[go: up one dir, main page]

WO2003048050A1 - Production d'eau potable par separation ionique et desionisation - Google Patents

Production d'eau potable par separation ionique et desionisation Download PDF

Info

Publication number
WO2003048050A1
WO2003048050A1 PCT/US2002/038858 US0238858W WO03048050A1 WO 2003048050 A1 WO2003048050 A1 WO 2003048050A1 US 0238858 W US0238858 W US 0238858W WO 03048050 A1 WO03048050 A1 WO 03048050A1
Authority
WO
WIPO (PCT)
Prior art keywords
wall
ions
channel
positive
negative
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2002/038858
Other languages
English (en)
Inventor
William L. Warren
Richard Stolz
Jeff A. B. Bullington
M. G. Giridharan
Edward T. Knobbe
Robert M. Taylor
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sciperio Inc
Original Assignee
Sciperio Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US10/301,550 external-priority patent/US20040007452A1/en
Application filed by Sciperio Inc filed Critical Sciperio Inc
Priority to AU2002357785A priority Critical patent/AU2002357785A1/en
Publication of WO2003048050A1 publication Critical patent/WO2003048050A1/fr
Priority to AU2003291651A priority patent/AU2003291651A1/en
Priority to PCT/US2003/033843 priority patent/WO2004037727A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
    • B01D61/428—Membrane capacitive deionization
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D57/00—Separation, other than separation of solids, not fully covered by a single other group or subclass, e.g. B03C
    • B01D57/02—Separation, other than separation of solids, not fully covered by a single other group or subclass, e.g. B03C by electrophoresis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
    • B01D61/44—Ion-selective electrodialysis
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
    • B01D61/44—Ion-selective electrodialysis
    • B01D61/52—Accessories; Auxiliary operation
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/48—Treatment of water, waste water, or sewage with magnetic or electric fields
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/08—Seawater, e.g. for desalination
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
    • Y02A20/124—Water desalination
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
    • Y02A20/124—Water desalination
    • Y02A20/131—Reverse-osmosis

Definitions

  • the present invention is directed to a method and system for fluid purification. More particularly, the present invention is directed to methods and systems for purifying fluid using ionic separation and deionization.
  • Quality water is a shared resource that is becoming increasingly scarce in both developed and developing countries, due to rapidly changing agricultural and industrial uses as well as to the rapid population increases being seen in arid regions of the world.
  • Sources of interest include saline waters, brackish waters, and seawater.
  • Water purification and desalination are focus areas of preventative defense and environmental security because they not only meet future global water demands but can be used for humanitarian assistance in water-starved regions.
  • the amount of energy used by the present desalting technologies is high relative to the minimum energy of separation of salt from seawater.
  • the minimum free energy requirement for desalting seawater is 3.7 kWh/1000 gallons or 1.0 k m3 at 25 °C.
  • a typical brackish water RO unit operates at 1000 psi (6.9 MPa) pressure, 30% water recovery, and 70% pump efficiency consumes 33 kWh/1000 gallons (8.7 kWh/m3).
  • At an average retail cost of $0.10/kWh just the energy costs for that method of removing the salt from brackish water would be $3.30/1000 gallons ($0.87/m3).
  • LISA and FD are fundamentally orthogonal and scalable de-ionization technologies (e.g., water desalination technologies) that gains the following advantages when compared to such state-of-the-art ion separation technologies as reverse osmosis, distillation, and variants thereof: LISA and FD can be several times more energy-efficient; LISA and FD can require less maintenance (can minimize no fouling); LISA and FD can have greater water throughput;
  • LISA and FD can be implemented with any charged ionic species and in any fluid medium (gas, plasma, solutions, etc.).
  • the LISA and FD approaches can decrease energy consumption, simplify design, construction, and operation of deionization system, overcome bifouling, and provide sizable improvements in the ability to process in-line any harmful ionic contaminants (e.g., heavy metals, radioactive elements, salt, water hardners) from any fluid stream.
  • harmful ionic contaminants e.g., heavy metals, radioactive elements, salt, water hardners
  • FIG. 1 illustrates an effect of a moving charge in the presence of a magnetic field
  • FIGS. 2A and 2B illustrate how a current flow reacts to a magnetic field: FIGS. 3 A and 3B illustrate directions of electric and magnetic forces; FIG. 4 illustrates a pseudo-virtual impactor; FIG. 5 illustrates a three stage pseudo-virtual impactor;
  • FIG. 6 illustrates an exemplary apparatus for removing concentrated ions
  • FIG. 7 illustrates an exemplary apparatus for separating ions from a fluid stream using Lorentz and electrophoretic forces
  • FIG. 8 illustrates an exemplary magnetodialysis process
  • FIG. 9A-9C illustrates exemplary segmented electrode configurations
  • FIG. 0 illustrates an exemplary energy-recovery LC system
  • FIG. 11 illustrates an exemplary rotating magnetic field system
  • FIG. 12 illustrates another exemplary rotating magnetic field system according to another embodiment
  • FIG. 13 illustrates an exemplary single channel counter-current flow design.
