Effect of Reaction Medium on V-Ti Oxide Catalyst Composition in 2-Methyl-5-Ethylpyridine Ammoxidation

<p>A chemical composition of V-Ti oxide catalyst changes in accordance with the reaction medium composition in a process of 2-methyl-5-ethylpyrydine ammoxidation into nicotinonitrile in an integral reactor. The presence of alkylpyridine concentration gradient along the catalyst bed leads to the appearance of V₂O₅ content gradient in the catalyst. V₂O₅ concentration increases in the conditions of alkylpyridine completed conversion in consequence of oxidative decomposition of VO₂-TiO₂ solid solution under the influence of N2O nitrogen oxide, which is formed upon the NH₃ oxidation. An increase of V₂O₅ contents over 5 wt% causes rising of the share of the 2-methyl-5-ethylpyridine and nicotinonitrile destructive oxidation. An introduction of small amounts of alkylpyridine directly into the catalyst bed permits to create the definite alkylpyridine concentration gradient, which the optimal content of V₂O₅ is corresponding to, for any given conditions of oxidative reaction. The catalysts containing 1-5 wt% of V₂O₅ and solid solution of VO₂-TiO₂ possess of the highest selectivity to nicotinonitrile.</p>

Research on Severe Accident Mitigation Strategy of Injecting Into the OTSG of ACP100

The China multipurpose module small reactor named ACP100 is developed by the China National Nuclear Corporation (CNNC). The severe accident management guidelines (SAMGs) of ACP100 reactor is necessary to be developed to mitigate the severe accident induced by in the multi-cause extreme conditions. Inject into the steam generators (SGs) is one of the most significant strategies, this strategy aims at protecting the SGs tubes from creep rupture, removing the heat from the reactor coolant system (RCS) and depressurizing the RCS. The entry condition of the severe accident guideline of injecting into the SGs, as usual, is low SG Water level in the most of the present pressurized water reactors that adopt the inverted U-tubes SGs. The integral reactor of ACP100 adopts the design of annular tube once-through SGs. In the normal conditions, the secondary side of the OTSGs is operating in a given steady pressure, any water level measure tool is impossibly set in the OTSGs. Therefore, on the basis of the design features of ACP100, the strategy of injecting into the OTSG at severe accident is studied, the potential entry condition of the corresponding guideline is discussed. And the validity and feasibility of the strategy is validated by the analysis of the integral systems analysis code.