Biodiesel Production via Esterification of Palm Fatty Acid Distillate Using Sulphonated Multi-walled Carbon Nanotubes as a Solid Acid Catalyst: Process Study, Catalyst Reusability and Kinetic Study

作者：Shuit Siew Hoong; Tan Soon Huat^*

来源：Bioenergy Research, 2015, 8(2): 605-617.

DOI：10.1007/s12155-014-9545-2

• Heterogeneous esterification
• Palm fatty acid distillate (PFAD)
• Sulphonated multi-walled carbon nanotubes
• Kinetic model
• Acid regeneration

This study reports on biodiesel production via the esterification of palm fatty acid distillate (PFAD) using sulphonated multi-walled carbon nanotubes (s-MWCNTs) as a catalyst. The process parameters studied included the methanol-to-PFAD ratio (8-30), catalyst loading (1-3 wt%), reaction temperature (80-200 A degrees C) and reaction time (1-5 h). A fatty acid methyl ester (FAME) yield of 93.5 % was obtained at a methanol-to-PFAD ratio of 20, catalyst loading of 3 wt%, reaction temperature of 170 A degrees C and reaction time of 2 h. The s-MWCNTs exhibited good catalytic activity, with a FAME yield higher than 75 % even after five repeated runs. Moreover, the regeneration of the spent s-MWCNTs (after five runs) with sulphuric acid was able to restore the catalytic activity to its original level. The catalyst stability and activity were enhanced by acid regeneration to achieve a FAME yield of 86.2 %, even at the fifth cycle of reaction after acid regeneration. A pseudo-homogeneous kinetic model for the esterification of PFAD with methanol using s-MWCNTs as a catalyst was then developed based on the experimental results. The pre-exponential factor, molar heat and activation energy for the esterification were found to be 1.9 x 10(2) L mol(-1) min(-1), 84.1 kJ mol(-1) and 45.8 kJ mol(-1), respectively.

• 出版日期2015-6