Nickel Catalysts For Dual-Gas Resources Polygeneration Reforming Reaction

Key Laboratory of Coal Science and Technology of Taiyuan University of Technology proposed the project named"Gasified coal gas(GCG) and coke oven gas(COG) mixed to make the syngas", which established the dual-gas coal resources polygeneration system. The reforming reaction of the system utilise the rich resources of GCG and COG will reduce the CO₂ emissions at source. The process to prepare CO and H2 from CH₄ and CO₂ is the core module, key technology of which is preparation of high-efficiency catalysts. Based on the problems offerde above, this paper makes the catalysts about nickel as the active component, Al2O3, alkaline MgO and MgO-Al2O3 dual as the supporters, inspects different catalysts'activity tests on the fixed bed. Combined with characterization means of XRD, Thermal analysis, BET, H2-TPR, H2-TPD, CO₂-TPD, we approach the structures, catalytic mechanism, the results was as follows:Nickel catalysts with dual supporters of Al2O3-MgO have higher activity than unitary supporter's catalysts. The former has quite good stability, whose feed conversions remained 85 % for 6 hours. The XRD and physical adsorption results show that, there are proper pore structures and more active sites on dual supporters'catalysts. So they have good catalytic activity.Thermodynamic calculations have surveyed of the synthesis processes of mixture of H2,CO,CH₄,CO₂,H2S,N2. The original mixed gas data (GCG and COG) are from the 973 project, Definition M=n(GCG)/n(COG). After thermodynamic calculations, the most optimum parameter for CH₄/CO₂ reforming reaction are M=1.4¹.7. the optimal reaction conditions are T=1173 K¹223 K, P=0.1 MPa,n (CO₂)/n_CH4=1～1.2. Then the methane and carbon dioxide's conversion will be 93.2⁹8.7% and 90.2～96.9% respectively. nH2/nCO will be 1¹.3. With simulated ratio of the dual-gas resources poly-generation system, we have performed the mixed feed gas reaction through the dual supporters of NiO/Al2O3-MgO catalyst, The test results the best gas time space velocity(GSHV) is 4.0×10⁴ ml·gcat^-1·h⁾(-1).Under the conditions, carbon dioxide's conversion remained 80 % and methane's 60 % after 35 hours.