# US 10,308,537 B2 · Desalination systems and associated methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,308,537 B2 - Document ID: US10308537B2 - Status: Granted - Kind: B2 - Application number: 14/494,101 - Filed: 2014-09-23 - Published: 2015-03-26 - Granted: 2019-06-04 - Earliest claimed: 2013-09-23 - Assignees: Gradiant Corporation - Applicants: Gradiant Corporation - Inventors: Prakash Narayan Govindan; Steven Lam; Maximus G. St. John; Mark Zaloudek; Anurag Bajpayee - Web page: https://patentgrep.com/patent/US10308537B2 ## CPC - C02F 9/00: Multistage treatment of water, waste water or sewage - B01D 1/30: Accessories for evaporators {; Constructional details thereof} - C02F 1/04: by distillation or evaporation - C02F 1/042: {Prevention of deposits} - C02F 1/42: by ion-exchange (ion-exchange in general B01J) - C02F 1/463: by electrocoagulation - C02F 1/52: by flocculation or precipitation of suspended impurities {(C02F1/463 takes precedence)} - C02F 5/02: Softening water by precipitation of the hardness - C02F 2001/425: {using cation exchangers} - C02F 2001/5218: {Crystallization} - C02F 2103/08: Seawater, e.g. for desalination - C02F 2201/007: Modular design - C02F 2301/046: Recirculation with an external loop - Y02A 20/124: Water desalination - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE ## Abstract Systems and methods related to the desalination of aqueous solutions containing one or more dissolved salts are generally described. ## Claims ### Claim 1 A method for desalinating water, comprising: removing, within an ion-removal apparatus, at least a portion of at least one scale-forming ion from an aqueous feed stream, the aqueous feed stream comprising the at least one scale-forming ion and at least one dissolved monovalent salt comprising a monovalent cation and a monovalent anion to produce an ion-diminished stream containing less of the scale-forming ion relative to the aqueous feed stream; removing, within a desalination apparatus, water from the ion-diminished stream to produce a concentrated saline stream enriched in the dissolved monovalent salt relative to the ion-diminished stream, wherein the removing comprises contacting a gaseous stream with the ion-diminished stream within a humidifier to evaporate water from the ion-diminished stream into the gaseous stream; and precipitating, within a precipitation apparatus, at least a portion of the dissolved monovalent salt from the concentrated saline stream to produce a product stream containing less of the dissolved monovalent salt relative to the concentrated saline stream; and recycling at least a portion of the product stream to the desalination apparatus; wherein: the precipitating comprises forming crystals comprising at least a portion of the dissolved monovalent salt, and/or the precipitating comprises adjusting the temperature of the concentrated saline stream. ### Claim 2 (depends on 1) The method of claim 1, wherein a concentration of the dissolved monovalent salt within the concentrated saline stream differs from a concentration of the dissolved monovalent salt within the ion-diminished stream by no more than about 20%. ### Claim 3 (depends on 1) The method of claim 1, wherein the ion-removal apparatus comprises an ion-removal medium contained within a vessel, and the ion-removal medium comprises a composition configured to induce precipitation of the at least one scale-forming ion. ### Claim 4 (depends on 1) The method of claim 1, wherein the at least one scale-forming ion comprises Mg2+, Ca2+, Sr2+, and/or Ba2+. ### Claim 5 (depends on 1) The method of claim 1, comprising transporting the gaseous stream to a dehumidifier and condensing at least a portion of the water within the gaseous stream. ### Claim 6 (depends on 1) The method of claim 1, wherein the precipitating comprises reducing the flow velocity of the concentrated saline stream. ### Claim 7 (depends on 6) The method of claim 6, wherein the reducing the flow velocity of the concentrated saline stream comprises substantially stopping the flow of the concentrated saline stream. ### Claim 8 (depends on 1) The method of claim 1, wherein the precipitating comprises adjusting the temperature of the concentrated saline stream. ### Claim 9 (depends on 1) The method of claim 1, wherein the bulk concentration of at least one of the dissolved monovalent salts within the concentrated saline stream exiting the desalination apparatus can be increased by at least about 1% without reaching a saturation limit. ### Claim 10 (depends on 1) The method of claim 1, wherein, during operation, at least about 1 wt % of the concentrated saline stream that enters the precipitation apparatus is precipitated as a solid salt in the precipitation apparatus. ### Claim 11 (depends on 