Towards an environmentally clean charcoal production.

Abstract

The aim of this research is to develop a sustainable process for a compact integrated wood charcoal retort. To assure efficiency and productivity, the design was first investigated via CFD simulations to monitor the temperature and velocity profiles inside the retort. The final compact design is formed of a double vessel arrangement where the wood is carbonized in the central vessel (i.e. carbonizer) and the outer vessel is the combustion furnace. A flue-gas recycle line leaves the furnace to preheat and dry the wood in the carbonizer during startup. This developed design allows the syngas-methane coming out of the carbonization process to be re-circulated into the combustion furnace to provide the necessary energy and to assure the sustainability of the process. The integrated compact retort is then tested experimentally, and as a result, only 2-3 hours were needed to achieve complete carbonization of oak wood. Different temperatures are achieved during operation with a maximum of 900 °C reached. The charcoal yield ranged between 37percent and 46percent on a dry basis, and the charcoal carbon contents were between 73percent and 78percent.