Clean, aerosol free gas is critical to equipment reliability and the economic efficiency of gas processing, petroleum refining and chemical
processing. Pall’s SepraSol™ double open-ended liquid/gas coalescer contains a patented hydrophobic/oleophobic treatment. This treatment provides maximum liquid and solid removal efficiency at a low saturated pressure drop to reduce the maintenance and operating costs associated with the use of contaminated gas.
The SepraSol double open-ended coalescer is recommended for applications at a pressure of 250 psig or greater. Some of the applications recommended for the double open-ended coalescer include:
- Protecting compressors and turbines
- Protecting combustion equipment, including low and ultra-low NOx burners by
- Removing lubrication oil, water, compressor wear products, corrosion products, and other dirt from effluent gas streams
- Minimizing solution losses downstream of gas purification process units
- Protecting gas flow meters and meter runs, ensuring accurate flow rate measurements
- Controlling injection well plugging during gas flooding
- Minimizing foaming in amine and glycol contacting towers
- Protecting catalysts, desiccants and absorbants
- Safeguarding gas separation membrane systems
- Preventing contamination of bioreactors
- Ensuring contaminant-free carbonated beverages and containers
Oleophobic/Hydrophobic Treatment - All of Pall's SepraSol liquid/gas coalescers receive a patented oleophobic/hydrophobic treatment. Chemically treating the coalescer lowers the surface energy of the medium and promotes rapid drainage of the coalesced liquids. This significantly increases the amount of liquid per unit area of medium the coalescer can handle. Added benefits to the chemical treatment include lower saturated pressure drop, which saves operating costs and rapid recovery from liquid slugs.
Features, Advantages and Benefits of the Pall SepraSol Double Open-Ended Liquid/Gas Coalescer
Pall’s SepraSol liquid/gas coalescers eliminate virtually all solids and liquids in a gas stream. Downstream liquid levels are as low as 0.003 ppmw1 and solids removal rating is 0.3 micron (µm) (99.99% efficiency).2
|Patented Oleophobic/ Hydrophobic Media Treatment||
|High Effective Filtration Area||
|High Efficiency Media and Draining Materials||
1 Test conditions used to measure efficiency area as follows:
Flow rate: 900 SCF/minute per 30 in. element at 37.8°C (100°F) and 6.9 bar (100 psig)
Liquid inlet: 50 ppmw oil
2 Per sodium chloride test
Additional Features of the Pall SepraSol Double Open-Ended Liquid/Gas Coalescing Filter
|Solid Removal Rating||0.3 µm (99.99%)|
|Temperature Rating||180°F (82°C)
150°F (65°C) with Water
|Clean & Saturated
|Sized to your specification|
Figure 1: Effect of Pressure Drop on Compressor Operating Costs3
3 Conditions: Delta P on inlet pressure
Inlet Pressure = 20 psia
Outlet Pressure = 200 psia
Gas compressed is methane
Costs based on $0.07 / kwhr
Pall Corporation applies a patented oleophobic/hydrophobic chemical treatment on all of its SepraSol liquid/gas coalescers. This allows the coalescers to operate at a lower saturated pressure drop. As shown on Figure 1, a small difference in saturated pressure drop can result in significant savings in operating costs.
About Coalescer Efficiency Ratings
The measurement of the efficiency and the pressure drop of a coalescer should reflect operating conditions. Many manufacturers of coalescers measure efficiency using the dioctyl phthalate (DOP) test. The DOP test was not originally designed to measure the performance of a coalescer under operating conditions seen in the oil and gas industry. Rather, the DOP test is performed under the following conditions:
- Measures only capture efficiency and does not indicate how much liquid is at the filter outlet. It is the outlet concentration, which will indicate whether downstream equipment and processes are vulnerable to damage.
- Measures only the percent removal of DOP aerosols that are 0.3 µm compared to a range of sizes normally seen in oil and gas applications.
- Measures the removal of DOP, a liquid not typically found in oil and gas applications.
- Performed under a vacuum, not typical of operating conditions.
- Performed on a dry coalescing element; the effectiveness of a coalescer should be measured when a coalescer is completely saturated.
Pall has developed a test called the Liquid Aerosol Separation Efficiency (LASE). Test to specially measure the performance of a coalescer under operating conditions. The table below compares the LASE and DOP test. For further details on the LASE test, see Pall literature GAS-4300b, “Recent Developments in Performance Ratings of Gas/Liquid Coalescers.”
Pall LASE Test vs. Conventional DOP
|Pall LASE Test||DOP Test||LASE Advantage|
Measures ppmw of total downstream aerosol concentration
|Measures only the capture efficiency of 0.3 µm DOP aerosols||Specifies performance
based on total liquid
|Test Contaminant||Polydispersed 20 wt. compressor lube oil (size range 0.1-1.0 µm)||Monodispersed dioctyl
phthalate (size range at
0.3 µm only)
|Closely simulates actual process contamination|
|Full flow membrane sampling of all size contaminants||Indirect light scattering of
0.3 µm contaminants
|Directly measures the amount of all liquid downstream|
|Pressure Conditions||Performed under positive pressure conditions||Performed under vacuum||More closely reflects
actual process pressure
|Cartridge Condition||Performed on a saturated
|Performed on dry cartridge||Reflects actual process
|Pressure Drop Measurement||Measures operating saturated cartridge pressure drop||Measures dry cartridge
|Provides a more realistic service pressure drop|