  • understanding the kinetics and energetics of desalting, the effects of charge, and performing active control of the ionic separation surface can decrease energy consumption, simplify design, construction, and operation of deionization systems, overcome biofouling, and provide sizeable improvements in the ability to process in-line any harmful ionic contaminants (e.g., heavy metals, radioactive elements, salt, water hardeners) from any fluid stream.
  • harmful ionic contaminants e.g., heavy metals, radioactive elements, salt, water hardeners
  • the Lorentz Ionic Separation Apparatus (LISA)
  • LISA is an approach based on the fusion of several technological advances. This approach takes any ionic species (dissolved minerals, radioactive elements, chromium, arsenic, salt, etc.) out of any fluid (brackish water, hard water, seawater, plasmas, gases, etc.). In the case of seawater desalination, LISA is quite different than RO processes, which take purified water out of the salt solution. The LISA process can remove dissolved ionic species or toxic chemicals from polluted water, or desalt seawater, with potentially 10 times less energy than state-of-the-art RO and at least 100 times less energy than seawater distillation.
  • This new-to-the-world, energy- efficient process can be made possible by exploiting electromagnetics (the Lorentz force), virtual impactors, fluid dynamics, ion-selective membranes and/or porous walls, and can use energy recovery via magnetohydrodynamics (MHD) and net ionic currents in the separated fluidic streams.
  • MHD magnetohydrodynamics
  • F q(v x B) where F is the force vector acting on the charged particle due to interaction with the magnetic field vector B, q is the scalar charge of the article, and v is the velocity vector of the charged particle perpendicular to the magnetic field B.
  • FIG. 1A provides a graphical illustration.
  • the Lorentz force has been utilized for many applications, including cyclotrons, mass spectrometers, electric motors, loudspeakers, and generators.
  • the Lorentz force can separate charged ions from fluidic media.
  • the Hall effect principally states that when a current-carrying conductor is placed within a magnetic field, a voltage is generated perpendicular to the direction of both the field and the flow of current.
  • a constant current is passed through a thin sheet of a conducting material. The sheet has measurement connections attached at right angles to the current flow. With no magnetic field, current distribution is uniform, and no potential difference exists at the output contacts.
  • a perpendicular magnetic field is present, as illustrated in FIG. 2B, the current flow is distorted. The uneven distribution of electron density creates a potential difference across the output terminals. This voltage is called the Hall voltage.
  • the Hall voltage is a direct consequence of the Lorentz force; the separation of the ions and/or electronic charges by the magnetic field establishes the compensating Hall voltage.
  • q ⁇ is the electric force component and ⁇ (v x B) is the magnetic force component.
  • the electric force is straightforward, being in the direction of the electric field if the charge q is positive, but the direction of the magnetic art of the force is given by the right-hand rule.
  • the electric and magnetic forces are schematically illustrated below in FIGS. 3 A and 3B, respectively.
  • the magnetic field (Lorentz force) component separate ions in a fluid; however, in the absence of electronic or ionic current flow in the vertical direction, a compensating Hall voltage develops.
  • the Hall voltage is the basis of magnetohydrodynarnics (MHD), the study of the motions of electrically conducting fluids and the interactions with magnetic fields.
  • the electrons in the dynamic generator's armature wire are forced to travel in one direction under the influence of a magnetic field.
  • An electrical conductor moving through a magnetic field will dynamically create electricity.
  • an electromotive current is created in a wire that traverses through magnetic lines of force.
  • a concentration of electrons along the length of the wire creates a voltage difference between the ends of the wire.
  • Dynamic generators convert the kinetic energy of the moving armature wire into electrical energy.
  • the spinning wire is used to produce electrical power by attaching a shaft to the armature and driving it with a turbine.
  • MHD systems use high velocity, electrically conducting fluids, chiefly plasmas or liquid metals, to produce electrical power. These systems are described as direct energy conversion because the rotating generator mechanisms discussed above are replaced with the flowing, electrically conductive fluid. In the channel, the charge carriers are deflected via the Lorentz force by a magnetic field applied perpendicular to the fluid flow. The charge carriers move through the fluid and are deflected to one of the electrodes that carries the electrical current to the load.
  • the advantage of MHD systems over conventional dynamic generators is that the MHD systems have no moving parts except for the flowing charge carriers. LISA Operation
  • LISA removes any ionic species from any fluidic source.
  • a magnetic field generated by a permanent, electric, and/or superconducting magnet is used to generate a Lorentz force on the positive and negative ions in the fluid to be treated.
  • water is used as the illustrative example; however, in principle, any fluidic medium can be used.
  • the Lorentz force separates the positive ions from the negative ions.
  • the water flows through a ductlike construct, and, with the Reynolds number less than 2000, the flow will be laminar in nature.
  • the mobilities of ions in- water are typically_quite low, e.g., approximately 5 x 10 ' m V " s " .
