A study on the production and engine analysis of organic liquid fuel from jatropha and castor oil by catalytic cracking over solid acid catalysts

Abstract

Catalytic cracking of non-edible oils such as jatropha and castor was done in fixed bed catalytic reactor. The microporous catalysts such as Hβ, HY and HZSM-5 and mesoporous catalyst like AlMCM-41 were synthesised and characterised by XRD and BET surface area analyzer. The reaction parameters such as temperature of reaction, WHSV (Weight hourly space velocity) and reaction time were optimised over Hβ catalyst using jatropha oil. Organic liquid products (OLP) comprising of green gasoline (GG), green kerosene (GK) and green diesel (GD) and gaseous products were found to be major products. The liquid products were analysed using gas chromatograph (Shimadzu GC-9A) fitted with Apeizon-L packed column and gaseous products were analysed using Poropak Q column. The % conversion, yield of OLP and selectivity towards GG, GK and GD were found to be higher at temperature of 400 °C, WHSV of 4.8 h−1 and reaction time of 1 h. The cracking of jatropha oil was done over HY, HZSM-5 and AlMCM-41 at this optimised condition. Among the microporous materials HZSM-5 produced more OLP with more selectivity towards GG fraction (50%) but yielded higher % of gaseous products. While AlMCM-41 (Si/Al = 25) was selective towards middle distillates fraction like GK (45%) & GD (35%) and yielded low gaseous products. The mechanism of reaction proceeds via carbocation formation. The activity of HZSM-5 and AlMCM-41 were examined with castor oil. The OLP viability as a replacement fuel in a single-cylinder diesel engine under various loads was evaluated in an IC engine test. Here, we look at how different engine operating conditions affect fuel efficiency, Brake Thermal Efficiency (BTE), and emissions of Carbon Monoxide (CO), Carbon-di-oxide (CO2) and Nitrogen Oxide (NOx). Overall analysis indicates that OLP cracked from Jatropha oil serves as a best fuel in comparison with OLP obtained from Castor oil.