Liqui-Cel® membrane contactors are used to efficiently remove gases from liquids or add gas to liquids. These membrane devices have displaced older technology such as vacuum towers, forced draft deaerators and oxygen scavengers for over 20 years. Typical applications are O2 removal from water and CO2 removal from water; however, membrane contactors are quite capable of controlling several types of dissolved gasses. For example, adding or removing nitrogen carbonation, humidification of gasses, VOC removal and control of gases for improved ultrasonics are some of the other applications.
Boiler feedwater deaeration, dissolved gas removal and corrosion control
Liqui-Cel® membrane contactors are often installed to control corrosion in boilers, piping and system components. By removing gases such as oxygen and carbon dioxide the amount of oxidation is reduced, thereby protecting against costly replacement and repairs. In addition, because these devices do not require chemicals to operate, blow down frequency is reduced and operating costs are less.
For these reasons, Liqui-Cel® membrane contactors have become the technology of choice to control dissolved gas removal in many industries. These types of installations are particularly popular in the power, chemical and other processing industries.
Water degassing for microelectronics, semiconductor wafers and flat panel displays
Liqui-Cel® contactors have become the degassing standard in the microelectronic and flat panel industry because they are clean, have very low extractables and do not negatively impact the water quality. Since Liqui-Cel® contactors are small, compact and can easily remove dissolved oxygen down to 1ppb and dissolved carbon dioxide down to 1ppm, it is a match that makes perfect sense.
Semiconductor wafers and flat panel displays go through a multi-step process where ultrapure water is required to wash the residual processing materials off the wafer or display media. Any gasses present in the water can deposit on to the wafer surface and cause defects.
EDI and CDI technology
EDI and CDI have also become common technologies in the semiconductor and pharmaceutical industries. These technologies operate more efficiently when dissolved CO2 is removed from the water so excess CO2 cannot load the EDI. This reduces the number of EDI stacks required because they operate more efficiently.
Pharmaceutical degassing
High purity water is an integral part of processing pharmaceuticals. Pharmaceutical plants require a continuous supply of water, often with a conductivity of <1.3µS/cm. This level of purity has to be constant and maintained throughout processing. CO2 removal is the optimal means to achieve this level of purity.
Liqui-Cel® membrane contactors are an efficient, chemical-free means to accomplish carbon dioxide removal. Additionally, Liqui-Cel® systems are closed systems that do not introduce environmental contaminants into the water like an old forced draft deaerator used to do.
Chemical dosing with NaOH was also commonly used to control CO2 in plant water for many years. However, environmental pressures, safety concerns and cost has pushed the industry away from chemicals.
As with the microelectronics industry, EDI and CDI have become common technology in the pharmaceutical industry. These technologies operate more efficiently if the dissolved CO2 is first removed from the water.