History and current status of reverse osmosis technology
Pure water preparation industry
Eight years ago, the American company’s reverse osmosis membrane products entered the mainland market as a symbol. The domestic reverse osmosis pure water preparation process technology has entered a stage of rapid development, in power, petroleum, chemical, metallurgy, electronics, medicine, food and other industries Industry and municipal water supply, direct drinking water and other civilian applications have been widely used. Compared with the traditional ion exchange and electrodialysis methods, the reverse osmosis membrane method occupies most of the market share of the pure water preparation process. Reverse osmosis technology was first used in the preparation of flushing water in the microelectronics industry in China. In recent years, the technology and consumption wave formed by the direct osmosis reverse osmosis process has swept the country from south to north and from east to west, greatly promoting The popularity of RO technology.
The increase in national power and corporate purchasing power, and the increase in personal consumption levels, on the other hand, have promoted the widespread popularity of reverse osmosis technology, promoted direct drinking water, municipal water supply, and various industrial industries have successively accepted reverse osmosis technology and its products, forming their respective industry technologies An important part of progress. In turn, it has played a certain role in promoting the overall domestic industrial progress.
Reverse osmosis membrane products
In terms of the structure of reverse osmosis membranes, the market for hollow membranes, tubular membranes, and plate membranes is relatively narrow, which has caused the production of hollow membranes by Du Pont in the United States, and the hollow membranes of Toyobo in Japan. The domestic sales volume is also extremely limited, and because of the low pretreatment requirements of the roll-up membrane, the wide range of water treatment, the wide range of applications, and the huge market, the roll-up membrane is almost synonymous with reverse osmosis membrane. In terms of membrane materials, due to defects such as high working pressure and low desalination rate, cellulose acetate membranes have basically withdrawn from the market, and low-pressure and ultra-low-pressure aromatic polyamide composite membranes have become the absolute mainstream of the market. The development trend of membrane products is toward low pollution membranes, positively charged membranes, sodium filter membranes and other varieties of multi-purpose.
The low pollution membrane (LFC1, LFC3 series) of Hyde Energy Company has strong chemical anti-pollution performance. It is an additional layer of anti-pollution material on the original polyamide composite membrane, so that the surface of the original negatively charged membrane is charged. At the same time, it improves its hydrophilicity, thereby effectively improving the membrane’s ability to resist organic contamination. The low pollution membrane (BW30-FR series) of Dow Chemical Company has strong physical anti-pollution performance, it improves the smoothness of the membrane surface, increases the thickness of the membrane inlet water barrier layer, and reduces the turbulence of the membrane surface 1. The flow rate is accelerated, which effectively improves the membrane’s ability to resist microbial contamination. In terms of surface water, reclaimed water, sewage treatment and other solutions concentration and purification treatment, low-pollution membranes have unique effects. Since they entered the domestic market in 1998, they have been increasingly valued and popularized quickly. In recent years, the surface of the positively charged membrane has a positive charge, which can remove cations more effectively. When used in the second-stage reverse osmosis, it can effectively improve the desalination rate of the entire system, making it less than 1μS/cm. System water quality requirements. Nanofiltration membranes do not belong to the category of reverse osmosis membranes in a strict sense. The variety of membrane materials is not limited to aromatic polyamides. The quality assessment of membranes can be various indicators such as viruses, bacteria, amine nitrogen, BOD, and not only low desalination rates. Therefore, the applications of nanofiltration membranes are very extensive, and need to be vigorously developed.
Reverse osmosis membrane market
In the RO membrane product market, the membrane products of Hydranautics (Nitto Denko) and Dow Chemical (Filmtec) account for about 80% of the current domestic market. The remaining foreign membrane manufacturers, such as Koch / Fluid System, Osmonics / Desal, Trisep, South Korea (csm / Saehan), Japan Toray (Toray) and other companies occupy a total of about 20% of the market.
From 1996 to 2001, the domestic sales of various types of roll film were about 200, 500, 800, 1000, 15 million, and 25 million US dollars, respectively, and the estimated sales in 2002 were 30 million US dollars. Global RO membrane sales were approximately US$500 million in 2001. Excluding regional price differences and variety price differences, the domestic membrane sales volume was approximately 10% of the global sales volume. In 2001, Hyde Energy took the lead in investing in a factory in Shanghai (Songjiang) to produce roll film. The product was put into the domestic market in May 2002. I believe that other foreign membrane manufacturers will also build factories in China.
Application of reverse osmosis membrane
In the application field of RO membranes, the US YUMA water plant (treatment of canal water), which was put into operation in the 1980s, remains at the top of the world’s reverse osmosis membrane water treatment project with its daily water treatment capacity of 280,000 tons. Seawater desalination is one of the important fields of application of reverse osmosis technology. The three largest seawater desalination projects with a production scale of more than 100,000 tons per day in the world are built in the UAE, Saudi Arabia and Spain. The processing capacity of Fujairah Water Plant is up to 140,000 tons/day. According to incomplete statistics, the current pure water produced by reverse osmosis technology in the world exceeds 12 million tons per day. Due to economic and geographic factors, reverse osmosis projects are relatively concentrated in Shandong Province and Dalian. With the intensification of drought in northern my country and the continuous improvement of industrial and civil requirements for water volume and water quality, membrane desalination will inevitably develop from the current marine and island use to the industrial and municipal fields, and the market has great potential.
Reverse osmosis supporting products
Synchronous development with the membrane product market is its supporting product market. ARGO scale inhibitors, GRUNDFOS and DP vertical multistage centrifugal pumps, PROCON and NOCCHI vane pumps, CODELINE membrane pressure vessels, AUTOTROL and FLACK water softener multi-way valves, PARK and STRUCTURE fiberglass filter barrels, BLUEWHITE and KING’s panel flowmeter and many other foreign supporting products once dominated the membrane supporting product market. With the unanimous and unremitting efforts of domestic membrane agents and manufacturers of similar supporting products, the above-mentioned membrane supporting products are gradually being localized. At present, product quality has basically passed the mark, and market prices have fallen sharply. Some products are also sold to the origin of the United States and other products, opening up a brand-new field for the development of the industry.