Black liquor is a by-product of the paper pulp industry. It is formed from wood pulp, during the chemical separation of cellulose fibres used for paper production from lignin and hemicellulose.
Composition and use of black liquor
Black liquor is therefore composed of lignin, hemicellulose and chemical residues. This by-product is mainly used locally as a liquid fuel to provide energy for paper mills.
Black liquor and its environmental applications
New processes are used to convert this black liquor into syngas, dimethyl ester or even methanol. Black liquor may therefore be a source of biogas or second generation biofuels which can be used by vehicles.
A technician at Vision Paper examines a black liquor sample. © Keith Weller / Agricultural Research Service, public domain