Synthesis and Characterization of Core-Shell Modeled AlMCM-48/HZSM-5 Composite Catalyst and Studies on Its Catalytic Activity in Cracking of Pongamia Oil into Bio Liquid Products

Abstract

The growing demands on alternative fuels which can be used in present-day engines have imposed strong necessity on this proposal. Biofuels, the hydrocarbons less than C18, are believed to be the promising alternative fuel. In the present work, the abundantly available pongamia oil was experimented to produce biofuel using hydrothermally synthesized porous catalysts such as HZSM-5 and AlMCM-48 and synergistic composite catalyst AlMCM-48/HZSM-5. Characterization techniques such as XRD, BET, TPD, and TEM were used to study the characteristics of catalysts. The catalytic activity of the catalysts in cracking of pongamia oil at optimized reaction conditions—temperature, 400 °C; WHSV, 4.6 h−1; and reaction time, 1 h in a pilot scale stainless steel high pressure fixed bed reactor (100 ml volume; 15 mm id)—was studied. Among mesoporous AlMCM-48 with different Si/Al ratios, AlMCM-48 (27) efficiently cracked 69% of pongamia oil into 45% bioliquid products (BLP) with 34% and 44% selectivity towards green gasoline (GG). The composite catalyst was synthesized with the most active microporous catalyst (HZSM-5) as core and mesoporous material AMCM-48(Si/Al = 27) as a shell. The composite material AlMCM-48/HZSM-5 proved to be an excellent catalyst in converting 97% of pongamia oil into 70% bioliquid hydrocarbons with 70% selectivity towards gasoline. The calorific value (ASTM D 240) of the biofuel was observed to be higher, while the viscosity (ASTM D 445) and specific gravity (ASTM D 1298) were found to be lower than biodiesel produced through transesterification process.