ORGANOSOLV PULPING OF WHEAT STRAW

Abstract

The aim of the study was the development of scientifically grounded technological modes for the production of pulp from wheat straw by more environmentally friendly organosolv methods of delignification and its application in the composition of cardboard and paper products.The influence of the temperature mode, cooking time and the consumption of chemicals on the quality indices of organosolv straw pulp was studied in details.The influence of the catalytic action of anthraquinone on the quality indices of straw pulp obtained by ammonia sulfite-alcohol and twostage alkaline-alcohol methods of cooking was studied.It was established that the use of anthraquinone with the consumption of 0.1% of oven dry material contributes to an increase in yield by 2-6% in the case of twostage alkaline-alcohol delignification, a decrease in the content of lignin by 0.4-1.0 and 0.3-1.9%,respectively, and an increase in physical and mechanical properties on average by 25-30%, compared with similar pulping without catalyst.The regression equations of the processes of obtaining straw pulp using the method of a full factorial design were obtained.Optimization methods using a generalized Harrington's desirability function were applied to obtain optimal parameters for organosolv delignification of wheat straw.The indices of the selectivity of lignin dissolution from wheat straw during pulping and the kinetic characteristics of the investigated methods of delignification were calculated.It was established that the highest selectivity correspond to ammonia-sulfite-alcohol and alkaline-sulphite-alcohol methods of delignification of wheat straw.It was proved that organosolv delignification is described by kinetic equations of the second order and is characterized by lower values of activation energy in comparison with wood delignification.The possibility of bleaching of organosolv straw pulp