| CPC C02F 1/441 (2013.01) [B01D 61/025 (2013.01)] | 4 Claims |
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1. A method for concentrating high-salinity raw water to obtain produced water satisfying the following <Equation 1>, the method comprising passing the high-salinity raw water having a salt concentration of 70,000 ppm or greater through a separation membrane at a temperature of 40° C. or less and a pressure of greater than or equal to 400 psi and less than or equal to 900 psi:
Ns=B*(Cm−Cp), <Equation 1>
wherein in the <Equation 1>:
B is a salt permeability constant (B-value) of the separation membrane, and is 3 gallons per square foot per day (GFD) (gal/ft2/day)≤B≤150 gallons per square foot per day (GFD) (gal/ft2/day);
Ns is an amount of salt permeating the separation membrane (GFD*ppm), and has a value of Fp*Cp;
Cm is a raw water-side separation membrane surface concentration (membrane concentration) (ppm); and
Cp is a produced water salt concentration (permeate concentration) (ppm),
wherein Fp is produced water flux (permeate flux), and is 5 GFD≤Fp≤100 GFD,
wherein an osmotic pressure of the produced water is from 15% to 90% of an osmotic pressure of the high-salinity raw water, and
wherein the separation membrane is a reverse osmosis membrane.
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