Synergistic catalytic effects of nickel-based catalysts on calcium aluminate supports in methane dry and combined reforming processes

Abstract

The significance of converting natural gas, particularly methane, into valuable chemical components is crucial across various industries. In this investigation, calcium aluminate powders (CA) with various CaO/Al₂O₃ molar ratios were synthesized and the resulting calcined samples were employed as support for the preparation of nickel-based catalysts. The research indicated a significant impact of the calcium aluminate content on the physical and chemical structures as well as the catalytic efficiency of the samples. Among the evaluated samples, 12 wt%Ni/CA with a cement percentage of 30.55 % and a BET area of 8.56 m².g⁻¹ demonstrated superior catalytic activity, stability, and carbon deposition suppression in methane dry reforming. The results indicated that increasing the nickel loading from 6 to 15 wt% enhanced the conversion of CH₄ and CO₂. However, the maximum conversion values for CH₄ and CO₂ were achieved at 92.9 % and 98.4 %, respectively, at 800 ℃ over the sample containing 15 wt% Ni. Additionally, the selected catalyst, 12 wt%Ni/CA, was utilized in the direct reduced iron (DRI) process to assess its potential in DRI process. The study revealed an improvement in CH₄ conversion from 20 % to 91.6 %, and the H₂/CO ratio decreased from 2.55 to 1.9 with an increase in temperature from 600 to 800 ℃. The results also demonstrated satisfactory performance of the studied sample under real feed conditions containing 5 vol% propane.