1) The method of claim 1, wherein there are substantially no regions within the desalination apparatus in which the ion-diminished stream is quiescent. ### Claim 12 (depends on 1) The method of claim 1, comprising removing at least one of the ion-removal apparatus, the desalination apparatus, and/or the precipitation apparatus while performing the method. ### Claim 13 (depends on 1) The method of claim 1, wherein the precipitating comprises forming crystals comprising at least a portion of the dissolved monovalent salt. ### Claim 14 (depends on 1) The method of claim 1, wherein the precipitating comprises precipitating, within the precipitation apparatus, sodium chloride. ### Claim 15 (depends on 1) The method of claim 1, wherein the recycling comprises recycling at least the portion of the product stream from the precipitation apparatus to the desalination apparatus via a direct fluidic connection between the precipitation apparatus and the desalination apparatus. ### Claim 16 A method for desalinating water, comprising: removing, within a desalination apparatus, water from an aqueous feed stream, the aqueous feed stream comprising at least one dissolved monovalent salt comprising a monovalent cation and a monovalent anion to produce a concentrated saline stream enriched in the dissolved monovalent salt relative to the aqueous feed stream; precipitating, within a precipitation apparatus, at least a portion of the dissolved monovalent salt from the concentrated saline stream to produce a product stream containing less of the dissolved monovalent salt relative to the concentrated saline stream; and recycling at least a portion of the product stream to the desalination apparatus; wherein substantially no precipitation of the dissolved monovalent salt occurs within the desalination apparatus; and wherein: the precipitating comprises forming crystals comprising at least a portion of the dissolved monovalent salt, and/or the precipitating comprises adjusting the temperature of the concentrated saline stream. ### Claim 17 (depends on 16) The method of claim 16, wherein the removing comprises contacting a gaseous stream with the aqueous feed stream within a humidifier to evaporate water from the aqueous feed stream into the gaseous stream. ### Claim 18 (depends on 16) The method of claim 16, wherein the precipitating comprises forming crystals comprising at least a portion of the dissolved monovalent salt. ### Claim 19 (depends on 16) The method of claim 16, wherein the precipitating comprises adjusting the temperature of the concentrated saline stream. ### Claim 20 (depends on 16) The method of claim 16, wherein the precipitating comprises precipitating, within the precipitation apparatus, sodium chloride. ### Claim 21 (depends on 16) The method of claim 16, wherein the recycling comprises recycling at least the portion of the product stream from the precipitation apparatus to the desalination apparatus via a direct fluidic connection between the precipitation apparatus and the desalination apparatus. ### Claim 22 A water desalination system, comprising: an ion-removal apparatus configured to receive an aqueous feed stream, the aqueous feed stream comprising at least one scale-forming ion and at least one dissolved monovalent salt, and to remove at least a portion of the at least one scale-forming ion to produce an ion-diminished stream containing less of the scale-forming ion relative to the feed stream; a desalination apparatus fluidically connected to the ion-removal apparatus and configured to remove water from the ion-diminished stream to produce a concentrated saline stream enriched in the dissolved monovalent salt relative to the ion-diminished stream; a precipitation apparatus fluidically connected to the desalination apparatus and configured to precipitate at least a portion of the dissolved monovalent salt from the concentrated saline stream to produce a product stream containing less of the dissolved monovalent salt relative to the concentrated saline stream, wherein the precipitation apparatus comprises a crystallizer; and a recycle stream directly fluidically connecting the precipitation apparatus to the desalination apparatus and configured to recycle at least a portion of the product stream from the precipitation apparatus to the desalination apparatus. ### Claim 23 (depends on 22) The system of claim 22, wherein the desalination apparatus comprises: a humidifier configured to evaporate water from the ion-diminished stream to produce a vapor-containing gaseous stream and the concentrated stream, and a dehumidifier fluidically connected to the humidifier and configured to condense at least a portion of the water from the gaseous stream, wherein the dehumidifier comprises a bubble column condenser.