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    ABSTRACT: Biodiesel derived from edible and non-edible oils has received much attention as a chemical feedstock or as a raw fuel alternative to the traditional diesel due to its renewability and biodegradability. However, the crude biodiesel containing large amounts of polyunsaturated fatty acid methyl esters (FAMEs) is susceptible to oxidation upon exposure to heat, light, and oxygen. Catalytic hydrogenation of biodiesel has been considered as a feasible and powerful technique to improve the oxidative stability of biodiesel and hence to provide stable raw materials for industrial applications. The catalytic hydrogenation of FAMEs is a complex process but basically consists of hydrogenation of CC or CO, depending on the desirable properties of final products. In this review, we summarize recent developments in hydrogenation of CC and CO in FAMEs with focus on catalysts, reaction mechanisms, and reactor conditions. The features of hydrogenation of FAMEs are generalized and the opportunities for future research in the field are outlined.
    07/2014; 4(8). DOI:10.1039/C4CY00267A
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    ABSTRACT: Heterogeneous catalysts enabling multiple reaction sequences in one pot have a great potential for large-scale production processes in terms of productivity, cost-effectiveness, and low environmental impact. This paper reviews the most representative examples and the recent achievements in the field of solid bifunctional metal/acid-site catalysts and their application to the production of fine chemicals through selective, cooperative, or sequential processes in single reactor units. The literature that appeared from January 2009 to January 2012 is covered.
    Berichte der deutschen chemischen Gesellschaft 08/2012; 2012(24). DOI:10.1002/ejic.201200529
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    ABSTRACT: Potentially dominant factors governing the shape selectivity in n-hexane hydroconversion over a Pt/H-ZSM5 catalyst were evaluated by means of single-event microkinetic (SEMK) model regression against experimental data. The observed product distribution could be adequately modeled, and a corresponding physically meaningful interpretation could be made only when accounting for intracrystalline diffusion limitations for each hexane isomer involved in the reaction network, rather than considering physisorption effects or transition-state shape selectivity. Simultaneous diffusion and reaction inside the catalyst crystallites were expressed via Ficks second law, while the alkane Fick diffusion coefficients were assessed by explicitly accounting for mixture nonideality effects. A 3-fold lower diffusion coefficient was found to be required for 3-methylpentane compared with 2-methylpentane to explain the typically high selectivity toward the latter alkane. Once formed inside the catalyst crystallite, dimethylbutane isomers remained nearly immobile as was evident from their significantly lower diffusion coefficients. Reaction at the crystallite external surface was primarily responsible for the marginal conversion toward the former species, as observed experimentally.
    Industrial & Engineering Chemistry Research 10/2014; 53(40):15333-15347. DOI:10.1021/ie500164q · 2.24 Impact Factor