In this paper,an axial dispersion mathematical model is developed to simulate a three-phase slurry bubble column reactor for direct synthesis of dimethyl ether（DME） from syngas.This large-scale reactor is modeled us...In this paper,an axial dispersion mathematical model is developed to simulate a three-phase slurry bubble column reactor for direct synthesis of dimethyl ether（DME） from syngas.This large-scale reactor is modeled using mass and energy balances,catalyst sedimentation andsingle-bubble as well as two-bubbles class flow hydrodynamics.A comparison between the two hydrodynamic models through pilot plantexperimental data from the literature shows that heterogeneous two-bubbles flow model is in better agreement with the experimental data thanhomogeneous single-bubble gas flow model.Also,by investigating the heterogeneous gas flow and axial dispersion model for small bubblesas well as the large bubbles and slurry（i.e.including paraffins and the catalyst） phase,the temperature profile along the reactor is obtained.Acomparison between isothermal and non-isothermal reactors reveals no obvious performance difference between them.The optimum values ofreactor diameter and height were obtained at 7 m and 50 m,respectively.The effects of operating variables on the axial catalyst distribution,DME productivity and CO conversion are also investigated in this research.展开更多
The effect of iridium and iron impregnation of HZSM-5 zeolite on the methanol to propylene reaction （MTP） was investigated. The selectivities ofpropylene and other hydrocarbons, and the conversion of methanol were c...The effect of iridium and iron impregnation of HZSM-5 zeolite on the methanol to propylene reaction （MTP） was investigated. The selectivities ofpropylene and other hydrocarbons, and the conversion of methanol were compared by performing MTP in a small pilot plant. The results indicate that HZSM-5 zeolite modified by iron and iridium increased propylene selectivity by 6.3% and 8%, respectively. The selectivity ofpropylene was higher for Ir/ H-ZSM-5 than for Fe/H-ZSM-5, where Fe/H-ZSM-5 was more stable than Ir/H-ZSM-5. Analytic techniques, including X-ray diffraction, BET surface area, temperature-programmed desorption of ammonia, and inductively coupled plasma atomic emission spectroscopy, were used to characterize the modified zeolites as well as the parent zeolites.展开更多
文摘In this paper,an axial dispersion mathematical model is developed to simulate a three-phase slurry bubble column reactor for direct synthesis of dimethyl ether（DME） from syngas.This large-scale reactor is modeled using mass and energy balances,catalyst sedimentation andsingle-bubble as well as two-bubbles class flow hydrodynamics.A comparison between the two hydrodynamic models through pilot plantexperimental data from the literature shows that heterogeneous two-bubbles flow model is in better agreement with the experimental data thanhomogeneous single-bubble gas flow model.Also,by investigating the heterogeneous gas flow and axial dispersion model for small bubblesas well as the large bubbles and slurry（i.e.including paraffins and the catalyst） phase,the temperature profile along the reactor is obtained.Acomparison between isothermal and non-isothermal reactors reveals no obvious performance difference between them.The optimum values ofreactor diameter and height were obtained at 7 m and 50 m,respectively.The effects of operating variables on the axial catalyst distribution,DME productivity and CO conversion are also investigated in this research.
文摘The effect of iridium and iron impregnation of HZSM-5 zeolite on the methanol to propylene reaction （MTP） was investigated. The selectivities ofpropylene and other hydrocarbons, and the conversion of methanol were compared by performing MTP in a small pilot plant. The results indicate that HZSM-5 zeolite modified by iron and iridium increased propylene selectivity by 6.3% and 8%, respectively. The selectivity ofpropylene was higher for Ir/ H-ZSM-5 than for Fe/H-ZSM-5, where Fe/H-ZSM-5 was more stable than Ir/H-ZSM-5. Analytic techniques, including X-ray diffraction, BET surface area, temperature-programmed desorption of ammonia, and inductively coupled plasma atomic emission spectroscopy, were used to characterize the modified zeolites as well as the parent zeolites.
