Modification of acacia pulp yield in pre-hydrolysis kraft cooking by addition of anthraquinone and pol sulfide

摘要

Kraft cooking is an important industrial method in pulp and paper industry. In this research, in order to get a higher pulp yield under better cooking conditions, polysulfide (PS) and anthraquinone (AQ) were added to the kraft cooking process, and then the effect of combination of pre-hydrolysis (PH) process with PS-AQ cooking on fiber properties of acacia pulp was clarified as well. PH process of acacia wood chips was conducted at the temperature range of 145-149°C for 90 min. Liquor to wood ratio(L/W) of 4 ml/g was applied. After the PH process, acacia wood chips were cooked for kraft and PS-AQ methods under various conditions. Subsequently, estimation of pulp yields and analysis of hexenuronic acid (HexA) contents of pulp were conducted for each cooking. At the same time, the kappa number and viscosity of pulp were determined according to the TAPPI methods. Other pulp properties (carbohydrate composition, brightness) were estimated in this research as well. Lorentzen-Wettre fiber tester was used to test fiber properties.