Organosolv pulping: a versatile approach to wood refining

The fractionation of hardwoods into pulp, lignin, and hemicellulose has been studied in a multi-stage alcohol extraction pilot plant. By adjusting processing conditions, pulps of different properties were obtained. They have been found to be suitable to furnish components for writing, printing, and high-absorbency papers and as dissolving grades. By-product lignin and hemicelluloses are recovered in separate, high-yield fractions for which several potential commercial applications have been identified. The process is a low-capital-cost, low-environmental-impact alternative to kraft and sulfite pulping.