The top layer was biodiesel, and the lower was glycerol and small amounts of glycerides. The biodiesel was collected for chromatographic e quantitative analysis of the product was carried out on a temperature programmed Shimadzu chromatograph (GC-14C) with ov-17 column using nitrogen as carrier gas and fid detector. The column temperature was raised from 40 to 260C at a heating rate of 10C/min. The content of fatty acids (wt ) in soybean oil was as follows: palmitic (C16:0) — 20, stearic (C18:0) —30, oleic (C181) — 31, linolenic (C183) — 9, and linoleic (C18:2) -. The biodiesel yield was calculated from the content of methyl esters analyzed by gc using methyl laurate as internal standart: where Mw is the average molecular weight. The pure biodiesel was obtained under the optimal reaction conditions and the isolated yield also fits well with the gc analysis with a difference within. The effect of the calcination temperature. As was shown in the experimental part, the active basic sites were produced during calcination.
The novel solid base was obtained by calcination in air at high temperature for 4 h with the heating rate of 1C/min. During the calcination process, Mg(OH)2, Mg(OAc)2 4H2O and koac were transformed to MgO and K2CO3 which could act as the support and active base sites. During the calcination, koac decomposed to highly defective k2CO3, which would further decomposed to much stronger base sites K2O. The procedure of biodiesel synthesis, typically rapeseed dissertation oil (5 g methanol and the solid base (or other comparative catalysts) were mixed together and stirred at 70C for the specified period. The reaction was monitored by gc analysis. After completion, catalyst was filtered and the filtrate was distilled to remove excess of methanol. Then the filtrate was centrifuged with the formation of two phases.
Mg(OAc)2 koh solid reaction. Certain amounts of Mg(OAc)2 4H2O and koh were mixed together in a mortar and grinded for half an hour to form a paste. During the process, Mg(OH)2 and koac were produced with an exothermic effect, and the products could be mixed well. Then, the starchy intermediate products were dried in the oven at 308, zhang. Content, wt, yield _ weight of ester Mw off methyl ester) 3 (weight of oil Mw of oil) x 100. The tg analysis of the intermediate products. 80C for.
Innovation in the process of biodiesel synthesis
Therefore, various environmental friendly heterogeneous catalysts were developed to replace conventional homogeneous catalysts. Many solid base catalysts such as K2CO3/klc 8, koh/KL 9, koh/nay 10, kf/cao 3) 11, caal 12, kf/cao 13, Sr(NO3)2/Al2O314, cao 15, 16, htlcs 16, fa/k-x 17, na2SiO3 18, ZnO 19, 20 and K2CO3/MgO 21 were used to catalyze the trans-esterification reactions. Although some solid bases are convenient in use and provide assignment high yields, most catalysts suffer at least from one of the following disadvantages: relatively low catalytic activities, use of harmful solvents, high temperature needed, sensitivity to moisture, high cost, toxicity, and easy saponification. Moreover, the base-catalyzed transesterification is easily affected by the trace water and free fatty acids. Therefore, the raw oil should be strictly pre-treated to remove the water and reduce the acidity. Aiming to expand the application areas of the base catalysts, we developed a novel solid base with water and acid resistance for the biodiesel synthesis from rapeseed oil.
The results showed that the catalyst is very efficient for the reaction with high water and acid resistances. Experimental, all the reagents were commercial products with the highest purity available ( 98) and used for the reactions without further purification. Rapeseed oil was obtained from the Shanghai oil Plant. The acidity of the oil was about.23 (mg koh g and the average molecular weight was 850. Synthesis of the catalyst, short here we provide a simple solid state reaction method for the preparation of the novel catalysts.
The novel efficient procedure has been developed for biodiesel synthesis from rapeseed oil and methanol on the new solid base catalyst with water and acid resistant ability. The catalyst exhibited high activities even for the rapeseed oil with a high water content and acidity. Operational simplicity, low cost and reusability of the novel catalyst, high yields and short reaction time are the key features of this methodology. Doi:.7868/s, because of the shortage of traditional mineral fuels and environmental pollutions, the renewable bio-fuels are received wide attention. Biodiesel is the well-known renewable diesel fuel for replacing the mineral diesel fuel. Biodiesel has many useful properties and can be directly used in the compression-ignition (diesel) engines.
