Method for the simple and environmentally benign pulping of nonwood fibrous materials

摘要

A process for producing a pulp suitable for papermaking from a nonwood fiber source material is described. Exemplary nonwood fiber source materials include kenaf and industrial hemp. The process includes the steps of washing the nonwood fiber source material with a washing solution in a washing screw (12); compressing the nonwood fiber source material to form a compressed plug in an impregnation screw (32); impregnating the compressed plug of the nonwood fiber source material with a pulping solution at ambient temperature and at atmospheric pressure in an impregnation vessel (38); feeding the impregnated nonwood fiber source material to form a papermaking pulp at a bottom port (54). Additional treatment of the papermaking pulp by acid chelation; by bleaching or by acid chelation and bleaching are also described.