Economic Assessment of the Hydrogenation of CO₂ to Liquid Fuels and Petrochemical Feedstock

To remove high concentrations of CO2 from the off-gas of coal-driven power plants, a new process was proposed. The catalytic hydrogenation of the CO2 leads to the production of C2 – C4 (petrochemical feedstock) and liquid C5+ hydrocarbons (fuel). Thus, environmentally harmful CO2 may be converted sustainably to useful products. On the basis of a process flow sheet, the costs for processing the CO2 are estimated for different plant sizes. The price of hydrogen contributes significantly to the overall production costs. Further price reductions may be achieved by final engineering optimization of the process as a whole and specific unit operations

Entwicklung einer wissensbasierten Optimierstrategie für die Katalysatorentwicklung mit Hochdurchsatzmethoden : Teilbericht Leibniz-Institut für Katalyse ; Abschlussbericht für das Verbundprojekt ; Laufzeit 1.1.2004 - 31.12.2006

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Catalyst Development for CO₂ Hydrogenation to Fuels

New active and selective catalyst compositions for the hydrogenation of CO2 to mainly fuel-type higher hydrocarbons were developed by application of an evolutionary strategy. It was shown that Fe and K supported on TiO2 and modified by Cu plus other modifiers resulted in highest selectivity for C5–C15 hydrocarbons at high degrees of CO2 conversion. Co containing catalysts were less suited since they produced methane and light hydrocarbons with high selectivities. A detailed study of reaction conditions showed that selected catalyst compositions were able to reach high CO2 conversion with still low selectivities to methane at higher reaction temperatures and a higher H2/CO2 ratio. conversion with still low selectivities to methane at higher reaction temperatures and a higher H2/CO2 ratio

Genesis of active and inactive species during the preparation of MoO3/SiO2-Al2O3 metathesis catalysts via wet impregnation

The wet impregnation of ammonium heptamolybdate onto silica-alumina is used to prepare MoO3/SiO2-Al2O3 heterogeneous metathesis catalysts. The preparation is inspected in details in conjunction with physico-chemical characterization tools with the aim to identify the parameters that dictate the genesis of active and inactive metathesis species. The effects of the MoO3 loading and of the calcination temperature are systematically explored. The samples are characterized by N2-physisorption, ICP-AES, XRD, Raman, 27Al MAS-NMR and XPS and evaluated in the metathesis of propene to butene and ethene. Particular attention is brought to the interaction of the mesoporous silica-alumina support with the active component, to the decomposition of the precursor salt and to the location of the molybdenum oxide phase with respect to the pores of the support. It is shown that the temperature of calcination influences markedly the performances of the catalyst. High temperature treatments are necessary to decompose efficiently the Mo salt precursor. In the metathesis of propylene, the performances are levelling off when the MoO 3 loading is increased above ∼8 wt.%. This effect is correlated to the build up of MoO 3 crystals and of Al2(MoO4)3 at relatively high loading. © 2010 Elsevier B.V. All rights reserved

Transient studies of low-temperature dry reforming of methane over Ni-CaO/ZrO2-La2O3

The low temperature reforming of methane by carbon dioxide is studied over a calcium oxide promoted Ni catalyst supported on a tetragonal zirconia stabilized by lanthana, which presents an improved stability compared to the non-promoted catalyst. Steady-state catalytic activity measurements, diffuse reflectance infrared Fourier transform spectroscopic analysis and isotopic temporal analysis of products experiments reveal the occurrence of a bifunctional mechanism on the promoted catalyst: methane is activated on the Ni particles, carbon dioxide interacts with the calcium oxide to form carbonates which scavenge carbon from nickel at the Ni-O-Ca interphase, thus restoring Ni particles to the original state. This is assumed to hinder the formation of deactivating coke, which explains the improved catalytic stability of the promoted catalyst. The main route for the carbon deposit formation is found to be the methane cracking in spite of the low temperature reaction.Financial support by the MICINN of Spain (project CTQ2008-03068-E/PPQ) and the German Ministry of Education and Research (BMBF, contract no. 03X216) are gratefully acknowledged.Peer Reviewe