  • the heights of the ducts will likely be limited to relatively small (centimeter or millimeter) size regimes to reduce the time required to separate the slow-moving ions. While the ion-containing water is flowing through the ducts, the separation of the ionic species creates a Hall voltage. As this develops, it begins to counteract the Lorentz force.
  • flow in the channels should generally be laminar; turbulence would dominate over separation. Since the drift mobilities and drift velocities, v d ⁇ ⁇ ( ⁇ x B), of ions in water are relatively low, the total length of the duct the water traverses can be long, and the width of the channel in the direction of the separation should be less 1 cm to minimize duct length.
  • the Hall voltage may be disrupted using a pseudo-virtual impactor.
  • a virtual impactor is a device used to separate particles by size into two airstreams. It is similar to a conventional impactor, but the impaction surface is replaced with a virtual space of stagnant or slow-moving air. Large particles are captured in a collection probe rather than impacted onto a surface.
  • a pseudo-virtual impactor may be employed to separate more highly concentrated ions in a flow of water near the periphery of the duct from less concentrated ions near the center of the duct. The Lorentz force causes the ions to be more highly concentrated near the duct periphery.
  • the duct walls then can be fabricated of materials that do not shield the magnetic field, but they should be conductive if energy is to be recovered via MHD. The properties of the duct walls are discussed further below.
  • FIG. 4 shows a schematic diagram of an exemplary pseudo-virtual impactor that includes concentric ducts comprised of different geometries.
  • the inlet duct 40A has a wider opening than the outlet duct 40B.
  • the two concentric ducts 40A and 40B are displaced from each other by a relatively small distance, depending on water velocity (momentum) and relative size (duct length and height).
  • the water may pass through accelerating nozzle and be directed toward a collection tank. At this point, a portion of the flow is diverted away from the collection duct, at which place separation occurs. Water with a higher concentration of ions flow with the streamlines near the periphery and will be carried away to a reject stream.
  • This reject stream may be returned to the original water source, e.g., back to the originating ocean, or to a reject reservoir (the case for radioactive or otherwise contaminated solutions). Alternatively, the reject stream may be recycled into earlier LISA stages or used for energy-recovery processes, as described in further detail below.
  • the water flow near the center of the duct, with a lower concentration of ions, also largely follows its original flow-lines and continue moving axially in its forward path down the collection tank.
  • the separation efficiency curve is determined in part by the water flow velocity, the magnetic field strength, the physical dimensions of the duct, the separation between the concentric ducts, and the duct nozzle geometries.
  • the three-stage pseudo-virtual impactor separates the outer flow from the inner flow, or the concentrated saltwater from the dilute saltwater, respectively, as one example.
  • the concept of placing several pseudo- virtual impactors in series is functionally similar to fractional distillation. At each stage, the water becomes more deionized and/or purified. This occurs because once the higher-concentration solution is removed from the periphery, the compensating Hall voltage is reduced and the magnetic Lorentz force dominates the process to continue the separation of the positive and negative ions in the water stream for the next stage.
  • the one disadvantage to this scheme is that the process rejects water at every pseudo- virtual impactor stage, thus requiring consideration of water recovery, an issue yet to be resolved. If the water recovery fraction should prove too low, then a hybrid approach (e.g., LISA followed by RO) may prove to be the optimal configuration, as discussed below. Similarly, the exit stream may be recycled into earlier LISA stages as further discussed below.
  • a hybrid approach e.g., LISA followed by RO
  • the Hall voltage may be disturbed and the water capacitor discharged by defined geometric "holes" in the duct to separate the more highly concentrated ions near the duct periphery from the less concentrated ions near the duct center.
  • This concept is similar to the pseudo-virtual impactor. As is shown in FIG. 6, the water flow near the periphery impacts the trailing edge of the designed hole and exits the duct to the reject reservoir via impaction. The fluid flowing near the center of the duct is not largely disturbed and continues to travel down the duct. Once the more concentrated solution is removed from the periphery, the compensating Hall voltage will be reduced and the magnetic Lorentz force will dominate the process to continue to separate the positive and negative ions in the water stream.
  • the Hall voltage is distributed, the water capacitor of ionic charges is discharged, and the charge carriers are further separated by using electrophoresis in combination with the Lorentz force. Because the Lorentz force can be too small depending on water velocity and/or magnetic field strength, the length of the channel required for separation can be very large and impractical in the first two embodiments described above for pseudo-virtual impactor and geometrically defined holes.
  • electromagnets instead of permanent magnets, because iron-core electromagnets can produce field strengths of 3-4 T (or even higher with special high-permeability magnetic steels) compared to the ⁇ 1 T of permanent magnets.
  • Electrophoretic separation is achieved by applying an external voltage to the periphery of the duct.
  • the magnetohydrodynamic (Hall) voltage created by the Lorentz force can be used to partially supply the potential necessary to perform electrophoresis, thereby increasing overall system efficiency.
  • This concept can be actualized by simply connecting wires from the Lorentz separation section as shown in FIG. 7 to supply the potential to the electrophoresis section of the LISA.
