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US 10,538,445 B2Granted
Process for purification of produced water
AssigneeAquatech International Corporation
InventorsRavi Chidambaran, Narendra Singh Bisht, Pavan Raina
Life of this patent
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Abstract
We provide a process for treatment of produced water, including but not limited to water produced by a “steam flood” process for extraction of oil from oil sands, including the removal of color from the water. This removal may be accomplished through addition of color-removal polymers and flocculents. This process may also be useful for other water treatment processes including reverse osmosis and filtration.
Claims20
A process for purification of water, comprising:
- collecting produced water including an oil/water mixture from an oil well;
- separating and recovering oil from the produced water;
- decreasing the pH of the produced water by addition of acid;
- removing color, organics, and silica from the produced water;
- adding a flocculent, including, optionally, a coagulant and a polyelectrolyte, to the produced water to aggregate solids in the produced water;
- removing solids from the produced water, thereby producing a first sludge;
- conditioning and disposing of the first sludge;
- sending the produced water to an evaporator, producing a distillate stream and a brine stream;
- sending the distillate stream to a boiler for evaporation into steam;
- and
- sending a portion of the brine stream to a crystallizer for removal of additional distillate and production of a slurry to achieve zero liquid discharge without formation of a tarry mass.
8 more elements
A process for preconditioning water prior to treatment in an evaporation or reverse osmosis treatment, comprising:
- providing a water stream including color;
- removing color, organics, and silica from the water stream by the steps of:
- adding an acid;
- adding a color removal chemical;
- and
- adding a flocculent to aggregate solids in the water stream;
- removing the solids from the water stream;
- increasing the pH of the water stream;
- and
- sending the produced water to at least one of a evaporator and a reverse osmosis unit,
- wherein a portion of the water leaving the at least one of the evaporator and the reverse osmosis unit is sent to a crystallizer for production of a slurry to achieve zero liquid discharge without formation of a tarry mass.
8 more elements
A process for preconditioning water prior to treatment in a reverse osmosis unit or evaporator, comprising:
- providing water comprising silica, color, and organics;
- decreasing the pH of the water by addition of acid;
- removing color, organics, and silica from the water by addition of color-removal chemicals;
- adding a flocculent to the water to aggregate solids in the water;
- removing aggregated solids from the produced water, thereby producing a first sludge;
- conditioning and disposing of the first sludge;
- mixing the water with one or more of lime, magnesium oxide, calcium oxide, and sodium hydroxide, thereby precipitating additional solids;
- removing the additional solids as a second sludge conditioning and disposing of the second sludge;
- and
- sending the water to an evaporator or reverse osmosis unit,
- wherein a portion of the water leaving the evaporator or the reverse osmosis unit is sent to a crystallizer for production of a slurry to achieve zero liquid discharge without formation of a tarry mass.
8 more elements
A process for purification of water, comprising:
- collecting produced water including an oil/water mixture from an oil well;
- separating and recovering oil from the produced water;
- decreasing the pH of the produced water by addition of acid;
- removing color, organics, and silica from the produced water;
- adding a flocculent, including, optionally, a coagulant and a polyelectrolyte, to the produced water to aggregate solids in the produced water;
- removing solids from the produced water, thereby producing a first sludge;
- conditioning and disposing of the first sludge;
- mixing the produced water with one or more of lime, magnesium oxide, magnesium hydroxide, calcium oxide, and sodium hydroxide, thereby precipitating silica from the produced water;
- removing precipitated silica as a second sludge;
- conditioning and disposing of the second sludge;
- sending the produced water to an evaporator, producing a distillate stream and a brine stream;
- sending the distillate stream to a boiler for evaporation into steam;
- and
- sending a portion of the brine stream to a crystallizer for removal of additional distillate and production of a slurry to achieve zero liquid discharge without tar formation.
11 more elements
A two-stage process for silica reduction from water, comprising:
- from a water stream comprising silica, water, and organics, coprecipitating at least some silica with color and organics;
- precipitating additional silica from the water stream by addition of at least one silica-precipitating compound selected from the group consisting of lime, magnesium oxide, magnesium hydroxide, calcium oxide, and sodium hydroxide upstream of an evaporator or reverse osmosis system,
- wherein a portion of the water leaving the evaporator or the reverse osmosis system is sent to a crystallizer for production of a slurry to achieve zero liquid discharge without formation of a tarry mass.
Dependencies are inferred from the claim text.