Modeling of a Real-Life Industrial Reactor for Hydrogenation of Benzene Process

A dynamic model of the hydrogenation of benzene to cyclohexane reaction in a real-life industrial reactor is elaborated. Transformations of the model leading to satisfactory results are presented and discussed. Operating conditions accepted in the simulations are identical to those observed in the chemical plant. Under those conditions, some components of the reaction mixture vanish, and the diffusion coefficients of the components vary along the reactor (they are strongly concentration-dependent). We came up with a final reactor model predicting with reasonable accuracy the reaction mixture’s outlet composition and temperature profile throughout the process. Additionally, the model enables the anticipation of catalyst activity and the remaining deactivated catalyst lifetime. Conclusions concerning reactor operation conditions resulting from the simulations are presented as well. Since the model provides deep insight into the process of simulating, it allows us to make knowledge-based decisions. It should be pointed out that improvements in the process run, related to operating conditions, or catalyst application, or both on account of the high scale of the process and its expected growth, will remarkably influence both the profits and environmental protection.

Determination of Radiation Exposure to Iodine-131 Emissions During Normal Operation of the Industrial Reactor Installation at Fsue “PO Mayak” Taking into Account Physical and Chemical Forms

The determination of the physicochemical forms of radioiodine in the gas-air environment of an industrial nuclear reactor is necessary to solve related problems – technological control and radiation safety. In the technological context, the results obtained make it possible to adequately assess the efficiency of purification of emissions of radioactive iodine isotopes, the choice of instruments and methods for controlling emissions. In the context of radiation safety, research results make it possible to correctly assess the radiation effects on the environment and humans, substantiation of emission standards for the atmosphere and confirmation of the safety of operation of an industrial reactor installation. The research method is based on the difference in the deposition of radioiodine on a set of one AFA-RMP aerosol filter and six filters of the AFA-SI type, which makes it possible to separately determine the 131I aerosol, easily and hardly sorbed form. It has been shown that the non-purified gas-aerosol mixture mainly contains radioactive iodine in the form of gaseous hardly adsorbed compounds. For 131I, the most probable percentage in volumetric activity of hardly adsorbed, easily adsorbed compounds and iodine aerosols was obtained. Based on the data obtained, an assessment of dose loads was carried out taking into account the annual emissions of the reactor installation and weather conditions. A conservative approach to assessing the radiation exposure of 131I emissions is 47 times higher than the assessment taking into account its physicochemical forms.

First-Principles-Based Simulation of an Industrial Ethanol Dehydration Reactor

The achievement of new economically viable chemical processes often involves the translation of observed lab-scale phenomena into performance in an industrial reactor. In this work, the in silico design and optimization of an industrial ethanol dehydration reactor were performed, employing a multiscale model ranging from nano-, over micro-, to macroscale. The intrinsic kinetics of the elementary steps was quantified through ab initio obtained rate and equilibrium coefficients. Heat and mass transfer limitations for the industrial design case were assessed via literature correlations. The industrial reactor model developed indicated that it is not beneficial to utilize feeds with high ethanol content, as they result in lower ethanol conversion and ethene yield. Furthermore, a more pronounced temperature drop over the reactor was simulated. It is preferred to use a more H2O-diluted feed for the operation of an industrial ethanol dehydration reactor.