Performances techniques et environnementales du four de carbonisation Green Mad Retort à Madagascar

Charcoal-making trials with eucalyptus from plantations in northern Madagascar were conducted in the field using Green Mad Retort (GMDR) external combustion chamber kilns. Analyses of some fifty trials show that these kilns produce high (34%) and very stable mass yields, even from wood with a high moisture content. The study confirms the direct link between higher mass yields and lower greenhouse gas emissions from charcoal-making (CO 2 and CH 4 ). Measurements made in two kilns at different stages in development also show that it is possible to eliminate most methane emissions at the outflow from the combustion chamber. In this case, methane emissions are around 4.3 kg/t of charcoal produced, which is 5 to 17 times lower than published emission figures for other carbonisation techniques, with the exception of industrial retort furnaces.