oo..e... 38 Charcoal Productionoo....................0...0...0..0 38 Briuti qgooo u e t t i ngooooo*o***ooo* 38 Energy vs. Non-Energy Uses... ses..................0..0.. 38 Secondary Manufacturing and Export p. o rt.........o... 39 Cottage Industry Woodworking........o.o..oo.......... 39 Particle and Fiber Board Productiono.o..o.ooo.o..o.oo 39 Summary of Present Residues Utili zation................. 39  Sawmill Process Heat...............*.***.,**,0.9......000 128 Cogenerationo.........................0.0..o.o....... 131 Direct Utilization in the Industrial Sector............. 132 Residue Substitution for Oil Fuels................... 132 Residue Substitution for Fuelwood.................... 133 Conversion Alternativeso ........... o.o...eo...oo..o..o 133 Improved Charcoal Making............................. 133 Sawdust Briquetting.....0.o...0.o.00oq.e.eO.*0o.0.... . 133 Briquette Carbonization.............................. 134 National Investment Implications........................ 134 Total Investment Potential........................... 134 Competition for Residue Resources.................... 135 Residue Utilization Priorities....................... 136 Uncertainties and Risk Factors.......................... 138 Health of the Wood Processing Industryoo..00.0...00.. 138 Location of Wood Processing Facilities............... 138 Wood Supply/Demand................................... 138 Oil Prices ...o...e.o..o...oo.. 4*o*o*ooooooo* 138 Electricity Costs.o000* * oo....................... 139 Inveatment Recommendations.. .o.....o o.................. t39 Sawmill Process Beat........................ 139 Sawdust Briquettingo................ 0000000000000000 139 Technical Assistance Recommendations.................... 140 Pilot/Demonstration Projects .o....o........o...o.ooo. 140 Improved Solid Residues Carbonization ........00..... 140 Briquette Carbonization.0 0 0.000o0.00.0o0............o 141 Policy Recommendations....o............................. 141 Sawmill Process Heato...................... .0.0...... 142 Residue Conversiono................................... 142 Areas for Further Investigation........................s 142 TABLES 2.1 Value Estimates for Industrial Forest Products in Export and Domestic Trade.o.. o... ......e........*o.*o 9 2.2 Industrial Timber Processing Facilities, 1986........... 10 2.3 Distribution of Sawmills by Size of Production, 1986.... 11 2.4 Distribution of Production by Sawmill Size, 1986........ 12 2.5 Annual Cut from High Forest............................. 14 2.6 Projected Distribution of the Industrial Hardwood Timber Harvest...o.v.s.... .o......... 0.0..0..0 14 3.1 Densities and Moisture Contents of Selected Ghanaian Woods.....................s 18 3.2 Moisture Content of Typical Saw Timber Species Mix ....... 19 3.3 Fuel Characteristics of Selected Ghanaian Woods......... 20 3.4 Nominal Characteristics of Wood Processing Industry Residues ..... .... 21 3.5 Sawmill Residue Production, 1986........................ 23 3.6 Combined Mill Residue Production, 1986.................. 25 3.7 Wood Processing Industry Residue Production, 1986 ....... 25 3.8 Surplus Sawdust Concentrations....0*.0*..........0.....o 29  3.9 Planned Additions to Wood Processing Facilities Utilizing Mill Residue for Process Heat Generation... 30 4.1 Wood Processing Facilities Utilizing Kill Residue for Process Heat Generation, 1986.................... 32 4.2 Wood Processing Facilities Utilizing Mill Residue for Co-Generation of Steam and Power, 1986........... 35 4.3 Wood Processing Industry Disposition of Residues by Region, 1986......................... 40 4.4 End-Uses of Wood Processing Industry Residues by !.ype, 1986........................................ 42 4.5 Disposi..on of Wood Processing Industry Residues by End-Use, 96.........................4 5.1 Matrix of Technical Options for Improving and/or Increasing On-Site Residue Utilization ..60*-*4000.. 49 5.2 Wood Processing Facilities Visited by Miss9ion**on..... 50 5.3 Secondary Species Requiring Kiln Drying..o..oo...0..g 52 5.4 Summary of Capital and Annual Operating Costs for Sawmill Process Heat Unit Production Model.oo..o... 54 5.5 Potential Gross Contribution to Forest Industry Value Added through Lumber Kiln Dryingoo ing.......... 56 5.6 Financial Analysis Results, Swmill Process Heat Unit Production Motl 57 5.7 Economic Analysis Results, Sawmill Process Heat Unit Production Moee l 57 5.8 Summary of Incremental Capital and Annual Operating Costs for STP Cogeneration Alternative 2......... 60 5.9 Summary of Incremental Capital and Annual Operating Costs for STP Cogeneration Alternative 3......... 62 5.10 Pinancial Analysis Results, Grid Connected Co-Generation Models (STP).... 63 5.11 Economic Analysis Results, Grid Connected Co-Generation Models (8TP ) 64 5.12 HIM Cogeneration Options Decision Matrix..0*0*.........0 67 5.13 Mim Area Electrical Demand and Consumption, 1985...5.... 69 5.14 Utilization of Residues at MIM 70 5.15 Charcoal Sales Prices, Mim Timber Co 70 5.16 Summary of Capital and Annual Operating Costs for MIM Cogeneration Alternatives........o........ee... 19 5.17 Net Present Cost of MIM Alternatives with No Grid Extension Assumed .............. . 81 5.18 KIM Alternative 3A vs. IA Financial and Economic Analysis Beet ...... .....81 5.19 KIM Alternative 5B vs. Base Case B Financial and Economic Analysis Results....... ..................... 83 6.1 Matrix of Technical Options for Improving and/or Increasing Off-Site Residue Utilization.............. 87 6.2 Industries and Institutions Visited to Evaluate Potential for Direct Utilization of Wood Residue..... 89 6.3 Financial Analysis Results, Oil to Sawdust-Fired Boiler Conerson ....................................90  6.4 Economic Analysis Results, Oil to Sawdust-Fired Boiler Conversion ......... ~ ........ .......................... 90 6.5 Financial Analysis Results, Fuelwood to Sawdust-Fired Boil'r Conversion............................ ........ 91 6.6 Economic Analysis Results, Fuelwood to Sawdust-Fired Boiler Conversion...... .........*......00.0.000..... 92 6.7 Earth Mound Charcoal Kilns, Ruia s i 96 6.8 Mill Residue Charcoal Marketing, Kumasi................. 96 6.9 Comparison of Charcoal Knl n s 99 6.10 Summary of Annualized Capital and Operating Costs of Charcoal Production Alternatives.................. 100 6.11 Financial/Economic Analysis Results, Beehive Brick Kiln Charcoaling Improvement......................... 108 6.12 Chaowus Ltd. Briquetting Machine Specificationsations*** 110 6,13 Chaowus Ltd. Briquette Fuel Characteristicsoo0.00...0000 111 6.14 Estimated Sawdust Briquette Demand m a nt.................. 113 6.15 Financial and Economic Costs of Fuelwoodl.............o. 113 6.16 Briquettes vs. Fuelwood Comparison in Bread Bakingt Accraccra............................................ 115 6.17 Briquettes vs. Fuelwood Comparison in Brick Manufacturing, Cape Coast... 115 6.18 Briquettes vs. Inland Fuel Oil Comparisont Accraa....... 126 6.19 Characteristics of Proposed Sawdust Briquette Manufacturing Plants..l a n ts.........................0 118 6.20 Summary of Capital and Annual Operating Costs for Proposed Briquetting Plantsa.n t.s.......o............ 129 6.21 Summary of Briquette Production and Transport Financial Costs........... ........................... 121 6.22 Financial Analysis Results, Proposed Sawdust Briquetting lns 121 6.23 Estimated Wood Balance, 1986-20008..... 122 6.24 Economic Analysis Results, Proposed Sawdust Briquetting Plants ..... .... 123 7.1 Net Economic Contribution to Export Lumber Unit Value through Kiln Dr y i n g 129 7.2 Sawmill Process Heat Investment Potentia1............... 130 7.3 Total Investment Potential for Increased and/or Improved Utilization of Wood Industry Residues....... 134 7.4 Net Benefit/Residue Resource Ratio for Energy Uses in Kumasi 135 7.5 Residue Energy Utilization Priorities .................. 136 7.6 Residue Utilization Profiles for Kumasim.... 137 FIEURES 2.1 Timber Export Volumes, 1976-1986; 1990 (Projected)...... 7 2.2 Timber Export Values, 1976-1986; 1990 (Projected)....... 8 2.3 Distribution of Sawmill Capacity by Size, 1986.......... 12 3.1 Sawmill Residual Fractions vs. Recovery Fraction, 1985 ..... 24 3.2 Surplus Residues by Type, 1986.......................... 28  3.3 Surplus Residues by Region, 1986 ....................... 28 4.1 Residue Utilization by Region, 1986 ..................... 41 4.2 Residue End-Us by Type, 1986........................... 43 4.3 Residue Disposition by End-Use, 1986 .................... 45 5.1 STP Ltd. Schematic - Alternative 1...................... 53 5.2 STP Ltd. Schematic - Alternative 2..................... 59 5.3 STP Ltd. Schematic - Alternative 3...................... 61 5.4 MIM Complex Daily Load Profile .......................... 66 5.5 Mim Timbers Ltd. Schematic - Base Case A/ Alternative 1A...........................72 5.6 Mim Timbers Ltd. Schematic - Alternative 2A ............. 74 5.7 Mim Timbers Ltd. Schematic - Alternative 3A............. 76 5.8 Him Timbers Ltd. Schematic - Alternative 4A............. 77 6.1 Typical Earth Mound Charcoal Production................. 94 6.2 Tropical Development Research Institute (TDRI) Steel Charcoal Kiln ........... 98 6.3 Clay/Metal Charcoal Kiln (Subri Semi-Mobile Kiln)....... 101 6.4 Missouri Charcoal Kiln (Subri River Project)............ 103 6.5 Casamance Charcoal Kiln........... ...................... 105 6.6 Beehive Brick Charcoal Kiln............................. 107 6.7 Continuous Briquette Charcoaling Machine................ 126 BIILIOGRAPHY MAP IBRD 20619: Chana Wood Processing and Other Industrial Centers  EXECUTIVK SUNKARY 1. Ghana harvested 1.07 million m3 (round wood equivalent) of i3dustrial hardwood timber in 1986 and consumed or exported about 600,000 m of timber products or logs. The difference, which can be considered as wood industry residues, had an energy value of 94,000 toe. About three-quarters of these residues were utilized at varying efficiencies in the domestic sector and in the wood processing sector itself. The remaining 23 percent, with 22,000 toe energy value, found no usage. Efficient use of these residues as a source of energy, especially in the wood processing industry, could have a significant impact on the financial health and foreign exchange earnings of the sector. This sector accounted for 6.2 percent of GDP in 1985 and approximately 6.4 percent of total export earnings in 1986. Converted surplus residues, after accounting for mill consumption, could significantly contribute to the energy demands of the commercial and household sectors. These possibilities and the investment requirements necessary to realize them are discussed below. Sector Performance (Chapter II) 2. Improving the performance of the Ghana forestry industry has been the primary target of the Export Rehabilitation Program (ERP) financed by credits from IDA, the Overseas Development Adminstration and the Canadian International Development Agency. As a result, productivity in the sector has demonstrated marked gains since 1984 after experiencing a sharp drop in output during the period 1976-1983. At present, only about 55 percent of wood industry processing capacity is utilized. In the short term, further gains in capacity utilization are unlikely due to forest resource constraints. Total timber harvest is expected to remain close to the 1986 level through the end of the century. However, two industry trends have been identified that have implications for residue production and consumption: (a) increases in the level of domestic processing for higher value- added; and (b) a shift to higher production of secondary (non-traditional) species. The primary effects of these two trends will be to change the quantity, type and characteristics of the residues generated as well as most likely increase the on-site utilization of residues as a result of increased needs for process heat. Supply of Wood Industry Residues (Chapter III) 3. Types. Wood industry residues can be bruadly classified into two major categories: solids (slabs, edgings, offcuts, veneer wastes and cores); and fines (sawdust, planer shavings and sander dust). Solids  - ii - accounted for 79 percent of the residues produced while sawdust accounted for the remaining 21 percent. Table 1 presents a summary of the distribution of residues by type. Table 1: PRODUCTION OF WOOD INDUSTRY RESIDUES, 1986 (3 SUE) Slabs & veneer EdgIngs Offcuts Sawdust Waste Cores Total quantity 213,175 66,747 93,269 34,723 26,698 434,612 Percent 49% 1% 21% 9% 6% 100% 4. Location. The production of wood industry residues is primarily concentrated in a few major wood processing centers. In fact, 66 percent of the total residue production is concentrated within an 8 km radius in the Kumasi area. An additional 23 percent is distributed between three ' other centers: Takoradi (9X); Mim (9Z); and Akim-rda (5X). The remaining 11 percent is scattered amongst eight other locations. 5. Future Supply. So long as the wood industry continues its recovery, total residue production is expected to remain fairly stable though the types and characteristics of the residues could change slightly. Increases in the level and quality of processing and shifts to harvesting of more secondary species will be the primary factors influencing change in the characteristics of the residues. On the whole, it is expected that effects will be counterbalancing and that the energy value of residues will also remain fairly stable. 