Purification of gases from water using reverse osmosis
First Claim
1. A process for purifying water including removing cations, anions, carbon dioxide and/or ammonia from a water feed stream to produce high purity water having a resistivity of greater than 1 megohm-era, comprising the steps of:
- (a) providing water feed stream to be purified, said stream containing cations, anions, carbon dioxide and/or ammonia;
(b) pretreating said feed stream by passing said feed stream through a nonofiltration membrane to remove membrane foulants prior to introducing said feed stream to a first reverse osmosis membrane;
(c) introducing said water feed stream to a high pressure side of a first reverse osmosis membrane module;
(d) passing water through said first reverse osmosis membrane to provide a first retentate having cations and anions concentrated therein and a first permeate depleted in cations and anions and containing carbon dioxide and/or ammonia;
(e) passing said first permeate to a high pressure side, of a first gas permeable hydrophobic membrane module, andpermeating carbon dioxide and/or ammonia through said gas-permeable membrane from said first permeate in the high pressure side of said gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of said hydrophobic membrane and to provide a carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from said first permeate;
(f) maintaining the low pressure side of said hydrophobic membrane liquid free and subjecting said low pressure side of said hydrophobic membrane to a gas purge to remove carbon dioxide or ammonia that has permeated the hydrophobic membrane; and
(g) transferring said carbon dioxide and/or ammonia depleted retentate to the high pressure side of a second reverse osmosis membrane, andfurther purifying said carbon dioxide and/or ammonia depleted retentate by passing at least a portion thereof through said second reverse osmosis membrane to provide a second retentate and a second permeate, the second permeate having low levels of carbon dioxide and/or ammonia and having a resistivity of greater than 1 megohm-cm.
3 Assignments
0 Petitions
Accused Products
Abstract
A process for purifying water including removing cations, anions and carbon dioxide and/or ammonia from water feed stream to produce high purity water having a resistivity of greater than 1 megohm-era comprising the steps of providing a water feed stream to be purified, the stream containing cations, anions and carbon dioxide and/or ammonia; introducing the water feed stream to a high pressure side of a first reverse osmosis membrane module; passing water through the first reverse osmosis membrane to provide a first retentate having cations and anions concentrated therein and a first permeate depleted in cations and anions and containing carbon dioxide and/or ammonia; adding the first permeate to a high pressure side, of a gas permeable hydrophobic membrane module; passing carbon dioxide and/or ammonia through the gas-permeable membrane from the first permeate in the high pressure side of the gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of the hydrophobic membrane and to provide a carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from the first permeate; transferring the carbon dioxide and/or ammonia depleted retentate to the high pressure side of a second reverse osmosis membrane; and further purifying the carbon dioxide and/or ammonia depleted retentate by passing at least a portion thereof through the second reverse osmosis membrane to provide a second retentate and a second permeate, the second permeate having low levels of carbon dioxide and/or ammonia and having a resistivity greater than 1 megohm-cm.
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Citations
21 Claims
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1. A process for purifying water including removing cations, anions, carbon dioxide and/or ammonia from a water feed stream to produce high purity water having a resistivity of greater than 1 megohm-era, comprising the steps of:
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(a) providing water feed stream to be purified, said stream containing cations, anions, carbon dioxide and/or ammonia; (b) pretreating said feed stream by passing said feed stream through a nonofiltration membrane to remove membrane foulants prior to introducing said feed stream to a first reverse osmosis membrane; (c) introducing said water feed stream to a high pressure side of a first reverse osmosis membrane module; (d) passing water through said first reverse osmosis membrane to provide a first retentate having cations and anions concentrated therein and a first permeate depleted in cations and anions and containing carbon dioxide and/or ammonia; (e) passing said first permeate to a high pressure side, of a first gas permeable hydrophobic membrane module, and permeating carbon dioxide and/or ammonia through said gas-permeable membrane from said first permeate in the high pressure side of said gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of said hydrophobic membrane and to provide a carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from said first permeate; (f) maintaining the low pressure side of said hydrophobic membrane liquid free and subjecting said low pressure side of said hydrophobic membrane to a gas purge to remove carbon dioxide or ammonia that has permeated the hydrophobic membrane; and (g) transferring said carbon dioxide and/or ammonia depleted retentate to the high pressure side of a second reverse osmosis membrane, and further purifying said carbon dioxide and/or ammonia depleted retentate by passing at least a portion thereof through said second reverse osmosis membrane to provide a second retentate and a second permeate, the second permeate having low levels of carbon dioxide and/or ammonia and having a resistivity of greater than 1 megohm-cm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A process for purifying water including removing cations, anions, carbon dioxide and/or ammonia from a water feed stream to produce high purity water having a resistivity of greater than 1 megohm-era, comprising the steps of:
