J. Skrzypek

Effect of Mg and Mn oxide additions on structural and adsorptive properties of Cu/ZnO/ZrO2 catalysts for the methanol synthesis from CO2

Effect of addition of the Mg and Mn promoters on the activity of the Cu/ZnO/ZrO2 catalysts in the reaction of the synthesis of methanol from CO2 and H2, and the steam reforming of methanol, as well as on the catalysts’ adsorptive properties with respect to reactants (CO, CO2, H2O, methanol) was studied. Using the X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS) techniques as well as investigating the reactive N2O adsorption, it was revealed that addition of the promoters leads to an increase of the copper dispersion in the reduced catalysts. The surface layers are depleted of copper and enriched in zinc and zirconium. The promoters introduced are accumulated preferentially on the catalysts’ surface. Correlation between the adsorptive properties and the catalytic activity was established. The overall factor combining the adsorptive properties favoring the synthesis of methanol (RAF) and the catalytic activity increase in the series CuZnZr

Kinetics of methanol synthesis over commercial copper/zinc oxide/alumina catalysts

Abstract Kinetics of the low-pressure methanol synthesis over Polish commercial catalyst CuO (60% wt)—ZnO (30%)—Al 2 O 3 (7.5%) was investigated. The range of parameters applied was wide, especially concerning inlet concentrations of reactants: χ H 2 0 (10–80% mol), χ CO 2 0 (3–40% mol), χ CO 0 (0–20% mol). It was found that methanol synthesis occurs from CO 2 rather than from CO and that the basic reactions are: CO 2 +3H 2 ⇄CH 3 OH+H 2 O and CO 2 +H 2 ⇄CO+H 2 O. Dependence of the reaction rates on initial concentrations of CO 2 and H 2 was given by the functions with characteristic maxima. Langmuir-Hinshelwood type kinetic equations were determined.

Kinetics of the catalytic air oxidation of o-xylene over a commercial V2O5-TiO2 catalyst

Abstract The gas-phase oxidation of o -xylene over a commercial V 2 O 5 -TiO 2 catalyst was studied in fixed bed non-isothermal reactor. The experiments were carried out at initial o -xylene concentrations which differed greatly from each other. The following reaction network was suggested. It is suggested to use the Langmuir-Hinshelwood kinetic model in which a surface reaction between o -xylene and oxygen, chemisorbed on separate active centres, is the limiting step. It seems that the redox model is not adequate for the kinetic description of o -xylene oxidation.

Thermodynamics and kinetics of low pressure methanol synthesis

Abstract The results of our investigations on methanol synthesis, carried out over a number of years, have been presented in the form of an interpretative review. The present article is an attempt to summarize this research against the background of what has already been done in this area in the world. Special attention was focused on the role of CO2 in the process.

Methanol synthesis from CO2 and H2: dependence of equilibrium conversions and exit equilibrium concentrations of components on the main process variables

The effects of the initial feed composition, temperature and pressure on the equilibrium convesrions and concentrations of the components were examined for methanol synthesis from CO2 and H2. The two-reaction system Co2 + 3H2 ⇄ CH3OH + H2O, CO2 + H2 ⇄ CO + H2O was analyzed. From a thermodynamic viewpoint, direct methanol synthesis from CO2 and H2 is quite promising for industrial applications.

Theoretical analysis of two parallel and consecutive reactions in isothermal symmetrical catalyst pellets using the dusty-gas model

Abstract The courses of the simplest multiple reactions such as two parallel reactions and two consecutive reactions proceeding in the isothermal symmetrical ca

Methanol synthesis from carbon dioxide and hydrogen over Mn-promoted copper/zinc/zirconia catalysts

Mn-promoted copper/zinc/zirconia - catalysts have been investigated. Our investigations confirmed literature informations concerning advantageous influence of zirconium on the catalyst activity. Doping of Mn to Cu/Zn/Zr catalyst additionally increases the rate of methanol production.

Kinetics of the synthesis of higher aliphatic alcohols from syngas over a modified methanol synthesis catalyst

Abstract Kinetic investigation on the synthesis of a mixture of methanol and higher aliphatic alcohols from the synthesis gas has been conducted over a Cs-doped CuZn composite catalyst in an experimental gradientless reactor. The kinetic equation was described in a simple power law form.

Kinetics of the esterification of phthalic anhydride with 2-ethylhexanol. I. Sulfuric acid as a catalyst

Abstract The kinetics of the esterification of mono-2-ethylhexyl phthalate in the presence of sulfuric acid as a catalyst has been investigated in an isothermal semibatch reactor. The reaction appears to be first order with respect to mono-2-ethylhexyl phthalate alone and the reaction rate does not depend on the concentration of 2-ethylhexanol. The kinetic parameters have been determined.

Kinetics of the esterification of phthalic anhydride with 2-ethylhexanol: Part IV: Non-catalytic process. Final kinetic comparison of the catalysts

The kinetics of the non-catalytic esterification of mono-2-ethylhexyl phthalate has been investigated in an isothermal semibatch reactor. The reaction appears to be second order with respect only to mono-2-ethylhexyl phthalate and the reaction rate does not depend on the concentration of 2-ethylhexanol. The kinetic parameters have been determined. Final comparison of the esterification process in the presence of acid catalysts, amphoteric catalyst and for the non-catalytic reaction has been carried out.