The wet ammonia desulfurization process can be retrofitted for combined removal of SO2 and NO from the flue gases by adding soluble cobalt(Ⅱ) salt into the aqueous ammonia solution. Activated carbon is used to catalyze the reduction of hexamminecobalt(Ⅲ) to hexamminecobalt(Ⅱ) to maintain the capability of removing NO of the hexamminecobalt solution. The effects of temperature, pH, activated carbon particle size, and superficial liquid flow velocity on hexamminecobalt(Ⅲ) conversion have been investigated. An apparent activation energy is obtained. According to the experimental results, the catalytic reduction reaction rate increases with temperature. The batch reactor experiments show that the best pH range lies in between 3.5 and 6.5. In a fixed-bed reactor, superficial liquid flow velocity obviously affects the reaction and a high yield of cobalt(Ⅱ) is obtained at a pH value lower than 9.0. The experiments manifest that the hexamminecobalt solution coupled with catalytic regeneration of hexamminecobalt(Ⅱ) can maintain a high nitric oxide removal efficiency during a period of time.

The impact of some engineering aspects such as space velocity, catalyst metal loading, hydrogen, and temperature on carbon nanotube (CNT) production rate, productivity, and morphology in carbon monoxide disproportionation has been studied. The morphology and quality of the CNTs produced were examined by high resolution transmission electron microscopy (TEM). It was found that space velocity and metal loading have significant effects on the production rate and CNT productivity. The presence of H2 dramatically increased the productivity, but altered the CNT structure. The synthesis temperature also influenced the carbon productivity and structure. The results were interpreted according to the traditional model for CNT growth, and the implications for large-scale CNT production were suggested.

Gas phase propylene epoxidation on gold catalysts has attracted wide attention from industry and academia due to its high selectivity. However, it suffers from low propylene conversion and rapid catalyst deactivation. Experiments showed that propylene conversion could be increased by raising H2, O2, or C3H6 concentration in the feed, but the feed compositions were within the explosion limit. It was also shown that the activity of the used catalyst could be fully recovered, but the regeneration temperature was 280℃, much higher than that for reaction. Therefore a microchannel reactor was devised to suppress explosion and was constructed with Fecralloy, to raise the temperature rapidly for catalyst regeneration by electric heating. In two minutes the temperature of the reactor could be raised from 50 to 300℃. Catalysts were coated on the alloy belt by dip coating, and the performance of the reactor was evaluated under different operating conditions. Results showed that in the microreactor the overall reaction rate was controlled mainly by the intrinsic reaction rate, and also influenced by film diffusion to a certain extent. The deactivated catalyst was regenerated in the microchannel reactor and the activity was fully recovered.

The effect ofpartial internal wetting ofcatalyst pellets on apparent reaction kinetics at elevated temperatures and pressures is investigated experimentally and by modeling for benzene hydrogenation. A new method that combines adsorption and chemical reaction is introduced to study the kinetics influenced by capillary condensation ofreagents at steady-state conditions. It is shown that the extent ofliquid filling in the pellet interior has a critical effect on the global kinetics, and the current state of the catalyst depends on the history. Under certain conditions two steady states ofthe effectiveness factor exist. Moreover, either a decrease in temperature or increase in total pressure can increase the effectiveness factor. The model exhibits good agreement with experimental results.

Understanding the mechanism of liquid-phase evaporation in a three-phase fixed-bed reactor is of practical importance, because the reaction heat is usually 7-10 times the vaporization heat of the liquid components. Evaporation, especially the liquid dryout, can largely influence the reactor performance and even safety. To predict the vanishing condition of the liquid phase, Raoult's law was applied as a preliminary approach, with the liquid vanishing temperature defined based on a liquid flow rate of zero. While providing correct trends, Raoult's law exhibits some limitation in explaining the temperature profile in the reactor. To comprehensively understand the whole process of liquid evaporation, a set of experiments on inlet temperature, catalyst activity, liquid flow rate, gas flow rate, and operation pressure were carried out. A liquid-region length-predicting equation is suggested based on these experiments and the principle of heat balance.