Features of the ion exchange membrane technologies of Asahi Glass, Asahi Kasei, and DuPont

There are currently three 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. ??1. 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. The initial current efficiency of DuPont’s perfluorinated ion exchange membranes is very high, reaching up to 97% in some cases; even after 3–4 years of operation, their current efficiency can still remain 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. 2. Perfluorinated ion exchange membranes from Asahi Kasei Corporation. 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’s perfluorinated ion exchange membranes. Since 1982, the F1emion 700 series and 800 series of membranes have been successfully developed, and through modifications, various types of membranes such as Flemion 723, 725, 733, and 753 have been created. The 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-electrostatic properties, 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. ??Nippon Nitto’s 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. In addition, sulfonic acid/carboxylic acid bilayer composite membranes have been widely developed. ?? The ultimate goal of Asahi Glass 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. ??3. Asahi Kasei Film. 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 starting from that year it began to export ion exchange membrane electrolysis technology abroad. 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 creating the new ACIPLEX-F series of ion exchange membranes. The F4000 series of membranes was developed in the 1980s (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.

Currently, ion exchange membranes used in chlor-alkali enterprises across the country are all from three companies: DuPont membranes, Asahi Kasei membranes, and Asahi Glass membranes. Each of these companies’ membranes has its own characteristics; let’s discuss their respective performance.

As far as I know, only two companies can produce ion exchange membranes: DuPont and Asahi Glass. DuPont’s membranes are durable but more expensive. Asahi Glass, on the other hand, can produce both electrolyzers and ion exchange membranes; however, the quality of its membranes seems to be somewhat inferior. We should increase consumption. Our factory used Asahi Glass’ membranes in the past, but now we use DuPont’s ones. . . . . . . .

DuPont PET transparent film is suitable for screen printing on flexible circuits, as well as for use in flexible circuit boards, thin-film button circuits, and thin-film switches. Such circuits are widely used in various keyboard designs, such as computer keyboards, as well as in various toys and educational products. A next-generation product for microprocessor-based electronic control assemblies, incorporating combined keys and conductive rubber. They are products supplied by manufacturers of electronic instruments, computers, medical equipment, CNC machines, office equipment, and household appliances. Asahi Kasei membranes are also suitable for use in wastewater treatment, especially for ultrafiltration. Nippon Glass membranes can be used in fuel cells, and the company sells the membrane electrodes it produces in the automotive industry.

Back to floor 2: Asahi Kasei can produce both electrolytic cells and membranes, while Asahi Glass no longer manufactures electrolytic cells.

Thank you to the original poster for the information. Does anyone have their sales phone number? I plan to buy some films for experimental use. Thanks.

I support the view from the sixth floor; I just participated in a bidding process for an electrolysis unit.

Back to the 7th floor; I have the sales numbers for Asahi Kasei and Chlorine Engineering, which were given to me when I participated in the bidding process. If you want it, I’ll give it to you

As the purchasing department, we have heard that there are also manufacturers in China producing ion exchange membranes for caustic soda:victory:. Could someone give a lesson on DX? :lol

What was covered on the 2nd floor is already quite comprehensive. In fact, ion membranes were first developed by DuPont for fuel cell vehicles that provided power to the lunar rovers used in the Apollo moon landing mission. 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 all have a certain understanding with their respective electrolyzer producers. 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 Chlorgen, and since then, Chlorgen’s new electrolyzers have basically been equipped with Asahi Glass’ membranes. Woody’s new grooves basically use DuPont film. However, I personally think that membranes are basically universal in current slots. As mentioned on the fourth floor, DuPont’s membranes are more durable, but they require a higher voltage (currently, the voltage required for DuPont’s latest N2030 membrane 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. I am currently acting as an agent for DuPont products. If anyone on the 7th floor is interested, they can contact me via email at hanxhanx@gmail.com

As far as I know, Asahi Glass’ membranes are mainly used in single-polar 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. 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-up and shutdowns, along with 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. To maintain stable production, users are forced to compensate for the damage caused by starting and stopping the process to the ion membranes 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.

