Kinetic Model of Catalytic Steam Gasification of 2-Methoxy-4-methylphenol Using 5% Ni-0.25% Ru/γAl2O3 in a CREC-Riser Simulator

Hydrogen is an energy vector with a great potential due its ample range of applications and clean combustion cycle. Hydrogen can be produced through biomass steam gasification, with novel catalysts being of significant value to implement this process. With this goal in mind, in the present study, 5 wt % Ni/gamma Al2O3 promoted with 0.25 wt % Ru was synthesized and characterized. It is assumed that ruthenium facilitates hydrogen transfer to nickel oxide sites, promoting a hydrogen spillover effect, with the H-2 adsorbed on Ru being transported to Ni sites. To describe chemical changes, the present study considers a kinetic model involving Langmuir-Hinshelwood-based rate equations, as a sum of independent reactions, with this being applied to the steam gasification of 2-methoxy-4-methylphenol (2M4MP). This tar biomass surrogate was studied in a fluidized CREC (Chemical Reactor Engineering Centre) Riser Simulator reactor, at different reaction times (5, 20 and 30 s.) and temperatures (550 degrees C, 600 degrees C and 650 degrees C). The proposed kinetics model was fitted to the experimentally observed H-2, CO2, CO, CH4 and H2O concentrations, with the estimated pre-exponential factors and activation energies being in accordance with the reported literature data. It is anticipated that the postulated model could be of significant value for the modeling of other biomass conversion processes for hydrogen production using other supported catalysts.

Automated summary

In this study, a catalyst composed of 5 wt % Ni/gamma Al2O3 promoted with 0.25 wt % Ru was synthesized and characterized for the steam gasification of 2M4MP. A kinetic model based on Langmuir-Hinshelwood rate equations was applied, and the model parameters were found to be in accordance with experimental data.