Carbon dioxide hydrogenation over nickel-, ruthenium- and copperbased catalysts: review of kinetics and mechanism

Abstract: This study critically reviews the mechanism of CO2 hydrogenation over Ni, Ru and Cu, and the effect of catalyst properties and operating conditions on reaction kinetics. Most studies have reported the presence of CO and formate species on Ni-, Ru- and Cu-based catalysts, where subsequent conversion of these species depends on the type of catalyst and the physicochemical properties of the catalyst support. Methane is the major product that forms during CO2 hydrogenation over Ni and Ru catalysts, while methanol and CO are mainly produced on Cu catalysts. A different approach for catalyst formulations and/or process development is required where long chain hydrocarbons are desired

Fischer-Tropsch synthesis Over titaniasupported cobalt catalyst : optimum pressure for C5+ hydrocarbons production

Abstract: Fischer-Tropsch (FT) runs were performed using a titania-supported cobalt catalyst at total operating pressures of 1, 10 and 20 bar respectively, to determine the optimal pressure for C5+ hydrocarbons production. The reaction temperature and feed flowrates were kept constant as 220oC and 20 Nml/gCat/min respectively. Lower methane and higher C5+ hydrocarbons selectivities were measured at higher pressure. However the highest rate of C5+ hydrocarbons production was measured at an optimum pressure of 10 bar

Effect of pressure, temperature and steam to carbon ratio on steam reforming of vegetable oils : simulation study

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Vegetable oil to biofuel by cracking : equilibrium product selectivities

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Simulation of vegetable oils steam reforming process and comparison with literature experimental data

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Effect of space velocity on Fischer-Tropsch reaction over Co/TiO2 catalyst

Abstract: The effect of space velocity on FT reaction has been evaluated over a 10%Co/TiO2 catalyst prepared by incipient wetness impregnation method. The catalyst was tested in a fixed-bed reactor at 220oC, 20 bar and various feed gas space velocities (20, 40 and 60 Nml/gCat/min). The CO consumption rate, olefin to paraffin ratio, C5+ selectivity and the chain growth probability (alpha) were found to increase with an increase in feed gas flow rate. The results were explained in terms of reactants partial pressures and mass transfer in the reactor as function of CO conversion levels

Fischer-Tropsch synthesis over Co/Tio2 catalyst : effect of catalyst activation by CO compared to H2

Abstract: Co/TiO2 catalyst activation for Fischer-Tropsch (FT) reaction by CO in comparison to H2 has been performed. The catalyst, prepared by incipient wetness impregnation, has been characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses after separate reduction using CO and H2 respectively. Temperature programmed reduction (TPR) analyses were also conducted to study the reduction behaviour of the catalyst in presence of H2 and CO respectively. CO improved catalyst reduction and produced a more stable and active catalyst with higher selectivity and yield for C5+ hydrocarbons at extended time-on-stream

Effect of temperature on CO rate and product distribution during Fischer-Tropsch reaction over Co/TiO2 catalyst

Abstract: A 10%Co/TiO2 catalyst has been synthesized by incipient wetness impregnation method and tested in a fixedbed reactor at 20 bar and various temperatures to assess the effect of operating temperature on Fischer-Tropsch (FT) reaction. Increasing the operating temperature (from 200oC - 220oC) led to an increase in methane and light product selectivity but increased the CO conversion rate and the net C5+ production rate. Apparent activation energy for CO conversion and light alkanes (up to C4) formation has also been estimated using Arrhenius plot

Energy requirement estimates for two step ethanolysis of waste vegetable oils for biodiesel production

ChemCad 6.4 simulation package was used to model a two-step biodiesel production process from waste vegetable oils (WVO) and ethanol using homogeneous acid and alkali catalysts respectively. The developed process flowsheet consisted of pre-esterification and transesterification of WVO, ethanol and glycerol recovery, and biodiesel refining. The energy required for each processing unit as well as the energy required for the whole process have been estimated. Ethanol recovery accounted for the highest portion of the energy required for the entire process estimated as 2.75 MJ per kg of biodiesel produced

Effect of operating temperature, pressure and potassium loading on the performance of silica-supported cobalt catalyst in CO2 hydrogenation to hydrocarbon fuel

Abstract