1. Straw charcoal

Each kilogram of straw charcoal contains about 53g potassium, 4.3g nitrogen, 2.6g phosphorus, 3.52g magnesium, 0.015g copper (trace element), 0.58g iron, 0.11g zinc, and has a specific surface area of about 71-220m2/g. Straw charcoal can be mixed with biomass extract and nitrogen, phosphorus and potassium fertilizers to make carbon-based compound fertilizers which are rich in essential nutrients for crop growth, have a long-term slow-release effect on water and fertilizers (phosphorus, nitrogen, etc.), and help improve and repair heavy metal-contaminated and degraded soils (especially cadmium).

2. Wood/bamboo charcoal and fruit shell charcoal

Their fixed carbon content is about 80~85%. They can be made into high quality activated carbon through physical method. The wood/bamboo charcoal can be made into machine-made charcoal directly.

3. Rice husk charcoal

The fixed carbon content is about 45~50%. It can be used to produce carbon-based compound fertilizer or sold as the thermal insulation material to the steel plants.