NiMo-sulfide supported on activated carbon to produce renewable diesel / NiMo-sulfuro soportado en carbón activado para producir diesel renovable / NiMo-sulfeto suportado em carvão ativado para produzir diesel renovável

Resumen Gracias a su débil polaridad y gran área superficial, los soportes de carbón activado tienen el potencial de aumentar la dispersión de los sulfuros metálicos. La ausencia de una interacción fuerte metal-soporte puede conducir a la formación de una fase Ni-Mo-S muy activa y estable. En este estudio se prepararon catalizadores por el método de co-impregnación, con diferentes cantidades de níquel y molibdeno y soportados sobre carbón activado comercial, y se caracterizaron por técnicas BET, XRF y SEM. Se evaluó su actividad catalítica para el hidroprocesamiento de aceite de Jatropha utilizando un reactor por lotes, y se determinó la composición de los productos líquidos y gaseosos. Los resultados mostraron que los productos gaseosos están compuestos principalmente de grandes cantidades de propano y pequeñas cantidades de otros hidrocarburos livianos (C1 a C5). Los hidrocarburos líquidos fueron principalmente una mezcla de n-parafinas de C15-C18 y de algunos compuestos oxigenados. Los catalizadores presentaron una fracción de masa de 3 % Ni, 15 % Mo (Ni3Mo15/AC) y mayor selectividad hacia hidrocarburos C17-C18, con una distribución de productos similar al catalizador Ni-Mo-S soportado en alúmina comercial.

Abstract Due to their weak polarity and large surface area, activated carbon supports have the potential to enhance the dispersion of metal-sulfides. It is expected that the absence of a strong metal-support interaction can result in the formation of a very active and stable Ni-Mo-S phase. In this study, catalysts with different amounts of nickel and molybdenum supported on a commercial activated carbon were prepared by a co-impregnation method and characterized by BET, XRF, and SEM techniques. The catalytic activity for hydroprocessing of Jatropha oil was evaluated in a batch reactor, and the composition of the liquid and gaseous products were determined. Results showed that gaseous products are mainly composed of high amounts of propane and small amounts of other light hydrocarbons (C1 to C5). Liquid hydrocarbon products consisted of a mixture containing mainly n-paraffins of C15-C18 and some oxygenated compounds. The catalysts with a mass fraction of 3 % Ni, 15 % Mo (Ni3Mo15/AC) presented the highest selectivity toward C17-C18 hydrocarbons, with a product distribution similar to a commercial alumina-supported Ni-Mo-S catalyst.

Resumo Devido a sua baixa polaridade e amplia área superficial, os suportes de carvão ativado possuem o potencial de aumentar a dispersão de sulfetos metálicos. A ausência de uma forte interação suporte-metal pode levar a formação de uma fase Ni-Mo-S muito ativa e estável. Neste estudo, foram preparados catalizadores com diferentes teores de níquel e molibdênio suportados em carvão ativado comercial por um método de co-impregnação e caracterizados pelas técnicas BET, XRF e SEM. A atividade catalítica foi avaliada para o hidroprocessamento do óleo de Jatropha em um reator por lotes, e se determinou a composição dos produtos líquidos e gasosos. Os resultados mostraram que os produtos gasosos são compostos principalmente por altos teores de propano e pequenos teores de outros hidrocarbonos leves (C1-C5). Os hidrocarbonos líquidos consistiram de uma mistura contendo principalmente n-parafinas de C15-C18 e alguns compostos oxigenados. Os catalizadores apresentaram uma fração de massa de 3 % Ni, 15 % Mo (Ni3Mo15/AC) e uma maior seletividade em relação aos hidrocarbonos C17-C18, com uma distribuição de produtos similar ao catalizador comercial Ni-Mo-S suportado em alumina.

Breeding of High Lipolytical Bacteria by Acclimation to Jatropha Oil and Resultant Strain-catalyzed Esterification Reaction / 微生物学通报

A strain, Pseudomonas sp. X-2-45, with high and stable lipolytical activity was screened by continuously subculturing a lipase-producing bacterium P. sp. LP-1 in culture medium containing Jatropha oil as a sole carbon source. Its hydrolytic activity was 29.79 U/mL, which was increased by 288% as compared to that of parent strain. Furthermore, the growth and lipase synthesis of X-2-45, its catalytic ability to hydrolyze vegetable oils, as well as ester synthesis between fatty acids and organic alcohols were studied. Results showed that rates of bacterial growth and lipase synthesis were significantly raised. Bacterial biomass and lipase activity reached the highest level after 30 h of incubation. Moreover, growth stationary period was prolonged and lipase produced exhibited good stability in culture media during incubation period. Hydro- lytic activity of P. sp. X-2-45 lipase toward Jatropha oil was increased by 378% as compared to parent strain, suggesting that acclimation to Jatropha oil was an effective approach for improving substrate selectivity oflipase. Finally, results of ester synthesis catalyzed by P. sp. X-2-45 lipase indicated that this lipase could catalyze esterification reactions between lauric acid and n-butanol, n-octanol, 1-dodecanol or glycerol, palmitic acid or stearic acid and methanol, n-octanol, 1-dodecanol or glycerol, oleic acid and methanol, n-butanol, n-octanol, 1-dodecanol or glycerol.