As of the end of 2023, there are 156 existing seawater desalination projects nationwide, with project scale252.29 million tons/day, up 52.06% year on year.Among them, there are 55 seawater desalination projects of ten thousand tons and above, with a project scale of 2.3007 million tons/day.As of the end of 2023, the national applicationreverse osmosis technologythe number of projects is 140, accounting for the scale of total projects67.24%。

Shandong Province, as a major maritime province, has a per capita water resource possession less than the national average1/6. By the end of 2023, Shandong Province had a seawater desalination project scale71.32 million tons/day。

Wanhua not only initiated a seawater desalination project using reverse osmosis technology, but as a global leading company in chemical new materials, Wanhua Chemistry has leveraged its integrated upstream and downstream raw material advantages to build a completemembrane materialR&D and manufacturing system, successfully developed thermal method through independent innovationhollow fiber ultrafiltration membrane, industrial reverse osmosis membrane (polyamide desalination layer), household reverse osmosis membrane, seawater desalination membraneand series of products, this product matrix has significant advantages such as high desalination rate, high boron removal rate, strong chemical stability, and strong adaptability to high salinity water quality, and has provided customized water treatment solutions for customers in the fields of chemical industry, steel, new energy, photovoltaic, and municipal.

In September 2023, the completion ceremony for the second phase of the Wanhua Chemical Membrane Plant project was held. The project is located within the Wanhua Industrial Park, with a total investment of approximately 470 million yuan and a total area of about 68,000 square meters. The total production capacity of the membranes in this project is6.19 million ㎡/a, the component production capacity is 50,000 units/year, and the filter element production capacity is 100,000 units/year. Among which,RO membrane (reverse osmosis membrane) is 3 million square meters/year, NF membrane (nanofiltration membrane) is 600,000 ㎡/a, UF membrane (ultrafiltration) is 500,000 ㎡/a, hollow fiber membrane is 1,000,000 ㎡/a, MF membrane (microfiltration) is 1,000,000 ㎡/a, modified separation membrane is 90,000 ㎡/a.

Wanhua Chemical successfully independently developed a high-performance seawater desalination membrane in 2023, and applied it to the Xiaoqin Island seawater desalination project. The standard desalination rate of the seawater desalination membrane reaches99.8%, the desalination system has a desalination rate of 99.6%, with the boron content in the produced water as low as 0.4 ppm (far below the upper limit requirement of 1 ppm in GB5749).

In 1948, the proposal of the semi-permeable membrane concept laid the theoretical foundation for the development of reverse osmosis technology. In 1953, Reid first used a 6μm thick homogeneouscellulose acetatePreparation of homogeneous symmetric reverse osmosis membranes, marking the scientific research of reverse osmosis membranesthe beginning. In 1960, the world's first generation of asymmetric cellulose acetate reverse osmosis membrane was successfully developed, promoting the commercialization process of reverse osmosis technology. In 1965, the first industrial-scale brackish water desalination demonstration plant was built in Coalinga, California, USA.Engineering. The first in 1974industrial scalethe seawater desalination reverse osmosis project establishment.

Domestic reverse osmosis membrane technology development started in the late 1950s. In 1984, China's first 500m³/d reverse osmosis seawater desalination unit was put into operation in Shengshan County, Zhoushan, Zhejiang, marking the beginning of large-scale application of seawater desalination in the country. Since the 1990s, based onpolyamide materialThe reverse osmosis composite membrane and its spiral wound devices became popular worldwide. In 1996, foreign reverse osmosis membrane manufacturers significantly reduced their prices, and domestic RO membrane products lacked market competitiveness, leading to the shutdown of most domestic reverse osmosis membrane production factories. At the beginning of the 21st century, domestic enterprises introduced reverse osmosis technology from abroad.The full-process production line and process technology for membrane, after the introduction and digestion of technology, domestic membrane brands have begun to show advantages in cost-effectiveness, with their market share in China increasing year by year.。

On the development history of seawater desalination and reverse osmosis membrane technology in China, there is a crucial figure who isAcademician Gao CongjieIn 1995, at the age of 53, Gao Congjie was elected as an academician of the Chinese Academy of Engineering, becoming one of ourthe first academician in the field of seawater desalination and membrane technology, the national reverse osmosis membrane unit and engineering technology development project it participated in won an award in 1992National Science and Technology Progress First Prize, resolvednational membrane industry existencethe issue. June 2024,Academician Gao Congjie andThe achievements of the new membrane water treatment project jointly developed by two other academicians won the First Prize of National Science and Technology Progress, elevating our country's membrane technology fromgreat power strides towards becoming a strong nation。

From the perspective of global market share,DuPontReverse osmosis membrane market share dominates globally. Major foreign reverse osmosis membrane manufacturers include DuPont, Nitto Denko (in 1987, Hydranautics was acquired by the Nitto Denko Group and became a member of Nitto's global membrane division), Toray, Koch, GE, LG Chem, etc.

Domestic reverse osmosis membrane enterprises mainly include Vontech, Hangzhou Water Treatment (a member enterprise of Sinochem Environmental Platform), Wisewell, Originwater, Jiuhua High-Tech, Trinda, etc. ToJiuwu Hi-Tech products as an example,Different types of membrane elements commonly used membrane sheet materials and applications are as follows.