Computational fluid dynamics simulation of an Inert Particles Spouted Bed Reactor (IPSBR) system

A novel system for contacting gases and liquids, suitable for many applications involving gas-liquid contact such as CO2 capture and brine desalination, has been simulated and experimentally validated. The system comprises a vertical vessel with gas and liquid ports and inert particles that enhance mixing and provide a high gas-liquid interfacial area. A low gas flow rate was statistically demonstrated and experimentally verified to be the optimum condition for CO2 capture and brine desalination; however, the gas velocity can have a considerable effect on the motion of inert particles inside the reactor. Uniform particles motion ensures good mixing within the reactor and hence efficient absorption and stripping process. A computational fluid dynamics (CFD) model, namely Eulerian model, presented in this paper, will help demonstrate the effect of mixing particles at specific conditions on the gas and liquid velocities inside the reactor, gas and liquid volume distribution through reactor, and eddy viscosities stresses of the mixing particles. A mesh-independent study was conducted to demonstrate the independency of mesh structure and size on the output responses. A quasi-steady state was attained to ensure the stability and feasibility of the selected model. The assembled model exhibits remarkable applicability in determining the optimum mixing particles densities, volume ratios, and sizes to ensure best velocity distribution and gas spreading inside the reactor and accordingly enhance the associated chemical reactions.Research funding: Abu Dhabi National Oil Company, Refining Research Center, Abu Dhabi, UAE (Grant no. 21N224). https://dx.doi.org/10.13039/501100002672 .Scopu

A CFD Investigation on the Effect of IPSBR Operational Conditions on Liquid Phase Hydrodynamics

This study used a computational fluid dynamics simulation of an inert-particle spouted-bed reactor, which consists of a cylindrical vessel with a conical base, to investigate the effect of different operational parameters on the hydrodynamics of the process. The reactor was composed of three phases, namely, air, water, and mixing particles 0.850 m high and 0.078 m in diameter. Water was the continuous phase, whereas air was the dispersed phase operating in the turbulent region. All runs were accomplished in a 2D axisymmetric, unsteady, and Eulerian model using ANSYS Fluent 15 software. The influence of feed gas velocity, orifice diameter, liquid head, mixing particles diameter, and mixing particle loading on the water velocity distribution, water volume fraction, eddy viscosities distribution, and turbulent kinetic energy was studied. Significant changes were observed when the operational parameters were examined under different ranges of conditions, indicating the extreme importance of determining the optimum conditions where the process is perfectly performed, which shall be an objective for future work.The authors are sincerely grateful to ADNOC Refining Research Center, Abu Dhabi, UAE, for the financial support it has extended for the completion of this research.Scopu