Turning Sawdust Into Charcoal, In Malaysia.
from Auke Koopmans
The sawdust is dried (typical moisture content as received is about 45%). Sawdust before being processed is dried in rotary dryers bring down the moisture content of about 45% down to about 5%.
These are basically sawdust briquettes which are carbonized right after briquetting. Right after coming out of the briquetting machine (screw type with heated dies - about 300 degrees C) the briquettes are cut into pieces with a length of about 40-45 cm. The cut lengths fall onto conveyorbelts which transport the briquettes to the loading stations.The briquettes are stacked in double rows on a kind of open container with the bottom and the two end sides being protected by refractory bricks.
This container, once loaded with the briquettes is moved by forklift to the charcoal making section.
Charcoal kilns are built in batteries side by side and the container is pushed in the kiln and sealed with clay/mud. The charring process starts by dropping in a few burning pieces of wood (briquettes) at least that's what I was told (I did not see this). The charcoaling process is controlled(manual) by experienced operators.
This picture shows the cart just being pulled out of the charcoal kiln whereafter a metal hood is placed over it.
When the charring process is finished(efficiency about 20-25%), the containers are pulled out and covered with the metal hood and sealed with sand.
After the briquettes are cold, they are packed directly in boxes which go straight into containers for shipment to Korea, Japan, Taiwan, etc.
The factory requires about 600 cubic meters of sawdust a day which after drying, briquetting, conversion, etc. would result in an output of about 15 tons of high grade charcaol briquettes. Selling price in 1995/96 was about 1.2 Malaysian Ringgit per kg. (about 0.5 US$ at that time) versus 0.30 Ringgit for ordinary wood charcoal. In Thailand, under different conditions, the price of charcoal at that time was about 4-5 Baht (about 0.4-0.5 Ringit)versus 7 Baht for carbonized sawdust briquettes which were sold in the local market. However, at present due to the adverse economic conditions the export market has virtually collapsed.