CHARACTERIZATION AND BIOMETHANATION FROM NAPIER GRASS

Abstract

Indians are paying attention to biogas as the next possible green fuel. It is anticipated that the use of biogas as a fuel would increase more drastically than ever in the years to come Energy crops like Napier grass or lignocellulosic biomass has the ability to produce biogas and get rid of fossil fuels for us. Elephant grass, also known as Napier grass, is a valuable energy crop that is native to East Africa and does well in temperate, subtropical, and tropical environments. Napier Grass as a lignocellulosic biomass has high percentage of cellulose content which help in hydrolyzing faster and producing more biogas. This crop grows faster, regenerates quickly, to store and transport, availability through the year and most important it can be harvested easily. In this report, characterization of Napier grass was done to understand it properties and parameter like C: N, TKN, VS, TS, tCOD etc. Batch assays was carried out to evaluate the biomethane potential of the substrate at different condition. Different conditions like ISR and C: N were to set derive the optimum level required for the biogas yield. Substrate and inoculum in bottles incubated at an appropriate temperature require by microorganism to survive. ISR of 1:1, 1.2 and 2.1 and C: N of 20:1, 25:1, 30:1, 35:1 and 40:1 was studied in batch test. Batch test also performed between new Napier (8 month after harvest) and old Napier (1 month after harvest) to study the biogas yield from both. Further Pre-treatment of substrate was done to analyze the biogas potential. Physical and chemical pretreatment was carried out and results were analyzed before and after pretreatment. It is concluded, Characterization study gave us the parameter of raw Napier grass like C: N, TKN, TS, MS, etc. C: N of Napier grass is high that is 59.15:1, which shows less of nitrogenous matter. Batch assays study showed that ISR of 2:1 has high biogas potential then 1:2 and 1:1 while for C: N batch assay it showed 35:1 has highest biogas potential then others. Old vs. new Napier grass study revealed that older the substrate more is the potential for biogas as this indicate more rupture of lignin in old. Pretreatment has significant effect on biogas yield, after pretreatment with alkali hydrothermal there is an increment of hydrolysis stage and reduction of lignin content.