Production of Fuels and Chemicals from a CO2/H2 Mixture

In order to explore co-production alternatives, a once-through process for CO2 hydrogenation to chemicals and liquid fuels was investigated experimentally. In this approach, two different catalysts were considered; the first was a Cu-based catalyst that hydrogenates CO2 to methanol and CO and the second a Fisher–Tropsch (FT) Co-based catalyst. The two catalysts were loaded into different reactors and were initially operated separately. The experimental results show that: (1) the Cu catalyst was very active in both the methanol synthesis and reverse-water gas shift (R-WGS) reactions and these two reactions were restricted by thermodynamic equilibrium; this was also supported by an Aspen plus simulation of an (equilibrium) Gibbs reactor. The Aspen simulation results also indicated that the reactor can be operated adiabatically under certain conditions, given that the methanol reaction is exothermic and R-WGS is endothermic. (2) the FT catalyst produced mainly CH4 and short chain saturated hydrocarbons when the feed was CO2/H2. When the two reactors were coupled in series and the presence of CO in the tail gas from the first reactor (loaded with Cu catalyst) significantly improves the FT product selectivity toward higher carbon hydrocarbons in the second reactor compared to the standalone FT reactor with only CO2/H2 in the feed.

Researches on the Simulation of the Degasifying Column Used in Nuclear Power Plant

The degasifying column is an important unit in nuclear power station. In order to verify the performance of the column, the degasifying process has been simulated by using the well-known software ASPEN Plus and on a basis of some proper hypothesizes and simplified models. Degasifying column is found that it has good capability on taking out key components such as krypton and oxygen from reactor coolant. On the other side, it’s difficult to carry out radioactive gas experiment on site which is seriously enslaved to the potential radioactive harm on operators. Simulation by using ASPEN Plus is a good way to solve this problem. Furthermore, three kinds of experiments such as ASPEN simulation, deoxidation experiment and radioactive gas experiment on site which are used for validating the performance of column are compared. The comparison shows that ASPEN simulation has less risk and less costs, but the simulation results are more exact and credible. Moreover, the debugging process of the column can be inducted and improved according to the simulation.