Enhanced recovery of H-2 gas from rice husk and its char enabled with nano catalytic pyrolysis/gasification

摘要

This report describes the enhanced recovery of more useful H-2 gas, from rice husk employing nano size nickel particles as catalyst. The bio char obtained after the catalytic pyrolysis also produces more amount of H-2 gas while subjecting on steam gasification. The nano sized nickel particles used in this process are prepared from wet chemical reduction method in which hydrazine hydrate is used as a reducing agent. The structural features of as obtained nano particles are evaluated using XRD, FESEM with EDX. Pyrolytic distillation of rice husk is performed with and without nano particles and it produces different quantities of tar, gaseous and carbonaceous rich char contents. The characteristics of oil and gaseous materials are assessed through Gas Chromatography-Mass Spectrometry (GC-MS) and Inductively Coupled Plasma - Optical Emission Spectrometry (ICP - OES). In comparison to thermal pyrolysis, the catalytic pyrolysis offers more percentage of gaseous fuel (33.33%) than that obtained from thermal pyrolysis (21.67%) at 400 degrees C. On analysing the tar obtained from both processes, it has been found that the oil obtained through catalytic process has more percentage of aromatic contents. The char obtained after pyrolysis produces more amount of gaseous contents (CH4, CO2, CO, and H-2) in varying percentages on carrying out steam gasification at 700 degrees C, 750 degrees C, 800 degrees C, and 850 degrees C. The nickel nano particles present in the char after catalytic pyrolysis favours the formation of syn gas to higher amounts (H-2: 49.46% and CO: 32.32%) than the same formed from the char obtained in thermal pyrolysis (H-2: 38.24% and CO: 28.68%) at 750 degrees C.