  • a more sophisticated energy- recovery scheme may be used to exploit the Hall voltage, as described below with regard to energy harvesting.
  • the energy efficiency of the device depends upon the particulars of the MHD process.
  • the potential created by MHD and transferred to the electrophoretic capacitor will not be sufficient to further separate the ions due to the principle of conservation of charge. Therefore, an external bias should be applied to further the ion-separation process.
  • the electrophoresis stage is used in a separate channel.
  • the external bias is not being used to absorb ions, as is the case for flow- through capacitors and/or capacitive deionization apparatuses; instead, it is merely used to further separate the ionic species.
  • Drift velocity (scalar, vector): V & , V d Average water velocity (scalar, vector): u, u Electrophoretic voltage (scalar, vector): V x , V x
  • to disturb the Hall voltage to discharge the water capacitor of ionic charges, and to further separate e charge carriers is to use a LISA-type process that can be considered "magnetodialysis,” which process is illustrated in FIG. 8.
  • ions are driven through an ion-selective membrane under the influence of an electric field.
  • the key to the ED process is a semipermeable barrier that allows passage of either positively charged ions (cations) or negatively charged ions (anions) while excluding the passage of ions of the opposite charge.
  • These semipermeable barriers are commonly known as ion-exchange, ion-selective, or electrodialysis membranes.
  • a magnetic field is used to separate the ions via the Lorentz force rather than an electric field.
  • a magnetic field is required to separate ions in the channels, but it does not precipitate them. Therefore, the process can be termed magnetodialysis (MD).
  • MD magnetodialysis
  • the compensating Hall voltage is discharged through the concentrate/reject ports, i.e., through the walls.
  • an external magnetic field separates the anions from the cations.
  • the electrostatic attraction between the cations e.g., Na + at the cation transfer membrane and the anions (e.g., Cl " ) at the anion transfer membrane forces these ions to transport across their respective membrane walls and to concentrate in the reject/concentrate flow.
  • the electrostatic attraction of the anions and cations near their respective ion-selective membranes provides the potential to drive or transport the ions and cations to blend in the concentrate stream, thereby "discharging" the compensating Hall voltage.
  • Chambers e.g., with flow parallel to the magnetic lines of flux, adjacent to the channels, collect anions from a channel on one side and cations from another channel on the other side, and contain a sweep fluid to remove the ions.
  • a porous partition on one side can allow fluid enriched in one ion to enter the chamber where electrostatic attraction pulls the other type ions through a ion-selective membrane. Either procedure avoids ion build-up on the channel walls and allows the separation to continue.
  • the electrostatic attraction is similar in spirit to the electrophoresis voltage used in FIG. 7.
  • One MD arrangement is opposing, laminated magnet poles, with brine flowing in channels between the poles.
  • Separators e.g., ion-selective membranes
  • ions e.g., Cl " ions to the left side and Na + ions to the right
  • recombination chambers concentrating a sweep solution
  • the ions remix in the recombination chamber and exit, e.g., between the laminations.
  • Controlling the pressure difference across the separator can control flow through the separator.
  • Flows are preferably laminar on the input side so the size of the flow channels should probably be small, e.g., 01 cm.
  • the magnetic poles may have a circular arrangement (e.g., a circular north pole as an outer ring, with the south-pole inside), such that end channels with recombination chambers only on one side are avoided.
  • the separators might have a miniature "ricer” shape such that inertia helps scoop the heavier ions out of the input channels.
  • At least one of the faces of the wall is an ion-selective membrane.
  • membranes that have been used allow selective passage of certain ions.
  • ion-selective materials have been widely used to adsorb either anions or cations out of a liquid, with the ion being bonded, e.g., to a surface site on a zeolite material.
  • a home water softener uses anions loosely bonded on such sites, and the exchange of anions to "soften" water (e.g., a calcium ion replaces a sodium ion on the surface).
  • an ion-selective membrane can allow the passage of either anions or cations from a primary fluid, through an ion-sensitive membrane, to a secondary fluid, with little or no passage of either fluid.
  • the loosely bonded ions are on the surface of pores, and the pores pass through the material.
  • a sodium ion from the primary fluid pushes on, and replaces a sodium ion loosely bonded on the material surface, which ion in turn replaces an adjacent ion. This continues until an ion on the far side of the membrane passes into the secondary fluid.
  • the primary fluid can be depleted and the secondary fluid can be enriched in the opposite type of ion by an opposite type of ion- selective membrane (e.g., removing chlorine) at the opposite channel wall of the primary fluid.
  • an opposite type of ion- selective membrane e.g., removing chlorine
  • the ion-selective membranes provide a more effective way of de-ionizing.
  • a distribution of ions is produced where, at one wall, anions are concentrated and cations are partially depleted (vice- versa at the opposite wall).
  • Removing fluid from adjacent the walls is productive in that it removes ions of higher concentration than the input fluid, but counter-productive in that fluid is being removed which is partially depleted in other ions. If both concentrations and both depletions were all of an equal number of atoms, no deionization of the primary fluid would result.
