No abstract

No abstract

No abstract

Nickelthe preferred reforming catalystwas modified and used for producing syngas from dry methane reforming. This process is attractive because it suitably uses two greenhouse gases: CH4 and CO2. Catalyst Ni/MgO–Al2O3 was prepared by successive impregnation and tested in a fixed-bed reactor between 773 and 1073 K at 0.1 MPa pressure. When the space-time was 0.17 g·h/L and feed was equimolar, 89.4 and 92.9% CH4 and CO2 were converted at 1073 K. As the CO2/CH4 ratio in feed changed from 0.5 to 2 mol/mol, the syngas ratio (H2/CO) decreased from 1.24 to 0.61 mol/mol. Another catalyst, Ni–Pt/Al2O3, was synthesized by coimpregnation, and its performance was tested. It was found that 94.2 and 95.1% CH4 and CO2 from a 1:1 feed mixture were converted at 1073 K and 0.1 MPa pressure and the syngas ratio was 0.9 mol/mol. Both catalysts were characterized using SEM, XRD, TGA–DSC, and TPR/TPD methods. The effects of reaction parameters on performance were studied, and catalysts were found durable for up to 30 h. Between 873 and 973 K, kinetic data were obtained in a differential reactor and models based on power-law and Langmuir–Hinshelwood kinetics were suggested. This parametric and kinetic study gave insight into the performance of modified Ni catalysts in dry methane reforming.

Dry reforming of methane (DRM) provides valuable syngas from two greenhouse gases, CH4 and CO2. Three alumina‐supported noble metals, Ru, Pt, and Pd, were used as catalysts for the DRM process. Using CO2/CH4 mixtures in the range of 0.5–2 mol mol−1, catalyst performance was assessed in an integral fixed‐bed reactor between 773 and 1073 K. All catalysts were stable for at least 10 h. The DRM kinetics was studied in a differential reactor in the range of 848–898 K, using the power law model. The apparent activation energy values for the consumption of CH4 (86, 89, and 95 kJ mol−1) and CO2 (84, 86, and 91 kJ mol−1) over Ru/Al2O3, Pt/Al2O3, and Pd/Al2O3 as catalysts were found. Several kinetic models of the Langmuir‐Hinshelwood type were considered. A pathway with slow surface reaction between CH4 and CO2 chemisorbed on different types of active sites was found to be most suited to describe the kinetic data.