双峰孔分布CN—18催化剂上甲烷蒸汽转化宏观动力学

CN-18气态烃蒸汽转化催化剂是以α-Al

STUDY ON MACROSCOPIC KINETICS OF METHANE-STEAM REFORMING REACTION ON CN-18 NICKEL CATALYST WITH DOUBLE HUMPED DISTRIBUTION IN PORE STRUCTURE

CN-18 catalyst of hydrocarbon gas steam reforming with supporter of ɑ-Al2O3,by nickel component impregnated on it.The pore distributions were:the actived micropore radial sizes were 500×10-10～5000×10-10m,and the transfered micropore radial sizes were 10 000×10-10m.The effective diffusion coefficient in pore of catalyst was 2.450×102～2.905×102(cm2/s),which was more than twice as large as the catalyst was usually used in industry.It played an active role on reducing the interdiffusion stagnation,when chemical reaction were taking on catalyst.By used of the internal recycle gradientless reactor at 3.0 MPa absolute pressure,reaction temperature ranges 550～750℃,steam-to-carbon molar ratios of 2.0～4.0,carbon space velocities of 4.5×105～1.1×106h-1,the data of methane steam reforming reaction on CN-18 catalyst were measured.The paralled:CH4+H2O=CO+3H2,CH4+2H2O=CO2+4H2 reaction models were used for describing the process.The experimental data were handled with damping least squares method.The macroscopic rate equations of carbon monoxide and dioxide formation can be expressed:RCO=6.13×106exp［-2.274×105/(RgT)］P1.1CH4(1-βCO),RCO2=5.09×106exp［-1．124×105/(RgT)］P0.8CH4P-1.2H2P0.8H2O(1-βCO2).The macrokinetics may be used for calculating quantity of CN-18 catalyst used.