Rotary Compression Unit: A Novel Technology to Produce Biochar in a Continuous State Using Various Biomass Streams

Frictional Carbonization has recently been coined in a publication in FUEL by Enginuity Worldwide and a colleague from the University of Bozen-Bolzano. This method of carbonization is carried out by a novel technology in a Rotary Compression Unit (RCU). The process has most commonly been utilized in one configuration to produce solid biofuels for combustion. In a second configuration, this method is capable of producing a biochar from various forms of biomass and waste wood and pyroligneous acid as a by-product. The RCU is a low energy method of thermally upgrading biomass requiring no external heat source, only the heat of friction and compression from a rotary screw. The novelty of this technology lies with its ability to continuously process any type of woody or non-woody, fibrous biomass including, but not limited to: coffee grounds, nut shells, sawdust, grasses, and agricultural residues. Animal wastes such as poultry litter, feedlot manures, and anaerobic digester solid waste can be processed with added adequate fiber. The elegant design of the RCU allows for not only continuous processing of these biomass streams but also at thru-puts of 3-5 Tons/hour input. The RCU can readily process biomass streams of various sources and varying moisture contents with no need for tooling changes to the technology itself. Particularly high moisture contents may require preprocessing in the form of screw pressing to dewater a portion of the biomass. Recent experiments using the biochar produced using the RCU have indicated increased growth rates, increased germination success, increased porosity, increased stability of soil pH and moisture, and increased water holding capacity. Processing of animal wastes such as poultry litter and cow manure into biochar produces a biochar source containing levels of PKN to be used as a fertilization medium in agriculture or the domestic gardening market place.