Catalytic potential of natural zeolites and selected metalic ores in pyrolysis of groundnut shells for bio-oil production

Abstract

Catalytic pyrolysis is a promising thermochemical method of conversion of biomass to chemicals and fuels compatible with current petrochemical engines. Catalytic modification of pyrolyzed bio-oils are geared towards the elimination and substitution of oxygen and oxygen containing functionalities in addition to increasing hydrogen to carbon ratio in the final product. Recent progress has focused on both hydrodeoxygenation and hydrogenation of bio-oil using a variety of metal catalyst in the production of aromatic compounds from bio-oil using catalytic pyrolysis. However, current effectiveness of catalysts and conversion efficiency remain a challenge. In this study five naturally occurring inorganic materials from Usuuku rock, Kilembe mines rock, Tiira soil, Katwe salt and Manafwa river zeolites, having traces of transition metal elements were investigated for their influence on H/C and O/C ratio of bio-oil produced by pyrolysis of groundnut shells. The results showed bio-oil catalysed by zeolitic with metallic ore in the framework had a high H/C ratio and generated are hydrocarbons, that is, paraffins, olefins and aromatics than those without catalyst. Basing on the results of the study, it was concluded that different catalysts have impact on product composition, with catalysts of highest SiO2/Al2O3 producing more light gases. This result agrees with Cheng et al. (2000) who studied furan conversion to aromatics and olefins using HZSM-5. It was also concluded that the natural catalytic materials enhanced yields of the petroleum like compounds mentioned above, i.e., Kilembe ore for benzofuran; Katwe salt for aromatics; and Manafwa catalyst for olefins, CO and aromatics. This was based on eraspec fuel analyser and showed that the materials selected had catalytic potential for pyrolysis of groundnut