6. Surplus Residues. Only 23 percent of wood industry residues are presently not utilized. The total surplus residues have an energy potential of 27,000 toe or equivalent to 13 percent of the 1985 industrial woodfuel consumption. Green (wet) sawdust is the only residue in abundant surplus accounting for 84 percent of the total available surplus residues. Ninety percent of all sawdust produced is not utilized and present disposal costs are estimated at approximately US$80,000 to 125,000 per year. This does not account for the potential environmental damage as a result of burning (smoke) or dumping (leaching). Demand for Wood Processing Industry Residues (Chapter IV) 7. End Uses. Table 2 provides a summary of the 1986 end-use of wood proceising industry residues. At present only 23 percent of the residues are consumed for on-site process heat generation or cogeneration. Approximately 32 percent is used off-site for firewood or  - iii - charcoal production while 22 percent is used for non-energy purposes (e.g. local furniture, fencing, etc.). 8. On-Site Use. There are 21 wood processing facilities that have wood-waste fired boilers for generation of steam and process heat. Almost all are combination mills producing sawn timber, plywood and/or veneer. These mills generally consume 50 to 60 percent of their wood residues. There are four mills that have cogeneration equipment installed on-site. However, only one currently operates in a cogeneration mode; the others have either experienced equipment problems or have not completed their installation. When cogenerating, these mills could consume most of their residues to meet their heat and electricity requirements. At present, only two major mills are not connected to the grid. Table 2: END-USES OF WOOD PROCESSING INDUSTRY RESIDUES, 1986 Cm SUE) Fuel for MtIl Firewood/ Non-Energy Surplus Pracess Heat/Cogeneration Charcoal Production Purposes Residues Total Solids 92,235 136,468 96,341 16,177 341,343 Flues 6,674 3,195 - 83,400 93,269 Total 99,031 139,663 96,341 99,577 434,612 (23S) (32%) a/ (22%) (23%) (100%) a/ includes 3% on-site charcoal production at MIN. 9. Off-Site Use. More than half of the wood industry residues are used off-site; 29 percent is for energy and 22 percent for non-energy purposes. Of the residues utilized off-site for energy, about 28 percent is used directly as firewood for food preparation in the commercial and household sectors. The majority, 70 percent, is converted to charcoal in primitive earth mound kilns. The resulting output represents 2 percent of the total charcoal production in Ghana. Only 2 percent is sawdust which is converted to briquettes at a private plant in Oda for sale to bakers and brickmakers. Of more than 60 industrial sites surveyed in the vicinity of the wood processing industries, only one is a regular consumer of unprocessed sawmill residues. Other industries using woodfuels obtain their firewood from the natural forests at competitive prices. With the exception of a minor amount of sawdust for briquetting, no other sawdust is presently used off-site for energy.  - iv - On-site Options for Residue Utilization (Chapter V) 10. Opportunities exist not only to utilize surplus sawdust but also to improve the present use cf solid residues so as to obtain the maximum economic benefit from all residues produced. The most economically attractive on-site options for improving and/or increasing residue utilization are: (a) Steam generation to meet process heat needs for kiln drying and wood treatment; (b) Improved saw blade guide and sawdust storage/handling systems to reduce water content in the sawdust residue and increase the net energy available; (c) Furnace modifications to enable substitution of sawdust for solid residues; and (d) Furnace improvements for greater combustion efficiency. Investments in cogeneration systems proved to be marginal at best and are not recommended. Table 3 summarizes the estimated financial and economic IRRs for the major investment. Detailed discussions and evaluations of each are presented in Chapter V and highlighted below. Table 3: SUMMARY OF ESTIMATED FINANCIAL AND ECONOMIC IRR FOR ON-SITE RESIDUE UTILIZATION OPTIONS OPTION FIRR EIRR Saw.ill Process Heat 27-56S 30-52S Cogeneratlon at SrId Connected Mills Negative 4%8 Cogeneration at Non-grid Connected Mills (MIN) o/ Negative <12% oZ Comparison Is against the option of grid extension costs. 11. Sawmill Process Heat. Results of the analysis on the possible uses for residues at a typical large sawmill point to the potential for significant economic gain from oa-site generation of process heat for wood treatment and kiln drying. Major economic benefits are derived from:  v (a) Higher value-added through export of kiln dried products; and (b) Increased range of economically exploitable species through log sterilization and lumber drying. Financial and economic IRR exceeding 30 percent are possible. National investment requirements in the range of US$ 7.4 to 13.8 million would be required (depending on the level of value-added processing as3umed) with resulting net annual economic benefits in the range of US$ 2.7 to 4.5 million respectively. 12. Sawdust Utilization: Benefits could be maximized if provisions are made to utilize surplus sawdust as a fuel at mills. This would entail incorporation of measures to improve the fuel quality of sawdust such as more efficient sawblade guide systems and sheltered sawdust handling and storage systems. Retrofit costs are minor compared to other sawmill capital investments. Additionally, provisions must be made to install boilers with appropriate combustion systems for direct sawdust utilization. 13. Coseneration. Almost all large sawmills in Ghana are connected to the national grid and therefore receive the benefit of low cost hydro- power. The marginal financial cost of residue fueled cogenerated electricity at these large mills is estimated at 5.6 to 7.1 US cents/kWh. With present industrial tariffs set in the range of 3.5 US cents/kWh, there are no financial incentives for mill owners to undertake investments in cogeneration. Lack of financial incentives is not the onlv barrier. Marginal economic costs of residue fueled cogeneration is estimated at 5.8 to 7.6 US cents/kWh which is still higher than the present estimated marginal cost of 5.2 US cents/kWh for grid system elec- tricity. In the short term at least, residue fueled cogeneration at saw- mills cannot be supported. In the longer term however, the marginal cost of grid system electricity is expected to rise as all low cost hydropower sites in Ghana have been fully exploited. Based on data in a recent system expansion study for VRA by Acres International, an estimate of LRNC for electricity in the range of 8 US cents/kWh is not unrealistic. Given this scenario, residue fueled cogeneration could be competitive. It must be pointed out, however, that the total potential power from this source would likely not amount to more than 20 MW whereas the Acres study indicates a need to bring on between 200 to 400 MW by the mid 1990s. 14. Two large mills are presently located off-grid. One, African Timber and Plywood Ltd. (AT&P) located in Samreboi, is not expected to be connected to the national grid in the foreseeable future. Its options for electricity are either diesel generation or residue fueled cogeneration. AT&P is presently undergoing renovation with Bank of Scotland financing and expects to cogenerate its electricity when it recommences operation in 1988. Clearly, in this case residue fueled cogeneration is more economic that diesel generation. The other mill, Mim Timber Co, Ltd. (MIM) located 47 kM from Sunyani, is scheduled to be connected to the grid in 1989 when VRA undertakes a US$2.2 million grid  - vi - extension. To date, construction has not yet begun on the extension. An anslysis of the least-cost electricity supply option at MIM, assuming grid extension to be uncommitted, confirms that grid extension is the best choice. A 1.2 MW base/intermediate load residue-fueled cogeneration plant coupled with existing diesels for peaking power results in marginally cheaper electricity when grid extension costs are considered. A US$2.1 million investment is required for the cogeneration plant yielding an economic IRR of only 12 percent. A recommendation for a cogeneration plant cannot be strongly supported given the additional management and risk factors associated with operating the cogeneration plant, the financial disincentives for MIN management, and the fact that social benefits to the surrounding area are not fully provided. Off-site Options for Residue Utilization (Chapter VI) 15. Several options are available for improving and/or increasing the off-site utilization of wood industry residues. As indicated earlier, over 70 percent of the residues used off-site for energy are converted to charcoal in primitive, inefficient earth mound kilns. Over 89 percent of the total Sawdust production is unutilized. And, the present known demand for s'wdust briquettes exceeds the supply. Given these facts, four key options were investigated in detail: (a) Direct utilization of sawdust in industrial/commercial oil- fired or wood-fired combustion systems; (b) Improved charcoal producti,n techniques; (c) Increased sawdust briquetting capacity; and (d) Introduction of briquette carbonization techniques. A summary of the estimated financial and economic IRR for the first three options is presented in Table 4. Detailed discussions and evaluations of a range of these options are presented in Chapter VI and highlighted below. Table 4: SUMMARY OF ESTIMATED FINANCIAL AND ECONOM'C iRR FOR OFF-SITE RESIOtE UTILIZATION OPTIONS OPTION FIRR EIRR Conversion of Industrial/Comercial Negative Negative Oil-fired Combustion Systems Conversion of Industrial/Commercial 11-23% a/ 32-42% a/ Wood-fired Systems Improved Charcoal Production 300% 500% Techniques Increased Sawdust Briquetting Capacity Negative-19% b/ 9-19% b/ I/ Represents the IRR from two of the most attractive candidates. b/ Variable depending on scale of project.  - vii 16. Substitution for Oil Fuels. The economics of substituting unprocessed sawdust. or solid residues for oil fuels (RFO/IFO) in industrial/comercial combustion systems in Ghana are unfavorable. Evaluation of a wide range of possible industrial/ccmmercial candidates indicated that petroleum prices would have to rise above US$ 30/bbl in 1986 dollars before savings from fuel costs could amortize the capital costs required for conversion. Alternately, capital costs would have to decline by 40 to 100 percent in order to yield favorable returns. One of the primary reasons for the negati -e economics is the fact that most potential industrial/commercial candidates have low utilization factors associated with their combustion equipment and therefore a relatively low base from which fuel savings can be derived. 17. Substitution for Fuelwood. The economic potential for substituting unprocessed sawdust for fuelwood consumption in industrial/commercial combustion equipment is limited. Conversion of most fuelwood combustion equipment to utilize sawdust is generally feasible requiring modifications to the grate and feed systems. However, haulage costs for sawdust and the low financial costs of fuelwood limit the possible candidates to those in the immediate vicinity of the sawmills. 18. Improved Charcoal Making. Almost all charcoal production from sawmill residues is produced by the traditional "earth mound" method. The conversion efficiency of most of these charcoaling operations was found to be extr ,ely low. The earth mound technique is generally used in forest and land clearing operations because it requires little equipment and can move with the resource. Sawmill residues provide an excellent opportunity to utilize improved charcoaling techniques, thereby potentia11y doubling the output of charcoal derived from these residues without increasing residue consumption. 19. After evaluating several improved charcoaling techniques, it was determined that Beehive brick kilns and Casamance kilns were the most technically and economically attractive options for charcoaling sawmill residues in Ghana. If all residues presently carbonized in only the Kumasi area were converted in Beehive brick kilns, charcoal output would increase by 4,400 tonnes/yr or equivalent to an 80 percent increase over the present charcoal production from residues. The estimated total investment required to achieve this improvement is US$ 110,000 which would yield an economic rate of return near 500 percent. Clearly, a program to improve charcoal production from sawmill residues should be high on the agenda. 20. Sawdust Briguetting. Loose sawdust is cumbersome to manage, transport and use and as stated earlier has limited off-site potential. When briquetted, the sawdust can be effectively transpor'-i, stored and utilized. The potential for sawdust briquettes has already been established in Ghana with the operation of a 2,000 tonne/yr plant in Oda. Present demand greatly exceeds supply. Total estimated demand from just the bakers and brick manufacturers in the main urban areas is in  - viii - excess of 45,000 tonnes/yr which is about equal to the quantity of briquettes that could be produced if all surplus sawdust were to be briqu4tted. 21. Evaluation of three different capacity screw press sawdust briquetting plants indicates that definite economies of scale exist with respect to this technology. A 14,000 t/yr plant in Kumasi is economically attractive with financial and economic IR estimated at 19 percent. A plant of this scale would consume just over half the surplus sawdust in the Kumasi area yet meet only one-third of the potential demand for briquettes from the bakers and brick manufacturers. Total investment for the plant is US$780,000, of which 24 percent is local costs. 