Green diesel production from Karanja oil using mesoporous Ba(HPW₁₂O₄₀) solid acid catalyst

Abstract

Highly mesoporous Ba(HPW₁₂O₄₀) heterogeneous acid catalysts were successfully synthesized by the two-step impregnation method and characterized for their catalytic activities, the trans-esterification reaction of Karanja oil was evaluated. The various amounts of catalyst were loaded in the acidic medium and then Barium salt of tungstophosphoric acid. The acid catalyst was characterized using a techniques like FT-IR, XRD, BET, TGA, SEM and EDX.The results indicate that Ba²⁺ was incorporated into the HPW₁₂O₄₀ framework via isomorphous substitution between Ba²⁺ ions. During the tests, it was observed that Ba (HPW₁₂O₄₀), for transerterification of pongamia oil (89%) at optimized reaction conditions of 120 °C, 16:1 methanol to reactant molar ratio, 0.75 wt% catalyst loading, and 3 hrs reaction time. The results show that all of the solids have catalytic activity in the cracking reaction, which lowers the ultimate acidity of the products. The solids also have catalytic activity in the transesterification of triglycerides, resulting in high ester yields of 95% from Pongamia oil. The biodiesel production from pongamia oils was characterized by FTIR analysis and ¹H- NMR spectroscopy. With significant activity and stability, the used catalysts could be recycled up to three times.

Keywords:

• acid catalyst
• Ba (HPW₁₂O₄₀)
• biodiesel
• mesoporous
• pongamia oil
• ¹H-NMR