Abstract: A process is provided for treating produced water resulting from an oil recovery operation. Produced water is subjected to a softening process wherein a caustic or other softening reagent is added to the produced water to increase the pH of the produced water. Downstream of softening, there is provided an evaporator for evaporating at least a portion of the produced water and producing steam and a concentrated brine. At least a portion of the concentrated brine is recycled upstream of the evaporator and mixed with the produced water and the softening reagent to enhance the softening process.

Abstract: An oil recovery process is provided where an oil-water mixture is recovered from an oil-bearing formation. Oil is separated from the oil-water mixture to yield produced water. The produced water is typically subjected to a pre-treatment process. After pre-treatment, the produced water is directed to an evaporator that evaporates at least some of the produced water and produces steam and an evaporator blowdown. The evaporator blowdown is directed to a dual stage crystallizer that concentrates the evaporator blowdown.

Abstract: An oil recovery process where produced water is cooled through a flash evaporization process and the resulting vapor is utilized to heat steam generator feedwater.

Abstract: A process for treating wastewater or waste brines that include sodium and chloride ions. The waste brine is concentrated and thereafter directed to a Mirabilite crystallizer that produces hydrated sulfate salt crystals and a first solution. The hydrated crystals are melted to form an aqueous sulfate solution that is directed to a sodium sulfate crystallizer which produces sodium sulfate salt crystals. The first solution produced by the Mirabilite crystallizer is directed to a nanofiltration device which produces a permeate stream and a reject stream containing sulfate removed by the nanofiltration device. The permeate stream is directed to a sodium chloride crystallizer that produces sodium chloride salt crystals. The reject stream is recycled to the Mirabilite crystallizer.

Abstract: A process for recovering oil is provided. The process entails recovering an oil-water mixture from an oil-bearing formation. Next, the process entails separating oil from the oil-water mixture and producing produced water having hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil. A pre-treatment process is undertaken to remove hardness and other scale-forming compounds. This entails precipitating hardness and other scale-forming compounds. After the precipitation of hardness and other scale-forming compounds, the produced water is directed to a membrane separation unit for filtering the produced water and producing a retentate having suspended solids, hardness and other scale-forming compounds, free oil and emulsified oil. The membrane separation unit also produces a permeate stream substantially free of hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil.

Abstract: A method for treating produced water or a feedwater stream with an evaporator. The feedwater stream or produced water is directed to and through a deaerator located upstream of the evaporator. Steam produced by the evaporator is utilized to strip dissolved gases from the produced water or feedwater stream passing through the deaerator. To efficiently strip dissolved gases, the vapor pressure in the deaerator is maintained at below atmospheric pressure and the produced water or feedwater stream is heated to a temperature greater than the saturated vapor temperature in the deaerator.

Abstract: A method of recovering wood pulping chemicals from black liquor produced in a wood pulping process where the process entails burning the black liquor in a recovery boiler to form ash containing high levels of carbonate as well as sodium, potassium and chloride. The ash is dissolved to form a dissolved ash solution that is directed to a first stage crystallization unit that concentrates the dissolved ash solution and which results in the precipitation of sodium sulfate and sodium carbonate. Thereafter the concentrated dissolved ash solution is directed to a second stage crystallization unit which adiabatically cools the concentrated dissolved ash solution to form a glaserite slurry and a purge stream that is rich in chloride.

Abstract: Wood pulping process including pulping wood to produce a pulping effluent or liquor. Pre-concentrating the liquor in a pre-concentration unit produces concentrated liquor, a contaminated condensate and a non-contaminated condensate. Directing the concentrated liquor to a multi-effect train of forced circulation solids concentrators that further concentrating the concentrated liquor to form a highly concentrated liquor. Directing the contaminated condensate produced by the pre-concentration unit to a steam stripper and stripping gases therefrom and in the process producing a contaminated vapor stream. Utilizing the contaminated vapor stream and its thermal energy to power the forced circulation solids concentrators of the multi-effect train.

Abstract: A method of recovering wood pulping chemicals from black liquor produced in a wood pulping process where the process entails burning the black liquor in a recovery boiler to form ash containing high levels of carbonate as well as sodium, potassium and chloride. The ash is dissolved to form a dissolved ash solution that is directed to a first stage crystallization unit that concentrates the dissolved ash solution and which results in the precipitation of sodium sulfate and sodium carbonate. Thereafter the concentrated dissolved ash solution is directed to a second stage crystallization unit which adiabatically cools the concentrated dissolved ash solution to form a glaserite slurry and a purge stream that is rich in chloride.

Abstract: A method for cleaning a ceramic membrane used in an oil recovery process. The cleaning method includes online and offline modes. In the online mode, the method includes periodically backflushing the ceramic membrane with an aqueous media. In the offline mode, the method includes backpulsing or statically cleaning the ceramic membrane by utilizing an aqueous alkaline media, an aqueous acidic media, and a liquid hydrocarbon solution.

