Date of Award
Doctor of Philosophy in Chemical Engineering - (Ph.D.)
Chemical, Biological and Pharmaceutical Engineering
Robert Benedict Barat
Edward L. Dreyzin
Carbon nanotube-based Pt/Pd and Ru catalysts, independently synthesized by a microwave reaction technique, show good catalytic activity for CO2 reduction in the contexts of dry reforming (DR) of methane (CH4 + CO2 -> 2CO + 2H2) and reverse water gas shift (RWGS) (H2 + CO2 -> CO + H2O). Reaction temperatures range from 773 to 973 K, with system pressure at 30 psig. The feed molar ratios CH4/CO2 and CO2/H2 are varied from 0.5 to 2.0. Reactant conversions in DR and RWGS are strongly influenced by temperature and feed molar ratio, but insignificantly affected by flow rate.
Based on data from an integral packed bed reactor, a simple power law model of CO2 conversion indicates global reaction rates of DR and RWGS showing first order dependencies on each reactant. Linear Arrhenius plots of the global rate constants are also obtained. More robust semi-global 3-reaction models are developed based on regressions of experimental gas species concentration data. They adequately simulate observed species concentrations. Detailed catalytic chemistry simulations were made using a literature Ni-based catalyst mechanism. Adequate results were obtained for the Pt/Pd and Ru carbon nanotube catalysts used for DR. However, generally poor simulation results for the RWGS using Pt/Pd strongly suggest the limits of using the Ni mechanism within this context.
Zhu, Yuan, "CO2 reduction over noble metal/carbon nanotube catalyst" (2017). Dissertations. 50.