Microwave assisted chemical pulping of wood chips in a continuous digester to produce wood pulp and good lignin

摘要

A pulp mill using microwaves and chemicals to cook woodchip to produce unbleached wood pulp and lignin through chemical digestion which returns cooking chemicals for re use; the pulp mill uses: a continuous microwave pretreatment machine; a continuously heated microwave assisted digester which subjects the woodchip to microwave agitation during cooking; a pulp washer which uses alternating compression and washing to separate the pulping chemicals (black liquor) and wood pulp; a treatment process for the black liquor which separates lignin by applying carbon dioxide followed by a strong acid.