Furthermore, the emissions of the harmful substrates such as SOx, co, unburnt hydrocarbons and particular matter during the combustion process are greatly reduced. Generally, biodiesel is produced by transesterification of vegetable oils with short-chain alcohols (methanol or ethanol). Transesterification reactions are usually taken place in the presence of acid or base catalysts. Acidic catalysts, such as sulfuric acid, catalyze the reactions with low speed and produce a large amount of waste water. The base catalysts (e.g., koh and naoh) exhibit much higher activities. However, for those alkaline metal hydroxide catalyzed reactions, even if a water-free oil is applied as raw materials, certain amount of water is still produced in the reaction between the hydroxide and methanol. The trace of water in the reaction mixture would cause the hydrolysis of methyl esters products and soap formation during the process. The byproduct soap would decrease the biodiesel yield and add the glycerol separation difficulty. Furthermore, the homogeneous catalytic process requires catalysts separation, which is a tedious process and results in a large amount of wastewater.
Biodiesel with Supercritical Fluids Applied
A 67, 300 (2006) google Scholar. Sun, biomass bioenergy 35, wood 2787 (2011) CrossRef google Scholar. 255, 1 (2006) CrossRef google Scholar. C 112, 13563 (2008) CrossRef google Scholar. 25, 998 (2008) CrossRef google Scholar. 8, 2074 (2007) CrossRef google Scholar. Hu, energy fuels 25, 2679 (2011) CrossRef google Scholar Springer ScienceBusiness Media dordrecht 2012. From rapeseed oil 2014. Institute of Applied Chemistry, shaoxing University, china *E-mail: received.
107, 53 (2006) CrossRef google Scholar. B 99, 111 (2010) CrossRef google Scholar. 34, 282 (2005) google Scholar. Han, fuel 89, 2267 (2010) CrossRef google Scholar. Zou, fuel 97, 651 (2012) CrossRef google Scholar. B 79, 186 (2008) fashion CrossRef google Scholar. A 427, 58 (2012) google Scholar. 322, 91 (2010) google Scholar.
24, 3810 (2010) CrossRef google Scholar. 98, 936 (2007) CrossRef google Scholar. 131, 574 (2009) CrossRef google Scholar. B 106, 550 (2011) CrossRef google Scholar.
Keywords, biodiesel Grinding method ZnO/Ca(OH)2/KF Transesterification, notes. Acknowledgments, this work was supported by the national Natural Science foundation of China (21176125 the Science research Project of the ministry of Education of heilongjiang Province of China (2012TD012, 12511Z030, 12521594) and the Science research Project of Qiqihar of China (gygg201108). 11, 1300 (2007 crossRef, google Scholar. A 363, 1 (2009 hippie crossRef, google Scholar. 6, 142 (2012 google Scholar. 16, 2839 (2012 crossRef, google Scholar. 63, 1375 (1986 crossRef, google Scholar. Fernando, energy fuels 22, 2067 (2008 crossRef, google Scholar. 50, 650 (2011) CrossRef google Scholar.
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Article, first Online: 07 December 2012, received: 18 September 2012. Accepted: 22 november Downloads 3 Citations, abstract, a novel ZnO/Ca(OH)2/KF solid base catalyst was prepared by the grinding method and applied to biodiesel synthesis by the transesterification of soybean oil. The effect of various parameters such as kf molar amount, calcination temperature, the amount homework of catalyst, molar ratio of methanol to oil, reaction temperature, and time on the activity of the catalyst were investigated. The catalysts were characterized by several techniques of thermogravimetry/derivative thermogravimetry, xray diffraction, hammett indicator method, and scanning electron microscopy. The analysis results indicated that the kf interacted with Ca(OH)2 and formed kcaf3 phase before calcination of the catalyst. The formed kcaf3 crystal phase was the main catalytic active component for the catalyst activity. In addition, the basicity of ZnO/Ca(OH)2/KF was greatly influenced by the different calcination temperates, and the catalyst activity was correlated closely with the basicity. A desired biodiesel yield.6 was obtained at catalyst amount of 3, methanol/oil of 12:1, and reaction time.5 h at.