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(a) providing water feed stream to be purified, said stream containing cations, anions, carbon dioxide and/or ammonia; (b) pretreating said feed stream by passing said feed stream through a nonofiltration membrane to remove membrane foulants prior to introducing said feed stream to a first reverse osmosis membrane; (c) introducing said water feed stream to a high pressure side of a first reverse osmosis membrane module; (d) passing water through said first reverse osmosis membrane to provide a first retentate having cations and anions concentrated therein and a first permeate depleted in cations and anions and containing carbon dioxide and/or ammonia; (e) adjusting the pH of said permeate to a pH in the range of 5.5 to 7.5 to favor removing CO2 gas using a hydrophobic membrane; (f) adding said first permeate to a high pressure side, of a first gas permeable hydrophobic membrane module, and passing carbon dioxide and/or ammonia through said gas-permeable membrane from said first permeate in the high pressure side of said gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of said hydrophobic membrane and to provide a carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from said first permeate; (g) maintaining the low pressure side of said hydrophobic membrane liquid free and subjecting said low pressure side of said hydrophobic membrane to a gas purge to remove carbon dioxide or ammonia that has permeated the hydrophobic membrane; and (h) transferring said carbon dioxide and/or ammonia depleted retentate to the high pressure side of a second reverse osmosis membrane, and further purifying said carbon dioxide and/or ammonia depleted retentate by passing at least a portion thereof through said second reverse osmosis membrane to provide a second retentate and a second permeate, the second permeate having low levels of carbon dioxide and/or ammonia and having a resistivity of greater than 1 megohm-cm. - View Dependent Claims (15)
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16. A process for purifying water including removing cations, anions, carbon dioxide and/or ammonia from a water feed stream to produce high purity water having a resistivity of greater than 1 megohm-era, comprising the steps of:
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(a) providing water feed stream to be purified, said stream containing cations, anions, carbon dioxide and/or ammonia; (b) pretreating said feed stream by passing said feed stream through a nonofiltration membrane to remove membrane foulants prior to introducing said feed stream to a first reverse osmosis membrane; (c) introducing said water feed stream to a high pressure side of a first reverse osmosis membrane module; (d) passing water through said first reverse osmosis membrane to provide a first retentate having cations and anions concentrated therein and a first permeate depleted in cations and anions and containing carbon dioxide and/or ammonia; (e) adjusting the pH of said permeate to a pH of greater than 8 to favor removing NH3 gas using a hydrophobic membrane; (f) adding said first permeate to a high pressure side, of a gas permeable hydrophobic membrane module, and passing carbon dioxide and/or ammonia through said gas-permeable membrane from said first permeate in the high pressure side of said gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of said hydrophobic membrane and to provide a carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from said first permeate; (g) maintaining the low pressure side of said hydrophobic membrane liquid free and subjecting said low pressure side of said hydrophobic membrane to a gas purge to remove carbon dioxide or ammonia that has permeated the hydrophobic membrane; and (h) transferring said carbon dioxide and/or ammonia depleted retentate to the high pressure side of a second reverse osmosis membrane, and further purifying said carbon dioxide and/or ammonia depleted retentate by passing at least a portion thereof through said second reverse osmosis membrane to provide a second retentate and a second permeate, the second permeate having low levels of carbon dioxide and/or ammonia and having a resistivity of greater than 1 megohm-cm. - View Dependent Claims (17)
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18. A process for purifying water including removing cations, anions, carbon dioxide and/or ammonia from a water feed stream to produce high purity water having a resistivity of greater than 1 megohm-era, comprising the steps of:
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(a) providing water feed stream to be purified, said stream containing cations, anions, carbon dioxide and/or ammonia; (b) introducing said water feed stream to a high pressure side of a first reverse osmosis membrane module; (c) passing water through said first reverse osmosis membrane to provide a first retentate having cations and anions concentrated therein and a first permeate depleted in cations and anions and containing carbon dioxide and/or ammonia; (d) adjusting the pH of said first permeate to a pH in the range of 5 to 8 to favor removing CO2 gas with a first hydrophobic membrane; (e) adding said first permeate to a high pressure side, of a first gas permeable hydrophobic membrane module, and passing carbon dioxide and/or ammonia through said first gas-permeable hydrophobic membrane from said first permeate in the high pressure side of said gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of said hydrophobic membrane and to provide a second carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from said first permeate; (f) adjusting the pH of said carbon dioxide and/or ammonia depleted second retentate to a pH of greater than 8; (g) introducing said second