22. Briguette Carbonization. While sawdust briquettes are an acceptable fuel-wood substitute in the commercial sector, they would face difficulties penentrating the household market where charcoal and charcoal stoves predominate. Sawdust briquettes produced by the heat extrusion screw press systems used in Chana could be carbonized either in separate kilns or in a carbonization tunnel appended to the last stage of the briquetting machine. Carbonization by the kiln method is proven and is practiced in Japan and Taiwan. The carbonization tunnel is still experimental but it has potentially significant energy efficiency advantages. Assuming a 32 percent yield of briquettes to charcoal and accounting for capital and operating costs results in charcoal briquette costs in the range of US$ 80 to 125/tonne. With charcoal FOB export value estimated at US$115 and charcoal prices in Takoradi of US$132/tonne, the possibility for a viable charcoal briquette market exists. However, the relatively experimental nature of this technology requires follow-up investigation before actual investments in this area are undertaken. Conclusions (Chapter VII) 23. Investments. Investments in sawmill process heat generation, sawdust briquetting and improved carbonization systems provide the most attractive options for improving and/or increasing the use of wood industry residues. Total potential levels of investment exceed US$8 million with economic rates of return ranging from 19 to 46 percent per sub-project. If a high level of log treatment and kiln drying is assumed, total investments in just process heat equipment could approach US$14 million. A summary of the total investment potential and associated residue consumption is presented in Table 5.  - ix - Table 5: TOTAL INVESTMENT POTENTIAL FOR INCREASED AND/OR IMPROVED UTILIZATION OF WOOD INDUSTRY RESIDUES Investment Annual Residue Investent Location Amount EliR NPV Consumption Sawmill US$7.4 N Process National at present wood 46S USS20.4 N up to 80,000 m3 Heat Industry output Sawdust Briquetting Kumasi USS0.78 N 19% US$0.50 M 27,000 m3 Plant Improved Charcoaling of Residues National a/ up to USS0.11 M 490% USS1.11 N 64,000 m3 a/ Amounts given are for Investment for improved utilization of all residues presently carbonIzed in Kumasl. 24. Competition for Residues. Options for residue utilization are mutually exclusive to the extent that they might compete for the same residue resource in terms of type and location. The primary source of competition would likely occur for sawdust in Kumasi if both maximum process heat generation and sawdust briquetting were promoted. The total sawdust production in Kumasi would not necessarily be sufficient under this scenario. Valuation of residue use for various options provides a basis for prioritization. The resulting residue utilization priorities are presented in Table 6. They indicate that sawdust should be used first at the mill boilers to the extent determined by process heat demand and technical feasibility of sawdust combustion. Solid residues should be used only to meet additional demand not met by sawdust. RemainirZ sawdust should be briquetted if available in sufficient quantities to realize necessary economies of scale. Remaining solid residues should be converted only in efficient charcoal kilns such as the Beehive brick kiln. An analysis of the situation in Kumasi based on this prioritisation would allow for construction of the 14,000 t/yr briquetting plant.  x oable 6: RESIDUE ENERGY UTILIZATION PRIORITIES Priority Ranking Utilization 1 Combust sawdust on-site for process heat generatlon/cogeneration, 2 Combust solid residues on-site for process heat generatlon/cogeneration. 3 Convert solid residues to charcoal In efficient kiIns. 4 Convert sawdust to briquettes. 5 Utilize solid residues as firewood. Recommendations (Chapter VII) 25. Investments. As a result of this investigation the following key investment recommendations can be stated: (a) Primary attention should be focused on investments to promote the on-site utilization of sawmill residues for generation of process heat used in value-added processing; (b) Attention should also be focused on the possibility of investments in the 14,000 t/yr briquetting plant in Kumasi; (c) Any investment in increasing residue utilization should incorporate technical assistance and resources to minimize water contamination of sawdust through improved saw blade guides and storage and handling systems; (d) Financing should be provided to institute a program to convert all sawmill residue charcoaling operations to improved methods; (e) If donor funding is made available, a small briquette carbonization project should be instituted to demonstrate the technical and economic feasibility of this option. 26. Policies. Government policies on residue utilization can have a major effect on the ultimate disposition of waste wood resources. With appropriate policies of fuels pricing, tax/fee levels, regulation, and market information dissemination the government can guide the development and use of this indigenous resource. Specific policy recommendations are  - xi - discussed in Chapter 7. Key policies recommended to improve residue utilization include: (a) Market development and information dissemination relating to export opportunities for kiln dried and treated lumber; (b) Differential taxation on value-added forest products, and phased extension of log export ban to wider group of marketable species (with attendant increase in requirements for lumber treatment and drying); (c) Institution of permit/fee systems for wood residue dumping and a ban on open residue incineration; and (d) Provision of domestic loan financing and training schemes, possibly from National Energy Board resources, for improved charcoaling of wood industry residues. 27. Further Investigation. Logging residues constitute more than 1.0 million mJ/yr of waste wood with an energy potential of more than double that available from the wood processing industry residues. To date only a small fraction of these residues are recovered. Clearly, an investigation into the logistics and economics of recovering this potentially more significant source of indigenous energy is needed to complement any efforts to improve and/or increase the utilization of wood residues. Subjects to be addressed include methods of carbonizing waste wood from timber operations in the forest, incentives that would be required to induce a shift of traditional charcoal-making into the logging areas and present technical, institutional and infrastructural constraints to wide scale charcoaling of forest residues.  I. INTRODUCTION Back!round 1.1 The Joint UNDP/World Bank Energy Sector Assessment Program conducted a comprehensive review of the Ghana energy sector in October, 1985. The results of this review were contained in a final report issued in November, 1986, entitled, Ghanas Issues and Options in the Energy Sector. The assessment determined that, in 1985, energy end-uses in the economy were supplied primarily by biomass fuels (i.e., woodfuels and agricultural residues), 72 percent, and imported petroleum, about 24 percent. Only 4 percent of end-use energy demand was met by electricity obtained primarily from two large hydropower plants on the Volta River. 1.2 While forest resources are ample in Ghana, they are subject to significant over-exploitation especially for meeting the large woodfuel needs of the rural and urban populations. The Bank/UNDP Energy Assessment concluded that this resource could be seriously depleted by. the early 1990s if deforestation pressures are not eased. Similarly unsettling is the fact that in 1985 imported petroleum absorbed 26 percent of the foreign exchange earnings of Ghana. The Assessment states that even if petroleum prices were to remain at two-thirds of their 1985 levels and Ghana succeeded in increasing exports, petroleum imports would still account for nearly 20 percent of foreign exchange earnings unless expansion of indigenous energy sources were to become viable. In helping identify possible options to improve the energy situation in Ghana, the Assessment identified the nearly 1.2 million tonnes/year of wood wastes generated in logging and sawmilling as a potentially important source of indigenous energy. The Assessment estimated that recovery and efficient use of these residues could reduce the offtake from the natural forests by at least 10 percent, or 0.8 million tonnes/yr. 1/ 1.3 Given the conclusions of the Ghana Energy Assessment, the Bank's Energy Sector Management Assistance Program (ESMAP) is executing a series of studies to assist the Government of Ghana (GOG) to exploit the potential of its wood wastes. The first undertaken, as represented by this report, was a study of the feasibility for increasing, and/4r. improving the use of sawmill and wood processing industry residues. 'he study was co-financed by the Canadian International Development Agency (CIDA) and was initiated in June 1986. A reconnaissance mission to Ghana fielded in that month identified the main issues to be addressed in the study. In addition, two Ghanaian consultants were engaged to conduct a complete survey of wood processing industry residue production and energy consumption patterns and also to identify and survey potential commercial 1/ Ghana: Issues and Options in the Energy Sector, Report No. 6234-GH, World Bank, November, 1986.  -2- and industrial wood energy consumers. 2/ An ESMAP mission followed in October 1986, consisting of a mission leader, energy economist, wood industry/residue specialist, biomass conversion specialist and biomass combustion/energy applicat-,ns engineer. 3/ The data collected by both the local consultants and the ESMAP mission have been extensively evaluated and the results are documented in this report. Objectives 1.4 The main objectives of this study are to identify and evaluate technically and economically feasible opportunities for improving and/or increasing the use of wood processing industry residues as an energy source. In this context, the specific issues evaluated include: (a) The rate of production, availability and location of different types of wood industry residues, and the characteristics determining their energy potential; (b) The technical and economic potential of different opportunities for utilization of the residues both at the site of residue production as well as externally; (c) The infrastructure, social and policy constraints presently inhibiting the increased use of wood industry residues as an energy source; and (d) The technical assistance and investment requirements necessary to realise the economically feasible potential of Ghana's wood industry residues. 1.5 On the basis of the evaluation of the above issues, the final objective of this ESMAP study is to formulate a comprehensive strategy and follow-up program to promote, where economic, the increased and 2/ "Survey of Wood Residue Generation and Utilization in Ghana," Essel Ben Hagan (Consultant) and Martin Ben-Dzam (Consultant - Wood Industries Specialist), Ru-Tek Consultants and Industries Ltd., Kumasi, Ghana. 3/ This report is based on the findings of a mission which visited Ghana from October 17 to November 7, 1986. The mission members were Messrs. Matthew Mendis (Mission Leader), Charles Feinstein (Energy Economist), Brian Hickman (Consultant - Wood Industry-Residues), Peter Neild (Consultant - Biomass Conversion), and Philip Trees (Consultant - Biomass Combustion/Energy Applications). The report was authored by Messrs. Mendis and Feinstein. Secretarial support was provided by Vernet Mason.  - 3 - efficient use of Ghana's wood industry residues. In this regard, particular emphasis is placed on: (a) Identifying and evaluating potential pilot/demonstration projects which would help establish the effectiveness and viability of increased and/or efficient residue utilization; (b) Defining investment requirements for a program to increase utilization of surplus residues both at wood processing facilities as well as in other commercial and industrial enterprises; (c) Defining appropriate policy instruments and organizational/.nstitutional measures required to support the recommended program; and (d) Identifying areas for further investigation and/or development which will help promote efficient use of wood residues. Scope of Study 1.6 This study focuses only on the wood processing industry resi,ues. It does not consider forest residues produced in the process of logging or land clearing. Of the total estimated 1.2 million tonnes of wood residues produced in Ghana annually, wood processing industry residues account for approximately 342,000 tonnes or about 28 percent. However, this represents the most readily accessible and inexpensively obtained portion. The forest residues, while constituting a significant quantity, require additional resources to collect and transport to potential markets. At present some unknown portion of these residues is collected and converted to charcoal to supply the more luv ive urban markets. Aspects for increasing the recovery of forest -,a, while worthy of further investigation, are not covered in this - 1.7 In conducting this study, over 90 percent - the wood processing industries were directly surveyed to establish present and projected patterns of residue production, consumption and disposal. In addition, surveys of energy consumption patterns at major industrial and comercial enterprises in the vicinity of the wood processing areas were also conducted to help identify opportunities for wood residue consumption. The study also investigated present means for conversion of residues to either charcoal or sawdust briquettes for transport to distant markets. In the case of charcoal, on-site observations were carried out to characterize charcoaling operations including conversion efficiencies, productivity and economics, with the intent of identifying methods for improving charcoal conversion. A detailed analysis of the sawdust briquetting operation in Oda, one of only a few commercially operating plants in Africa, was also undertaken to assess the scope for similar briquetting plants elsewhere in Ghana.  -4- 1.8 The study considered the inputs of over sixteen GOG agencies either directly or indirectly related to the forestry, wood processing and energy sectors. These inputs were essential in understanding the organizational and institutional influences on residue utilization. Information on sector performance and trends was ottained to assist in the evaluation. Finally, fuelwood and charcoal prices at the wholesale/retail levels were surveyed at the major urban markets to ensure incorporation of current energy price information in the subsequent evaluations. Organization of Report 1.9 The report is structured to provide a clear picture of the overall potential and investment requirements necessary to improve and/or increase the use of wood industry residues as an economically attractive energy source in Ghana. Chapter II provides a brief profile of the Ghana wood processing sector including past, present and projected performance. Emphasis is placed on industry trends affecting residue production and disposition, especially as it relates to processing for greater value added and exploitation of secondary species. Chapter III presents information on the supply of wood industry residues including sources, types, characteristics, locations, quantities, stockpiles and surpluses. Chapter IV contains the demand side of the picture outlining present on-site and off-site uses including energy versus non-energy uses for the residues. 1.10 Potential options for improving and/or increasing the use of wood industry residues as a fuel are covered in Chapter V for options at the mill sites and Chapter VI for off-site options. Both generic and specific case studies are evaluated to determine technical, financial and economic feasibility. In the case of on-site options, emphasis is given to use of residues for process heat generation and to cogeneration of electricity. Economics of cogeneration at both grid and non grid connected mills are evaluated. Residue handling and combustion efficiency improvements to increase the quality and usefulness of residues are also investigated. Off-site options considered included: substitution of sawdust for petroleum and fuelwood consumption; improved charcoal production; sawdust briquetting; and briquette charcoaling. In all cases, detailed cost estimates for implementing the proposed option are developed as a precursor to the financial and economic assessment. Key organizational and institutional factors that could alter the results are identified. 1.11 Conclusions regarding increased and/or improved utilization of wood residues are summarized in Chapter VII. Economically attractive options identified in Chapters V and VI are extrapolated to determine their national potential. Possibilities of cross competition for residues are accounted for by prioritizing the alternative utilizations using a benefits/scarce resources ratio. Total national requirements to  implement all economically attractive options are then estimated. Uncertainties and risks associated with investments in this sector are briefly discussed. Lastly, the chapter presents recommendations for key investments and technical assistance. Pilot projects to demonstrate technical and economic feasibility of options unfamiliar to Ghana are identified along with pro,ected costs. Policy recommendations to help promote the economically attractive options for improving and/or increasing residue utilization are presented at the conclusion of the report.  - 6 - II. TME GCHEtAI VOOD PROCESSING INDVSTRY Sector Performance 2.1 In parallel with the general decline in the country's economic situation, the Ghana forest product sector experienced a sharp drop in output during the period 1976-1983. However, due largely to changes in Government of Ghana (COG) policies and increased donor assistance, the wood industry has demonstrated a substantial recovery since reaching a low point four years ago. A twelve year summary of the value of industrial forest product values is given in Table 2.1. Forestry and logging contributed 5.9 percent of the 1984 GDP; 1985 figures are estimated at 6.2 percent of the total, or about 7 percent if the manufacturing wood industry is included. 4/ 2.2 Export performance is shown graphically in Figures 2.1 and 2.2. The strength of the present recovery can be gauged by noting that estimated 1986 forest product exports of US$ 48.0 million represent a 65 percent increase over comparable figures for 1985, or a performance which has not been achieved in absolute terms since 1978. The drop in export growth rates represented by the 1990 projections reflect limitations on supply of the most readily marketable species, as will be discussed later. 2.3 The COG has received credits for forestry rehabilitation and development from IDA totalling US$25.9 million for: (a) the Export Rehabilitation Project (Credit 1435/SP9-GH), and (b) the Export Rehabilitation Technical Assistance Project (Credit 1436-GH), and has also received credits granted by the Overseas Development Administration (ODA) and the Canadian International Development Agency (CIDA). The Export Rehabilitation Program (ERP) concentrates on the establishment of quick-disbursing IDA credits to the forest industry to (a) finance purchase of equipment, materials and spare parts to enable an increase in production and exports, and (b) restructure the timber marketing organizations which would enable the forest industry to export with a minimum amount of Goverment control. A total of sixty-two mills have received credit assistance under IDA. In addition, the ERP has provided two Government-owned industries with technical assistance. ERP assistance has been targetted at removing bottlenecks in order to restore basic log extraction and primary productive capacity. 4/ Draft Forest Sector Review, West Africa Projects Department, Agriculture Division, World Bank.  -7- Figure 2.1: TIMBER EXPORT VOLUMES, 1976-1986; 1990 (PROJECTED) 1486 368 .6 77 78 79 88 81 82 83 84 8S586 87 88 89 98 Year 23 Logs z Lumber a/ World Bank projection. b/ Lumber includes secondary wood products such as profiles, flooring and furniture components. Sources TEDS; World Bank.  Figuie2.2: TIMBER EXPORT VALUES, 1976-1986; 1990 (PROJECTED) 538 ~28 * - - _ ___ __ U 76 7778 79 8881 828384 8586 8788 89913 Year a Logs E3 Lumber al World Bank projection. b/ Lumber includes secondary wood products such as profiles, flooring, and furniture components. Sources TUB; World Bank.  Table 2.1: VALUE ESTIMATES FOR INDUSTRIAL FOREST PRODUCTS IN EXPORT AND DOMESTIC TRADE (Millions of Current US Dollars) Est. Year 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1964 1985 1986 Rcorded Exports 78.5 78.8 91.4 72.6 63.8 44.5 41.3 20.4 15.3 14.8 18.7 29.1 48.0 Domestic warket 29.3 34.6 61.8 111.1 64.9 63.6 64.4 49.0 46.9 27.6 30.3 49.5 - TOTAL 107.8 113.4 153.2 183.7 128.7 108.1 105.7 69.4 62.2 42.4 49.0 79.6 - Source: World Bank, TEDS.  - 10 - Type, Capacity and Location of Wood Processing Facilities 2.4 The wood processing industry in Ghana consists, for the most part, of primary producers such as sawmills, plymills, veneer plants, and combinations thereof. A small amount of secondary manufacturing exists producing small items such as mouldings, broom handles, parquet flooring and knock-down furniture components. Some 72 of the active mills in Ghana are straight sawmills, i.e. performing log break-down and producing sawn timbers for domestic consumption and export. An additional 21 mills produce rotary veneer/plywood (principally for the domestic market) and/or sliced veneers (primarily for export). The plywood and veneer mills are nearly always sited next to a sawmill; if not physically located in the same complex, then common ownership and management assure the input log supply. For this reason, sawmill facilities which include plywood or veneer lines will be referred to as combination mills. The number and regional distribution of the industrial timber processing facilities is shown in Table 2.2. Not included in the compilation are approximately 12 forest mills (so-called "bush mills") which are scattered mostly within the high forest zone surrounding Kumasi and which employ gasoline-engined mini-saws. Their small output and remote possibility of residues recovery preclude study consideration and were thus not surveyed. Table 2.2: INDUSTRIAL TIMBER PROCESSING FACILITIES, 1986 Rotary Veneer/ Sliced Region Sawmills Plywood MIIls Veneer Mills Ashanti 43 4 7 Brong Ahafo 8 - 1 a/ Central 3 Eastern 6 1 2 Western 12 4 2 Total 72 9 12 a/ On-site but not operational. Source: Ru-Tek. 2.5 Based on the GOG's Ministry of Land and Natural Resources (NLIR) guidelines, sawmills can be classified as large, medium or small according to their annual saw log input capacity:  - 11 - Classification Annual Saw Log Input (m3) Large >10,000 Medium 5,000 - 10,000 Small 5,OOO Ghana sawmills have been classed in Table 2.3 according to their size of estimated 1986 actual production. The Ashanti region, comprising 43 sawmills almost all of which are located within an 8 km radius of each other in the Kumasi area, is the dominant wood processing zone. The Western region is of second significance in terms of log volumes processed and is clustered around the centers of Sekondi-Takoradi, Samreboi, and Sefwi-Wiawso. The wood industry of the Brong Ahafo region is dominated by the state-owned Mim Timber Co. Ltd., the largest single sawmill in Ghana, while the mills in the Eastern region are located in Akim-Oda and Nkawkaw. The three wood processing facilities of the Central region are situated in Dunkwa and Cape Coast. Table 2.3: DISTRIBUTION OF SAWMILLS BY SIZE OF PROOUCTION, 1986 Mills with Annual Production of a/ Regilon <5000 m3 5000-10000 m3 >10,000 u3 Total Ashanti 14 11 18 43 Brong Ahafo 6 - 2 8 Central 2 - 1 3 Eastern 3 1 2 6 Western 3 2 7 12 Total 28 14 30 72 a/ Size classes according to saw log Input. Source: Ru-Tek. 2.6 Large sawmills having lO,OOO m3 or greater annual log input capacity account for 72.6 percent of the total installed sawmill capacity, as shown in Figure 2.3. The five largest sawmills in Ghana account for 25 percent of the total installed sawmill capacity. 2.7 Estimated actual 1986 industrial timber processing mirrors installed capacities and points to the dominance of the large sawmills in  - 12 - primary production and, hence, residue production. As shown in Table 2.4, production at the large class sawmills in the Ashanti, Western and Central regions account for nearly three-fourths of the total in those areas, while in Brong Ahafo the fraction exceeds 80 percent. Only in the Eastern region does the share from large mills slip, and then only to 61.7 percent. Industrial Timber Production 2.8 Industrial timber harvesting occurs almost exclusively in the high forest zone which covers one-third (8.2 million ha) of the total Ghana land area of 23.9 million ha. Practically all existing forest is under concession. The concessions have not been rationalized which results in certain mills experiencing a shortage of raw material input and having to operate in others' concessions, often at considerable distance from the mill. Present knowledge of standing wood volumes is incomplete and dates back to PAO surveys of 1980-1982. The Overseas Development Administration is presently carrying out a new resource inventory in the high forest zone and preliminary findings are expected to be available in 1987. Figure 2.3: DISTRIBUTION OP SAWMILL CAPACITY BY SIZE, 1986 - < 5.000 m3/yr Oman (12.2%) 135,0000 U,000 - mm 5,6~18000 ./y >x m3/ys 168,00 >i/yr (72.6%)5 FIGURES Mg LOG INPUT IN M3/YM Source: NLNR.  - 13 - Table 2.4: DISTRIBUTION OF PROOUCTION BY SAWMILL SIZE, 1986 (Percentage of Tota I Product ion) Mills with Annual Production of a/ Region < 5000 SOOO-10,000 m3 > 10,000 o3 Ashanti 12.8 12.5 74.7 Western 7.4 17.8 74.8 Eastern 19.4 18.9 61.7 Central 27.1 - 72.9 Brong Ahafo 18.3 -- 81.7 a/ Size classes according to saw log input. Source: Ru-Tek. 2.9 Approximately 180 species occur in the Chanaian forest, of which a minority have commercial economic value. Silviconsult Ltd. has classified the species into three groups according to their degree of commercialization. 5/ Group A comprises 40 species presently considered commercial and for which doii,estic and export markets exist. Group B contains 20 species presently considered marginally commercial. However, these species are considered potentially commercial and are likely to be increasingly exploited in the near future as markets are developed. Group C contains the remaining species which grow to a utilizable size. A listing of Group A and B species by botanical and trade names is given in Annex 3. 2.10 Fourteen of the 40 species in Group A species are consie red highly desirable and are banned from export in log form. These so-called "primary" species are indicated in Annex 3. The remaining species are considered "secondary" and when harvested are often unrecorded as to species by the Forest Products Inspection Bureau (FPIB). Thus an accurate breakdown of annual cut by species is not possible at present. A geieral comparison of the estimated 1985 commercial roundwood production to the Silviconsult recommended annual allowable cut has been made in Table 2.5. The comparison reveals that he recommended annual allowable cut for the primary species of 185,000 ma was already exceeded 5/ The Forest Department Review and the Requirements of the Forest Products Inspection Bureau and the Timber Export Development Board (Draft Report), Silviconsult, Bjarred, Sweden, September 1985.  - 14 - Table 2.5: ANNUAL CUT FROM HIGH FOREST IN RESERVES 1985 Sliviconsult Annual Estimated RWE Allowable Cut Production bl Recommendation Species Group (million m ) (mIllilon m3) Group A 0.523 0.719 of which 14 primary (0.225) (0.185) of which 26 secondary (0.298) (0.534) Group 8 0.004 0.386 Unallocated by species a/ 0.400 - TOTAL 0,927 1.105 a/ Unrecorded as to species. b/ 1966 RWE product estimated at 1.065 millIon m3. Source: World Bank, Sliviconsult; TE0O; Mission estimates. 