Flow Field Structure Design And Numerical Simulation Of Plate-and-Frame Electrolyzer

The electrolyzer is the core device for realizing the organic electrosynthesis process.Among them,the plate-and-frame electrolyzers have wide applications in the organic electrosynthesis industry due to its small pressure loss,high space utilization,compact structure and low tank pressure.During the electrosynthesis reaction,the reactor structure has a great influence on the electrochemical reaction and the mass transfer process.In order to investigate the flow law of fluids in different structural reactors,optimize reactor structure and operating parameters,and improve the mass transfer effect and reaction efficiency of the reactor,five different flow passage structual plate-and-frame electrolyzers?Hilbert/Nerve/Alveolate/Intersected/Vertical?that were self-designed.The residence time distribution data of the designed reactors were determined by pulse tracing method.By comparing the average residence time and the dimensionless variance of the five reactors,it was found that the fluid flow condition in the reactor of the Alveolate flow passage structure was closest to the ideal mixed state,the effect of mass transfer is optimal.Combined with the CFD method,the electrolyzer models were modeled and processed,and the fluid flow condition in the reactors was numerically simulated using Fluent software.The distribution of the flow field in the electrolyzer with different structures was obtained.It is found that the inlet flow rate has a great influence on the flow performance of the reactor fluid.At low flow rates,the fluid passage flow and short circuit conditions in the reactor are more serious,and there are stagnant zones.As the flow rate increases,the passage flow,short circuit and stagnation phenomenon are improved.In addition,the reactor structure has a great influence on the fluid flow performance.Among the five reactors designed,the Alveolate flow passage structure reactor has good mixing performance.Compared with other structural reactors,the short circuit and dead zone area are significantly reduced,and the numerical simulation results are consistent with the measurement results of the residence time distribution.A preliminary study on the process of preparing accelerator NS for the electrooxidation of mercaptobenzothiazole and tert-butylamine using a plate-and-frame electrolyzer with a Alveolate passage structure.The product is electrolyzed for 180 minutes at a current density of 300A·m^-2,the yield is 75.3%,which provides a new way for the green synthesis of this product.