retentate to the high pressure side of a second gas permeable hydrophobic permeable membrane module, and passing carbon dioxide and/or ammonia through said second gas-permeable hydrophobic membrane from said second retentate in the high pressure side of said second gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of said second hydrophobic membrane and to provide a third carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from said second retentate; (h) maintaining the low pressure side of said second hydrophobic membrane liquid free; (i) transferring said third carbon dioxide and/or ammonia depleted retentate to the high pressure side of a second reverse osmosis membrane; and (j) further purifying said third carbon dioxide and/or ammonia depleted retentate by passing at least a portion thereof through said second reverse osmosis membrane to provide a fourth retentate and a second permeate, the second permeate having low levels of carbon dioxide and/or ammonia and having a resistivity of greater than 1 megohm-cm. - View Dependent Claims (19)
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20. A process for purifying water including removing cations, anions, carbon dioxide and/or ammonia from a water feed stream to produce high purity water having a resistivity of greater than 1 megohm-cm, comprising the steps of:
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(a) providing water feed stream to be purified, said stream containing cations, anions, carbon dioxide and/or ammonia; (b) introducing said water feed stream to a high pressure side of a first reverse osmosis membrane module; (c) passing water through said first reverse osmosis membrane to provide a first retentate having cations and anions concentrated therein and a first permeate depleted in cations and anions and containing carbon dioxide and/or ammonia; (d) adjusting the pH of said first permeate to a pH of greater than 8 to favor removing NH3 gas with a first hydrophobic membrane; (e) adding said first permeate to a high pressure side, of a first gas permeable hydrophobic membrane module, and passing carbon dioxide and/or ammonia through said first gas-permeable hydrophobic membrane from said first permeate in the high pressure side of said gas-permeable hydrophobic membrane to provide an ammonia and/or carbon dioxide permeate on a low pressure side of said hydrophobic membrane and to provide a second carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from said first permeate; (f) adjusting the pH of said carbon dioxide and/or ammonia depleted second retentate to a pH in the range of 5 to 8 to favor removing CO2 gas; (g) introducing said second retentate to the high pressure side of a second gas hydrophobic permeable membrane module; (h) passing carbon dioxide and/or ammonia through said second gas-permeable hydrophobic membrane from said second retentate in the high pressure side of said second gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of said second hydrophobic membrane and to provide a third carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from said second retentate; (i) maintaining the low pressure side of said second hydrophobic membrane liquid free; (j) transferring said third carbon dioxide and/or ammonia depleted retentate to the high pressure side of a second reverse osmosis membrane; and (k) further purifying said third carbon dioxide and/or ammonia depleted retentate by passing at least a portion thereof through said second reverse osmosis membrane to provide a fourth retentate and a second permeate, the second permeate having low levels of carbon dioxide and/or ammonia and having a resistivity of greater than 1 megohm-cm.
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21. A process for purifying water including removing cations, anions, carbon dioxide and/or ammonia from a water feed stream to produce high purity water having a resistivity of greater than 1 megohm-cm, comprising the steps of:
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(a) providing water feed stream to be purified, said stream containing cations, anions, carbon dioxide and/or ammonia; (b) pretreating said feed stream by passing said feed stream through a nonofiltration membrane to remove membrane foulants prior to introducing said feed stream to a first reverse osmosis membrane; (c) introducing said water feed stream to a high pressure side of a first reverse osmosis membrane module; (d) passing water through said first reverse osmosis membrane to provide a first retentate having cations and anions concentrated therein and a first permeate depleted in cations and anions and containing carbon dioxide and/or ammonia; (e) passing said first permeate to a high pressure side, of a first gas permeable hydrophobic membrane module, and permeating carbon dioxide and/or ammonia through said gas-permeable membrane from said first permeate in the high pressure side of said gas-permeable hydrophobic membrane to provide a carbon dioxide and/or ammonia permeate on a low pressure side of said hydrophobic membrane and to provide a carbon dioxide and/or ammonia depleted retentate thereby removing carbon dioxide and/or ammonia from said first permeate; (f) introducing an inert gas to the high pressure side of said hydrophobic membrane to sparge carbon dioxide thereinto for removal through said hydrophobic membrane; (g) maintaining the low pressure side of said hydrophobic membrane liquid free; and (h) transferring said carbon dioxide and/or ammonia depleted retentate to the high pressure side of a second reverse osmosis membrane, and further purifying said carbon dioxide and/or ammonia depleted retentate by passing at least a portion thereof through said second reverse osmosis membrane to provide a second retentate and a second permeate, the second permeate having low levels of carbon dioxide and/or ammonia and having a resistivity of greater than 1 megohm-cm.
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Specification