Catalytic upgradation of pyrolytic products by catalytic pyrolysis of sawdust using a synthesized composite catalyst of NiO and Ni (II) aluminates

Abstract

A significant comparative study was done on thermal and catalytic pyrolysis of sawdust via metal-induced active site NiO and Ni (II) aluminates composite catalyst by integrating sawdust into a fixed-bed reactor and assessing product profile distribution from a temperature range of 773–873 K at 30 K min−1 heating rate under nitrogen purge gas (300 mL min−1). With an increase in temperature from 773 to 873 K, bio-oil yield was increased with a decrease in the yield of biochar. From thermal bio-oil characterization, it was observed that d-Allose was the prominent compound along with Beta-d-Glucopyranose-1,6-Anhydro with a remarkable Cp value of 2.0 Jg-1 K−1 and an ignition temperature of 397.95 K. Catalytic upgradation of bio-oil using 10 % and 20 % catalyst resulted in phosphonic acid, (p-hydroxyphenyl)- and 6-Hepten-3-one, 5-Hydroxy-4-Methyl- as the candidate compounds with slightly decreased Cp values of 0.095 Jg-1 K−1 and 0.826 Jg-1 K−1 respectively due to catalytic tar cracking of polyaromatic hydrocarbons present in the bio-oil. Biochar revealed amorphous graphitic multilayer nanosheets with polycrystalline and hexagonal crystal systems of the lattice structure with the presence of aromatic ring structures and –CN stretching as evident from FTIR analysis.