Kung-Tung Chen

Biodiesel Production from Soybean Oil Catalyzed by K2SiO3/C

A solid base catalyst (K2SiO3/C) capable of microwave absorption was used for the transesterification of soybean oil under microwave radiation. The K2SiO3/C catalyst was prepared by an impregnation method that loaded K2SiO3 on carbon particles (1-3.5 mm diameter) followed by drying at 120 °C. The catalysts were characterized by X-ray diffraction, scanning electron microscopy-energy dispersive spectrometry, and the Hammett indicator method. K2SiO3 was well distributed on the support. The effects of reaction variables such as catalyst loading, molar ratio of methanol to oil, and reaction time (under microwave radiation and conventional heating) were studied. When the conventionally heated reaction was carried out at 65 °C with a methanol/oil molar ratio of 30:1 and a catalyst concentration of 24 wt%, the biodiesel conversion was 96.5% after 2.5 h reaction time. The same reaction reached equilibrium after 1.5 h under microwave radiation, and the conversion of biodiesel was 96.7%.

Production of Biodiesel from Soybean Oil Using Li4SiO4 as a Heterogeneous Catalyst

This study synthesized biodiesel from soybean oil using transesterification over a lithium orthosilicate (Li4SiO4) catalyst. Under the optimal reaction condition of a methanol/oil molar ratio of 18:1, a 4 % (wt/wt oil) catalyst amount, and a reaction at 65°CC for 2 h, the conversion to biodiesel could achieve 93.3 %. Prepared using a solid-state reaction, the Li4SiO4 can be directly used for biodiesel production without being further dried or thermal pretreated, avoiding the usual activation of solid catalysts at high temperature. The effects of the methanol/oil ratio, catalyst amounts, reaction time and reaction temperature on the conversion were also examined and are reported in this paper. The solid base catalyst was highly active, air-insensitive and can be reused for at least ten cycles without loss of activity. The catalysts were characterized by means of XRD (X-Ray Diffraction), and Hammett indicator method.