Nickel-infused zeolite catalytic upgrade of pyrolysis oil from lignocellulose fibers of Syzygium cumini leaf litter for biofuel production

Abstract

Although pyrolysis oils have been identified as a cleaner renewable and sustainable fuel source, their application is limited due to undesirable properties including high viscosity, high oxygenates and low calorific value. In this study, pyrolysis oil obtained from lignocellulosic fibers of Syzygium cumini leaf litter was upgraded in a fixed-bed reactor at 450 °C and 10 °C/min heating rate using a synthesized nickel-infused zeolite catalyst. Characterization of the Nickel/Zeolite Socony Mobil-5 (Ni/ZSM-5) catalyst using EDXRF showed an abundance of NiO (31.05%), SiO (24.5%) and Al₂O₃ (2.5%). Physicochemical and ultimate properties of the oil including viscosity, density, acid value, calorific value, carbon, hydrogen, oxygen, sulfur and nitrogen contents fell within ASTM standards for pyrolysis oils and conventional hydrocarbon diesel. The upgraded oil was mainly composed of carboxylic acid esters (30.69%), phenols (21.3%), 5-methyl-2-furancarboxyaldehyde (14.12%), hydrocarbons (14%) and 1,5-dimethyl-1-H-imidazole (8.3%). These findings underscore the potential of Ni/ZSM-5 catalyst as a viable tool for converting pyrolysis oil to biofuel, thereby contributing to sustainable energy solutions.