Gradiant Corporation

Massachusetts Institute of Technology

King Fahd University of Petroleum and Minerals

Karim M Chehayeb

Prakash Narayan Govindan

Maximus G St John

Steven Lam

Mark Zaloudek

Samar Shah

John H Lienhard

Ronan Killian McGovern

Syed Mohammad Zubair

Gregory P Thiel

Jonn-Ross Andrews

Looh Tchuin Choong

Sarit K Das

Mohammed A Antar

John-Ross Andrews

Provided herein are osmotic desalination methods and associated systems. According to certain embodiments, multiple osmotic membranes may be used to perform a series of osmosis steps, such that an output stream having a relatively high water purity&#x2014;compared to a water purity of an aqueous feed stream&#x2014;is produced. In some embodiments, multiple draw streams can be used to produce aqueous product streams having sequentially higher purities of water. Certain embodiments are related to osmotic desalination systems and methods in which forward osmosis is used to produce a first product stream having a relatively high water purity relative to an aqueous feed stream, and reverse osmosis is used to perform a second step (and/or additional steps) on the first product stream. In some embodiments, multiple reverse osmosis steps can be used in series to perform a net desalination process.

Osmotic desalination methods and associated systems

Systems and methods related to desalination systems are described herein. According to some embodiments, the desalination systems are transiently operated and/or configured to facilitate transient operation. In some embodiments, a liquid stream comprising water and at least one dissolved salt is circulated through a fluidic circuit comprising a desalination system. In some embodiments, a portion of the desalination system (e.g., a humidifier) is configured to remove at least a portion of the water from the liquid stream to produce a concentrated brine stream enriched in the dissolved salt. In certain cases, the concentrated brine stream is recirculated through the fluidic circuit until the concentrated brine stream reaches a relatively high density (e.g., at least about 10 pounds per gallon) and/or a relatively high salinity (e.g., a total dissolved salt concentration of at least about 25 wt %). In certain embodiments, additional salt is added to the concentrated brine stream to produce an ultra-high-density brine stream (e.g., a brine stream having a density of at least about 11.7 pounds per gallon). Some aspects relate to a system that is configured to promote energy efficiency by recovering heat from the recirculated concentrated brine stream upon discharge from the fluidic circuit.

Production of ultra-high-density brines using transiently-operated desalination systems

A counter-flow simultaneous heat and mass exchange device is operated by directing flows of two fluids into a heat and mass exchange device at initial mass flow rates where ideal changes in total enthalpy rates of the two fluids are unequal. At least one of the following state variables in the fluids is measured: temperature, pressure and concentration, which together define the thermodynamic state of the two fluid streams at the points of entry to and exit from the device. The mass flow rate of at least one of the two fluids is changed such that the ideal change in total enthalpy rates of the two fluids through the device are brought closer to being equal.

Feedback control optimization of counter-flow simultaneous heat and mass exchange

A counter-flow simultaneous heat and mass exchange device is operated by directing flows of two fluids into a heat and mass exchange device at initial mass flow rates where ideal changes in total enthalpy rates of the two fluids are unequal. At least one of the following state variables in the fluids is measured: temperature, pressure and concentration, which together define the thermodynamic state of the two fluid streams at the points of entry to and exit from the device. The flow rates of the fluids at the points of entry and/or exit to/from the device are measured; and the mass flow rate of at least one of the two fluids is changed such that the ideal change in total enthalpy rates of the two fluids through the device are brought closer to being equal.

Transiently-operated desalination systems and associated methods

Transiently-operated desalination systems with heat recovery and associated methods

A carrier-gas mixture is directed through a fluid flow path in a combined heat and mass transfer device, which can be operated at sub-atmospheric pressure. Heat and mass are transferred from or to the carrier-gas mixture via interaction with a liquid composition that includes a vaporizable component in a liquid state to substantially change the content of the vaporizable component in the carrier-gas mixture via evaporation or condensation. The mass flow rate of the carrier-gas mixture is varied by extracting or injecting the carrier-gas mixture from at least one intermediate location in the fluid flow path, and/or the mass flow rate of the liquid composition is varied by extracting or injecting the liquid composition from at least one intermediate location in the fluid flow path; and the flow of the carrier-gas mixture or the liquid composition is regulated to reduce the average local enthalpy pinch in the device.

Thermodynamic balancing of combined heat and mass exchange devices

A carrier-gas mixture is directed through a fluid flow path in a combined heat and mass transfer device operating at a sub-atmospheric pressure. Heat and mass are transferred from or to the carrier-gas mixture via interaction with a liquid composition that includes a vaporizable component in a liquid state to substantially change the content of the vaporizable component in the carrier-gas mixture via evaporation or condensation of the vaporizable component. The mass flow rate of the carrier-gas mixture is varied by extracting or injecting the carrier-gas mixture from at least one intermediate location in the fluid flow path, and/or the mass flow rate of the liquid composition is varied by extracting or injecting the liquid composition from at least one intermediate location in the fluid flow path; and the flow of the carrier-gas mixture or the liquid composition is regulated to reduce the average local enthalpy pinch in the device.

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Beirut, Lebanon

Karim M Chehayeb