Known as the Kraft process, the chemical wood pulping process is applied to wood to extract cellulose fibers – the main compound used to produce paper. White liquor, a hot mixture of water and chemicals, is used to break the bonds containing cellulose fibers. Black and green liquors, named largely based on their coloration, are waste solutions formed at different points of the Kraft process. Wood pulp is largely extracted during the cooking phase, leaving a dark mixture of remaining organic matter and chemicals.
