Esterification of palm fatty acid distillate with methanol via single-step pervaporation membrane reactor: A novel biodiesel production method

• Published in: Energy conversion and management Vol. 201; p. 112110
• Main Authors: Shuit, Siew Hoong, Tan, Soon Huat
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2019; Elsevier Science Ltd
• Subjects: Ammonium; Ammonium sulfate; Batch reactors; Biodiesel; Biodiesel fuels; Biofuels; Catalysts; Crosslinking; Diesel; Distillates; Esterification; Esters; Fatty acid methyl esters; Fatty acids; Feasibility studies; Integrated pervaporation membrane reactor; Membrane reactors; Membranes; Methanol; Multi wall carbon nanotubes; Nanotechnology; Nanotubes; Naphthalene; Pervaporation; Production methods; Reaction time; Reactors; Separators; Simultaneous reaction and separation; Temperature; Thermal decomposition; Thermal stability; Water treatment; Integrated pervaporation membrane reactor; Biodiesel; Esterification; Simultaneous reaction and separation
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2019.112110

•Biodiesel production via a single-step pervaporation membrane reactor.•Thermal treatment improved hydrophilicity of the 6FDA-NDA/DABA polyimide membrane.•About 18% of FAME yield increment as compared to batch reactor. In this study, the feasibility of a single-step reaction and separation of palm fatty acid distillate (PFAD) to biodiesel via integrated pervaporation membrane reactor was investigated. An integrated pervaporation membrane reactor system that combined both reactor and membrane separator into one unit was developed. The catalyst and membrane involved in this study were sulfonated multi-walled carbon nanotubes (s-MWCNTs) synthesized via thermal decomposition of ammonium sulfate ((NH4)2SO4) and copoly(1,5-naphthalene/3,5-benzoicacid-2,2′-bis(3,4-dicarboxyphenyl) hexafluoropropanedimide (6FDA-NDA/DABA). Esterification of PFAD with methanol was performed in both batch reactor and integrated pervaporation membrane reactor under the same reaction conditions: reaction temperature of 135 °C, methanol-to-PFAD ratio of 20, s-MWCNTs loading of 3 wt% and reaction period of 3, 5 and 10 h. At 10 h of reaction time, the thermally cross-linked 6FDA-NDA/DABA polyimide membrane was able to remove 94.8% of the generated water from the reaction mixture. The thermally cross-linked polyimide membrane was found to be a hydrophilic membrane and demonstrated negligible swelling in the reaction solvent, high thermal stability even at high reaction temperature and pressure. The high removal percentage of water by the thermally cross-linked polyimide membrane has triggered an increment of 17.9% fatty acid methyl esters (FAME) yield in pervaporation membrane reactor as compared to the batch reactor.