2.11 Table 2.6 depicts the present and projected future distribution of the industrial hardwood timber harvest. Figures for 1986 estimate that exports itz log form accounted for 18.8 percent of the total harvest of ',065,000 e , and 37.1 percent of the roundwood equivalent (RaE) of total exports. As is reflected in the projections, by 1986 the total hardwood timber harvest had essentially reached the Silviconsult recommendation for annual allowable cut. Harvest projections thus assume adoption of a sustained yield resource management strategy. Increases in the total harvest would be dependent on substantial production occurring in the high forest areas outside reserves and in the estimated 52,000 ha of timber plantations. However, neither of these resources is systematically managed at present. Table 2.6: PROJECTED DISTRIBUTION OF THE INDUSTRIAL HAROWOOD TINDER HARVEST (thousand m3) Product Exports Log RWE of RWE Totel Lumber a/ Veneers Plywood Exports Exports Domestic Harvest 1986 110 29 1 200 539 526 1,065 1990 124 33 2 251 589 511 1,100 1995 176 28 10 180 589 511 1,100 2000 210 20 30 80 555 545 1,100 a/ Includes secondary wood products such as profiles, flooring, and furniture components. Source: World Bank.  - 15 - Wood Industry Trends Affecting Residues Disposition 2.12 Two trends in local wood processing have been identified through data analysis and industry discussions as having potentially significant impacts on residues production and utilization. These are (a) a trend to further domestic processing for higher value-added, and (b) a shift to higher production of secondary species. Each is expected to be a gradual trend occurring over the next five to fifteen years. The primary effects to be examined in succeeding chapters include changes in the amounts, types and characteristics of the various residues generated, as well as changes in the demand for these residues within the mills as a result of increases in processing. Trend to Greater Value-Added 2.13 Unless new inventory estimates and resultant management plans indicate that a higher level of harvesting is sustainable, production and sector revenues will face a constraint in log availability. A shift to greater value-added per unit log harvested is therefore anticipated in order to maintain growth in export value in 1990 and beyond. Specific manifestations of the trend include: (a) Greater processing of logs into export lumber, so that export in log form is eventually phased out past the turn of the century; (b) higher product recovery through improved sawmilling techniques and machinery and installation of more re-saw equipment; (c) increased secondary manufacture of wood products such as mouldings (profile boards), fiooring, broom handles and furniture components. 2.14 The rapidity of this shift will be governed by: (a) Pace of modernization and expansion of wood processing facilities; (b) Success in development of expanded markets for sawn and secondary manufactured wood products; (c) Pace of improvement of transport, handling and shipping infrastructure for timber products; (d) Rate of depletion of commercially valuable timbers, and resultant rise in economic pressures within the sawmill industry; (e) Political factors, such as a near ban on log exports as proposed in the Lagos Plan of Action for the Year 2000; and  - 16 - (f) Government policies such as industrial timber stump&ge fee levels and value-added taxation. Trend Toward Exploitation of Secondary Species 2.15 As noted, the wood processing industry is already facing constraints on the availability of the readily exportable fourteen primary species. These limitations are most evident in the Ashanti and Brong Ahafo regions, and sawmills relying on logs from these areas will be forced to move to processing of secondary species or face declining log throughputs. Mill managers in Kumasi report having to go 240 km one- way to log the high demand redwood species, approaching the limits of economic logging given the high transport and logging road construction costs. The production manager at Mim Timber Ltd. forsees a 30-50 percent reduction in primary species throughput with a corresponding increase in secondary species production over the next five to ten years, while the manager of Specialized Timber Products in Kumasi envisions a virtually complete shift at his mill in the long run. 2.16 A number of barriers on increased sales of secondary species, especially in export markets, presently exist: (a) Uncertainty as to the resource base and total availability of secondary species. Many overseas customers are unwilling to accept lesser known species unless a regular supply is assured for ten years. (b) Perishability. Many of the secondary species are subject to attack by staining and rotting fungi unless specialized treatment and drying measures are incorporated. (c) Lack of knowledge among processors and customers of species working properties and uses. The Porest Products Research Institute (PPRI) has primary responsibility for investigating and reporting on these characteristics. (d) Conservatism of industry and variable market tastes. Market demands are dictated by the uncertain whims of "changing fashion," and the current "in" phase of whitewoods is of uncertain duration. The Timber Export Development Board (TEDB) is charged under PNDC Law 123 with the responsibility "to develop markets for and promote the sale and export of lesser known timber species." While by far the greater part of secondary species exports have been in log form, significant exports in product form are expected to begin by 1990.  - 17 - III. SUPPLY OF WOOD INDUSTRY RESIDUES Summary 3.1 Estimated total wood processing industry residue production amounted to 434,612 m3 SWE in 1986, and was composed of slabs/edgings (49%), sawdust (21X), offcuts (15%), veneer wastes (9%) and cores (6%). In their green condition, the residues have an average density of 786 kg/mr at a nominal moisture content of 36 percent (wet basis), implying a net energy value of 94,000 toe. Major concentrations of residue production occurring in the Kumasi and Sekondi-Takoradi areas coincide with locations of major non-wood processing industries. Other locations where residues are found host little or no non-wood processing industrial activity. 3.2 So long as the wood industry continues its upward trend of rehabilitation as in the last three years, it can be safely assumed that the supply of residuals is reliable. Log throughput levels will continue to hold the greatest influence on the production levels of residues. Net effects of trends to increasing product recovery, secondary manufacture and secondary species exploitation on the suitability and reliability of wood processing residues as a fuel is not expected to be significant. 3.3 Sawdust is the only wood processing residue presently in abundant surplus amounting to some 83,400 mi SWE with a net energy value of 18,000 toe. Ninety percent of all sawdust produced is unutilised at present. Surpluses of solid residues totallinj 15,000 m SWE are primarily found at the isolated sawmill of Mim Timber Co. Sources, Types and Chares-eristics of Residues 3.4 The residues produced by the saw, ply, veneer and secondary manufacturing operations consist of: (a) Slabs and edgings, including slicer boards and bark strips; (b) offcuts; (c) sawdust, including planer shavings; (d) veneer waste (both green and dry), including dry plywood trim; and (e) cores (bouls). The residues are largely in the green condition, although some dried veneer, dry trim and sawdust is present in the veneer and plymills, and  - 18 - some dried offcuts, sawdust and planer shavings is available in the sawmills and secondary manufacturing plants. The density and moisture content of the residues are significant when estimating their tonnage and associated energy value. 3.5 Table 3.1 contains the densities and green moisture contents of many of the more common wood species found in Chana. The densities are given in the green and oven dry conditions. The densities and moisture contents are shown for the average green condition and are not indicative of changes in these properties due to handling or manufacture. Changes in properties can be expected due to: (a) The addition of water due to excessive sawguide lubrication; (b) addition of water due to precipitation when residues are stored in uncovered stockpiles; (c) natural drying in storage; or (d) forced drying in manufacturing processes or fuel drying facilities. Table 3.1: DENSITIES AND MOISTURE CONTENTS OF SELECTED GHANAIAN NOOS Green Green Moisture Moisture Densities Content Content Oven Dry (kg/) _ Green (kg/n) (Dry Basis) (Wet Basis) Species Low Avg High Low Avg High (%) (N) African Walnut 440 560 640 750 825 900 47.3 32.1 Afromosia - 650 - 950 1,050 1,200 61.5 38.0 Ayan 570 710 860 900 950 1,000 33.8 25.3 Bublnga 600 750 880 1,000 1,050 1,100 40.0 28.6 Candellei - 650 - 900 930 950 43.0 30.0 Ceiba 200 260 400 600 700 850 169.0 62.8 Cordia 160 230 290 700 750 80 226.0 69.3 DOnta 660 720 770 700 750 800 31.9 24.2 Edinam - 520 - - 9O0 - 73.0 42.2 Eusri - 500 - 800 825 850 65.0 39.4 Guarea 550 600 700 8a0 900 1,000 50.0 33.3 Hyedus 660 750 880 1,000 1,050 1,100 40.0 28.6 Kyenkyen - 430 - 700 750 80o 74.7 42.8 Kyere 460 500 570 900 925 950 85.0 45.9 Mahogany 420 490 570 650 725 800 48.0 32.4 Mekore 510 590 690 850 9D0 950 52.5 34.4 MNnsonia 540 600 650 850 950 1,000 58.3 36.8 Odum 480 600 670 990 1,045 1,100 74.1 42.6 Sopele 490 620 720 690 890 1,065 43.5 30.31 Utile 450 590 700 750 825 900 39.8 28.5 Wawa 250 350 520 530 590 650 68.6 40.7 Source: Vaa.nfurh/Scheiber Holzatias, Veb Fachbuchverlag, Leipzig, 1974; Mission estimates.  - 19 - 3.6 The utilization of mixed wood species within the mills may result in the accumulation of species mixtures or surges of one or two species. There is an advantage to mixing species when the mixture is to be used as fuel in the green condition as the low moisture content (m.c.) fuels will assist the higher m.c. fuels to burn, and an average density fuel will occupy less space and ease the fuel conveying and furnace problems which may attend very low density fuels, or very wet fuels. The anticipated shift to secondary species indicates a trend toward less dense and wetter species. In the short term, this trend will not be seen in certain concessions such as African Timber and Plywood (Ghana) Ltd. (AT6P) and Clikstan West Africa Ltd. (CWA). An evaluation of the average moisture content of green residues and the anticipated shift in about five years has been calculated for certain mills surveyed. The analysis is based on their present and future species mix and a-pears in Table 3.2. The increase in wet basis moisture content of approximately 1.5-2.5 percent at some processing sites would have the effect of reducing lower heating values (LHV) 6/ of undried residues by 2.8-4.7 percent. Table 3.2: MOISTURE CONTENT OF TYPICAL SAW TIMBER SPECIES MIX CS) 1986 Est. 1991 wet Dry Dry Wet Mill Basis Basis BasEs Basis Specialized Timber Prod. 61.1 38.2 - - A.G. Timbers 49.5 32.9 - - A,E. Saoud 57.0 36.3 - - HIM Tiober Co. 52.3 34.3 58.5 36.9 Gliksten (W.A.) Ltd. 46.9 31.9 46.9 31.9 TVLC: Plywood 66.7 40.0 70.6 41.4 TVLC: Timber 52.8 34.5 56.5 36.1 TVLC: Combined a/ 45.4 31.2 48.5 32.5 a/ Includes dried residuals. Source: Mission estimates. 6/ The LHV represents the energy content of a fuel after the heat of water vaporization is deducted.  - 20 - 3.7 The effect on the aggregate moisture content of using a portion of dried fuel is evident from the data for "TVLC Combined" when the figures are compared to the plywood and timber green mixed species inputs. The average moisture content has been significantly reduced by incorporating the dried components. 3.8 The higher heating values (HHV) 7/ of Ghanaian hardwoods are difficult to find in the literature, but the figures in Table 3.3 are available for the eleven species shown. Table 3.3: FUEL CH^ACTERISTICS OF SELECTED GHANAIAN WOODS Higher Percent Ash Species Heating Value, 00 Volatile Content (NJ/kg) (S) (S) Wawa 20.17 82.9 1.3 Esa (Celtis) 19.22 81.1 2.1 Ekki 20.61 80.4 0.3 Kyeokyen 19.12 80.9 2.9 Sapele 19.66 81.3 1.0 Doha"s 20.35 81.0 O.S Danta 20.22 81.2 1.3 Odum 20.24 75.2 2.7 Kane 20.77 82.2 1.0 Celba 18.59 81.7 3.2 Otie 19.19 76.4 3.6 Sources BMI; P-E International. 3.9 Estimated useful average characteristics for Ghana wood processing industry residues are summarized in Table 3.4. 7/ The MMV represents the oven-dry or calorific heat of a fuel.  - 21 - Table 3.4: NOMINAL CHARACTERISTICS OF WOOD PROCESSING INDUSTRY RESIDUES Oven Dry Density 503 kg/03 Green Molsture Content 36% (vet basis) Green Density 786 kg/m3 Volatiles 81.3% Ash Content 1.6% Higher Heating Value 20.0 MJ/kg (oven dry) Lower Heating Value 11.9 MJ/kg (at 36% mcwb) Source: Mission estimates. 