Development of chromium-impregnated sulfated silica as a mesoporous catalyst in the production of biogasoline from used cooking oil via a hydrocracking process

The production of biofuels as an alternative to fossil fuels has been a significant challenge until recently. The present work focuses on hydrocracking used cooking oil (UCO) into biogasoline over chromium impregnated on a sulfated mesoporous silica catalyst. The effects of varying sulfuric acid concentration, calcination temperature, and impregnated chromium content were systematically studied in the synthesis process employing TEOS and NaHCO3 by sol–gel method. A sulfuric acid concentration of 2 M and calcination temperature of 600 °C produced an SO4–SiO2 catalyst with the best acidity of 8.46 mmol g−1. Variation of chromium content (wt%) of 1% had Cr/SO4–SiO2 catalyst with the best acidity of 8.57 mmol g−1. SiO2, SS 2–600, and Cr-SS 1 catalysts were tested for their performance in the hydrocracking of UCO into biogasoline at an optimum temperature of 450 °C, H2 gas flow rate of 20 mL min−1, catalyst-to-feed ratio of 1:100 wt%, and time of 2 h. Hydrocracking using a Cr-SS 1 catalyst produced the most liquid product at 37.14% with the highest gasoline fraction selectivity of 29.38%. Graphical abstract: (Figure presented.)