Solid Acid Catalyst for Biodiesel Production from Waste Used Cooking Oils

Abstract

This paper presents a study of the methanol based transesterification of waste used cooking oil (WCO, 15% free fatty acid content) with the synthesized solid acid catalyst at different temperatures and reaction times. The optimized conditions for fatty acid methyl ester (FAME) yield were investigated using methanol/WCO weight ratios of 0.15−0.35 and catalyst/WCO ratios of 0.25−1.25%. The results show that the methanol/WCO ratio of 0.3 and the catalyst/WCO ratio of 1.0% give the highest yield of 97.5% FAME at 383 K in 2 h. In addition, the capacity of porous supports for WO x synthesized catalysts, based on FAME yield was in the following order: Al2O3 > SiO2 > SnO2 > ZnO. The WO x /Al2O3 catalyst was found to be readily reusable and exhibited consistency in activity upon reuse for three times without loss of selectivity.

Economic analysis of two processes for biodiesel production

“…The esterification reaction takes place at a molar ratio of methanol to oil of 8.3:1, a temperature of 383 K, and a pressure of 4.5 bar (Komintarachat and Chuepeng, 2009). The catalyst (WO x /Al 2 O 3 ) is also present at 1 wt% (base on oil).…”

“…Solid acid catalysis has the advantage that the catalyst can be removed easily from the product, and it nearly produces no waste water. Considerable research has been presented on solid catalysts for biodiesel production over these years, and numerous kinds of powerful solid catalysts have been found (Abreu et al, 2005;Zabeti et al, 2009;Komintarachat and Chuepeng, 2009;Srilatha et al, 2011). WO x /Al 2 O 3 , which is found to be readily reusable and powerful in biodiesel production using raw material of waste cooking oil, would be taken as a catalyst in the solid acid catalyzed process of this study.…”

The Use of Biodiesel in Diesel Engines

“…2. Transesterification of triglyceride with alkyl alcohol (Komintarachat & Chuepeng, 2009) To prepare biodiesel, the most commonly used process is the base catalyst (e.g. sodium hydroxide, NaOH) reaction (Graboski & McCormick, 1998), due to its cost effectiveness and reaction stability.…”

“…The by-products generally are glycerol, water, methanol and catalyst traces, and un-reacted triglycerides (Babu & Devaradjane, 2003). In the biodiesel production from waste used cooking oil (WCO), the methanol based transesterification over the synthesized solid acid catalyst at high free fatty acid (FFA) of 15% w/w was extensively studied by Komintarachat & Chuepeng (2009). The type of porous support of the catalyst affected the amount of the FAME yield.…”

“…The catalytic activities of conventional catalysts, i.e. potassium hydroxide (KOH), potassium carbonate (K 2 CO 3 ), sulfuric acid (H 2 SO 4 ) with the WO x /Al 2 O 3 catalyst under the optimum condition, previously mentioned were also compared and studied by Komintarachat & Chuepeng (2009). The WO x /Al 2 O 3 and KOH catalysts gave the highest activity by yielding the maximum FAME.…”