Status quo and development trend of alkaline water electrolytic membrane technology
Hydrogen is a truly renewable and clean source. Alkaline water electrolysis (AWE) is currently the most promising green hydrogen production technology. The key part of the alkaline electrolyzer is the diaphragm, which acts as a conductive OH- and barrier gas (preventing the mixing of hydrogen and oxygen to produce ** gases). At present, the PPS separator used on a large scale in alkaline electrolyzers has the disadvantages of poor hydrophilicity, high resistance and poor gas insulation, resulting in high energy consumption and low safety. Therefore, it remains a challenge to develop high-performance alkaline water electrolyzed separators with low surface resistance (reduced energy consumption), high bubble point pressure (improved safety), and high stability.
Composite separators are generally composed of polysulfone (PSU), zirconia nanoparticles (ZRO2) and polyphenylene sulfide (PPS) grids coupled, and casting and phase conversion strategies are used to achieve efficient alkaline water electrolysis. The composite separator has high hydrophilicity, ultra-low surface resistance, ultra-high bubble point pressure and excellent mechanical properties, and exhibits excellent stability and high water electrolysis performance in the electrolysis process, and the hydrogen produced is of high purity, which is considered to be the next generation of advanced alkaline water electrolytic membrane.
PPS Japanese industry development
Japan dynamics.
Recent industry trends in Japan (especially Japanese fiber substrate manufacturers) have studied more on the basic materials of PPS materials.
*For reference only).
The PPS substrate imported from Japan has very obvious advantages in thickness and uniformity, which helps diaphragm manufacturers to improve product performance.
Introduction to PPS substrates
1) Material: PPS polyphenylene sulfide 100%.
2) Product form: special paper (a kind of special non-woven fabric, similar to carbon paper processing products, but the material is 100% pps).
3) Uses: separator for hydrogen production by alkaline water electrolysis, or separator for hydrogen refining and purification equipment.
4) Specifications can be developed according to customer requirements.
PPS domestic market status:
Demand side:
With the continuous expansion of downstream application fields, the demand for polyphenylene sulfide non-woven fabrics is increasing year by year. Especially in the fields of environmental protection, automobiles, electrical and electronics, due to the unique advantages of product performance, the market demand for polyphenylene sulfide non-woven fabrics continues to expand.
Supply side:
There are a large number of domestic polyphenylene sulfide non-woven fabric enterprises, but most of them are small in scale, and there is still a gap between production technology and product quality and the international leading level. At present, the domestic market is dominated by a few large enterprises, but the overall supply still cannot meet the growing market demand.
Trends:
With the rise of domestic polyphenylene sulfide non-woven fabric enterprises and the improvement of technology, international cooperation and competition will become an important trend in the development of the industry. In the future, the company will strengthen cooperation with international advanced enterprises to jointly promote the development and application of industry technology.
The reasons for the use of PPS polyphenylene sulfide are as follows:
1. Acid and alkali resistance (especially alkali resistance).
2. High temperature resistance
3. Resistant to organic solvents
4. Non-flammable
5. Fine pore size distribution
6. Uniformity.
7. It is not easy to deform (especially in high temperature and humid environment).
8. Stable mechanical strength
PPS Non Woven PPS Mesh.
1，ppsNonwovens:
Microfiber PPS non-woven fabric is a material with excellent properties. It has a relatively uniform fine pore size distribution, and has the characteristics of acid and alkali resistance (especially alkali resistance), organic solvent resistance, high temperature resistance, not easy to deform (especially in high temperature and humidity environment) and stable mechanical strength.
Material
Polyphenylene sulfide 100%.
Product form
Specialty papers. Features:
1.It has a fine pore size.
2.Sheet designs with high porosity are possible, resulting in low pressure loss.
3.It has a high plane uniformity, which is conducive to diaphragm coating.
4.It has high heat resistance, chemical resistance (alkali resistance, acid resistance, organic solvent resistance).
Basic physical property specifications:
Weight: 10 150g
Thickness: 20 300 m
Width: max 1400mm
Each specification can be developed according to customer needs.
2. PPS grid:
Width: max 3000mm
Thickness specifications
1. Thickness: about 80 m, reduce the thickness of the substrate, and the separator becomes thinner, which can effectively improve the ionic conductivity. (According to the current market demand, 100 m homogeneous substrate still needs to be imported.) ）
2. Thickness: about 300 m, conventional type products. Both imported products and domestically manufactured products are available, and the raw materials of imported substrates are relatively pure and of high quality.
3. Thickness: about 500 m, the thickness is on the thick side, and the manufacturing cost of this specification in China is relatively cheap. However, the thickness of the substrate becomes thicker, and the coating film is wasted, which will greatly increase the cost of the coating film.