CFD simulation of accidents in industrial batch stirred tank reactors

Investigation of Palladium Membrane Reactor Performance during Ethanol Steam Reforming using CFD Method

The main purpose of present study is the analysis of dense palladium membrane reactor (MR) performance during ethanol steam reforming (ESR) reaction using computational fluid dynamic (CFD). To this aim, a two-dimensional and isothermal model based on CFD method was developed and results validation was tested by our experimental data achieved in ITM-CNR of Italy. In this work, Pd-based MR modeling was performed by using COMSOL-MULTIPHYSICS software. Regarding to model validation results, a good agreement was found between CFD model results and experimental data. Moreover, in this study, the effects of the some important operating parameters (reaction temperature and pressure) on the performance of Pd-based MR was studied in terms of ethanol conversion and hydrogen recovery. Concerning to simulation results, the CFD model presented velocity and pressure profiles in both side of MR and also compositions of various species in permeate and retentate streams. The simulation results indicated that the Pd-based MR has better performance with respect to traditional reactor (TR) in terms of the ethanol conversion, especially, at lower reaction temperatures and higher reactions pressures. As a consequence, CFD model results illustrated that Pd-based MR performance was improved by increasing the reaction pressure, while this parameter had negative effect on the TR performance. This result related to enhancement of hydrogen permeance through the palladium membrane by increasing the pressure gradient. Indeed, this shift effect can provide a higher ethanol conversion in lower temperatures in the Pd-based MR. In particular, 98% ethanol conversion and 37% hydrogen recovery was achieved at 350°C and 2 atm.

Modelling Study of Palladium Membrane Reactor Performance during Methan Steam Reforming using CFD Method

The main aim of this study is the investigation of dense palladium membrane reactor (MR) performance during methane steam reforming (MSR) reaction using computational fluid dynamic (CFD). To this purpose, a two-dimensional isothermal CFD model was developed and its validation was realized by comparing the theoretical results with our experimental data achieved in ITM of Italy. In this work, the CFD model was presented by COMSOL- Multiphysics software version 5. The reaction rate expressions and kinetics parameters were used from literatures. According to validation results, a good agreement between modeling results and experimental data was found. After model validation, the effect of the some important operating parameters (temperature and pressure) on the performance of palladium MR was studied in terms of methane conversion and hydrogen recovery. The CFD model presented velocity and pressure profiles in both side of MR and also molar fraction of different species in permeate and retentate streams. The modeling results showed that the palladium MR presents comparable performance with respect to traditional reactor (TR) in terms of the methane conversion, especially, at lower temperatures and higher pressures. In fact, CFD results indicated that palladium MR performance was improved by increasing the reaction pressure, while this parameter had negative effect on the TR performance. This result related to increasing the hydrogen permeance through the palladium membrane by enhancement of pressure gradient. Indeed, this shift effect can provide a higher methane conversion in lower temperatures in the palladium MR. In particular, 99% methane conversion and 43% hydrogen recovery was achieved at 500°C and 1.5 atm.