What is the charcoal conversion rate

The charcoal conversion rate measures how efficiently biomass material can be turned into charcoal through pyrolysis. It’s an essential factor for those investing in charcoal production, as raw materials are quite costly.

Let’s take a common example: converting sawdust into charcoal. The process involves three main stages where weight loss occurs: drying, briquetting, and carbonization.

To produce 1 ton of charcoal, we typically need to carbonize about 3 tons of sawdust briquettes. These briquettes are carbonized in a furnace or earthen kiln, and their weight reduces significantly during this step.

Making 3 tons of sawdust briquettes requires at least 3 tons of dried sawdust with a moisture content of less than 12%. We use a sawdust briquette machine to turn the sawdust into briquettes. The change in moisture during this process is minimal, so we can ignore it.

Before making briquettes, the sawdust must be dried to have a moisture content of less than 12%. So, the carbonization rate mainly depends on the humidity of the raw material.

Naturally dried materials usually have a moisture content of around 20%. But after drying in a sawdust dryer, this can be reduced to about 10%. To get 3 tons of 10% moisture sawdust, we need to dry around 3.5 tons of sawdust with 30% moisture.

And for fresh biomass materials, the humidity can be as high as 50%-60%. That means we would need 6-7 tons of wet materials to get 3 tons of 10% moisture sawdust.

Charcoal Conversion Rate at Different Humidity Levels

• Naturally Dried Materials (20% Moisture):
  • The charcoal conversion rate is roughly 1/4 to 1/3.
  • This means for every four parts of naturally dried materials, you can expect to get around one part of charcoal.
• Wet Materials (50%-60% Moisture):
  • The conversion rate drops significantly to around 6:1.
  • This indicates that it requires six parts of wet materials to produce one part of charcoal.
• Sawdust Briquettes:
  • The conversion rate is more favorable, at 3:1.
  • This means that three parts of sawdust briquettes can be converted into one part of charcoal.

Please note that these are general approximations, and the actual conversion rates may vary based on specific conditions and processes used during the conversion process.Feel free to contact us at Durable Machinery if you would like more information.