Abstract: The present invention relates to a process for treating evaporator concentrate. The process includes generating or producing a vent stream that includes carbon dioxide and mixing the carbon dioxide with the evaporator blowdown to reduce the pH of the evaporator blowdown. In cases where the evaporator blowdown includes a significant concentration of silica, lowering the pH will precipitate silica from the evaporator blowdown.

Abstract: A process is described for recovering alkali-chloride and alkali-sulfate salts from a salt solution. The salt solution comprises alkali metal, chloride and sulfate ions and is directed to a hydrous salt crystallization unit which crystallizes hydrated sulfate salts that comprise sulfate and at least one alkali metal. A purged solution from the hydrous salt crystallization unit is directed to a chloride salt crystallization unit while the hydrated sulfate salt crystals are melted to form an aqueous sulfate solution which is directed to a sulfate crystallization unit. Anhydrous sulfate salts are crystallized from the aqueous sulfate solution to form sulfate salt crystals comprising sulfate and at least one alkali metal. In the chloride salt crystallization unit, chloride salt is crystallized to form chloride salt crystals. A purge from the chloride salt crystallization unit is directed to the hydrous salt crystallization unit.

Abstract: A process is described for recovering alkali-chloride and alkali-sulfate salts from a salt solution. The salt solution comprises alkali metal, chloride and sulfate ions and is directed to a hydrous salt crystallization unit which crystallizes hydrated sulfate salts that comprise sulfate and at least one alkali metal. A purged solution from the hydrous salt crystallization unit is directed to a chloride salt crystallization unit while the hydrated sulfate salt crystals are melted to form an aqueous sulfate solution which is directed to a sulfate crystallization unit. Anhydrous sulfate salts are crystallized from the aqueous sulfate solution to form sulfate salt crystals comprising sulfate and at least one alkali metal. In the chloride salt crystallization unit, chloride salt is crystallized to form chloride salt crystals. A purge from the chloride salt crystallization unit is directed to the hydrous salt crystallization unit.

Abstract: A method is provided for treating brine recovered from a coal seam gas operation. The process entails directing brine recovered from a coal seam gas operation to a mixed reactor and mixing an alkaline earth reagent with the brine. This results in the precipitation of alkaline earth salts and silica, which form alkaline earth salt crystals having silica adsorbed thereto. Thereafter, the alkaline earth salt crystals and adsorbed silica are directed to an evaporator that produces a concentrate having the alkaline earth salt crystals and adsorbed silica.

Abstract: A process for treating feedwater with a microfiltration or ultrafiltration membrane unit and a downstream reverse osmosis unit. An aluminum salt coagulant is added and mixed with the feedwater upstream of a membrane separation unit. An aluminum salt coagulant is added and mixed with the wastewater upstream of the membrane separation unit. The membrane separation unit produces a permeate that is directed to the reverse osmosis membrane. The concentration of aluminum in the permeate is controlled by controlling the hydraulic residence time for aluminum salt reaction products in a concentrate loop associated with the membrane separation unit.

Abstract: An oil recovery process includes recovering an oil-water mixture from an oil-bearing formation and separating the produced water from the oil-water mixture. The produced water includes dissolved gases and the method includes heating and pressurizing the produced water. After the produced water is heated and pressurized, it is flash vaporized through a lesser pressure which produces a vapor and residual produced water. The flash vaporization of the produced water evaporates dissolved gases and the dissolved gases are vented away with the vapor.

Abstract: An oil recovery process where produced water is cooled through a flash evaporization process and the resulting vapor is utilized to heat steam generator feedwater.

Abstract: Oil sands process water (OSPW) is directed to an evaporator that evaporates the OSPW and produces steam and a concentrated brine. The OSPW includes alkalinity and calcium hardness. To inhibit calcium carbonate scaling of the evaporator, magnesium oxide is mixed with the OSPW, resulting in the precipitation of magnesium hydroxide which acts as a seed material for calcium carbonate precipitation to prevent fouling. The process crystallizes the calcium carbonate and the mixture of magnesium hydroxide and calcium carbonate crystals are circulated through the evaporator as well as recirculated to a point upstream of the evaporator.

Abstract: An oil recovery process is provided where an oil-water mixture is recovered from an oil-bearing formation. Oil is separated from the oil-water mixture to yield produced water. The produced water is typically subjected to a pre-treatment process. After pre-treatment, the produced water is directed to an evaporator that evaporates at least some of the produced water and produces steam and an evaporator blowdown. The evaporator blowdown is directed to a dual stage crystallizer that concentrates the evaporator blowdown.

Abstract: A process is provided for treating produced water resulting from an oil recovery operation. Produced water is subjected to a softening process wherein a caustic or other softening reagent is added to the produced water to increase the pH of the produced water. Downstream of softening, there is provided an evaporator for evaporating at least a portion of the produced water and producing steam and a concentrated brine. At least a portion of the concentrated brine is recycled upstream of the evaporator and mixed with the produced water and the softening reagent to enhance the softening process.