Developments Of Ultra-high Current Density Ion-exchange Membrane Electrolyzer

The chlor-alkali industry is a foundational chemical raw material industry that produces sodium hydroxide?chlorine and hydrogen by electrolysis of sodium chloride to provides industrial raw materials for many industries.The chlor-alkali production capacity of about 40 million tons in China,accounting for about half of the world's chlor-alkali capacity,is one of the main pillars of chemical base materials.The rapid development of the national chlor-alkali industry began after 2000,subject to the electrolysis structure and ionic membrane property at that time.It starts the maximum capacity of 20,000 cells per electrolytic cell,and the maximum per unit does not exceed 100,000 tons.Then the largest of each cell increased to 30,000 tons,and each device does not exceed 250,000 tons.At present,the whole set of devices in the early stage has been reaching the stage of upgrading,Without increasing energy cost,improving the productivity of single sets and complete sets of equipment that can save a investment in fixed assets for Consumer.The current capacity of a single cell is mainly determined by the operating current density and the electrolysis area of the cell.At present,the design current density of the mainstream electrolysis device in China is 6KA/m2.Through the research of this abject,the design current density in China is 7KA/m2.Then the Maximum capacity of each cell can be expanded to 45,000 tons by means of the appropriate expansion of the electrolytic area.This article focuses on the improvement of current density,related to the conductive area,conductive structure,gas-liquid separation,membrane utilization,internal circulation and leakage current.At the same time,the design and manufacture of new cell made an effective attempt,hoping to design and manufacture more competitive products,serving the majority of chlor-alkali customers.This article focuses on the goal of improving the current density of the electrolysis device,involving conductive structures,conductive areas,gas-liquid separation,membrane utilization,internal circulation and leakage currents.The increase of the operating current density will inevitably cause the increase of the voltage of the electrolytic cell.Through the calculation of the conductive structure,the voltage drop of the electrolytic cell structure will be effectively controlled.A large number of gas-liquid mixture products under ultra-high density will be concentrated in the electrolytic cell.The gas-liquid separationstructure can effectively guide the product to be separated and discharged in an electrolytic chamber in a timely manner.A reasonable structure design can greatly improve the utilization of the membrane,and is also an effective means for increasing the productivity.The more vigorous the electrolytic reaction,the more electrolyte is needed.In addition,a more reasonable internal circulation structure is also needed to make the mass transfer of the electrolyte more uniform.Reducing the leakage currents can increase the current utilization rate and protect the service life of the equipment.While carrying cut the above research,the electrolytic structure is modeled.The key structure is verified through simulation.The key structure is experimentally designed.The level of the key factor is analyzed and defined and the design range of the structure in the design process is determined and passed.Reasonable design optimization determines the structure program.In addition,combined with the actual production process,an effective attempt is made to design and manufactures a new electrolytic cell.Related manufacture process flow is formulated,and related operational processes are studied and discussed.It is also hoped that a more competitive product can be designed and manufactured,serving the majority of chlor-alkali customers.