3.10 Other important physical characteristics of sawdust and veneer wastes found in Ghana should be noted. Due to the abnormally deep cuts made in the large diameter logs and cants in Ghana, feed speeds are low, and therefore the sawdust is very finely divided. If not overly wetted down, this fine sawdust is easily air conveyed and is a very combustible fuel. It can present a disadvantage in a furnace in that it can become entrained in the combustion gases and carried up the stack, causing high emission levels and fly ash problems. Therefore, a furnace approporiate to the combustion of fine sawdust should be used. 3.11 Veneer wastes found at the combination mills come in long and thin sheets, tend to curl, are flexible, and tend to bulk up to large volumes. These "as clipped" residuals are therefore difficult to handle and convey mechanically and labor-intensive manual methods are commonly employed. Location of Residues Forest Residues 3.12 Residues from forest operations are available when the trees are felled and are approximately equal to the volume of roundwood extracted. Butt and top logs, branchwood and non-sawlog material left i the forest from commercial logging thus amounts to some 1.1 million m  - 22 - annually, or 860,000 t/yr green weight. An unknown amount of these residues makes up part of the estimated 8.6 million t/yr national woodfuels gross supply, 8/ but the greater portion remains in the forest to rot over a period of time. Mim Timbers Ltd. is presently the only mill making use of some forest residues; Afrormosia branches of 40 cm diameter and larger are fed to Scanstyle Ltd. for processing into furnit3re parts. IiJgh financial haulage costs of ipproximately 1,500 Cedi/m (US$ 10/mJ) for a typical 150 km haul limit greater utilization. Assisted through a US$3.5 million FAO project, the Forestry Department has experimented with mobile metal kilns in the Subri River basin as a means of efficient on-site carbonization of forest residues. The kilns' high cost and difficulty in moving them from logging site to site along with the potential forest fire hazards have thus far severely limited their application. However, the COG has created a corporation, Subri Industrial Plantations Ltd. (SIPL), for large scale clearing and reforestation within the Subri forest reserves. Aided by US$ 16 million financing from the African Development Bank, SIPL plans to cut 4,000 ha during the first five years following start-up. Estimated yields per hectare are: Commercial timber -- 86 m3 Carbonizable wood 160 .3 Residaal firewood 164 m3 Charcoal supply to the Sekondi-Takoradi area is thus expected to be boosted by 11,500 t/yr, and for firewood, 131,000 m3/yr. Although worthy of further examination, potential forest residue utilization is beyond the scope of the present study. Wood Processing Residues 3.13 Concentrations of residues occur in parallel with saw and combination mill activity. In the case of mills located in the Sekondi- Takoradi area and, to a lesser extent, the Kumasi area, these concentrations coincide with locations of major non-wood processing industries. The Akim-Oda, Nkawkaw and Dunkwa areas host only minor non- wood processing industrial activity, and in the isolated company towns of Him, Sefwi-Wiawso and Samreboi the mills represent virtually the sole source of non-agricultural employment. 8/ Ghana Energy Assessment.  - 23 - Quantities Produced 3.14 Information on residue production is based on a direct survey of the 66 mills listed in Annex 2. Residue volumes were elicited by questioning mill management on production figures and estimated numbers of carts or loads per day of each of the residue types. The data gathered at any one mill, however, may be very subjective and affected by the vagaries of question interpretation, experience, mood, and time availability of the interviewee. The survey data has therefore been utilized as follows. Data derived from the sawmill questionnaires has been plotted on Figure 3.1 which shows fractions of slabs/edgings, offcuts and sawdust as ordinates plotted against the lumber recovery factor as abscissa. Fitting the curves to this plot results in a more statistically powerful method to determine the sawmill residuals. 3.15 The average recovery factor (weighted by production level) was determined for each region in Ghana and the annual residual volume determined by type as shown in Table 3.5. All volumes represent solid wood equivalent (SUE) volumes and can be converted to oven dry or green weights using the nominal characteristic values in Table 3.4. Table 3.5: SAWMILL RESIWUE PRODUCTION, 1986 Weighted Log Slabs/Edgings Offcuts Sawdust Total Average Inpt Frection Voaliu Fraction VolVe Voiure Resiues Resgion Recovery (mJ) (a') uJ) (m') (a) Ashanti 0.423 348,599 0.331 115,386 0.104 36,254 48,804 200,444 Brong Ahafo 0.434 19,400 0.322 6,247 0.100 1,940 2,716 10,903 central 0.485 22,644 0.284 6,341 0.086 1,947 3,170 11,548 Eastern 0.451 32,549 0.310 10,090 0.096 3,125 4,557 17,772 Western 0.585 72,668 0.216 15,696 0.064 4.651 10,174 30,521 495,860 153,850 47,917 69,421 271,188 Overall Weighted Average Lumber Recovery: 0.453 Note: All volumes expressed In solid wood equivalents (SWE). Source: Mission estimates. 3.16 The data from the plymill, veneer mill and combined mill questionnaires cannot be evaluated by similar methodology due to dissimilarities between mills and the small number of mills (twelve) falling into these categories. Therefore, the residuals from this group of mills was taken at face value from the questionnaires. The residues from these mills are summarized in Table 3.6. Again, all volumes represent solid wood equivalents.  - 24 - Figure 3,18 SAWMILL RESIDUAL FRACTIONS VS. RECOVERY FRACTION, 1985 .. . ...- /1 * * 158 : -1S -'1- SS 1-- 1 1 Itl":t I1--~~ t ~~~~~FtAt t0JS- 3 ~ ~~~~ H-Fcs !,W  - 25 - Table 3.6: COMBINED MILL. RESIDUE PRODUCTION, 1986 a/ Im3 SWE) Slabs a Sawdust Veneer Edgings Offcuts Shavings Waste Cores Total 59,325 18,830 23,848 34,723 26,698 163,424 af Includes plywood and veneer mills. Source: Ru-Tek. 3.17 The total wood processing industry residues are the sum of the volumes given in Tables 3.5 and 3.6 and are shown in Table 3.7. Slabs and edgings are the most abundantly produced residues at 213,175 m3 SWE, representing 49 percent of the estimated 1986 total residuals production of 434,612 m3 SWE. Sawdust at 21 percent and offcuts at 15 percent follow in terms of abundance, while veneer waste and cores are relatively less common at 9 and 6 percent respectively. In their green condition, the total residue production has an energy value of 94,000 toe or 4 percent of fuelwood primary energy production in Ghana. Table 3.7: WOOD PROCESSING INDUSTRY RESIOUE PRODXCTION, 1986 iM SWE) Slabs & Veneer Mills Edgings Offcuts Sawdust Waste Cores Total Sawmills 153,850 47,917 69,421 - - 271,188 Combined 59,325 18.830 23.848 34723 26698 163.424 Total 213,175 66,747 93,269 34,723 26,698 434,612 Industry Percentages 49% 15% 21% 9% 6% 100% Source: Misslon estimates. Existing Stockpile 3.18 The wood processing facilities in and adjacent to Kumasi and Takoradi commonly have depressed areas land-filled with sawdust. Such stockpiles become contaiminated with dirt and water and inevitably bio- degrade with time and are generally not a satisfactory fuel source. The  - 26 - use of sawdust residues stockpiled out-of-doors in depressions and ravines as an energy source is not recom_ended. The operating costs to recover such residues, to process them to remove contaminants and to dry them in rotary dryers, and the high capital costs of the necessary ancillary fuel-handling equipment, are usually prohibitive. Capital facilities should only be planned based upon a confirmed ongoing supply of sawdust residue which can then be handled following practices appropriate to the process. Reliability of Supplies 3.19 So long as the wood industry continues its upward trend of rehabilitation as in the last three years, it can be assumed that the supply of residuals is reliable. Supply of residuals for on-site use would, of course, be assured as the mills control the utilization of their own residues. OnRoing supply of residues for off-site uses could be assured by contractual arrangements with producers. 3.20 Effects of the earlier noted wood products industry trends on the reliability of residue volumes and characteristics can be summarized as follows. (a) Greater processing of logs into export lumber. Increases in the volume of logs converted into sawn products will have the obvious effect of increasing the volumes of slab/edging, offcut, and sawdust residuals which are a direct by-product of the log break-down and cutting operations. (b) Higher product recovery. Mill improvements increasing recovery tend to reduce the amount of residues. Examples are: reduced kerf diminishes sawdust volumes% improved edging practices reduces edgings volumes; greater sawing accuracy increases the number of boards produced; accurate charging reduces round-up losses; improved clipping reduces veneer clips; more accurate lay-up reduces dry trim, etc. As demonstrated in Figure 3.1, the effect on sawmill residues is strongest as regards slabs and edgings, and weakest with sawdust. (c) Increased secondary manufacture. Secondary manufacture may increase some residues and diminish others. If small cuttings are recovered from edgings and offcuts, these residues will reduce while sawdust and shavings increase. If additional mouldings are produced, edgings may reduce and sawdust and shavings increase. As wood pieces for secondary manufacture must be kiln-dried, the shift is toward drier and more finely divided fuels and away from larger section residues. (d) Increased secondary species exploitation. As previously calculated, larger proportions of the less dense and wetter  - 27 - species will reduce green residue calorific values modestly. However, the kiln-drying requirements of many of the lesser- known species, to be discussed in Chapter 6, will increase the proportion of dry residues. In addition, the suitability of a number of these species for rotary veneer production will also produce more dry residuals. The effects of these trends will be most evident in the larger operations where capital is available to be invested in upgrading and converting plants. The smaller mills will continue to produce residues as they do today. Log throughput levels will continue to hold the greatest influence on the production levels of wood industry residues. Other effects are, to some extent, counterbalancing, and their overall net effect on the suitability and reliability of wood processing residues as a fuel is not expected to be significant on an industry-wide basis. Present and Projected Surplus Present Surplus 3.21 Sawdust is the only wood processing residue psesently in abundant surplus in Ghana, amounting in 1986 to some 83,400 m solid wood equivalent or 65,500 tonnes. Ninety percent of all sawdust produced is unutilized at present, which accounts for 8S percent of all surplus residues. At its nominal moisture content of 36 percent (wet basis), the surplus sawdust has a net energy value of 18,000 toe. Suqjpluses of slabs/edgings, offcuts and veneer wastes amounting to 13,900 m are found aS the isolated sawmill of Nim Timber Co. Ltd., with the balance of 2,270 m of slabs/edgings found at other remote mills. Residual volumes by type are graphed in Figure 3.2. 3.22 The regional distribution of the residue surplus is shown graphically in Figure 3.3. 3.23 Significant concentrations of surplus sawdust exist in the following five centers in the estimated amounts given in Table 3.8. Kumasi contains 63 percent of all surplus sawdust and 69 percent of the exploitable concentrations.  - 28 - Figure 3.2: SURPLUS RESIDUES BY TYPE, 1986 90 W~7 8' 78 0~6 P ~40- 209 - o ~10 0~~ Slabs/ Offcuts Sawdust Veneer Cores Edgings Wastes Figure 3.3: SURPLUS RESIDUES BY REGION, 1986 610- 3 ' . 050 * 40t > ~10 Ashanti Brong Central Eastern Western Ahafo 3 Sawdust 3 Other  - 29 - Table 3.8: SURPLUS SAWDUST CONCENTRATIONS Center m3 SWE % of Total Surplus Sawdust Kumasl 52,600 63 Mim 9,500 11 Sokondl-Takoradi 9,200 11 Nkawkaw 2,500 3 Ounkwa 2,500 3 91 Source: Mission estimates. Future Surplus 3.24 IJnder a "business as usual" scenario (i.e. assuming no new investment in improved residues utilization), the composition and distribution of surplus residuals would not be expected to change drastically, with sawdust continuing to be the main unutilized residue. Quantities of sawdust will be most sensitive to log throu*hput levels. A specific exception to this pattern is found at Cliksten Wea Africa Ltd. in Sefwi-Viawso, where the anticipated shut-down of cogneration operations will free an *nknown proportion of the sawdust presently used as boiler fuel (2,575 mJ in 1986). Similarly, solid residues not used for woodfuel by the surrounding community will be surplus. 9/ 3.25 Plans outlined by mill managers indicate a trend to increased use of wood residues for mill process heat generation, as depicted in Table 3.9. The additional heat demands will divert some off-site use of solid residues back to the mills. A decline in surplus sawdust volumes will occur to the extent that sawdust is utilized in mill boilers. 9/ The anticipated re-start of African Timber and Plywood Ltd. is not expected to affect surplus as the mill plans to use all its residues for cogeneration.  - 30 - Table 3.9: PLANNED ADDWITIOS TO WOOD PROCESSING FACILITIES UTILIZING MILL iRSIDUE FOR PROCESS HEAT GENERATION MiII Mill Type Descrlptlon Specialized Timber Products, Ltd. S Installation of cogenerating 70 t/hr at 20 Kumasi bar boiler and 480 kVA turbine-generator due for completion In 1987, plus associated steam pits and 6 x I5Om3 klIns. Nim Tlmbers Ltd. S/P/V Plans to expand present klIn capacity of imim 240 m3 to I X 0 .3 wIth S years. Hardwood Timber Products, Ltd. S 3 x 100 m3 kilns currently Idle due to high Takoradi operational cost of oil-fired boilers. Will convert to wood-fired boilers In mid-1987. WesXern Timbers Ltd. S 4 x 70 3 kilns to be installed In 1987. Takoradi Boiler on-site awaiting Installation. John Sitar Co. Ltd. S/P/V Plans to Install 12 x 25 .3 kilns, steam Takoradi pits, 2 x veneer dryers, and 2 x boilers. Scanstyle Furniture Ltd. F Current kiln capacity of 350 m3 to be Miii Increased by 28% In 1987. Poku Transport Industrial P/V Plans to Install 2 x locomotive type ComPlex Ltd. boilers. Kumasi Du-Paul Wood Treatment Co. Ltd. S New sawmill to be completed In 1987. WiII Takoradi utilize process heot for kiln drying of lumber for moulding line. A. E. Saoud Ltd. S New soamill under construction will Kumasi include 1 x 15 t/hr boiler. Note: 1. Mill types: S a Sawmill P a Plywood V a Veneer F a Furniture parts Source: Ru-Tek; Mission estimates.  - 31 - IV. DUIAnD 101 KOOD PROCESSING INDUSTRY ESIDUES Summary 4.1 About 27 percent of the 1986 total residue production was consumed within the mills themselves, primarily for process heat generation. The largest fraction of residues, 50 percent, was utilized outside the mill complexes for both energy and non-energy uses. The balance, or 23 percent, was surplus and was disposed of by burning or dumping. With the exception of Mim Timber Co. in Brong Ahafo, virtually all solid residues are utilized. The Ashanti region is the major consumer of wood processing by-products, both for on- and off-site uses. 4.2 The use of slabs and edgings for firewood and charcoal production is the largest end-use of wood residues at 31 percent of total residue production. Fuel for mill process heat/cogneration, other (non- energy) uses, and unused surplus evenly split the remainder. The chief non-energy use of residues is as a raw material for cottage industry woodworking. On-site Energy Uses and Disposal 4.3 Approximately 118,000 m3 (27 percent) of the wood processing residues produced in 1986 were consumed on-site, i.e. at the mills themselves. Nearly 84 percent of this consumption was for internal steam and process heat raising pu poses, including cogeneration of steam and electricity. About 10,750 m of the on-site total was carbonized at the Mim Timber Co. Ltd. plant, the only mill in Ghana engaging in this activity. The balance o)f on-site consumption was for non-energy purposes. Steam and Process Heat 4.4 As depicted in Table 4.1, 21 mill facilities have wood-waste fired furnace/boilers for the generation of steam and process heat. The heat thus raised is utilized in: (a) Steam/conditioning pits for preparation of veneer blocks and for sterilization of log species subject to spore and fungus infestation; (b) rotary and sliced veneer dryers; (c) dry-kilnas for the drying of wood stocks for secondary manufacture, manufactured components and export lumber.  - 32 - The majority of mills in this category presently combust 50-60 percent of their total residues. Almost all the mills utilizing process heat are combination mills, indicating process heat demand in the straight sawmills is quite low. Table 4.1: WOOD PROCESSING FACILITIES UTILIZING MILL RESIDUE FOR PROCESS HEAT GENERATION, 1986 Residue Ut I lized for No. of Process Wood-fired Boller Residue Heat Soilers/ Date MIII Generated Generation Nameplate of Name of MlII Type (m3 SWE) (*3 SWE) Ratings Manufacture ASHANTI REGION Poku Transport Industrial Complex Ltd. Veneer/PlymlIl P/V 7,281 4,611 (1) 465 MW 1978 Kumasl at 20 bar Poku Transport & Sawmills Ltd. Kumesi S 4,866 a/ (1) 720 MCaI/hr 1982 Logs and Lumber Ltd, Kumasi S/P/V 25,365 14,744 (3) 1S t/hr (1) 1972 3 t/hr (2) 1982 EJIsu Forest Products Ltd. Kumasi S/V 6,250 3.425 (1) Hot Water 1977 Boiler Fyne Limited Kumasi S/V 6,658 4,019 (1) 6 t/hr 1982 at 3 bars Wood Complex Kassl Ltd. Kumasl 5 7,349 a/ (1) 12 t/hr 1978 Atwima Timbers Ltd. Kumasl S 15,761 9,797 (1) 10 t/hr 1978 Lumber Processing Ltd. Kumasi P/V 11,080 6,023 (3) 4 t/hr 1977 each NaJa David Veneer S Plywood Kumasl P/V 13,035 7,085 (1) 18 t/hr 1977 Wood Industries Ltd. Kumasl S 5,760 a/ (1) 10 t/hr 1975 A. 0. Timbers Ltd. Kumasi S/V 14,240 7,204 (1) 20 t/hr 1975  - 33 - ERONG AHAFO lEGION Mlm Timber Company Ltd. Mi, S/P/V 45,377 3,173 (1) 6.5 t/hr 1979 at 23 bars Scanstyle Ltd. Mim F 4,473 1,200 (3) Hot Water 1969 Boiler CENTRAL REGION International Hardwood Ltd. Ounkwa S/F 8,750 6,073 (1) 20 t/hr at 5 bars 1957 EASTERN REGION Novotex Ltd. Nkawkaw S/P/V 2,101 368 (1) 15 bars 1976 Oda Wood Complex Ltd. Akim Oda S/P/V 12,661 7,881 (1) 5653.3 1982 x 103 kJ/hr WESTERN REGION A.T. 6 P. b/ Samrebol S/P 20,700 20,700 c/ (4) 7.5 t/hr 1948 each Gilksten W. A. Ltd. Safwl-Wlawso S/P/V 12,79M 12,793 cl (4) 15 bar 1950 T.V.L.C., Takoradi S/P 4,740 2,220 (1) 10 bar 1972 Ghana Prime Wood Products Ltd. Takoradi S/P 10,806 8,096 (1) 10 bar 1972 Biblanl Industrial Complex Ltd. Biblani S 1,474 319 (2) 5 bar 1974 TOTALS d/ 221,360 99,031 / Boiler not In use, but operatlonal. b/ Mill not In operaticn since February, 1986. 1985 estimate. cf Co-generation of steam and power. d/ Totals do not Include A.T. 6 P. Note: 1. Hili types: S a Sawmill P a Plywood V u Veneer F a Furniture parts PB a Perticle board Source: Ru-Tek.  - 34 - Cogeneration 4.5 Table 4.2 shovs that four wood processing facilities have turbo-generators or steam engines to enable use of high pressure steam for electricity generation. Three are state-owned: Mim Timber Co., African Timber and Plywood, and Gliksten West Africa. The fourth, Specialised Timber Products, is a private entity. Only Gliksten West Africa Ltd. is currently operative in a cogeneration mode, as explained below. 4.6 Cliksten West Africa Ltd. CUA presently burns all of its residuals, including hogged offcuts and cores, in four 1950 vintage locomotive-type boilers raising an average of 3.5 t/hr of steam at 15 bars. The steam is passed through 625 kVA and 437.5 kVA turbo- generators. No records of power production are kept, however plant demand is met through supplementation from a 690 kVA diesel set. The national grid passes within 1 km of the mill. An 800 kVA transformer is on-site and mill management hopes to connect to the grid in 1987 as soon as financing for the required second 800 kVA transformer can be arranged. At that time, local electricity production will cease and GWA will combust wastes only to meet process heat demands. 4.7 Specialized Timber Products Ltd. Installation of a 6.4 t/hr at 28 bar boiler and 480 kVA back-pressure turbine at this new sawmill is in progress and will be completed in the first half of 1987. The five year old equipment was acquired from a German mill for US$ 540,000 installed, approximately a 60 percent savings over comparable new units. The mill plans to combust essentially all of its residues and thereby meet 80 percent of its electrical energy demand plus the beat load from six 150 a kilnas and two steam pits. According to the mill manager, the chief motivation for the investment is to obtain a degree of independence from the ECC grid supply which was judged too prone to interruption. The STP management estimates the value of lost production due to electric supply faults in 1986 at Cedi 5 million (US$ 33,000). Synchronization for a power purchase/sell-back arrangement has been investigated, but it was concluded by STP that lack of VRA/ECG standards negate this option.  Table 4.2: WOOD PROCESSING FACILITIES UTILIZING WILL iESIDUE FOR 00-GENERATION OF STEAM AND POWER, 1986 Nb eplate Nameplate Rssidue Capacity of CapacIty of Total utilized Steam Engine/ DIesel Installed Rasidue for Turbine Gen- GeneratIng Generation Generated Co-Generation erating Sets Sets Caeacity Name of Mill (3 SWE/yr) (03 SWE/vr) (&VA) (kVA) (kVA) Gliksten West Africa Ltd., a/ Sefwl-Wiawso 12,793 12,793 1,062.5 690 1,752.5 Specialized Timber Products Co. Ltd., b/ Kumasi 20,736 20,736 480 National Grid 480 Mim Timber Co. Limited, Hli 45,377 0 420 c/ 3,126 3,S46 A.T. S P. Ghana Llmited, d/ Samreboi 20,700 20,700 3,750 850 4,600 s/ To be connected to national grid In 1987. Present condition of boilers Is poor. b/ Projection only. Equipment installation to be completed In 1987. c/ Steam engine presently not operational. d/ Mill not In operation since February, 1986. Estimates are for 1985. e/ 3 x 1250 kVA turbine-generators; 1 - fair condition; 2 - poor condition. Source: Ru-Tek; Mission estimates.  - 36 - 4.8 Mim Timber Co. Ltd. Steam raising equipment at Mim comprises two boilers, one wood-fired unit rated at 6.5 t/hr and 23 bars, and the other a 1 t/hr fuel oil-fired unit rated and 10 bars. A second wood- fired boiler, a 2 t/hr at 7 bar locomotive type, is slated for installation in 1987. High pressure steam from the large wood waste boiler is designed to feed a 420 kVA steam engine-generator iiatalled in 1980. However, during operation in the first year, lube oil contamination of the feedwater resulted in damage to the boiler. The steam engine has not been operated since 1981 because the condensate cannot be recycled due to lube oil contamination and there is a water supply shortage at Him during the 5 to 6 month dry season which will not permit open cycle operation. At present, only 7 percent of the residues are combusted for process heat; the balance is sold as firewood (18Z), charcoaled (24Z) or burnt off in a fire pit (52Z). Thus total electrical demands for the mill, the Scanstyle furniture factory, Mim Agro Ltd. and the surrounding community of 2.2 MW peak and 6.4 GWt. are met entirely by diesel generation. A 47 km Sunyani to Mim grid extension is proposed for 1989 at a capital cost of US$ 2.2 million (before firancing), financed by the European Investment Bank. 4.9 African Timber and Plywood (Ghana) Ltd. The large capacity ATP sawmill has been shut down since February, 1986 and the plywood line since mid-1984 because of financial and operational difficulties. A recently signed US$ 38 million financing agreement with the Bank of Scotland provides for mill rehabilitation and operation under a five year manAgement contract with Marktrace Projects Ltd. The ATP power house contains four 1948 manufacture 7.5 t/hr boilers, of which possibly two are in operable condition. These feed three 1,250 kVA turbo-generators; only one is considered serviceable. Plans are to refurbish the boiler house under the supervision of the manufacturer, Babcock and Wilcox (UK) Ltd. At such time when the mill complex returns into production, essentially all its residues will be utilized for steam and power generation. The national grid is 28 km away, but there are presently no plans for its extension to Samreboi. Charcoal Production 4.10 Thirty-one percent of the solid residues produced at Mim Timber Co. Ltd. were converted into charcoal at the mill in large earth mound kilns. Total charcoal production in 1986 is estimated at 865 tonnes, which translates to an apparent conversion efficiency on a dry weight basis of 13.9 percent. Sixty percent of the charcoal thus produced is sold to mill workers at 30 Cedis per 40 kg sack; the balance is sold to outsiders at various prices and leads to a average sale price of 64 Cedis/sack. As production costs are calculated by Mim Ltd. at 45 Cedis/sack (assuming a zero opportunity value of the residues), net mill income is 19 Cedis/sack. If charcoal consumption patterns follow estimated urban averages of 140 kg/person/year, then 6,180 persons meet their domestic cooking needs from the residue-derived charcoal.  - 37 - Disposal 4.11 Almost all solid residues (i.e. slabs/edgings, offcuts, and cores) which are not consumed at the mills are sold for off-site consumption. The main exception is Mim, where nearly 15,000 m* of slabs/edgings and offcuts were burned in an open fire pit as a means of disposal. 4.12 Sawdust is dumped away in land depressions or ravines near the mills using 5 m3 tractor-trailers and bulldozers. Depending on land availability, the sawdust may be burnt in large piles. Financial costs of equipment, operations and labor for sawdust disposal range from US$ 1,000 to 8,000 per annum per mill, with the latter figure pertaining,to the largest mills. Environmental costs and fire hazards are likely significantly greater. Hardwood Timber Products Ltd. of Takoradi dumps sawdust in city areas under city council permit, to the voiced displeasure of nearby residents. A sawdust pile spontaneously combusted on the premises the week before the mission's visit. In Kumasi, land filling around the Ahinsan-Kaase industrial area is no longer being allowed by the landowners. A large capacity mill complex, A.E. Saoud/Lumber Processing Ltd., had a serious fire accident two years ago as a result of sawdust disposal by burning. Off-site Energy Uses 4.13 The largest fraction (50 p-rcent), or some 217,000 m3, of the 1986 processing residues found their way to gses away from the mill complexes. Energy use consisted of 124,000 mn of slabs/edfings being sold for firewood and charcoal production, plus about 2,800 m of sawdust processed into briquettes. The principal application of this energy was for food preparation in bakeries, local restaurants and households. However, the sawdust briquettes are being adopted for use in brickmaking kilns. Industrial and Commercial Heat Raising 4.14 Of 61 industrial sites surveyed preliminarily for energy use, only one, Asokwa Brick and Tile Co. Ltd. in the Central Region, is a regular consumer of unprocessed sawmill residues. Ankaful Brick and Tile Co. Ltd. is a regular user of sawdust briquettes. Other industries utilizing woodfuels, which include soap and palm oil producers, brick factories and gold mines, obtain firewood from the natural forest. 4.15 Bakeries, small restaurants ("chop bars") and fish smokers located within a 10 km radius of the major wood processing centers are major consumers of slabs/edgings for use as firewood. Sale prices at the sawmill gate are about 400-500 Cedi/tonne (US$ 3/tonne) in Kumasi and 600 Cedi/tonne (U8$ 4/tonne) in Takoradi. In addition, about two dozen public boarding schools in these areas use from 60 to 450 tonnes/yr each for institutional cooking.  - 38 - Domestic Cooking 4.16 The balance of residues consumed directly as firewocS ib used in households for lomestic cooking on simple, inefficient stoves, often of the "three stone" variety. However, charcoal is the preferred domestic fuel in urban areas, exceeding firewood consumption by nearly 10 to 1 on a gross energy basis. 10/ Charcoal Production 4.17 An estimated 60 percent of the slabs/edgings sold as fuelwood in Kumasi, and 80 percent in Akim-Oda, are carbonized by charcoal makers working within a few kilometers of mill sites. Very little residue charcoaling activity takes place near the mills in Sekondi-Takoradi, and the town's main source of charcoal supply is from the forest areas surrounding Tarkwa. The solid residues are carbonized in so-called "earth mound" kilns, although in many cases the top covering iF actually sawdust. In the Kumasi area in 1986, approximately 64,000 m of slabs and edgings were convertee to 5,400 tonnes of charcoal with a calorific value of 3,750 toe. An estimated 300 persons were employed in this activity at 50 sites, earning amounts ranging from 100-300 cedis per person-day. Briguetting 4.18 There is one briquette plant presently operating in Ghana, Chaowus Ltd. in Akim-Oda. The plant is owned and operated by a Taiwanese entrepreneur and has been in production for approximately one and one- half years. Present actual production rate of 1,100 t/yr is only half stated capacity due to operational inefficiencies. Chaowus obtains sawdust at no charge from Akim-Oda area sawmills, using their own 7 tonne truck to haul the sawdust to the plant. Total sawdust demand, includinI amounts combusted to heat the sawdust drier, is approximately 2,800 m SUE at the current briquette production rate. The plant thus consumes about 60 percent of the sawdust produced in Akim-Oda. Energy vs. Non-Energy Uses 4.19 It is axiomatic that wood processing residues should be put to their hi hest and best use consistent with economics. Approximately 95,000 m of residues were put to non-energy uses which will be reviewed briefly for comparison with value in energy uses. In the case of offcuts and veneer cores, non-energy applications are the dominant utilization, accounting for the disposition of 77 percent of the former and 96 percent of the latter. 