electrolyzer

Perfluorinated ion exchange membranes: There are currently 3 major companies in the world that produce perfluorinated ion exchange membranes, namely DuPont in the United States, Asahi Glass in Japan, and Asahi Kasei. Their ion exchange membrane products are all composite membranes made of perfluorosulfonic acid or perfluorocarboxylic acid resins reinforced with tetrafluorofiber, with only slight differences in the membrane structure design. ??Perfluorinated ion exchange membranes from DuPont in the United States. In 1966, the United States developed NAFION, a perfluorosulfonic acid ion-exchange membrane with good chemical stability for use in fuel cells. In 1981, DuPont exchanged patent licenses for perfluorinated ion exchange membranes with Asahi Glass Company of Japan; in other words, DuPont’s perfluorosulfonic acid ion exchange technology was exchanged for Asahi Glass’s perfluorocarboxylic acid ion exchange membrane technology. This synergy enabled DuPont’s perfluorinated ion exchange membranes to be widely used in the chlor-alkali industry. The Nafion900 series of high-performance composite membranes based on perfluorosulfonic and perfluorocarboxylic acids feature high current efficiency, low membrane resistance, and good durability, making them suitable for the production of alkalis at high concentrations. At present, it has been widely applied and has been introduced to more than 30** countries and over 150 factories, including those in our country. DuPont’s perfluorinated ion exchange membranes have a very high initial current efficiency, sometimes as high as 97%; even after 3 to 4 years of operation, their current efficiency remains above 95%. These membranes possess high mechanical strength, but their cell voltage is slightly higher than that of the membranes produced by Asahi Glass and Asahi Kasei (when comparing membranes of the same type). Therefore, the focus of future improvements to Dupont membranes is on further reducing the membrane voltage; in addition, much work remains to be done in developing membranes resistant to impurity contamination. Perfluorinated ion exchange membranes from Asahi Kasei. As one of the two major companies in Japan that produce organic fluorides, Asahi Glass, building on its achievements in the research, development, and production of various fluorine chemicals, began in 1974 to conduct in-depth research on the development of perfluorinated ion exchange membranes for chlor-alkali production. In 1975, high-performance ion exchange membranes made from carboxylic acid-type perfluoropolymers were developed, and in the same year, a pilot plant for producing such ion membranes came online. Development of the FIEMION ion-exchange membrane electrolyzer began in 1978. In 1978, the industrial FIEMION chlor-alkali electrolysis plant was also put into operation. Between 1978 and 1979, Asahi Glass Company successively developed and produced the F1emion-230, 250, 330, and 430 films. In September 1981, a patent license for ion exchange membranes was exchanged with DuPont Company; in November of the same year, the high-performance F1emion DX membrane entered industrial production, and the AZEC new electrolysis system (cell with a narrow electrode spacing) was equipped with this FIEMION DX membrane, marking a great success for Asahi Glass’ perfluorinated ion exchange membranes. Since 1982, the F1emion 700 series and 800 series membranes have been successfully developed one after another, and through modifications, various membrane grades such as Flemion 723, 725, 733, and 753 have been created. FLEMION DX753 is an ion membrane with a carboxyl group layer; it exhibits uniform electrochemical properties. Its hydrophilic surface is coated with inert compounds that provide corrosion resistance and non-dielectricity, making it more suitable for electrolyzers with narrow electrode spacing (such as AZEC). In addition, special fibers are incorporated into the polymer matrix to enhance the strength of the ion membrane. Asahi Glass’ current latest products include ； F795, 893, 865, 892, and FX50. F795 is a perfluoroacid composite membrane with variable exchange capacity, while F893 is a perfluorocarboxylic acid and perfluorosulfonic acid composite membrane; both are used in AZECF2 cells. F865 is a membrane designed for large-scale electrolytic cells ； F892 is a composite membrane of perfluorocarboxylic acid and perfluorosulfonic acid ； FX-50 is a membrane used for producing 50% high-concentration caustic soda. Furthermore, sulfonic acid/carboxylic acid bilayer composite membranes have been widely developed. The ultimate goal of Asahi Kasei is to provide a perfluorinated ion exchange membrane that has low energy consumption, mechanical strength suitable for any type of electrolyzer, stable membrane performance, and a long service life. Asahi Kasei Films. Asahi Kasei’s research on ion exchange membranes for chlor-alkali production began in 1966. In 1975, it built the world’s first ion exchange membrane caustic soda plant with an annual capacity of 40,000 tons; this plant used polarized cells developed by the company itself and DuPont’s perfluorosulfonic acid membrane NAFION-315. In 1976, Asahi Kasei developed a carboxylic acid/sulfonic acid composite membrane, for which it obtained multiple patents, and began exporting ion exchange membrane electrolysis technology abroad starting from that year. In the late 