Chemicals from Wood: Batch Delignification of Southern Yellow Pine in Aqueous n-Butanol Solutions (Chemicals from Wood by Organic Solvent Delignification)

摘要

A 50:50 volume ratio of n-butanol:water solution was used to delignify Southern Yellow Pine wood containing 31 percent lignin to pulp containing 15.6 percent lignin. This was achieved by using wood particles of 30-70 Tyler mesh size, mild agitation (shaker oil bath unit at 100 strokes per minute), a hot separation method (pulp was separated from solvent immediately after treatment), a 15 to 1 solvent to wood ratio at 200 degrees Centigrade with no catalyst and a residence time of six hours. A shaker oil bath unit was used for the collection of large quantities of accurate data over a wide range of conditions. The chief advantages of this reactor include a short heatup time (10 minutes) which permits better correlation of hydrolysis results with treatment conditions and, by using a hot separation method, elimination of redeposition or repolymerization of lignin on the treated pulp. A prolonged contact time between pulp and solvent after treatment was shown to cause a lower lignin conversion and pulp recovery. These results were demonstrated by using water-cooled and air-cooled separation methods.