ORGANOSOLV PULPING USING A MICROWAVE-OVEN

The use of microwave energy to effect organosolv pulping of a hardwood (Tulip Poplar) and a softwood (Southern Yellow Pine) has been studied under a variety of conditions on a laboratory scale. Under the best conditions we have found a pulp yield of 45-60 %, with a residual lignin content of 2-4 %, obtained with hardwood after heating for 30 min at 185-190-degrees-C with 70% aqueous alcohol (ethanol or butanol). As expected, delignification of the softwood is more difficult and under our best conditions a pulp yield of 55-67%, with a residual lignin content of 17-18%, was obtained after heating for 30 min at 185-190-degrees-C with the same solvent systems.