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US 8,894,865 B2Granted
Process for depleting calcium and/or iron from geothermal brines
AssigneeBerkshire Hathaway Energy Company
InventorsJohn L. Featherstone, George Furmanski
Life of this patent
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Abstract
This invention relates generally to processes for extracting iron and/or calcium from geothermal brines.
Claims20
A method of depleting calcium from a geothermal brine solution, said method comprising:
- (a) contacting the geothermal brine solution with a QL reagent to create a reaction solution, wherein the QL reagent comprises a quaternary ammonium compound, a hydrogen ion exchange reagent, and an organic solvent, wherein the reaction solution comprises an organic phase and an aqueous phase, and wherein the reaction solution is maintained at a temperature in the range of about 180° F. to about 230° F.;
- (b) extracting calcium into the aqueous phase, wherein the organic phase becomes a calcium-depleted geothermal brine solution;
- (c) separating the aqueous phase from the organic phase;
- and
- (d) removing additional calcium from the calcium-depleted geothermal brine solution by extracting the calcium-depleted geothermal brine solution with an aqueous acidic scrubbing solution to form a scrubbed organic phase, wherein the aqueous acidic scrubbing solution has a manganese concentration of about 40 g/L to about 70 g/L.
2 more elements
A method of depleting iron from a geothermal brine solution, said method comprising:
- (a) contacting the geothermal brine solution with an oxidizing agent, wherein said oxidizing agent oxidizes soluble iron in the solution to form an insoluble iron oxide precipitate;
- (b) removing the iron oxide precipitate from the solution to form an iron-depleted geothermal brine solution;
- (c) contacting the iron-depleted geothermal brine solution with a QL reagent to create a reaction solution, wherein the QL reagent comprises a quaternary ammonium compound, a hydrogen ion exchange reagent, and an organic solvent, wherein the reaction solution comprises an organic phase and an aqueous phase, and wherein the reaction solution is maintained at a temperature in the range of about 180° F. to about 230° F.;
- (d) extracting metal components into the aqueous phase, wherein the organic phase becomes a impurity-depleted geothermal brine solution;
- and
- (e) separating the aqueous phase from the organic phase.
3 more elements
A method for recycling a quaternary ammonium compound in a QL reagent, said method comprising:
- (a) contacting a geothermal brine solution with a QL reagent to create a reaction solution, wherein the QL reagent comprises the quaternary ammonium compound, a hydrogen ion exchange reagent, and an organic solvent, wherein the reaction solution comprises an organic phase and an aqueous phase;
- (b) extracting metal components of the geothermal brine into the aqueous phase and the QL reagent into the organic phase;
- (c) separating the aqueous phase from the organic phase;
- and
- (d) neutralizing and washing the organic phase to reform the quaternary ammonium compound, wherein the reformed quaternary ammonium compound may be used in a subsequent geothermal brine extraction.
2 more elements
Dependencies are inferred from the claim text.