Methane partial oxidation over phthalocyanine catalyst

The partial oxidation reaction of methane over a zeolite-supported ruthenium phthalocyanine catalyst is studied in a packed bed reactor. The investigation of such reaction is desirable because partial oxidation of methane yields a synthesis gas that can be upgraded to liquid chemicals and fuels. Reactants of this study are He-diluted CH_4 and O_2. The effluent includes unreacted CH_4 and O_2, He, CO, CO_2, H_2, and H_2O vapor. Thermal conductivity gas chromatography is applied to identify the mole fractions of reactants and products. System pressure is maintained at 50 psig. Experiments are run at 250, 275, 300, 325, 350, and 375 C. For each temperature, the feed molar ratio of CH_4/O_2 is varied from 0.5 to 5.0. Although reaction temperature is more than 200 C lower than that of common catalytic methane partial oxidation, conversion of methane is obvious. Product analysis indicates that the highest conversion is 80.4% at 375 C, CH_4/O_2=0.5. Conversion of methane increases with increasing temperature, but it decreases with increasing molar ratio CH_4/O_2. Selectivities of both H_2 and CO increase with the increasing temperature or molar ratio CH_4/O_2. But selectivity of CO_2 decreases with the increasing temperature or molar ratio CH_4/O_2. Based on a differential packed bed reactor model, the global rate of CH_4 reaction shows first order dependencies on each of O_2 and CH_4. The overall reaction rate is a second-order reaction. The reaction rate constant k for each temperature was also determined. An Arrhenius plot of the global rate constants suggest that the reaction is limited by reaction kinetics between 250-300 C, and limited by mass transfer between 300-375 C. Equilibrium calculations are also made for all cases in this study. The result shows that products selectivities of equilibrium calculation are significantly different from that of catalytic reactions, which emphasizes the effective catalytic actions of the zeolite-supported ruthenium phthalocyanine.

Name thesis:degree_name

Master of Science in Chemical Engineering - (M.S.)

Discipline thesis:degree_discipline

Chemical, Biological and Pharmaceutical Engineering

Year

2013

Author dc:creator

• Zhu, Yuan

Contributors dc:contributor

• Robert Benedict Barat
• Edward L. Dreyzin
• Xianqin Wang

• Methane oxidation
• Partial oxidation reaction
• Chemical Engineering

Repository record dc:identifier

https://digitalcommons.njit.edu/theses/150

OAI identifier oai:identifier

oai:digitalcommons.njit.edu:theses-1149