In the semiconductor industry, creation of a single wafer — the substrate for microcircuits — requires ultrapure water at the rate of 7 L/cm2.
As much of the world faces water scarcity, industries that rely on UPW are benefiting from on-site production
Ultrapure water (UPW), as the name suggests, is water that is free of virtually all impurities. Production of ultrapure water typically begins with a pretreatment stage, followed by a primary stage and finally a polishing stage. A number of technologies can be used in the process chain, including ultrafiltration, reverse osmosis, gas transfer membrane (GTM) degasification, continuous electrodeionization (CEDI), and resin processes.
Ultrapure water is used in a number of industries, each with its particular challenges. In the semiconductor industry, creation of a single wafer — the substrate for microcircuits — requires 7 L/cm2 of UPW. This means that a typical manufacturer that processes 20,000 200 mm wafers a month can use as much as 3,000 m3/d of UPW. That’s the approximate daily domestic water requirement of a 20,000-resident community.
The semiconductor industry has recently dominated international media attention as it faces an unprecedented water shortage that makes production challenging. It’s especially true in Taiwan, which is experiencing its worst drought in more than a half century, prompting fears of global microchip shortages and price increases.
Sourcing Ultrapure Water
How can semiconductor manufacturers source enough ultrapure water to continue operations when long-term climate projections call for increasingly arid conditions? This year in Taiwan, the world’s largest chip manufacturer is expected to spend nearly $30 million trucking water from farther south, where water is more plentiful, and some are negotiating to drill groundwater wells. But more sustainable solutions are needed.
Desalination is coming to the fore in coastal regions and islands like Taiwan, and chip companies are also trying to recycle more of their process water. Between 2015 to 2019, some of the largest chip manufacturers recycled nearly 90% of their process water.
In the European Union, under pressure from new carbon tariffs, the semiconductor industry and governments are expected to invest aggressively in sustainable nontraditional water sources that can serve as source water for UPW production.
Ultrapure Water in Other Industries
Although the water crisis in the semiconductor sector has captured the world’s attention, ultrapure water is essential in many industries like the pharmaceutical, food and beverage, and oil and gas industries.
- In the pharmaceutical industry, UPW is used in many injection, inhalation, or irrigation products that require bacteriostatic or sterile water. It is also used for sterilization steam.
- Unsurprisingly, the food and beverage industry faces high water safety standards, and water must be demineralized and filtered to a high degree of purity to achieve the right flavor in certain products. Some brewers, for instance, demineralize water and then reintroduce minerals to achieve the desired balance.
- In the oil and gas industry, UPW is frequently used on offshore oil rigs for turbine washing and cooling, for hydraulic fluids, power augmentation machinery, and boiler feed water.
While these industries are large users of ultrapure water, any industry that generates steam, like power generation, can benefit from a steady supply of UPW.
Fluence Ultrapure Water Systems
Fluence containerized ultrapure water systems use a number of technologies, the choice of which depends on feed-water source and chemicals used. Typical processes include pretreatment with media, activated carbon, ultrafiltration, or cartridge filtration. Often, a double-pass reverse osmosis step follows to remove most of the dissolved solids in the water, creating permeate. GTM degasification then removes dissolved carbon dioxide and other conductive gases, and then a CEDI system polishes the demineralized water to the required quality.
Fluence has the decades of experience to transform virtually any feed water, from seawater to reused process water, into ultrapure water on-site for industry. Contact our experts to determine your industry’s most direct route to a reliable, climate resilient supply of UPW.
