Biodiesel production solid base catalysts

Kouzu, M., T. Kasuno, M. Tajika, Y. Sugimoto, S. Yamanaka, and J. Hidaka. 2008. Calcium Oxide as a Solid Base Catalyst for Transesterification of Soybean Oil and Its Application to Biodiesel Production. Fuel 87 (12) 2798-2806. 

Ba/CaO solid base catalyst was prepared from construction site marble waste and was employed in the transesterifieation of waste cooking oil to produce biodiesel. With 1 9 molar ratio of oil to methanol and 3% catalyst at 65° C, conversion of 88% was observed in 3 h reaction time. It was shown that the catalyst can be reused for over three cycles and the method is uses less energy and provides value addition to both waste cooking oil and construction waste [24]. Table 12.1 provides a brief description of the single metal oxides as base catalysts for the production of biodiesel. 

Rapeseed-based biodiesel production has been widely studied in terms of optimization and kinetics of alkali catalyzed transesterihcation reaction (Luque et al., 2011). Recaitly, production of solid base catalysts, such as Ca/Zr mixed oxide catalysts (Liu et al., 2015), CaO-based catalysts or4-sulfophenyl activated carbon-based solid acid catalyst, has been reported with a performance similar to commacial heterogeneous catalyst Amberly st-15 (Malins et al., 2015). Present researches are also focusing on the use of supercritical ethanol and methanol as reagents to avoid drawbacks due to the use of homogeneous catalysts (Farobie and Matsumura, 2015a,b). Technoeconomic and performance studies on the use of supercritical methanol concluded that lower direct costs and environmental impacts are achieved at highest biodiesel yields, where oil consumption per unit of biodiesel... 

Anastopoulos, G., Dodos, G.S., et al., 2013. Biodiesel production by ethanolysis of various vegetable oils using calcium ethoxide as a solid base catalyst. International Journal of Green Energy 10 (5), 468-481. 

The hydrotalcite (HT) family is one class of solid base catalyst that has attracted much attention in solid base—catalyzed biodiesel production since it possesses good anion-exchange properties (Allada et al., 2002 Sels et al., 2001), and tunable base strength for the transesterification reaction (Sels et al., 2001 Xie et al., 2006 Debecker et al., 2009). 

Dolomite is a naturally abundant material, used widely for construction applications, which comprises Mg(C03)-Ca(C03) layers in an arrangement very similar to calcite (CaC03) and is an interesting precursor to generate solid base catalysts. As the carbonate form, dolomite is relatively inactive, however upon calcination, dolomite forms an intermixed MgO-CaO composite that shows excellent activity for biodiesel production. 

Mahdavi, V., Monajemi, A., 2014. Optimization of operational conditions for biodiesel production from cottonseed oil on CaO—MgO/ALOa solid base catalysts. Journal of the Taiwan Institute of Chemical Engineers 45 (5), 2286—2292. Available at http //www. sciencedirect.eom/science/article/pii/S1876107014001254 (accessed 17.03.15.). 

Numerous types of basic heterogeneous catalysts, such as alkahne earth metal oxide, anion exchange resins and alkali metal compounds supported on alumina or zeolite can catalyze various chemical reactions such as isomerization, aldol, Michael, and Knoevenagel condensation, oxidation and transesterification [1], Today considerable attention is devoted to the production of biodiesel (FAMEs) as an alternative for petroleum-derived diesel fuel. Biodiesel is synthesized by direct transesterification of vegetable oil or animal fat with a short-chain alcohol, viz. methanol, ethanol, and isopropanol in presence of an acid, base or enzymatic catalyst [2], Considering the advantages of solid base catalysts, for easy separation and recovery, reduced corrosion and environmental acceptance [1], many studies have been conducted on basic heterogeneous catalysts development for biodiesel production [3-13],... 

Experiments showed that high methyl ester yields can be achieved with solid bases and super acids under moderate reaction conditions. The solid bases were more effective catalysts than the solid super acids. High stability can be achieved by an ordinary inexpensive preparation process, and the catalyst can be separated easily from the reaction products in the heterogeneous catalysis process. The costly catalyst removal process can be avoided compared with the homogeneous process. Therefore, the heterogeneous process using a solid catalyst should be more economical for biodiesel production. 