Nippon Glass’ membranes are currently mainly used in the cells of chlorine production plants, while most single-pole cells use DuPont membranes, and the reason for this is the better strength of the DuPont membranes, as you mentioned.

The chlor-alkali industry is developing rapidly, and technology is also advancing. Survival of the fittest remains unchanged forever! Time speaks volumes!

1. 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 membrane has high mechanical strength, but its cell voltage is slightly higher than that of the membranes produced by Asahi Glass and Asahi Kasei (when comparing membranes of the same type). 2. The perfluorinated ion exchange membrane manufactured 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 membranes. 3. The single-cell voltage of Asahi Kasei membranes is lower, and their performance is similar to that of DuPont membranes. 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, Asahi Kasei is next, and DuPont membranes come in third ； Therefore, a comprehensive consideration is needed when making a choice. This post was last edited by limingshuguang on 2008-8-20 19:54.]

DuPont has brought the 2000 series of membranes to market – the upgrade for 982 was the 2010 model, the upgrade for 966 was the 2020 model, and 2030 is the latest version (it has the same strength as the 2010 model, but its operating voltage is much lower). Both slot voltage and mechanical strength are closely related to film thickness – the thicker the film, the better the mechanical strength, but the higher the voltage. Such as DuPont 966 – when held in the hand and examined, it is immediately apparent that it is thicker than other options; however, its high breakdown voltage is also a point of criticism among users. With the continuous improvement in production management levels in factories, as well as the increasing sophistication of new electrolytic cells, the requirements regarding the strength of membranes have decreased compared to before; as a result, users can achieve a better balance between strength and energy consumption. However, in my opinion, if factors such as current efficiency (hydroxide ion back-migration at the cathode, the formation of hypochlorous acid and free chlorine in the brine at the anode), the potential costs resulting from these factors on the lifespan of the piping equipment in the overall brine system, and the damage to the electrolyzer caused by pinholes, bulging, or even rupture due to insufficient membrane strength are taken into account, it may not be cost-effective to focus solely on achieving a low cell voltage when selecting a membrane, while ignoring the hidden costs associated with long-term operation. Therefore, some factories choose membranes with a lower voltage when the tanks are new, and switch to membranes with higher strength once the tanks age and the system’s performance declines; this is also a form of balance.

Most of what we use in our factory is from Asahi Kasei; there’s also some from DuPont. It works well, but it’s a bit expensive. Asahi Kasei’s membranes get contaminated easily; when problems arose, they provided a lot of data, but the only conclusion was: it was due to our operational mistakes! This post was last edited by limingshuguang on 2008-8-20 19:56.]

DuPont membranes have a greater thickness and a higher slot pressure, such as the 982# membrane, but they still perform well and can handle greater fluctuations in saltwater quality. When the two Japanese membrane manufacturers (Asahi Glass and Asahi Kasei) are used together, they can also cope with fluctuations in saltwater quality in China, although their service life is somewhat shorter. The selection of membrane should be determined based on a combination of the quality of the brine and the operating current; no matter how good the membrane is, the quality of the brine is the key factor. The quality of saline remains stable; it is recommended to use DuPont membranes, which can last up to 5 years. Of course, it also depends on the slot type you choose. F1 cars cannot be driven on Chinese highways.

N982 represents the two previous generations of membranes. The strength of N2010 and N2030 is the same as that of N982, but their voltages decrease in sequence: V(982) > V(2010) > V(2030). Therefore, it is recommended to use 2030 in place of 982 to obtain a lower voltage and save energy consumption. If high mechanical strength is required, N2020 can be used as a substitute for N966. The lifespan of the membrane depends mainly on the stability of saltwater. The more stable the quality of the saline water, the smoother the membrane operation. For example, factories often purchase raw salt from different sources with varying qualities, and if the process parameters of the brine system are not adjusted in a timely manner, it often leads to problems with the membranes and tanks.