Sugarcane bagasse pyrolysis for green energy production

Abstract

Modern life depends on fossil fuels, an unrenewable resource, continually being depleted. As a result, developing viable alternatives is necessary. Pyrolysis, a thermochemical process using high temperatures to decompose organic matter in the absence of oxygen, has been highlighted as a possible solution. This study aimed to evaluate the effect of particle size, peak temperature and the addition of the Cu-SrO/ZSM-5 catalyst on the quality of bio-oil produced from sugarcane bagasse feedstock. The bagasse was sieve-separated into four size classes: <425 μm, <600 μm, <2.36 mm, and Raw (unseparated). Each size fraction was evaluated for baseline physical and chemical properties and applicability to pyrolytic bio-oil generation. Thermal gravimetric analysis (TGA) and scanning electron microscopy were performed on the bagasse feedstock to understand its physical and thermal properties better. TGA was used to understand the thermal decomposition of the sugarcane bagasse with and without catalyst influence, as well as to study the bagasse kinetic properties. Pyrolysis gas chromatography mass spectrometry (Py-GC/MS) was performed on catalytic and non-catalytic samples to evaluate the chemical product distribution. The quality of the bio-oil is based on maximising hydrocarbons and minimising the concentration of oxygenated compounds in the yield. Fibrous rind presents better quality bio-oil, and the inclusion of a catalyst greatly increases the concentration of hydrocarbons. The calorific value of the bio-oil was approximately 34.15 MJ kg–1 compared to 14.8 ± 0.4 MJ kg–1 of the feedstock bagasse. Therefore, the sugarcane bagasse’s energy density was increased through application of pyrolytic decomposition. This study presents valuable implications on the Australian sugar industry as a way to increase the potential profit from bagasse assets and increase the domestic availability of liquid fuels.