PRETREATMENT METHOD OF CELLULOSIC BIOMASS VIA FLOWABILITY CONTROL AND REACTIVE EXTRUSION PROCESS

摘要

In a pretreatment process for lignocellulosic biomass, lignin is separated from cellulose by a reactive extrusion process with flowability control of the biomass suspension. Flowability control via incorporation of flowability control agents renders biomass suspensions processable using equipment in which relatively high shearing stresses and pressures can be applied. In one embodiment, particulate cellulosic biomass is added to a fully-intermeshing twin-screw extruder with pH adjusters, water and flowability control agents. Upon the incorporation of the flowability control agent, the biomass suspension flows without phase separation and thus can be subjected to high mechanical shearing stresses and chemical reaction in the extruder. The screw configuration creates multiple mixing zones within the confines of the extruder. The flowability control agent may be a water-soluble polymer that allows a hydrogel to be formed or may be a recycled portion of the black liquor from the reactive extrusion process.