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Styrene-divinylbenzene copolymers (STY-DVB) have a wide range of applications as ion exchange resins and adsorbents. The synthesis of these copolymers has been the subject of studies for a long time due to the diverse variables that can be adjusted or modified, such as porogen, size, agitation time, agitation speed, and sulfonating agent, among others; with the purpose of obtaining polymeric support with adequate physicochemical characteristics such as inertness, thermal stability, capacity to be reusable, and low toxicity. In this work, we propose the variation of parameters of synthesis in the suspension of these resins, such as the amount of porogen to be used, the agitation speed, and the amount of crosslinking agent divinyl benzene (DVB), and determine its influence on the exchange capacity. It was possible to obtain three resins with particle size between 55-75 µm (Resin 1) and 90-200 µm (Resins 2 and 3), with exchange capacities between 3-4.38 mEq/g, values that correspond to acid macroporous resins that will allow their subsequent use as heterogeneous catalysts and solid acids. [ABSTRACT FROM AUTHOR]

Biofuels are a viable alternative to the partial or total replacement of fossil fuels, biodiesel is an ideal substitute for diesel as it can be used without modifying existing engines and offers a safe distribution process. In this review, the raw materials used in recent years for their production by the transesterification method are summarized, as well as the effect that the operating conditions have on the reaction yield, in addition to integrating the reaction mechanisms with base catalysis, acid and the heterogeneous catalyst CaO. Transesterification has been studied and modified, from the conventional process to the application of ultrasound, in supercritical conditions and in situ. The ideal process will depend on the available raw materials and equipment, using the least amount of energy, time and inputs, one of the most promising is transesterification with ultrasound and heterogeneous catalyst. [ABSTRACT FROM AUTHOR]

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Homogeneous and heterogeneous catalysts are widely used for diverse industrial processes in order to produce clean fuels and many other valuable products, being spent hydroprocessing catalysts the major solid wastes of the refinery industries and the main contribution to the generation of spent catalysts. Because of its hazardous nature, the treatment and metal recovery from this kind of residues has gained increasing importance, due to the depletion of natural resources and environmental pollution. Although there are techniques already available for these purposes, they generate large volumes of potentially risky wastes and produce the emission of harmful gases. Thus, biotechnological techniques may represent a promissory alternative for the biotreatment and recovery of metals contained in spent catalysts. To this end, diverse microorganisms, comprising bacteria, archaea and fungi, have been analyzed to characterize their metal removal abilities from spent catalysts. A broad scenario about the advances regarding to the management and traditional treatment of spent catalysts is presented, followed by a detailed overview of the microbiological biotreatment approaches reported to date. [ABSTRACT FROM AUTHOR]

Catalytic properties of Sulfated Zirconia (SZ) and Niobium Oxide (NBO), in sucrose inversion reaction to obtain invert sugar were studied. The reaction was performed in two types of solvents: water or water:ethanol (50:50). Materials were analyzed by X-ray Diffraction (XRD), Nitrogen Physisorption, Temperature Programmed Desorption (TPD) and Infrared Spectroscopy (IR). The results showed an important influence of the solvent on the catalytic activity for both catalysts. It was found that SZ had a higher conversion (%) corresponding to 98% in water:ethanol opposite trend than NBO, which exhibited better catalytic activity in water solvent with a conversion (%) of 66%, such behavior can be assigned to the possible conservation of structural stability of each of the catalysts in the solvents used. It was also showed a higher selectivity at 100 % to the interest product when NBO was used, it is attributed to acid-tolerant properties in polar liquids, while SZ caused a consequent degradation of sucrose giving rise to the formation of secondary products of reaction and selectivity (%) around of 80%, due to the significant acidity as showed in the TPD results. [ABSTRACT FROM AUTHOR]

This work shows the study of the hydrogenation of the palm oil using a heterogeneous catalytic process with solid type Cu-Ni supported in ZnO at 40 bar of pressure and 200°C of temperature. The aim of this study was to obtain fats alcohols from palm oil. The solids are actives and a mixture of fatty acids and alcohols was obtained. [ABSTRACT FROM AUTHOR]