  • some preferred embodiments use a pair of ion-selective membranes (one cation and one anion), and a sweep fluid (e.g., the same type of fluid as the input fluid or recycle from a later stage).
  • a sweep fluid e.g., the same type of fluid as the input fluid or recycle from a later stage.
  • one ion-selective member and one porous partition using fluid passing through the porous partition as the secondary fluid
  • Sodium and calcium ions pass much better than magnesium ions through some anion membranes.
  • a cation selective membrane and porous partition combination allows removal of magnesium ions as well. Large ions, e.g. carbonate ions, do not pass well through some cation selective membranes, but are removable by an anion-selective membrane and porous membrane combination.
  • a pair of ion-selective membranes might be used in one portion of a system, a cation selective membrane and porous partition combination in another portion, and anion-selective membrane and porous membrane combination in yet other portion.
  • a magnetic field is used to cause anions and cations to separate.
  • the walls are thinner than the channels are wide and the Hall voltage is at least largely offset by the electrostatic a cation from oppositely charged ions on the opposite side of the wall.
  • the electrostatic attraction is large enough to assist in moving the ions into the walls.
  • the fluid in the channels flows at a velocity such that the flow is laminar, and turbulent flow is avoided.
  • Flow within the hollow walls can be either laminar or turbulent.
  • channels are assembled into cylinder about an axis with an equal number of channels and walls, such that walls without channels on both sides are avoided.
  • ion-selective membranes are used on one side of the walls, and porous partitions are used on the other. In other embodiments, ion-selective membranes are used on both sides of the walls, and a sweep fluid is used within the walls.
  • the sweep fluid may be of the same type of fluid input into the channels.
  • the sweep fluid may be a portion of fluid output from the channels, which may be run as a counterflow sweep.
  • ion-selective membranes are used on both sides of the walls, and a sweep fluid is used within the walls in a first stage. At least one later stage uses ion-selective membranes on one side of the walls and porous partitions on the other.
  • Porous partitions e.g., porous membranes or ricer shaped partitions, can be used on both sides of the walls. Alternatively, an ion-selective membrane on at least one side may be used.
  • the fluid containing positive ions and negative ions may be saline water, brackish water, seawater, ion-containing gas, and/or nuclear waste.
  • the fluid containing positive ions and negative ions is deionized, and potable water is produced. In other embodiments the fluid containing positive ions and negative ions is partially deionized and further processed by reverse osmosis, and potable water is produced.
  • more than one stage of de-ionization is used and the ion- concentrated fluid exiting a later stage is recycled to an earlier stage.
  • the ions are attracted to the wall, and they are adsorbed onto the wall (high-surface-area electrode). Once adsorbed, desorbing the ions from the electrode surface is a technical challenge.
  • the ions are magnetically forced to the wall.
  • the separated ions are not adsorbed onto the duct walls, but are instead relatively free to pass through the walls if conditions are right.
  • the ions pass though the walls.
  • the ions are separated using the pseudo-virtual impactor and/or geometrically defined holes described above.
  • the wall is not the ion collection portal.
  • the ions are collected in ancillary concentrated/reject ports.
  • the wall need not be composed of impermeable materials to adsorb the ions nor to impede their relative motion.
  • the walls of the duct can be formulated as porous membranes on both sides (with relatively large pore sizes to allow ions to pass through, but to provide some flow resistance to the fluidic media), an ion-permeable membrane on one side and a porous membrane on the other, different ion-selective permeable membranes on both sides of the duct, with one side anion-selective and the other cation-selective, or electrode plates to collect the MHD potential. If electrode plates are used, the pseudo-virtual impactor and/or geometrically defined holes would be required to separate the ion-rich fluidic media from the ion-poor media.
  • the ions are removed almost as soon as they reach the walls, and their movement is very slow, then the ion distribution across most of the channel will be almost flat and will remain almost flat as the solution becomes more dilute as purification continues; the only major increase in ion density would be at the walls. In that case, the ion-flow-retarding Hall voltage across the channel is lower than the voltage across the wall-the counterions across the wall are closer than those across the channel, so the net electrostatic attraction increases the ion flow.
  • An essential element is forcing the ions to flow from a region of lower concentration within the channel to a region of higher concentration within the wall.
  • the forces tending to make the ions flow into the wall include (1) the action of the magnetic field upon the ions, (2) the net electrostatic attraction from the counterions within the wall, and (3) a somewhat lower pressure within the wall that partially offsets the concentration gradient.
  • the phenomena above can limit the degree of practical purification achieved per stage. For example, if ions only flow at practical speeds into a fluid with 0.2 molar (M) higher concentration, then the waste stream from a 0.6-M input could be 0.8 M. The waste stream from a 0.4-M input stage could be 0.6 M, or equal to the original input stream. Therefore, the first stage can go from 0.6 M to 0.4 M while the increased- concentration waste stream is discarded.
  • the second stage could go from 0.4 M to 0.2 M while the increased-concentration waste stream is recycled back to the first stage.
