The charcoal conversion rate is a measure of how efficiently a biomass material can be converted into charcoal by pyrolysis. It is an important reference index for customers who want to invest in charcoal production. Because raw material is one of the most costly parts.

Charcoal briquette factory in Zanzibar
Charcoal briquette factory in Zanzibar

How many tons of biomass materials to get one ton of charcoal

To make this question clear, we use the common case “sawdust to charcoal” to analyze the carbonizing ratio. About the steps of producing charcoal from sawdust, you can reference the below article.

After reading about the process of making charcoal from sawdust, we know that the weight loss happens in three stages: drying, briquetting, and carbonization

Charcoal making process of from sawdust to charcoal

Sawdust to Sawdsut briquettes to Charcoal

To get 1 ton of charcoal, we need to carbonize around 3 tons of sawdust briquettes. The sawdust briquettes are carbonized by a carbonization furnace or earthen kiln. In this step, the weight of sawdust briquettes will shrink greatly.

To make 3 tons of sawdust briquettes, we need at least 3 tons of dried sawdust with a moisture of <12%. From sawdust to briquettes, the needed machine is a sawdust briquette machine. In this process, sawdust moisture will reduce little, it can be neglected.

To make sawdust briquettes, the sawdust needed to be dried at <12% moisture. Therefore, the carbonization rate ultimately depends on the humidity of the raw material.

The moisture of naturally dried materials is around 20%. After being dried by the sawdust dryer, the water content can be reduced to around 10%. To get 3 tons of 10% moisture sawdust, we need to dry around 3.5 tons of 30% moisture sawdust.

For the fresh biomass materials, humidity can reach 50%-60%, it will need 6-7 tons of wet materials to get 3 tons of 10% moisture sawdust.

The charcoal conversion rate of raw materials at different humidity

For the naturally dried materials (20% moisture), the charcoal conversion rate is 1/4 to 1/3.

For wet materials (50%-60% moisture), the charcoal conversion rate is around 6:1

For sawdust briquettes, the charcoal conversion rate is 3:1

Contact us to know more about bio-charcoal production