Sawdust briquette charcoal are made from 70 - 80% pure natural sawdust of hard wood; 20 - 30% soft wood; or made from acacia, oak,...wood (therefore the price will be different depend on the wood quality).
Do not have chemical. Lignin are born at 273 degree celcius in the process heating of the screw machine. Sawdust briquette after screwing, are got to the carbonization kiln in about 15 - 17 days. Then the process, we have the sawdust briquette charcoal. Which have high value calorific, no sparks, smokeless, ...