ABSTRACT

In most Sub-Saharian Africa countries the production and trading of charcoal is illegal. Since early this year the Malawian government is actively supporting the legal production of charcoal on condition that the wood is harvested on a sustainable way. Charcoal is said to be bad for the environment (deforestation and emission of noxious gasses during the production). Yet other studies that from an energy point a view the difference between wood and charcoal is negligible. 

In this presentation, Giel de Pooter examines the efficiency of the presently used charcoal production using earth mound kilns (i.e. only about 10- 15 %) versus industrial units which are proven to have efficiencies up to 35 % (gravimetric yield) with the latter figure approaches the theoretical maximum efficiency. 

KEY HIGHLIGHTS

• The caloric value of charcoal is about twice the caloric value of wood the efficiency hence figures should in fact be doubled. 
• On the basis of test runs the researcher personally attended in China using 3 different types of furnaces, charcoal yield up to 1,500 kg/H). 
• Furnaces do what they are expected to do: produce charcoal on an efficient and cost-effective way. 
• It is extremely promising that Sawdust, bagasse, waste wood, water hyacinth, all of it can be converted to charcoal. 
• Since a direct carbonization for some of these types of biomasses is not possible pre-treatments like grinding, drying and briquetting is required - equipment for these pre-treatments is available and affordable.
• Yet, only in few countries in Sub Sahara Africa these types of furnaces are in operation - suppliers of affordable carbonizing equipment are concentrated around one single town in China (Zhengzhou).