  • the third stage could go from 0.2 M to 0.05 M while the increased-concentration waste stream is recycled back to the second stage.
  • One of the beneficial aspects of the LISA technology is energy recovery using MHD.
  • One of the unique aspects of the LISA technology or removing ions from fluidic media is energy recovery using capacitor charging/discharging schemes. Energy recovery helps make the process more cost-competitive.
  • the periphery of the duct will become largely concentrated with ions.
  • it is necessary to disturb the boundary layer to destroy the compensating Hall voltage as discussed above. Disturbing the boundary layer is equivalent to discharging the water capacitor.
  • the negative consequences of a compensating Hall voltage may be utilized in a positive manner.
  • the compensating Hall voltage can be used to increase total LISA system efficiency via MHD.
  • MHD systems use high-velocity electrically conducting fluids in the presence of a magnetic field to produce electrical power.
  • the ions are deflected by a magnetic field applied perpendicular to the flow via the Lorentz force.
  • These charge carriers move through the fluid and are deflected to one of the electrodes that carries the electrical current to the load.
  • the resulting electrical current can be used to increase system efficiency. For instance, this current can be reused to run the pumps moving the fluid (e.g., saline solution) through the ducts.
  • the fluid e.g., saline solution
  • FIGS. 9A-9C For the LISA system, one process by which to harness this energy is to use a segmented electrode construction as shown in FIGS. 9A-9C. It is possible to exploit MHD and to reduce the Hall voltage at the same time.
  • FIGS. 9A-9C it is possible to exploit MHD and to reduce the Hall voltage at the same time.
  • the electrode system includes four pairs of electrodes insulated from each other by three insulating barriers; however, any number of electrode pairs separated by an insulating layer can be used.
  • the insulating barriers may be ceramic insulators or nonconducting ion-selective membranes or porous partitions.
  • FIG. 10A and FIG. 10B show each pair of electrodes connected to a load;
  • FIG. IOC shows the four pairs of electrodes C connected in series to a common load.
  • the common load provides a means by which the Hall voltage can be discharged.
  • the common load could go back to the pump or control electronics or it could be used to charge the capacitor plates used for electrophoresis.
  • the two capacitors may be connected in parallel with appropriate switches.
  • the following analysis assumes these conditions: (1) both capacitors have the same capacitance; (2) only one of the capacitors is electrically charged and e switch connecting them is open; and (3) the process has zero resistance. Upon closing the switch, the charged capacitor will partially discharge to the other capacitor until their electrical charges equilibrate. The first capacitor discharges approximately 50% of its charge.
  • the benefit to this charge/discharge scheme of using two capacitors in parallel for the LISA process is simple when the MHD capacitor is electrically discharging, it can charge the electrophoresis capacitor.
  • the process simply shuttles electronic charge back and forth between the capacitors for partial energy recovery, with the energy recovery being approximately 25% efficient.
  • the rest of the charge required by the capacitor should be supplied by an external source (e.g., battery).
  • an external source e.g., battery
  • the MHD capacitor begins fully charged as shown in FIG. 10, panel (a). The charge leaves the capacitor plates and current begins to flow. The loss of charge in the capacitor decreases its potential energy ( ⁇ l2Cq 2 ), while the creation of a current causes the kinetic energy of the inductor (MILL) to increase with time as shown in panel (b). At some time, capacitor will fully discharge, panel (c).
  • the potential energy of the capacitor is zero (it has no more charge or electric field), while the kinetic energy of the inductor is maximized (in terms of current and magnetic field).
  • the current (moving charge) in the inductor will start to transport charge back to the capacitor in the circuit.
  • the capacitor in question will now be the electrophoretic capacitor. Energy now begins to transport from the inductor (decreasing kinetic energy) to the electrophoretic capacitor (increasing potential energy) as illustrated in panel (d). Eventually, the energy becomes completely transferred from the inductor to the electrophoretic capacitor, panel (e).
  • the process continues in a cyclic fashion; the charged capacitor will begin to discharge, converting its potential energy to kinetic energy of the inductor in panels (f) and (g).
  • the combined capacitor-inductor circuit shuttles energy from a capacitor (electric field energy), to an inductor (magnetic field energy), back to another capacitor, and back to the inductor in a cyclic fashion.
  • the LC harmonic oscillations shuttle charge with 700% energy recovery.
  • Ionic Current Besidesiv ⁇ D energy recovery, it is possible to recover energy from the concentrated/reject ion-rich ports. These reject ports are not only concentrated in ions, but because of the ion-separation process, they are also rich in one type of ion. Therefore, as the fluid flows in these reject ports, it conducts an ionic current. This ionic current may be recovered to further improve the energy efficiency of the LISA process.
  • the cation-rich and anion-rich ionic currents may be connected to an external load (e.g, capacitor plates).
  • LISA removes the charge-carrier solute from the solution rather than the solvent from the solution. That is, LISA removes minority constituents, not the majority constituent. (Reverse osmosis removes the solvent.)