1970s, Asahi Kasei developed a production technology for perfluorocarboxylic acid-type ion exchange membranes, covering everything from resin synthesis to membrane fabrication, and in collaboration with DuPont, succeeded in developing the new ACIPLEX-F series of ion exchange membranes. In the 1980s, the F4000 series of membranes was developed (these membranes are formed by laminating perfluorocarboxylic acids and perfluorosulfonic acids). In membrane development, Asahi Kasei’s guiding principle is to reduce the cell voltage while maintaining an initial current efficiency of over 95%. In the new variants, they reduced the cell voltage by 100 mV through improvements in polymers and film-forming techniques, as well as enhancements to the interface between the film and the electrolyte. The membrane voltage loss was further reduced by 20% through the use of reinforcing materials and polymers. At the same time, Asahi Kasei is also researching and developing membranes that can resist contamination by secondary brine impurities, as well as membranes with low oxygen content in chlorine and high stability. The ion membrane was first developed by DuPont for fuel cell vehicles that provided power to the lunar rovers in the Apollo moon landing program. In the 1970s, Asahi Kasei began to apply ion membranes in the chlor-alkali industry. DuPont’s 1XX series membranes can be used in fuel cells, water electrolysis, and other specialized electrolytic applications. Currently, the three ion membrane manufacturers have a certain understanding with their respective electrolyzer manufacturers. For example, in Asahi Kasei’s electrolytic cells, the membranes used are naturally those produced by Asahi Kasei. A few years ago, Asahi Glass sold its electrolyzer division to ChloTech; since then, the new electrolyzers produced by ChloTech have basically used Asahi Glass’ membranes. Woody’s new grooves basically use DuPont film. However, I personally think that membranes are basically universal in current slots. DuPont’s membranes are more durable, but they have a higher membrane voltage (currently, the membrane voltage of DuPont’s latest N2030 model has been significantly reduced) ； Asahi Glass and Asahi Kasei have an advantage in membrane voltage. But I think the condition of the ion exchange membrane in use mainly depends on the factory’s operations and management – such as the quality control of the saltwater and avoiding sudden shutdowns. The domestic membrane is said to have been developed through a collaboration between Dongyue and universities in Shanghai; it was even covered in the news the year before last. However, there are no reports of industrialization to date. However, China needs technical reserves in this area. Nippon Glass’ membranes are mainly used in unipolar cells, and not many are used in bipolar cells. Now, given the intense competition, ion exchange membranes from Asahi Kasei and DuPont are primarily used in the domestic chlor-alkali industry. Nippon Glass’ membranes are currently primarily used in the cells of chlorine production plants, while most single-pole cells use DuPont membranes, owing to their greater strength. DuPont’s ion exchange membrane has slightly better strength and a greater thickness, which results in a slightly higher cell voltage. Most of the electrolyzers produced by Asahi Kasei and Hokka Kikai use Asahi Kasei’s ion exchange membranes. In terms of operation, under normal conditions, the membrane voltage of Asahi Kasei is lower. However, for most users with limited operational skills, frequent start-stop operations and unstable pressure differences result in the membrane of Asahi Kasei not performing as well as it could. On the contrary, DuPont membranes have gained user acceptance due to their high strength; however, their slot voltage is slightly higher under these conditions of high strength. To maintain stable production, users are forced to compensate for the damage caused to the ion membranes by start-up and shutdown processes by increasing electricity consumption. The main reason is that DuPont’s price is higher; many users take this into consideration when making their choice and turn to Asahi Kasei instead. DuPont in the United States is a manufacturer of perfluorinated ion exchange membranes. The Nafion900 series of high-performance composite membranes based on perfluorosulfonic and perfluorocarboxylic acids feature high current efficiency, low membrane resistance, and good durability, making them suitable for the production of alkalis at high concentrations. ?The film has high mechanical strength, but the cell voltage is slightly higher than that of Asahi Glass and Asahi Kasei films (when comparing the same cell type). The perfluorinated ion exchange membrane produced by Asahi Glass has low energy consumption, and its mechanical strength is better than that of the other two types of membranes. Its mechanical properties are not as good as those of DuPont film. Asahi Kasei films have a lower single-cell voltage, and their performance is similar to that of DuPont films. Among the three types of membranes mentioned, the mechanical DuPont membrane is the best, followed by Asahi Kasei, with Asahi Glass in third place ； In terms of energy consumption, Asahi Glass is the best, followed by Asahi Kasei, with DuPont membranes coming in third; therefore, various factors need to be taken into consideration when making a choice. :lol

