Adsorption of FCC dry gas components, hydrogen(H_2), nitrogen(N_2), methane(CH_4), ethane(C_2H_6) and ethylene(C_2H_4) in zeolite Y was studied by performing the Grant Canonical Monte Carlo(GCMC) simulations at 298K a...Adsorption of FCC dry gas components, hydrogen(H_2), nitrogen(N_2), methane(CH_4), ethane(C_2H_6) and ethylene(C_2H_4) in zeolite Y was studied by performing the Grant Canonical Monte Carlo(GCMC) simulations at 298K and 823K and under a pressure range up to 10 MPa. Simulation results were analyzed using the Langmuir model, which presented fitting of dry gas components adsorption to be suggested as the monolayer adsorption. C_2H_4 presented most single adsorption amount, which reached 7.63 mol/kg at 298K under a pressure of 200kPa. Thermodynamic parameters of the Gibbs free energy change, enthalpy change and entropy change were analyzed based on adsorption equilibrium constant obtained from the GCMC simulations. The results suggested that it was more favorable for C_2H_4 to be adsorbed in zeolite Y. Adsorption molecules were in ordered arrangement in the zeolite, and C_2H_4 exhibited a more orderly arrangement than other components. Additionally, a competition in the adsorption of a mixture of dry gas components was found, and supercages were the priority adsorption space. The competition was favorable to CH_4 and C_2H_6, and the competitive power was affected by temperature.展开更多
The influence of operating parameters on ethylene content in dry gas obtained during catalytic cracking of gasoline was investigated in a pilot fixed fluidized bed reactor in the presence of the MMC-2 catalyst. The re...The influence of operating parameters on ethylene content in dry gas obtained during catalytic cracking of gasoline was investigated in a pilot fixed fluidized bed reactor in the presence of the MMC-2 catalyst. The results have shown that the majority of dry gas was formed during the catalytic cracking reaction of gasoline, with a small proportion of dry gas being formed through the thermal cracking reaction of gasoline. The ethylene content in dry gas formed during the catalytic cracking reaction was higher than that in dry gas formed during the thermal cracking reaction. The ethylene content in dry gas formed during catalytic cracking of gasoline with a higher olefin content was higher than that in dry gas formed during catalytic cracking of gasoline with a lower olefin content, which meant that the higher the amount of carbonium ions was produced during the reaction, the higher the ethylene content in the dry gas would be. An increasing reaction temperature could increase the percentage of dry gas formed during thermal cracking reaction in total dry gas products, leading to decreased ethylene content in the dry gas. An increasing catalyst/oil ratio could be conducive to the catalytic cracking reactions taking place inside the zeolite Y, leading to a decreased ethylene content in the dry gas. A decreasing space velocity could be conducive to the catalytic cracking reactions taking place inside the shape-selective zeolite, leading to increased ethylene content in the dry gas.展开更多
基金financial support from the National Natural Science Foundation of China (No. 41302101 and No. 21476263)
文摘Adsorption of FCC dry gas components, hydrogen(H_2), nitrogen(N_2), methane(CH_4), ethane(C_2H_6) and ethylene(C_2H_4) in zeolite Y was studied by performing the Grant Canonical Monte Carlo(GCMC) simulations at 298K and 823K and under a pressure range up to 10 MPa. Simulation results were analyzed using the Langmuir model, which presented fitting of dry gas components adsorption to be suggested as the monolayer adsorption. C_2H_4 presented most single adsorption amount, which reached 7.63 mol/kg at 298K under a pressure of 200kPa. Thermodynamic parameters of the Gibbs free energy change, enthalpy change and entropy change were analyzed based on adsorption equilibrium constant obtained from the GCMC simulations. The results suggested that it was more favorable for C_2H_4 to be adsorbed in zeolite Y. Adsorption molecules were in ordered arrangement in the zeolite, and C_2H_4 exhibited a more orderly arrangement than other components. Additionally, a competition in the adsorption of a mixture of dry gas components was found, and supercages were the priority adsorption space. The competition was favorable to CH_4 and C_2H_6, and the competitive power was affected by temperature.
文摘The influence of operating parameters on ethylene content in dry gas obtained during catalytic cracking of gasoline was investigated in a pilot fixed fluidized bed reactor in the presence of the MMC-2 catalyst. The results have shown that the majority of dry gas was formed during the catalytic cracking reaction of gasoline, with a small proportion of dry gas being formed through the thermal cracking reaction of gasoline. The ethylene content in dry gas formed during the catalytic cracking reaction was higher than that in dry gas formed during the thermal cracking reaction. The ethylene content in dry gas formed during catalytic cracking of gasoline with a higher olefin content was higher than that in dry gas formed during catalytic cracking of gasoline with a lower olefin content, which meant that the higher the amount of carbonium ions was produced during the reaction, the higher the ethylene content in the dry gas would be. An increasing reaction temperature could increase the percentage of dry gas formed during thermal cracking reaction in total dry gas products, leading to decreased ethylene content in the dry gas. An increasing catalyst/oil ratio could be conducive to the catalytic cracking reactions taking place inside the zeolite Y, leading to a decreased ethylene content in the dry gas. A decreasing space velocity could be conducive to the catalytic cracking reactions taking place inside the shape-selective zeolite, leading to increased ethylene content in the dry gas.