10/ "Report of Pilot Survey on Puelwood and Charcoal Consumption in Accra", Government of Ghana National Energy Board, October 1985.  Table 4.3: VOWD ROCESSINB IISSSRTY DISPO6ITION OF RESIOUES 6Y tMEBlon, 1906 t0m SW) UtilIzed Inldn thm Wilts UtIlied Outside1 tb Wills _w1 us Slabs Swdust Vener Slabs Saedust e Slabs vener ReolcnAlI I tdgings Offeuts ShavIngs Waste Cores Totals Edgings Offeuts Slavings Wast Coe Totals Edgings Otfeuts Snudunt Wste Totals Swnelils 14,400 3,760 - - - 18,160 100,966 52,494 390 - - 133,870 - - 46,414 - 48,414 Combined UD#DOO 3,8 3_418 28.398 - 45.201 5jj0 2.6? _ - 20,467 28.393 - - 4,197 - 4,197 Totals 24,400 7,145 3,418 26,396 _ 63,361 106,045 35,361 390 - 20,46? 162,263 - - 52,611 - 52,611 kron Alasto SnWlls _ - - - - - 6,247 1,940 - - - 8,187 - _ 2,716 - 2,716 Ccblned 10,739 ILI73 - - 13,912 8,054 - - - 8,054 8,055 4.603 94 1,249 23,411 Totals 10.739 3,173 - - 13,912 14,301 1,940 - - - 16.241 8,055 4.603 12,220 1,249 26,127 > Se I I s 2,663 1,423 209 - _ 4,295 1,498 524 - _ - 2,022 2,270 - 2,961 - 5,231 Combne - - - - - - - - - Totals 2,663 1,423 209 - _ 4,295 1,496 524 - - - 2,022 2,270 - 2,961 - 5,231 Eastrn semi I I - - - - - 10,090 3,125 693 - - 13,908 - - 3,864 - 3,864 Combined 5.37 1.503 - 3.091 - 9-971 - - 2,112 - 2.678 4.790 - - 378 376 Total s 5,377 1,503 - 3,091 - 9,971 10,090 3,125 2,805 - 2,676 18,698 - - 4,242 4,242 "esterm 5 ellils 1,334 1,205 - - 2,539 14,362 3,446 - _ _ 17,606 - - tO,174 - 10,174 CobIned 12,041 5,299 3,047 1.985 3.553 23.925 - - - - - - - - 1,192 - 1,192 Totals 13,375 4,504 3,047 1,985 3,553 26,464 14,362 3,446 - _ _ 17,608 - - 11,366 - 11,366 Industry otals 56,544 17,748 6,674 33,474 3,553 118,003 146,296 44,396 3,195 - 23,145 217,032 10,325 4,603 83,400 1,249 99,577 Soure: mI ssIan estieates.  - 39 - Secondary Manufacturins and Export 4.20 Approximately 8,200 m3 of solid residues were further processed within the mills to yield marketable products such as flooring, tool handles, broomsticks, fencing materials and wooden crates. Offcuts of high value species such as Afrormosia and Hyedua are ripped into strips for export, while cores (bouls) are sliced lengthwise and reassembled for strip shipping. These remanufacturing operations are usually highly profitable. Cottage Industry Woodworking 4.21 In addition to the industrial scale production of knock-dawn furniture parts, there is a large and active cottage industry centered around the sawmills based on the reworking of offcuts. These 3 to 10 man carpentry/furniture operations typically employ small band and circular saws to produce low cost structural timber, chairs, tables, beds, chests, toys, etc. for domestic consumption. It is prima facie evident that a good deal of employment, value and income is being generated by these artisan activies. Particle and Fiber Board Production 4.22 Novotex Ltd. in Nkawkaw feeds most of its slabs/edgings and offcuts to a domestic grade particle board plant which is part of the complex. About 1,350 m of solid residues were utilized in this ashion in 1986; the balance of the raw material input for the 8,000 m board production was extracted from the forest and hogged. Western Timbers Ltd. of Takoradi, the MLUR and SCM Engineering of West Germany are jointly investigating the feasibility of producing medium density fiberboard (MDF). The highest grade can coztain up to 20 percent sawdust and has an export value of about US$300/m FOB. Other grades roughly compete with domestic plywood and are composed of up to 50 percent sawdust. Although the mill manager asserts that MDF is in high demand as an export product, the high cost of shipping such a dense product and the current world surplus of MDF manufacturing capacity will likely dim the economic prospects of such a venture. Nevertheless, should the scheme prove successful it should be considered a higher value use for on-site sawdust residues than as fuel. Summary of Present Residues Utilization 4.23 The 1986 utilization of wood processing residues is broken down by region in Table 4.3 and displayed graphically in Figure 4.1. As to be expected from residue production statistics, the Ashanti region is the major consumer of wood processing by-products both for on- and off-site uses. However, the Western region utilizes a greater share of its residues within the mills, due in large part to the higher proportion of facilities equipped with boilers for process heat raising and cogeneration.  - 41 - Figure 4.1: RESIDUE UTILIZATION BY REGION, 1986 250 150 lee p4 50 0 Ashanti Brong Central Eastern Western Ahafo gg3 In-Mil1 Use 3Outside Mill JUse H Surplus  - 42 - 4.24 The end-use of residues is arranged by residue type in Table 4.4 and Figure 4.2. The use of slabs and edgings for fuelwood is the largest single employment of wood residues at 31 percent of the total residue production. Fuel for mill process heat/cogeneration, other (non- energy) uses, and unused surplus evenly split the remainder. Table 4.4: END-USES OF NOMD PROCESSING INDUSTRY RESIDUES BY TYPE, 1986 (a' SWE) Fuel for Furniture, MIII Process Flrewood/ Fencing, Surplus/ iHeat/Cogeneration Charcoal Prod. Export & Other Unused Slabs/ 48,746 134,918 19,186 10,325 b/ Edgings (49%) (97%) (20%) (10%) Offcuts 9,046 1,550 51,548 4,603 cl (9%) (1%) (54%) (S ) Sawdust 6,674 3,195 ", - 83,400 (7%) (2%) (84%) Veneer Waste 33,474 - - 1,249 c/ (34%) (1S) cores 1,091 - 25,607 - (1I) (26%) Totals 99,031 139,633 96,341 99,577 (100%) (100%) (100%) (100%) Industry Percentages 23% 32% 22% 23% a/ 2,805 m3 SWE for sawdust briquette production at Chaowus Ltd., Akio-Oda. b' 8,05S .3 SUE burned In firepit at Mim Timbers Ltd., Rim. c/ Burned In fire pit at Him TIlbers Ltd. Source: Mission estimates.  - 43 - figure 4.2t USIDUE MM-USE BY TYPE, 1986 140 w ~1310 1ao 110 90 0 ~80 50 0D 40 5 30 0 ~20 le 0 Mdl Fuel FLrewood/ Other Surplus/ Charcoal Unused 3g Slabs/ Offcuts E Sawdust dWste Cores Edgkngs Wae  - 44 - 4.25 Table 4.5 and Figure 4.3 re-organize this information by end- uses of the residues. Table 4.5: DISPOSITION OF NOD PROMCSSING INDUSTRY RESIDUES BY END-USE, 196 (U SWE) Veneer Slabs/Edgings Of fcuts Sawdust Waste Cores Fuel for W111 Process 48,746 9,046 6,674 33,474 1,091 Heat/Cogeneratlon (23%) (14S) (7%) (96%) (%) Firewood/Charcool 134,918 1,550 3,195 - - Production (63%) (2%) (3%) Furniture, Fencing, 19,186 51,548 - - 25,607 Export l Other (9%) (77%) (96%) Surplus/ 10,325 4,603 83,400 1,249 - Unused (S0 (7%) (90%) (4%) Totals 213,175 66,747 93,269 34,723 26,698 (100%) (100%) (100%) (100%) (100%) Source: MIssion estimates,  - 45 - Figure 4.31 RESIDUE DISPOSITION SY ND-USE, 1986 220 200 3 2180 gV) g160 148 120 100 80 a' 60 *3 1134e 9-40 o 20 - Slabs/ Offcuts Sawdust Veneer Cores Edgings Wastes S Mill Fuel F i rewood / Oth.r X Surplus  - 46 - The figures indicate that residues are utilized or disposed of as followgs Residue Utilization or Disposal Slabs/edgings Primarily sold for charcoal production or firewood. Burned to raise steam for process heating of dryers and conditioning vats at combination mills. Some minor secondary manufacture. Very minor use for particle board manufacture. Offcuts Primarily sold to furniture manufacturers and carpenters. Some use as fuel at combination mills and cogeneration sites and for charcoal production. Very minor use for particle board manufacture. Sawdust Usually disposed of by dumping or open burning. Minor use to raise steam at combination mills and for briquette production in Akim-Oda. Veneer waste Burned to raise steam at combination mills. Cores Re-sawn for export. Sold for domestic consumption. Minor use as hogged boiler fuel at GWA and for charcoal production. The types end locations of surplus residues are discussed in Chapter V. Costs of Utilization 4.26 In Chanaian mills most residues are collected by hand, although sawdust may be handled by chain conveyors or pneumatic systems in some of the larger plants. Slabs, edgings and trim blocks are normally placed on hand carts or collected in trailers for transport out of the mill area. Sawdust is most frequently transported to an adjacent pile for landfill or burning. These practices have costs associated with the labor of collection and for tractor/truck operations and maintenance. These costs are essentially the same whether the residues are to be sold, dumped, burned or utilized to fuel an on-site thermal plant. The delivered cost associated with off-site use is therefore transport to the point of consumption. 4.27 Additional costs would be associated with mechanized fuel handling at the thermal plant. For example, fuel silos, their unloaders, and fuel distribution conveyors may be required at the thermal plant which would need to be justified by labor savings or the value of  - 47 - continuity of operation. If air conveying of sawdust and shavings is utilized, there may be an increase in horsepower to redirect the the fuel up into a fuel silo. Determination of the incremental horsepower is site specific and would result in an incremental increase in power costs which should be considered in the economic evaluation of the specific project. Technical/Infrastructure Constraints to Residues Utilization 4.28 A number of technical and organizational constraints cause sawdust residues to go unutilized, thus diverting solid residues from alternative uses into use as boiler fuel. Rxisting technical shortcomings, as discussed below, result in inefficient combustion of the solid residue fuels. Water Spray Lubrication of Saw Blades 4.29 Numerous mills employ water spray for the lubrication of band and circular saw blades used in log break-down. The water is sprayed in excessive amounts, at some mills visited being applied on the sawblade by a garden hose resulting in most of the water simply splashing off the blade and excessively wetting the sawdust. The over 70 percent moisture content (wet basis) of the sawdust makes it very difficult or impossible to combust without expensive pre-drying, and is one cause of the low utilization of sawdust as a boiler fuel. Outside Storage of Sawdust 4.30 Want of demand for the fuel and lack of covered storage facilities causes the waste sawdust to be stored out-of-doors, exposed to the elements. Rainwater adds to the moisture content and difficulty of burning. Boiler/Furnace Configuration 4.31 Predominantly firetube wood-burning boiler/furnaces utilized throughout Ghana are designed to burn solid wood fuels. The large grate holes and insufficient airflow for suspension result in sawdust fuels falling through the grate. Proper support of sawdust combustion would in most cases require consid-rable modification of grates and air feed systems. Boiler Efficiency 4.32 At some of the wood-fired boiler sites visited, reported wood consumption and calculated heat loads imply boiler efficiencies as low as 15 percent. The evident excess combust5 n air results from missing furnace doors and inadequate control of tramp air volume and distribution.  - 48 - V. POTENTIAL ON-SITE ALTEREATIVRS FOR INPROVINC AND/OR INCREASING USE OF MOOD INDUSTRY RESIDUES AS FUEL Summary 5.1 Increased process heat requirements and cogeneration options could technically utilize all of the present residue surplus, while technical improvements in current residue handling, storage and utilization systems could make virtually 100 percent of the currently wasted sawdust suitable as a boiler fuel. However, actual improvements and increases in the use of the available residues will be dependent on the financial costs and economics of doing so when compared to other available alternatives. 5.2 This chapter outlines the components of the most promising technical options, discusses the possible technical constraints and estimates the capital and operating costs required for implementation. A financial and economic evaluation of each option is presented following the technical discussions. The alternatives are developed based on actual sites and conditions observed during the field work rather than on generic plants based on average conditions in Ghana. The selection of actual sites makes the analysis potentially useful. However, the results must be carefully evaluated if the conclusions are to be generalized across the sector. 5.3 Several options for improving andlor increasing the on-site use of wood industry residues in Ghana were identified during the field mission. The most promising options at the mill sites included: (a) Steam generation to meet increasing process heat needs for kiln drying and wood treatment; (b) Cogeneration to meet both electricity and process heat requirements; (c) Improved sawblade lubrication systems and sawdust storage to reduce the water content in the sawdust residue and increase the net energy available; (d) Furnace modifications to enable direct combustion of sawdust; and (e) Furnace improvements for greater combustion efficiency in existing boiler equipment. The first four options have the potential of increasing overall utilization of residues while the last, if implemented, may have the opposite effect. A summary matrix of the technically feasible options for improving and/or increasing the on-site use of wood residues and their potential impacts is presented in Table 5.1.  Table 5.1 MATRIX OF TECHNICAL OPTIONS FOR IMPROVINB AND/OR INCIEASINS ON-SITE R