South Korean plasma process turns wet coffee grounds into coal-grade biochar in 90 seconds

Researchers at the Korea Institute of Geoscience and Mineral Resources have developed a plasma-based process called Flame Plasma Pyrolysis that converts wet coffee grounds into a biochar with a heating value of 29.0 MJ/kg, matching anthracite coal. The method takes 90 seconds and requires no pre-drying, using a plasma flame to flash-vaporize trapped water and trigger internal micro-explosions that carbonize the material. The resulting fuel has higher energy density than wood pellets, contains no sulfur, and the process also creates highly porous carbon suitable for filtration applications. The key innovation is skipping the energy-intensive drying step that has made previous biomass-to-fuel approaches uneconomical for wet feedstocks. Coffee grounds typically contain over 50% moisture, and conventional torrefaction or hydrothermal carbonization takes 30 minutes to several hours. The KIGAM process is 20 to 240 times faster and produces a fixed carbon content of 46.2% from an initial 15.6%. The technology could redirect a portion of the 10 million tons of annual spent coffee ground waste from landfills into a usable solid fuel or industrial adsorbent material.