I've never taken any notice of charcoal before, as I don't use it, and in the past I have had no reason to learn anything about it. I knew there are many charcoal kilns in Perak, Malaysia, but I hadn't visited any. Then in Feb 2014 when I was in south Vietnam, I saw a small scale charcoal factory.
Then a few months later I had the chance to visit a charcoal factory in Perak. We went to the Chuah family charcoal kilns at Kuala Sepetang, which is west of Taiping. The factory has been in the family for 3 generations and is open to tours.
I learnt a lot about the "black diamond" of Perak. I took so many photos so I will just give a brief description here.
I always thought charcoal was burnt wood, but this is not so. It is not burnt at all, but baked, to reduce the water content. Only 2 species of mangrove wood are used, Rhizophora apiculata and Rhizophora mucronata, local name is green wood or in Malay bakau minyak. The mangroves grow locally in the huge 40,000 hectare Matang forest reserve. The State government allocates concessions.
On this visit we were unable to see the harvesting of the trees or bringing the logs to the factory by boat. As the name suggests, Kuala Sepatang is a large riverine area, and there are many canals leading from the river to the factories
Mangrove trees take 15-20 years to mature. Mangrove is a hard wood. So the logs are transported by boat as otherwise would sink. This can only be done for half the month as on the other days the water levels are too low.
The trees are cut in 1.6m lengths which weigh about 30 kg. It 1500 pieces to load a kiln = 50 ton. This produces just 10 ton of charcoal, as 80% of the initial weight is water. After baking, this leaves 3-7% water.
When the wood is brought to the factory the bark is skimmed off and the logs left in the sun to remove some moisture.
Loading the kiln -
It takes 2 days to load the kiln. Each log is placed on a charcoal block to allow the air to circulate as the steam has to reach the back and sides. Electric lights are used for loading. Once the kiln is loaded, the door is closed with clay and bricks, leaving enough space for the firewood. The small logs and offcuts are used for this -
There are 2 stages to the baking. First the big fire, then the small fire. The big fire is 85C and it takes about 10 days to get to temperature. Then the small fire for 14 days, it is 250C. If higher than 250C the wood turns to ashes.
An experienced worker can actually smell the steam to gauge the temperature. Once at 250C the eyes and door are sealed. This cuts off the oxygen to prevent the logs burning -
There are 4 vents in the kiln where the steam is forced out -
After 14 days, it takes 8 days for the kiln to cool, then half a day to unload the charcoal.
The kilns
Each kiln 6.7 m diameter at bottom, 7m high. Shaped like igloo to allow heat to circulate.
26,000 bricks for 1 kiln. Clay and not cement is used as clay retains heat for longer.
The kiln will last 7-10 years.
A new kiln in the factory next door -
Later that day we went to see more charcoal kilns, this time at Terong.
© Liz Price
No reproduction without permission
No reproduction without permission
