Kinetics of Methanol Synthesis from Carbon Dioxide Hydrogenation over Copper–Zinc Oxide Catalysts

Abstract

Kinetics of methanol synthesis from carbon dioxide hydrogenation is studied on two noncommercial catalysts: a copper–zinc oxide catalyst on alumina (CuZA) and a copper–zinc oxide catalyst on zirconia (CuZZ). The experiments have been performed in an isothermal fixed bed reactor with a temperature range between 200 and 230 °C, a total pressure comprised between 50 and 80 bar, a gas hourly space velocity (GSHV) between 7800 and 23 400 h–1 and for different hydrogen:carbon dioxide molar ratios (between 2 and 6). Unlike other works in the literature, no carbon monoxide is contained in the feed which corresponds to the conditions of some recent industrial applications, the influence of the catalyst support has been tested to improve the methanol selectivity. The experimental data were modeled using the kinetic laws and adsorption coefficients determined by Graaf et al. based on a Langmuir–Hinshelwood–Hougen–Watson (LHHW) mechanism. The reactor model was based on an isothermal pseudo-homogeneous plug flow model without mass-transfer limitations. An optimization procedure was performed in order to identify new kinetic parameters. A good agreement between experimental data and modeling results was highlighted.

A review on biomass: importance, chemistry, classification, and conversion

“…The typical scheme of the biomass pyrolysis process is shown in Figure 13. The biomass gasification process essentially involves four different processes (Portha et al, 2017) (Fig. 14):…”

Optimal Design Issues of a Methanol Synthesis Reactor from CO2 Hydrogenation

“…The reaction rates taking place inside the reactor (Eqs. 4 and 5), over copper-zinc oxide on a zirconia (CuZZ) catalyst, are the ones developed in [20]. Each reaction rate is a function of the partial pressures of the components and the reactor temperature.…”

Gas phase methanol synthesis with Raman spectroscopy for gas composition monitoring

“…Moreover, the isothermal hypothesis is also supported by the thermal Mears criterion. 15 Therefore, the steady state reactor model is given by the following ordinary differential equation: 57…”

“…† The modied Soave-Redlich-Kwong equation of state 58 has been applied for calculating components fugacity coefficients due to its proven accuracy in terms of methanol synthesis kinetic modeling. 15,19,27,59 The equilibrium constants for the kinetic expressions are based on the latest reassessment of the process thermochemical data. 60 Since no signal of other chemical species has been detected on the acquired Raman spectra, no additional kinetic equations were considered.…”

“…Flame ionization detector (FID) is usually applied for methanol concentration determination, while thermal conductivity detector (TCD) is used for analysis of other gaseous components. [7][8][9][10][11][12][13][14][15][16] However, although gas chromatography is a versatile and accurate analytical method, its application for continuous gas composition monitoring might be ineffective due to signicant temporal resolution limitations. 17 An additional issue of this method is the possible ambiguity in qualitative determination of unknown compounds within a complex mixture, which oen necessitates additional conrmatory identication.…”