Influence of cooking variables in the organosolv pulping of wheat straw using mixtures of ethanol, acetone, and water

In studying the organosolv pulping of wheat straw with mixtures of ethanol, acetone, and water, the researchers examined the influence of independent variables on the properties of the pulp and of paper sheets made from it. Equations were used to relate the dependent variables to the independent variables. To minimize solvent losses and to increase pulp yield, wheat straw can be cooked at 180°C for 60 min using a solution of ethanol mixed at 50% with ethanol plus acetone and using a solution of ethanol plus acetone mixed at 35% with a solution of ethanol, acetone, and water. Under these conditions, the properties of the pulp and paper sheets (except for burst index) differ by less than 22% from their optimum levels. Among ethanol-acetone, ethanol, and acetone pulping of wheat straw, acetone pulping produces the best pulp and the best paper sheets. However, it takes a higher concentration of solvent and higher pressure than ethanol-acetone pulping takes.