  • the embodiments of LISA use a minimal amount of external energy.
  • the sources of external energy include a pump to move the water and perhaps an external voltage supply for electrophoresis.
  • LISA has built-in energy recovery exploiting the MHD process and the charge- unbalanced ionic current discussed earlier. Determining the amount of energy recovered will require experimentation and testing. The energy recovered may be used for electrophoresis and/or water pumping. LISA Attributes
  • a LISA water purification system has many attributes. For example, it requires little or no water pretreatment. In principle, it has very low energy consumption and incorporates energy recovery. It does not require the use of harmful chemicals. It has minor logistics issues for deionization operate on. Its total costs (capital plus operating) are estimated to be highly cost-effective per unit of flow, and it is expected to be affordable to any person of any economic or social background. Since the water pressures used can be relatively low, 50-100 psi (340-690 kPa), low-cost plumbing and seals can be used. This is not the case with RO systems. It is a simple design and simple to operate. It can remove any charged species from any fluid medium. In principle, it can be constructed without membranes subject to fouling. Its design can be applied on many scales. It can purify water of any charged or chargeable contaminant, including both biological (viruses, bacteria), and chemical (radioactive nuclides) species.
  • the LISA process is a fundamentally orthogonal and scalable deionization technology (e.g., water desalination technology) that has many advantages in comparison to state-of-the-art ion separation technologies such as reverse osmosis, distillation, and variants thereof.
  • LISA can be at least ten times more energy-efficient.
  • LISA requires less maintenance (virtually no fouling), can have greater water throughput, and can be more cost-effective.
  • LISA can be used with any charged ionic species and in any fluid medium (gas, plasma, solutions, etc.). Integration of LISA and RO Technologies
  • the LISA and RO technologies may be combined in a hybrid approach for purification of aqueous solutions.
  • the LISA may be used upstream of an RO unit. This would significantly reduce the duty requirements on both systems in handling copious amounts of total dissolved solids; therefore it could reduce the total energy consumption of the integrated hybrid system.
  • LISA is better able to handle radioactive elements and heavy metals, with the additional benefit of being able to dispose of them in a safer manner during a concentrated discharge process, it can improve the effectiveness of a downstream RO unit.
  • An upstream LISA could also be used to significantly reduce the salt concentration in saltwater feeding into an RO unit, in which case the water flux through the RO membranes will increase substantially because the concentration polarization of salt near the membrane surface is reduced, leading to overall more efficient system.
  • a LISA device may also be used to feed into a forward or direct osmosis (FO) configuration. Examples
  • the use of a pair of ion selective membranes (one positive selecting and one negative selecting) on the sides of a hollow wall and a sweep stream within the wall can give a high ion extraction rate without causing a high retarding Hall voltage.
  • the combination of magnetic field induced molarity buildup at wall and mutual attraction of ions on opposite faces provides force that could transfer ions through the pair of ion selective membranes into the sweep fluid that has, e.g., a 0.15 to 0.20 higher molarity than the process fluid.
  • an additional 0.05 to 0.1 rise is available from the 100 to 200 psi higher pressure of the process fluid compared to the waste stream, and thus the ions can be transferred into a higher molarity sweep stream, with, .g., a total of .20 to .30 molarity rise, or even .40 with 400 psi.
  • the molarity rise of waste above the process fluid is also the amount the process fluid can be reduced in that stage, thus the first stage can reduce the molarity of the process stream from, e.g., the .4 of brackish water t a.2 or .1 stream.
  • the .6 of seawater can be reduced to a .4 or .3 or even a .2 stream.
  • Further stages of magnetic purification may use one ion selective membrane and a porous partition as sides of the wall.
  • Ion buildup on opposite sides wall from the combination of ion movement due to magnetic forces and mutual attraction of ions on opposite faces provide ion buildup to give a recycle stream of at least a 0.1 5 to 0.2 higher molarity than the average process fluid in the waste fluid stream.
  • Fluid is transferred tough a porous partition on one side while combination of molarity buildup at wall, and mutual attraction of ions on opposite side of ion selective membrane, provide force to transfer ions through the ion selective membrane.
  • part of output may be used as recycle in a counterflow flush in the further stages, and the recycle may be pumped back into the inlet, with sets of opposite ion selective membranes used throughout (a flush of saline of the same salinity as input saline, would still be used for stage I). If flowing in a direction opposite to the main flow, ions in recycle will tend to move in a direction to pull ions through the membranes, but flow may be turbulent in thee recycle stream.
  • Example 1 Stage I saline sweep waste stream input pressure 200 psi, input molarity; .4 molar (brackish water) waste molarity; up to ⁇ .l above that of input saline process fluid to waste, molarity rise: low at entrance,. .3 max product stream molarity; goes from .4 to .1 output molarity; .1 molar uses 2 ion selective membranes
  • Process fluid volume out of Stage I is only slightly less than the Stage I and sweep volume input, and sweep volume may be between 5 and 20 times the product volume.