1) As of now, the companies known to be involved are Woody, Lv Gongcheng, Asahi Kasei, Beihua Ji, ICI, and the British company INEOS. (1) Beihua Ji’s electrolyzers: Being the only domestically produced ones, they are inexpensive and easy to maintain (using Asahi Kasei’s technology). (2) Asahi Kasei’s electrolyzers have high mechanical strength, suffer little deformation after use, exhibit stable performance across all parameters, and are also simple to maintain. (3) Chlorine process cells: Chlorine process cells are preferred due to their stable performance, especially at high current densities (60 A/dm2), where their advantages become even more evident. Thanks to its special spring-sheet structure at the cathode, the slot voltage can be significantly reduced. Moreover, the unique design of the cathode and anode bases inside allows the electrolyte to circulate thoroughly, preventing the formation of any significant dead zones that could lead to corrosion or breakdown of the bases. Today, chlorine engineering cells have evolved to the n-BITAC type, which features a smaller pole pitch and superior performance. (Excerpt from HaiChuan’s post) (4) Woody: The quality of the electrolytic cells is excellent; all performance metrics are good after use. They are safe, environmentally friendly, and have stable performance, with high-quality anode and cathode plates. It is also easy to disassemble, but one thing is that maintenance is rather troublesome. But the price is also high! Other electrolyzers are less used domestically! Regarding membranes: According to what colleagues know, the membranes produced by DUPONT Company have stable performance and high strength, but their price is also relatively high! Next is Asahi Kasei, and then Asahi Sales! Therefore, a comprehensive consideration is needed; act according to the actual situation of your own company and within your capabilities!

In China, it seems that ICI has not been selling its products there in recent years; I’m not sure if INEOS and ICI’s battery cells are related in any way :P

The descriptions for the 2nd and 3rd floors are quite clear; the advantages and disadvantages depend on how they are compared, as each has its own strengths and weaknesses. We are currently using equipment from chlorine engineering projects, and it’s acceptable so far.

At present, Beijing Jinneng Fuel Cells also produces perfluorinated ion exchange membranes, but their product range is limited; it’s not clear whether these membranes can be used in the chlor-alkali industry Everyone can take a look at his company’s website at http://www.gefc.com/

The categories above are very clear. I’ll just mention that our company uses Asahi Kasei’s ion exchange membranes, and they have always performed very well.