Coal from biomass

Sustainable coal production in Buchi kiloclave Type 3E

Coal from biomass using hydrothermal carbonization (HTC)

Reactor: kiloclave 0.5 liter, 1 liter and 5 liter
Material: stainless steel & Hastelloy®
Temperature: 180 °C to 250 °C

At the Zurich University of Applied Sciences in Wädenswil the production of coal from biomass has been studying for almost a decade. 

The thermochemical process of hydrothermal carbonization (HTC) is used for this purpose. While the natural coalification of biomass substrates takes thousands to millions of years, using this process it is possible to produce lignite-like products within just a few hours. Moist biomass is converted into coal at elevated temperatures (180 °C to 250 °C) and under autogenous pressure in water within a very short time. The process opens new perspectives in the efficient and environmentally friendly use of resources. These include the production of CO2-neutral coal as an energy source, new approaches for the treatment of problematic biomasses and the prospect of sustainably improving damaged soils with HTC coal. 

The work of the Soil Ecology Research Group in the field of HTC focuses on applied research regarding the utilization of moist biomass for sustainable use. 

Main areas of research:

  • Hydrothermal carbonization of unused waste biomass from livestock farming (manure, liquid manure), food production (beet residues, spent grains, coffee grounds), plant residues and sewage sludge
  • Treatment of process water from hydrothermal carbonization


Read here the customer statement of Gabriel Garner, Research assistant, Zurich University of Applied sciences ZHAW, Wädenswil