Industrial charcoal making

Table of Contents


Mechanical Wood Products Branch
Forest Industries Division
FAO Forestry Department


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ISBN 92-5-102307-7

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© FAO 1985

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Table of Contents


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 products

2.9.1 Charcoal Moisture content Volatile matter other than water Fixed carbon content Ash content Typical charcoal analyses Physical properties Adsorption capacity The chemical composition of charcoal

2.9.2 Pyroligneous acid Acetic acid Methanol and acetone 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 carbonisation

4.2.1 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 stockpiles

4.3 Agricultural residues for carbonisation

4.3.1 Processing agricultural residues

4.4 Bark waste

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 equipment

5.5.1 Pressure-relief doors
5.5.2 Automatic temperature shutdown
5.5.3 Electric power failure devices
5.5.4 Temperature indication and control

5.6 Precautions for charcoal storing
5.7 General safeguarding of charcoal plants

5.7.1 Water supply
5.7.2 Detection of poisonous gases
5.7.3 Safety manual
5.7.4 First aid accessories

5.8 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 briquettes Making charcoal briquettes

6.2 Charcoal as fuel for industry

6.2.1 Specifications

6.3 Charcoal in metal extraction
6.4 Activated charcoal

6.4.1 Introduction
6.4.2 Production of activated charcoal
6.4.3 Applications
6.4.4 Manufacturing processes
6.4.5 Specifications

6.5 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 carbonisation

6.9.1 Introduction
6.9.2 Pyroligneous acid
6.9.3 yield of Pyroligneous acid
6.9.4 Refining pyroligneous acid

6.10 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 enterprises

7.3.1 The unit operations
7.3.2 Unit costs and budgeting

7.4 Costing models for charcoal production enterprise
7.5 Prefeasibility cost study for charcoal production

7.5.1 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 models

7.6 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 control

8.2.1 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

8.3 Bench - scale carbonisation tests

Appendix. Useful conversion factors


FAO technical papers