Microwave-Assisted Hydrotropic Delignification of Rice Straw

Rice straw is the stem and stalk of the rice plant after the rice grains are harvested. Rice straw is the largest agricultural waste that has not been utilized due to technical and economic factors. The high cellulose content in rice straw can be used in various ways, including as a substitute for wood, namely raw materials for making pulp, tissues, handicrafts or very strong ropes. In addition, rice straw waste is environmentally friendly. One of the stages in the biomass fractionation process is the delignification/pulping process. The method used for rice straw delignification is MAE (Microwave Assisted Extraction). MAE has several advantages including shorter extraction time, higher accuracy and precision, higher yield, lower energy, and solvent consumption. This study aims to find the optimum conditions for the delignification process of rice straw waste with microwave-assisted hydrotropic solvents. The process parameters studied include time (30-150 minutes) and differences in solvent addition. The results of the analysis showed that rice straw contains cellulose content of 35.59%, lignin content of 25.39%, and extractive content of 4.53%. The delignification process using microwave heating with a power of 180W, for 150 minutes and the addition of hydrogen peroxide produced a cellulose content of 53.34% and a lignin content of 21.46%.