Kinetics of sunflower oil methanolysis catalyzed by calcium oxide

Biodiesel from rapeseed oil (Brassica napus) by supported Li2O and MgO

“…The reaction rate for a solid phase catalysed transesterification, as suggested by other authors, might evolve through three stages [53,80]. Initially the conversion rate of BD is fairly low.…”

“…Considering a three-phase reaction system (methanol, oil, and catalyst), such rate might be due to possible mass transfer limitations, and the time needed to form the reactive methoxide phase over the catalyst surface may delay the BD production, all this followed by a possible pseudo second-order reaction rate on the early stages of the reaction [81]. In the second stage, when the BD production increases, the liquid phase of the reactant mixture might become more uniform and the methoxide complex forms faster in a two-phase reaction system (liquid-solid) leading to an increase in the reaction rate and at this stage the reaction rate has been reported to follow a pseudo-first-order reaction rate [53,80,[82][83][84][85][86]. The third stage is characterized by a decrease in the reaction rate that occurs due to the oil depletion (triglyceride source).…”

Utilization of constructional lime as heterogeneous catalyst in biodiesel production from waste frying oil

“…This reaction is called as transesterification. Figure 1 shows the scheme of the mentioned reaction (Leung et al 2010;Ghanei et al 2011;Veljković et al 2009, Boz et al 2009Helwani et al 2009). Since the cost of raw material has a major impact on final price of biodiesel, use of inexpensive feed stocks such as waste frying (WFO) and cooking oil (WCO) is recommended to reduce final price of biodiesel.…”

“…The main problem of these type oils is high free fatty acid (FFA) content which makes some difficulties in process (Jacobson et al 2008;Fraile et al 2009;Sharma and Singh 2009;Sabudak and Yildiz 2010). Although strong and homogenous bases are able to accomplish the reaction over 98 %, very fast recovery of catalysts is much difficult and makes hazardous waste waters (Ghanei et al 2011;Veljković et al 2009;Kawashima et al 2008;Silva et al 2010). Moreover, when waste oils are used as feed, the catalyst is consumed to form soap instead of biodiesel due to the high FFA of used oil (Jacobson et al 2008;Ghanei et al 2011;Balat and Balat 2010).…”

“…In the second group, further investigations have been performed due to good accessibility and high activity in moderate reaction conditions. Alkali earth metal oxide and methoxide and mixture of them, especially calcium oxide, are reported as active catalysts (Veljković et al 2009;Kawashima et al 2008;Sun et al 2010;Liu et al 2007;Wen et al 2010;Liu et al 2008aLiu et al , 2008bZabeti et al 2009b;Fraile et al 2009;Guo et al 2010). In most cases, laboratory grade or synthesized CaO, which is expensive, with or without support has been used as catalyst to transesterify the virgin edible oil to biodiesel, and high yield has been achieved (Liu et al 2008b;Kouzu et al 2008Kouzu et al , 2009Albuquerque et al 2008).…”