Influence of microwave-assisted chemical treatment on delignification of rice straw biomass

Abstract

Lignocellulosic biomass (like rice straw) provides an alternative for depleting non-renewable energy sources through its value-added utilization (like production of biofuels and nanocellulose) owing to its abundance, renewability, polymer presence and environmental friendliness. Prior to its utilization, any lignocellulosic biomass is subjected to a time-consuming delignification process for lignin free biomass recovery. The present study aims to reduce the time of delignification of rice straw along with enhancing the delignification percentage of biomass by use of microwave assisted sodium chlorite method. The experiments were done at two microwave power levels (640, 800 W), three bleaching solution concentrations (0.4, 1.7, 3.0 %) and three microwave treatment times (4, 8, 12 min). The delignification percentage of the rice straw for the whole experimentation varied from 24.7 to 90.12%. The results revealed that the time of delignification was greatly reduced (12 min) with a very high delignification (90.12%) percentage. The morphology of the delignified samples also revealed the deconstruction of the lignin structure. The improved method can thus be applied for the delignification of other biomasses as well for quick and effective delignification