FAO FORESTRY PAPER 63
Mechanical Wood Products Branch
Forest Industries Division
FAO Forestry Department
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 1985
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M-37
ISBN 92-5-102307-7
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© FAO 1985
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Chapter 1. Industrial charcoal making technologies
1.1 What are industrial charcoal making methods?
1.2 The 'new' and the 'old' in the industrial technology
1.3 The trade-offs in charcoal making
1.4 Yield - Investment interactions
1.5 The importance of wood preparation costs
Chapter 2. Wood carbonisation and the products it yields
2.1 Carbonisation
2.2 Efficiency in carbonisation
2.3 Measuring the yield
2.4 What happens during carbonisation
2.5 The stages in charcoal formation
2.6 Using heat efficiently in carbonisation
2.7 Continuous carbonisation
2.8 Classification of retort heating systems
2.9 Properties of carbonisation products2.9.1.1 Moisture content
2.9.1.2 Volatile matter other than water
2.9.1.3 Fixed carbon content
2.9.1.4 Ash content
2.9.1.5 Typical charcoal analyses
2.9.1.6 Physical properties
2.9.1.7 Adsorption capacity
2.9.1.8 The chemical composition of charcoal2.9.2.1 Acetic acid
2.9.2.2 Methanol and acetone
2.9.2.3 The tars
Chapter 3. Modern carbonising retort systems
3.1 Introduction
3.2 the Waggon or Arkansas retort
3.3 The reichert retort system
3.4 The Lambiotte or SIFIC process
3.5 The rotary hearth furnace
3.6 Fluidised bed and similar carbonisers
3.7 Recovery of by-products from carbonisation
3.8 Criteria for choosing carbonisation systems
Chapter 4. Raw materials for carbonisation
4.1 Introduction
4.2 Wood for carbonisation4.2.1 The unit operations in wood harvesting
4.2.2 Roading
4.2.3 Felling and skidding
4.2.4 Blocking and drying
4.2.5 Haulage to carboniser
4.2.6 Final block preparation and stockpiles4.3 Agricultural residues for carbonisation
Chapter 5. Safety precautions and environmental considerations
5.1 Safety precautions in charcoal operations
5.2 Explosions
5.3 Fires
5.4 Hazards to the public
5.5 Safety devices and equipment5.5.1 Pressure-relief doors
5.5.2 Automatic temperature shutdown
5.5.3 Electric power failure devices
5.5.4 Temperature indication and control5.6 Precautions for charcoal storing
5.7 General safeguarding of charcoal plants5.7.1 Water supply
5.7.2 Detection of poisonous gases
5.7.3 Safety manual
5.7.4 First aid accessories5.8 Environmental considerations for the charcoal maker
5.8.1 General considerations
5.8.2 Raw material preparation
5.8.3 Retorts and converters
5.8.4 Char handling
5.8.5 Retort condensates and gas
5.8.6 Waste water
Chapter 6. Charcoal utilisation and marketing
6.1 Charcoal as household fuel
6.1.1 Lump charcoal
6.1.2 Charcoal briquettes6.2 Charcoal as fuel for industry
6.3 Charcoal in metal extraction
6.4 Activated charcoal6.4.1 Introduction
6.4.2 Production of activated charcoal
6.4.3 Applications
6.4.4 Manufacturing processes
6.4.5 Specifications6.5 Speciality markets
6.6 Charcoal for producer gas
6.7 Summary of industrial markets
6.8 Pyroligneous acid as a fuel
6.9 Utilization of by-products from hardwood carbonisation6.9.1 Introduction
6.9.2 Pyroligneous acid
6.9.3 yield of Pyroligneous acid
6.9.4 Refining pyroligneous acid6.10 Using retort or converter gas
6.11 Synopsis of major usages for charcoal and by-products
Chapter 7. Economics and planning in charcoal production
7.1 Economic analysis and cost control
7.2 The methods of economic project analysis
7.3 Cost control in established enterprises7.4 Costing models for charcoal production enterprise
7.5 Prefeasibility cost study for charcoal production7.5.1 General considerations
7.5.2 The resource
7.5.3 Wood harvesting
7.5.4 Carbonisation
7.5.5 Packing and shipping
7.5.6 Cost analysis models7.6 Wood transport cost and fixed retort systems
7.7 Summary
Chapter 8. Quality control of charcoal and by-products
8.1 Introduction
8.2 Standard methods for quality control8.2.1 Moisture content
8.2.2 Ash content
8.2.3 Volatiles and fixed carbon
8.2.4 Sulphur
8.2.5 Screen analysis
8.2.6 Friability test
8.2.7 Tumbler test
8.2.8 Bulk density of charcoal fines
8.2.9 Viscosity of pyroligneous acid
8.2.10 Flash point of pyroligneous acid
8.2.11 Calorific value
8.2.12 General remarks