Esterification of used vegetable oils using the heterogeneous WO3/ZrO2 catalyst for production of biodiesel

Biodiesel Production by Using Heterogeneous Catalysts

“…The reactions were carried out using 9:1 molar ratio of methanol to oil, 0.29 g of catalyst per mol of oil at 75 °C. At all cases, a conversion of about 93 % was obtained (Park et al, 2010). Even when the results regarding conversion may seem promising, one should not forget that acid catalysts are more corrosive than basic ones.…”

“…Besides, heterogeneous catalysts exhibit a less corrosive character and can be used in a fixed-bed reactor, leading to safer, cheaper and more environment-friendly operations and the number of separation steps is less than when using homogeneous catalysts. The heterogeneous catalysts do not leave neutralization salts in the glycerol, and are plausible to be retained in the reactor by filtration (Di Serio et al, 2008;Kaita et al, 2002;Kawashima et al, 2009;Kovacheva et al, 2001;MacLeod et al, 2008;Madje et al, 2004;Park et al, 2010;Suppes et al, 2004;Waghoo et al, 1999;Xie & Li, 2006;Yan et al, 2008). The most commonly studied heterogeneous basic catalysts are alkaline metals carbonates (Na 2 CO 3 , K 2 CO 3 ), alkaline earth metal carbonates (CaCO 3 ), alkaline earth metal oxides (CaO, MgO, SrO, BaO) and other oxides as ZnO (Dossin et al, 2006b;Encinar et al, 2005;Fukuda et al, 2001;Liu et al, 2007;López et al, 2005;Ma & Hanna, 1999;MacLeod et al, 2008;Verziu et al, 2008).…”

Performance of heterogeneous ZrO2 supported metaloxide catalysts for brown grease esterification and sulfur removal

“…However, the drawback of using this method was the high energy cost associated with working under supercritical conditions required for the reactions. Finally, Park et al reported that a WO 3 /ZrO 2 catalyst was superior to a SO 2À 4 =ZrO 2 formulation and Amberlyst-15; achieving approximately 93% FFA conversion to FAME for a 4% oleic acid in soybean oil mixture at 75°C with a methanol to oil ratio 9:1 (Park et al, 2010).…”

Environmentally Sustainable Biofuels: Advances in Biodiesel Research

“…Thus, a variety of heterogeneous acid catalysts have been investigated to replace H 2 SO 4 . Zeolites, ion-exchange resins, and metal compounds like H-type mordenite with Si/Al molar ratio = 10 (HMOR(10)) [75], Amberlyst-15 [76,77], WO 3 /ZrO 2 [77,78], Cs-doped H 4 SiW 12 O 40 [79], sulphated zirconia [76], tungstated zirconia [80], and zinc stearate silica gel [81], show high efficiencies in FFA conversion (80-93%) at 60-75°C. However, the activity for transesterification is still low at a reaction temperature less than 200°C.…”