FRACTIONATION AND COMPLETE UTILIZATION OF WHEAT STRAW ATMOSPHERIC ACETIC ACID PROCESS

摘要

To establish a novel process for zero emission utilization of wheat straw, fractionation of the straw was investigated using atmospheric acetic acid process. The results showed that under a representative condition, wheat straw was fractionated to pulp, lignin and monosacchardes with yields of about 50%, 15% and 35%, respectively. Straw acetic acid pulp had an acceptable strength for paper and could be bleached to a high brightness over 85% with a short sequence. About 30% of polysaccharides in wheat straw were hydrolyzed to monosaccharides during acetic acid pulping and dissolved into water. Of the carbohydrates in the water solubles, about 70% were xylose, and glucose accounted only for about 12%. From the lignin, hot- and cold-setting adhesives were prepared for plywood. The results indicated that the adhesives had excellent dry and wet tensile shear strength. The lignin could also be converted to water soluble lignosulfonate under mild conditions by a procedure of methylolation-sulfonation.