Fractionation and Potential Applications of Components from Microwave Liquefaction of Chromate Copper Arsenate-Treated Wood

Abstract

Decommissioned chromate copper arsenate (CCA)-treated wood poles were subjected to a microwave liquefaction process. The liquefied products were separated into cellulosic component, lignin fractions, and spent liquor. Analysis of the distribution of the CCA elements showed that the resulting cellulosic component and lignins were detoxified. Compared with the CCA-treated wood, the fractionated detoxified cellulosic component had become micro-sized and had a higher glucan content, crystallinity, and glucose conversion yield, as well as a larger surface area. Thus, the detoxified cellulosic component has potential as a raw material for biorefinery usage or for cellulosic material reinforced composite production. The constituents, such as glucose, xylose, glycerol, and their derivatives, as well as the metal elements in the spent liquor, are appropriate ingredients for the preparation of antifungal and insect resistant polyurethane foams. The fractionated detoxified cellulosic component and lignin products, in addition to the potential application for the spent liquor in the polyurethane industry, confirmed that the microwave liquefaction process coupled with a fractionation procedure is an environmentally conscious approach for the integrated utilization of decommissioned chromate copper arsenate treated wood.