New Korean process quickly converts manure into biochar

Researchers at the Clean Air Research Laboratory of the Korea Institute of Energy Research have developed a process that converts 10 tonnes of livestock manure into biochar (biomass and charcoal) in a single day.

The core of this Manure To Biochar (MTB) process is a dehydration and drying technology that reduces the moisture content in livestock manure, which is over 80%, to less than 20%.

The research team successfully designed and built an integrated system that combines a drying process owned by the KIER, a dehydration process from the Korea Institute of Machinery and Materials (KIMM), a pretreatment process from DULI TECH Co., and a pyrolysis technology from YOUGI IND Co., thus reducing the process’ overall energy consumption to less than one-tenth compared to the conventional rotary kiln method.

Crushing manure

The process begins with a screw-type solid-liquid separator developed by the KIMM. This separator reduces the moisture content in livestock manure to less than 60%. The energy used in this step is minimized to 1% of that used in conventional heat-based processes like the rotary kiln method (horizontal, cylindrical). The separated manure chunks are then finely crushed to less than 1 cm by a three-stage blade crusher.

This process has been demonstrated at a pilot plant in the western Chungnam province, which is capable of handling 10 tonnes of livestock manure per day. The research team completed 100 hours of process operation, proving its commercial viability. In particular, the F-COMB drying device seems to be highly competitive in terms of energy efficiency and production cost.

Plans are in place to scale up to more than 100 tonnes per day to meet domestic demand as well as international demand from China, Australia, and Indonesia, which are pushing for environmentally friendly waste management and recycling.

At present, most of the livestock manure in Korea is being composted, and there is a lack of measures to reduce the greenhouse gases and ultrafine dust particles that are emitted during this process.

As of 2022, the amount of livestock manure produced was about 50 million tonnes, of which 87% was used as compost and liquid fertilizer after being fermented over a long period. During this treatment process, which can last more than 60 days, nitrous oxide (N2O), a greenhouse gas 300 times stronger than carbon dioxide, is emitted.

Additionally, ammonia (NH3), which causes ultrafine dust and odours, is also released, accounting for 70% of the total emissions nationwide. This has led to persistent odour complaints, becoming a chronic problem for livestock farmers.

Within this context, the Korean government designated biochar as a core technology area for carbon neutrality in the livestock sector and plans to expand the use of biochar and improve manure management in livestock farms through the “Livestock Sector 2030 Greenhouse Gas Reduction and Green Growth Strategy.”