Calcium oxide from Pomacea sp. shell as a catalyst for biodiesel production

Margaretha et al. International Journal of Energy and Environmental Engineering 2012, 3:33 http://www.journal-ijeee.com/content/3/1/33 ORIGINAL RESEARCH Open Access Calcium oxide from Pomacea sp. shell as a catalyst for biodiesel production Yosephine Yulia Margaretha, Henry Sanaga Prastyo, Aning Ayucitra* and Suryadi Ismadji* Abstract Heterogeneous catalysts are promising catalyst for the transesterification reaction of vegetable oils to produce biodiesel. In this study, the Pomacea sp. shell was used as the raw material for CaO catalyst. The calcination of Pomacea sp. shell was conducted at 900°C for 2 h. The raw material and the resulting CaO catalyst were characterized using X-ray diffraction, X-ray fluorescense spectrometry, and Fourier transform infrared spectroscopy analysis. From the experimental results, it was found that the maximum yield of fatty acid methyl esters was 95.61% at the following reaction conditions: reaction temperature of 60°C, a reaction period of 4 h, a ratio of methanol-oil at 7:1, and amount of catalyst at 4% w/w. The physical and chemical properties of biodiesel were determined based on ASTM standard, and the values obtained were confirmed with the Indonesian National Standard (SNI-04-7182-2006) and (B100)-ASTM D6751-07b. Keywords: Biodiesel, Transesterification, Solid catalyst, CaO, Palm oil Background The extensive use of fossil fuel in human activities during the last several decades causes the depletion of fossil fuel source; therefore, the search of other alternative energies is crucially important [1,2]. One of the alternative fuels which have been developed over a century ago is biodiesel. Biodiesel has been chosen as an alternative fuel because it is renewable, produces lower emission, and possesses high flash point, better lubrication, and high cetane number [3]. Studies about the transesterification of vegetable oils or animal fats into biodiesel have been conducted by various researchers. At the time of reaction, the triglycerides will gradually be converted into diglycerides, monoglycerides, and glycerol. At each change of conversion, one mole of ester formed [4]. Different kinds of catalysts have been in use to produce biodiesel from a different kind of oil. The catalysts commonly used for biodiesel production are categorized into several types: homogeneous catalysts (sodium hydroxide, potassium hydroxide, sulfuric acid, etc.) [5], heterogeneous catalysts (cation-exchange resin, hydrotalcites, etc.), and enzymes (Chromobacterium viscosum, Candida rugosa, and Porcine pancreas) [6]. * Correspondence: ; Department of Chemical Engineering Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya 60114, Indonesia Homogeneous catalyst has been used extensively for biodiesel production, but the use of this kind of catalyst began to decrease because it has several drawbacks: it cannot be recovered [7] or regenerated after the reaction and also it produced toxic wastewater. To replace the homogenous catalyst, enzyme and heterogeneous catalysts have been developed and studied. The use of enzyme as a catalyst is less desirable because it is much more expensive than the homogeneous catalyst. Heterogeneous catalysts such as KOH/Al2O3 [8] and alumina/ silica [9] have a high level of alkalinity and reliable performance for biodiesel production. Nevertheless, these catalysts have some drawbacks since they are easily dissolved in methanol, relatively difficult to synthesize, and susceptible to humidity. For acid catalyst, higher molar ratio of methanol/oil should be used, and it requires longer reaction time [8,10,11]. Therefore, a new heterogeneous catalyst should be developed, which is reactive at low temperature and pressure, has short time reaction for various raw materials, easy to get, has a high conversion, and low biodiesel production cost [12]. Golden snails (Pomacea sp.) are mostly found in muddy areas such as in a rice field. It is considered as pests; therefore, its presence in the rice field is not desired. However, the meat of Pomacea sp. has high protein content and can be utilized as animal feed or as © 2012 Margaretha et al.; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Margaretha et al. International Journal of Energy and Environmental Engineering 2012, 3:33 http://www.journal-ijeee.com/content/3/1/33 an alternative food for human consumption. In Indonesia, this mollusk has been cultivated in small industrial scale. Its meat has been utilized as raw materials for various kinds of food, while the shell is discarded as waste. The utilization of Pomacea sp. shell as an alternative raw material in the production of solid catalyst for biodiesel is expected to raise its economic value and helps to overcome the waste problems of Pomacea sp. Pomacea sp. shell can be utilized as a solid catalyst for biodiesel production because it contains CaCO3 which can be converted into CaO during calcination. CaO is a heterogeneous catalyst which is most widely studied because of its high alkalinity, low solubility, cheaper price than KOH/NaOH, and also the ease of handling [13,14]. This research was focused on developing a new type of catalyst for biodiesel production from Pomacea sp. shell. The capability of the catalyst derived from the snail shell was tested on the transesterification of palm oil into biodiesel. The process parameters for biodiesel production were also studied. Page 2 of 9 Table 1 Composition of fatty acid in palm oil and other characteristics Composition Fatty acid (%) Lauric acid (C12:0) 0.81 Myristic acid (C14:0) 1.22 Palmitic acid (C16:0) 42.42 Palmitoleic acid (C16:1) 0.21 Stearic acid (C18:0) 4.68 Oleic acid (C18:1) 40.78 Linoleic acid (C18:2) 9.45 Linolenic acid (C18:3) 0.11 Arachidonic acid (C20:0) 0.32 Water content (%) 0.05 Acid number (mg KOH/g oil) 0.85 D664, and the water content was determined according to ASTM D6304-07. Methods Materials and catalyst preparation Transesterification reaction procedure The Pomacea sp. shell was obtained from a small town called Pati, located in Central Java, Indonesia. Prior to use, the shell was repeatedly washed using tap water to remove dirt and other impurity material and then dried overnight at 100°C. The shell was then crushed and calcined at 900°C for 2 h in a tubular furnace to convert CaCO3 into CaO. After the reaction is complete, nitrogen with a flow rate of 3 l/min was introduced to furnace to cool down the system and to prevent the air entering the system. Subsequently, the catalyst was removed from the furnace and kept in a desiccator to prevent contact with air. Methanol used in this study was purchased as analytical grade from MERCK, Germany. Palm oil was purchased from the l (...truncated)