Study On Preparation Of Quaternary Ammonium Base By Electro-Electrodialysis

At present,the preparation process of high-purity quaternary ammonium base is complicated,the product quality is low and the cost is high,which restricts the production and application of the product in the industry,and the existing research mostly stays in the basic research in the laboratory,and the actual industrial application is relatively less.Achieving low-cost and high-quality production of quaternary ammonium in industrialization is of great value in promoting the development of this field.In this paper,for the demand of high-purity quaternary ammonium alkali in industrial production,the electrolytic electrodialysis(EED)method of adding alkaline electrolyte in the anode chamber was proposed for the first time.The product quality is low,the cost is high,the process is complicated and the energy consumption is around the preparation of quaternary ammonium base.In the advanced problem,the green process of the electrochemical membrane with the ion exchange membrane as the core is combined with electrolysis and electrodialysis technology,and is applied to the preparation of high-purity quaternary ammonium base.Through the construction and assembly of the reactor,the exploration and optimization of experimental conditions,the targeted research of special quaternary ammonium bases and the application in practical industries,the preparation of quaternary ammonium salts to quaternary ammonium bases has been achieved,and the product quality has been met.The performance requirements of the product in the industry have been promoted and applied in actual industrial production.The main research contents and results are as follows:1.In the process of preparing quaternary ammonium base by the traditional EED method,the introduction of alkaline anolyte avoids the formation of halogen acid and halogen element in electrochemical membrane technology,reduces operating voltage,energy consumption and preparation cost,and improves the process.Security.In the laboratory,the quaternary ammonium base was prepared in a constant voltage mode with the ion exchange membrane,EED device type,raw material type and temperature as variables,and the obtained product was of high purity,and the Br~-content was only 7.9 ppm.The metal ion content is 6.1ppm.Through the calculation,comparison and experimental investigation of the physical properties of the four quaternary ammonium ions,the results show that the yield and current efficiency decrease with the increase of the ionic radius;the I-V curve is drawn and four Limit current density of a quaternary ammonium base.In addition,the multi-cathode EED process was first proposed and the product quality of different product rooms was analyzed.2.The EED preparation process of tetrabutylammonium hydroxide(TBAOH)was studied.Among them,the mass transfer process in the EED process was studied,and the voltage of the EED device was calculated.The performance of the EED membrane stack was investigated from the operational parameters such as raw material concentration,current density and anolyte type.The effect of the anode product on the ion exchange membrane and the electrode,as well as the economic feasibility of the preparation of TBAOH on the EED membrane stack.The experimental results show that the current efficiency reaches the maximum when the concentration of the raw material is 0.8 mol/L;the optimal operating current is 20 A,the energy consumption is as low as 1.68 k Wh/kg,the device voltage is as low as 4.5 V,and the cost is only 0.84$/kg.And the anode product Na Br has no significant effect on the ion exchange membrane and the anode plate.3.The industrial application of high-purity quaternary ammonium alkali technology by EED method was realized by continuous amplification experiment.The structure and assembly method of the membrane stack were optimized,and the process flow chart was drawn.The results show that the operating voltage is 7V,the average current efficiency of the membrane stack is 66.7%,the energy consumption is 0.22 k W h/kg,the profit is 6194.82yuan/t,the product quality is 180ppm of average Br~-content,and the average metal ion content is 9 ppm,which meets the requirements of the industry.