During the last decade many industrial processes shifted towards using solid acid catalysts (6). In contrast to liquid acids that possess well-defined acid properties, solid acids contain a variety of acid sites (7). Sohd acids are easily separated from the biodiesel product they need less equipment maintenance and form no polluting by-products. Therefore, to solve the problems associated with liquid catalysts, we propose their replacement with solid acids and develop a sustainable esterification process based on catalytic reactive distillation (8). The alternative of using solid acid catalysts in a reactive distillation process reduces the energy consumption and manufacturing pollution (i.e., less separation steps, no waste/salt streams). 

In order to circumvent these problems, the use of heterogeneous catalysts has been explored. This approach eliminates the need for an aqueous quench and largely eliminates the formation of metal salts, thereby simplifying dovmstream separation steps consequently, biodiesel production can be more readily performed as a continuous process. Based on their ready availability, solid acid... 

The first part of this chapter is intended to survey recent literature on new catalytic materials because the development of new types of metal oxides and layered- and carbon-based materials with different morphologies opens up novel acid-base catalysis that enables new type of clean reaction technologies. Mechanistic considerations of acid- and base-catalyzed reactions should result in new clean catalytic processes for Green and Sustainable Chemistry, for example, transformations of biorenewable feedstock into value-added chemicals and fuels [21-35]. The latter part of this chapter, therefore, focuses on biomass conversion using solid acid and base catalysts, which covers recent developments on acid-base, one-pot reaction systems for carbon-carbon bond formations, and biomass conversion including synthesis of furfurals from sugars, biodiesel production, and glycerol utilization. 

Jothiramalingam, R. M. K. Wang (2009) Review of Recent Developments in Solid Acid, Base, and Enzyme Catalysts (Heterogeneous) for Biodiesel Production via Transesterification. Industrial Engineering Chemistry Research, 48, 6162-6172,ISSN 0888-5885. 

EujOj/AljOj was used as a super base novel solid catalyst for the trans-esterification of soybean oil with methanol. However, a biodiesel yield of 63.2% was obtained with oil to MeOH ratio of 1 6 at 70° C for 8 h with 5% catalyst [58]. Table 12.4 describes the base catalysts prepared in combination of AljOj for biodiesel production fi-om various oils. 

Rao, B. V. S. K., Chandra Mouli,K., Rambabu,N.,Dalai,A. K., and Prasad, R. B. N. Carbon-based solid acid catalyst from de-oiled canola meal for biodiesel production. Catal Comm 14,20-26 (2011). 

Soapstock acid oil, a concentrated by-product of the soybean oil rehning process based on fatty acid salts, was proposed by Soares et al. as a raw material for the production of biodiesel via acid heterogeneous catalysts using ethanol. The esterihcation reaction was conducted in a packed-bed bioreactor containing a lipase-rich fermented solid (sugarcane bagasse and sunflower seed meal fermented by Burkholderia cepacia) with a configuration that avoided inhibition of the catalyst by the presence of ethanol (Soares et al., 2015). 

Due to these disadvantages, research on the transesterification reaction using heterogeneous catalysts for biodiesel production has increased over the past decade (Lee and Wilson, 2014). Fig. 6.9 summarizes the classification of catalysts. Zhang et al. (2003) argued there is a considerable incentive for the substimtion of liquid bases by solid bases for the following reasons (1) energy intensive product/catalyst separation, (2) corrosiveness, and (3) the costs associated with the disposal of spent or neutralized caustics. 

This review has presented an overview of the impact of tuning both the surface properties and pore architectures of solid acid and base catalysts on their performance in biodiesel synthesis. Plant-oil viscosity and poor miscibility with light alcohols continue to hamper the use of new heterogeneous catalysts for continuous biodiesel production from both materials and engineering perspectives. Thus, the design of... 

Fu, X., et al., 2013. A microalgae residue based carbon solid acid catalyst for biodiesel production. Bioiesource Technology 146, 767—770. Available at http //www.sciencedirect. com/science/article/pii/S0%0852413011851 (accessed 22.06.14.). 

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