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Low temperature oxidative dehydrogenation catalysts are becoming a viable material for drastically altering the production of small chain alkenes. Among materials used, bimetallic and trimetallic nickel catalysts have shown great promise. In this study, we report a 38% increase in the rate of ethylene production with the addition of Ce to NiNb catalysts. Oxidative dehydrogenation of ethane was performed in the temperature range of 250–350 °C. At 300 °C, the rate of ethylene production was maximized with a rate of 6.91 × 10–4 mmol gcat–1 s–1. At higher temperatures, the rate of deep oxidation to CO2 outcompeted the rate of ethylene formation. The improved rate due to the addition of Ce is attributed to ceria’s ability to rapidly transport oxygen to the NiO active sites.

An alternative method for using monoethanolamine (MEA) in CO2 separation is developed from the viewpoints of the MEA–CO2 reaction environment and the process of spent sorbent regeneration. MEA–TiO2 (MT) CO2 sorbent is synthesized using pure MEA and a support material, TiO2. The performance of the MT sorbent on CO2 separation was investigated in tubular reactors under various experimental conditions. The sorption capacity of the MT sorbent reached 1.09 mol-CO2/kg-MT at 45 wt % MEA. However, an optimum of 40 wt % MEA loading was chosen for most of the sorption tests. Temperature affected the CO2 sorption capacity considerably, with optimum values of 45 °C for adsorption and 90 °C for regeneration, while humidity had a small positive effect. TiO(OH)2 appears to be the best support material for MEA, but more evaluation is needed. The MT sorbent is regenerable, with a multicycle sorption capacity of ∼0.91 mol-CO2/kg-MT under the given experimental conditions.

Both NOx conversion and CO2 conversion decrease with increasing percent-level CO2 concentration in nonthermal nitrogen plasma. The rate constants of electron collision reactions of both N2 and CO2 decrease with increasing CO2 concentration because electronegative CO2 reduces electron concentrations in the reactor due to the electron attachment process. The rate constant of CO2 dissociation through electron collision is 1−2 orders of magnitude higher than that of N2 dissociation because of low dissociation energy of CO2. Model data for reactor outlet NOx and COx concentrations agree well with experimental data. The effect of CO2 on NO, NO2, N2O, and CO concentrations can be explained on the basis of the proposed reaction mechanism and kinetic modeling.

All species that are likely to be responsible for nitrogen oxides (N2O, NO, and NO2) conversion in nitrogen plasma are analyzed in detail through carefully designed systematic experiments and theor...