Utilization of a cost effective solid catalyst derived from natural white bivalve clam shell for transesterification of waste frying oil

Optimization of methyl esters production from non-edible oils using activated carbon supported potassium hydroxide as a solid base catalyst

“…As a result, the number of the active sites available for the reaction will be less in number. These achievements agree with the previously reported data by other researchers (Al-Jammal et al, 2016;Girish et al, 2013;Takase et al, 2014 ). Moreover, deactivation of the catalyst could also be due to the adsorption of oil, methyl ester, glycerol and free fatty acids on the surface of catalyst (Girish et al, 2013).…”

“…Since the transesterification is a reversible reaction, and the higher methanol to oil molar ratio pushes the reaction forward the products, the methyl ester yield increases progressively. In addition, methanol facilitates the solubility of phases, thus favouring a smooth reaction with limited mass transfer resistance (Girish, Niju, Begum, & Anantharaman, 2013). It was noticed that both oils have given the highest methyl esters yield at 9:1 methanol to oil molar ratio, while molar ratios higher than the optimal decreased the methyl esters yield as shown in Figure 3(b), due to the difficulty of glycerol separation as a result of the dilution of the oil with the excess methanol, and thus reduces the methyl ester yield Zabeti et al, 2009).…”

Synthesis and catalytic activity of hydration–dehydration treated clamshell derived CaO for biodiesel production

“…It was suggested that longer reaction time to be implemented for reaction with small amount of untreated CS-CaO to provide sufficient time to initiate methoxide species generation. This fact was supported by Girish's study, which has suggested that low biodiesel yield was achieved (<40%) when 2 wt% of white bivalve clamshells derived CaO catalyst was applied under methanol/oil molar ratio 18:1 for 3 h of reaction time (Girish et al, 2013). From the present results, the suitable methanol to oil molar ratio for the transesterification of palm-based biodiesel over treated catalyst is 9:1.…”

“…This is potential to be converted into calcium oxide (CaO) to act actively as solid base catalyst for transesterification process. Several types of Ca sources have been used as green CaO catalyst for biodiesel synthesis, this included eggshell (Khemthong et al, 2012;Niju et al, 2014;Oliveira et al, 2013), snails (Birla et al, 2012;Viriya-Empikul et al, 2012), mudcrabs (Boey et al, 2009), cockles (Boey et al, 2010), scallops (Buasri et al, 2013), mussels (Sharma et al, 2010), oysters (Nakatani et al, 2009), waste capiz (Suryaputra et al, 2013), white bivalves (Girish et al, 2013), bovine bone (Smith et al, 2013), cuttle bone and sheep bone (Obadiah et al, 2012). In summary, the waste shells derived CaO rendered high transesterification activity with >98% of triglyceride conversion and biodiesel selectivity.…”

“…Calero reported high conversion rate of sunflower oil (100%) to biodiesel was achieved under 6:1 of methanol:oil molar ratio, 7 wt% commercial CaO catalyst, 65 • C within 1 h of reaction time (Calero et al, 2014). However, waste shell derived CaO required longer reaction time (>2 h) in order to reach high triglycerides conversion to biodiesel (Boey et al, 2009;Buasri et al, 2013;Girish et al, 2013;Obadiah et al, 2012). This is due to lower basicity and surface area of waste shell derived catalyst compared to commercially available CaO.…”