PROCESS FOR THE STEPWISE TREATMENT OF LIGNOCELLULOSIC MATERIAL TO PRODUCE REACTIVE CHEMICAL FEEDSTOCKS

摘要

A method for the fractionation of lignocellulosic materials into reactive chemical feedstock in a batch or semi continuous process by the stepwise treatment with aqueous aliphatic alcohols in the presence of sulfur dioxide or acid. Lignocellulosic material is fractionated in a fashion that cellulose is removed as pulp, or converted to esterified cellulose, cooking chemicals are reused, lignin is separated in the forms of reactive native lignin and reactive lignosulfonates and hemicelluloses are converted into fermentable sugars, while fermentation inhibitors are removed. In an integrated vapor compression stripper and evaporator system, aliphatic alcohol is removed from a liquid stream and the resulting stream is concentrated for further processing.