Biodiesel production solid acid catalysts

Apart from a few reports" on solid acid catalyzed esterification of model compounds, to our knowledge utilization of solid catalysts for biodiesel production from low quality real feedstocks have been explored only recently. 12-Tungstophosphoric acid (TPA) impregnated on hydrous zirconia was evaluated as a solid acid catalyst for biodiesel production from canola oil containing up to 20 wt % free fatty acids and was found to give ester yield of 90% at 200°C. Propylsulfonic acid-functionalized mesoporous silica catalyst for esterification of FFA in flotation beef tallow showed a superior initial catalytic activity (90% yield) relative to a... 

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). 

Sulfur-free fuel, since solid acid catalysts do not leach into the biodiesel product. 

Stepwise degradation of sugars under catalytic conditions leads to shorter-chain sugars and such by-products as CO, C02, and H20 depending on the conditions (see also next section).348 Sucrose or other carbohydrates have been used for the preparation of new solid acidic catalysts by partial carbonization followed by sulfonation. This leads to sheets of amorphous carbon bearing hydroxyl, carboxyl, and sulfonic groups. These have been used for the production of biodiesel fuel.349... 

Carbonized sugar derivatives are used as solid acid catalysts for the production of biodiesel fuel,349 and carbonized sucrose treated with ethylene and then pyro-lyzed provides materials used as hard-carbon anodes for lithium-ion batteries.439... 

Kiss, A.A., Dimian, A.C., Rothenberg, A., Solid acid catalyst for biodiesel production-towards sustainable energy, Adv. Synth. Catal., 368, 75-81, 2006... 

Kiss, A.A. A.C. Dimian G. Rothenberg. Solid acid catalysts for biodiesel production—towards sustainable energy Synth. Catal. 2006,348, 75—81. 

Lou, W., Zong, M., Duan, Z. (2008). Efficient production of biodiesel from high free fatty acid-containing waste oils using various carbohydrate-derived solid acid catalysts. Bioresource Technology, 99, 8752—8758. 

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). 

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... 

Wu, H.T., Liu, Y.P., et al., 2014. In situ reactive extraction of cottonseeds with methyl acetate for biodiesel production using magnetic solid acid catalysts. Bioresource Technology 174, 182-189. 

Table 6.6 Recent heterogeneous solid acid catalysts for biodiesel production... 

Fu, J., et al., 2015. Free fatty acids esterification for biodiesel production using self-synthesized macroporous cation exchange resin as solid acid catalyst. Fuel 154, 1—8. Available at http //www.sciencedirect.com/science/article/pii/S0016236115003440 (accessed 11.05.15.). 

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.). 

Sani, Y.M., Baud, W.M.A.W., Abdul Aziz, A.R., 2014. Activity of solid acid catalysts for biodiesel production a critical review. Applied Catalysis A General 470, 140-161. 

Su, F., Guo, Y., 2014. Advancements in solid acid catalysts for biodiesel production. Green Chemistry 16, 2934—2957. Available at http //xlink.rsc.org/ DOI=c3gc42333f (accessed 24.05.14.). 

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. 

There is a real opportunity to reduce biodiesel production costs and environmental impact by applying modem catalyst technology, which will allow increased process flexibility to incorporate the use of low-cost high-FFA feedstock, and reduce water and energy requirement. Solid catalysts such as synthetic polymeric catalysts, zeolites and superacids like sulfated zirconia and niobic acid have the strong potential to replace liquid acids, eliminating separation, corrosion and environmental problems. Lotero et al. recently published a review that elaborates the importance of solid acids for biodiesel production. ... 

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 alkali process for biodiesel production can achieve high purity and yield of biodiesel in a short time. However, vegetable oils high in free fatty acids result in the production of soap and the loss of catalyst in the alkali process. To overcome this, the free tatty acids should be removed before the transesterification reaction. Because a homogeneous acid catalyst like sulfuric acid can not be recovered and is toxic, a heterogeneous acid catalyst can be used for the esterification of free fatty acids. Solid catalysts can be easily recovered after the reaction and reused [10-12]. 

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. 

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... 

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