Conversion of Calotropis procera biocrude to liquid fuels using thermal and catalytic cracking

With the fast depletion of petroleum reserves, renewable resources like biomass are acquiring great significance. Calotropis procera, a laticiferous arid plant is identified as a potential petrocrop. The dried biomass of C. procera was subjected to non-polar (n-heptane) solvent extraction. Biocrude so obtained is a rich source of tri terpenoid type of hydrocarbons. The biocrude was upgraded to useful liquid fuels using different conversion processes such as thermal and catalytic cracking (fluid catalytic cracking, FCC). The temperature, pressure and reaction time maintained during thermal conversions were 430 and 460 °C; 1.2 and 0.2 MPa; and 15 and 30 min, respectively. Catalytic cracking was carried out in continuous mode micro reactor varying the catalyst to feed ratio (3-7.03) and temperature (460-520 °C) aiming at maximization of lighter fractions (up to diesel range). High conversions (up to 92%) were obtained using FCC as compared to thermal process (57.7%). The HPLC analysis of the liquid fuels indicated that thermal cracking yielded a better quality fuel compared to FCC. The fuel obtained by FCC was found to contain large proportions of aromatics and poly-aromatic hydrocarbons (PAH).