  • Example 1 2 ion selective membranes are used. A saline sweep of same salinity as the input saline is used, and a sweep flow of between 5 and 20 times the product flow.
  • Product fluid volume out is about 50% of the volume in Stage I, thus the first stage needs to have 2 times the capacity of product output.
  • Example 2 Stage I, with saline sweep waste stream input molarity; .4 molar input waste molarity; barely above that of input saline molarity rise: initially ⁇ 0 goes up to .2 rise at stage end product stream molarity; goes from .4 to .3 output molarity; .3 molar output uses, e.g., 2 ion selective membranes
  • the first stage needs to have a volume capacity of 8 times the product volume.
  • Example 2 has almost the same product output as new saline in, and thus avoids doing any extra pretreatment to the fluid.
  • Example 2 uses more relaxed requirements for molarity rise than example 1, and thus reduces needed residence time in the field and further reduces Hall voltage effects. Note also that the ion drift velocity near the porous partition can be the same order of magnitude as the velocity of the flow through the partition, but velocity of flow is much smaller near the opposite wall.
  • Example 3 Stage I, saline sweep waste stream input pressure 220 psi input molarity; .4 molar input waste molarity; barely above that of input saline molarity rise: -0 goes up to .1 rise at stage end product stream molarity; goes from .4 to .3 output molarity; .3 molar output uses, e.g., 2 ion selective membranes
  • Stage II exhaust stream recycled to Stage I input molarity; .3 molar input recycle molarity; goes from .45 to .35 (average .4) molarity rise: .15 rise product stream molarity; goes from .3 to .2 output molarity; .2 molar output uses, e.g., 1 ion selective membrane and one porous partition Stage HI, exhaust stream recycled to Stage ⁇ input molarity; .2 molar input recycle molarity; goes from .35 to .25 (average .3) molarity rise: .15 rise product stream molarity; goes from .2 to .1 output molarity; .1 molar output uses, e.g., I ion selective membrane and one porous partition Stage rV, exhaust stream recycled to Stage III input molarity; .1 molar input recycle molarity; about .25 to ⁇ ..15 (average .2) molarity rise: about
  • Example 4 Stage I, seawater input and sweep input pressure 400 psi, input molarity; .6 molar (seawater) waste molarity; up to ⁇ .l above that of input saline molarity rise: up to .4 rise product stream molarity; goes from .6 to .2 output molarity; .2 molar uses 2 ion selective membranes process fluid volume out of Stage I is only slightly less than the Stage I process volume input, and sweep volume may be between 5 and 20 times the product volume
  • Example 4 is a higher pressure system (although still much lower than a conventional RO system). It is also for seawater, rather
  • Example 5 Stage I, saline sweep waste stream input molarity; .6 molar seawater input waste molarity; barely above that of input seawater molarity rise: ⁇ 0 goes up. to .4 rise at stage end product stream molarity; goes from .6 to .4 output molarity; .4 molar output uses, e.g., 2 ion selective membranes
  • Example 5 has a seawater input, has counterflow recycling, and uses a moderate- pressure RO polishing at the end.
  • the sideways water flow can be the same order of magnitude as the sideways ion flow (drift). Note that this helps extract ions nearer their exit side, but slow or even stop drift of ions from the side opposite that ion's exit side. This effect tends to move ions near their exit wall out, but can tend to level the ion distribution somewhat. Thus it gives a net increase the extraction rate at the beginning and through most of the purification process, but also may slow the extraction rate later in the purification process.
  • Regions of high ion concentration may be separated from those of lower ion concentration using a psuedo- virtual impactor, geometrically defined holes in the duct, porous partitions, ion- selective membranes and/or variations thereof.
  • magnetohydrodynamics may be used, the charge may be shuttled between capacitive and inductive elements and/or the discharged ionic current that is comprised of mostly one ionic species may be used.
  • FD is an approach based on the fusion of several technological advances. This approach takes any ionic species (dissolved minerals, radioactive elements, chromium, arsenic, salt, etc.) out of any fluid (brackish water, hard water, seawater, plasmas, gases, etc.). In the case of seawater desalination, FD is quite different than RO processes, which take purified water out of the salt solution. The FD process can remove dissolved ionic species or toxic chemicals from polluted water, or desalt seawater, with potentially several times less energy than state-of-the-art RO and at least 100 times less energy than seawater distillation.
  • ionic species dissolved minerals, radioactive elements, chromium, arsenic, salt, etc.
  • RO processes which take purified water out of the salt solution.
  • the FD process can remove dissolved ionic species or toxic chemicals from polluted water, or desalt seawater, with potentially several times less energy than state-of-the-art RO and at least 100 times less energy than seawater
  • a rotating magnetic field (generated by a permanent, electromagnet, and/or superconducting magnet) may be used to generate a motive force (MF) on the positive and negative ions in the water or other fluid to be treated.
  • MF motive force
  • water is used as the illustrative example; however, in principle, any fluidic medium can be used.
  • the Faraday induced MF separates the positive ions from the negative ions.
  • the water flows through a ductlike construct, and, with the Reynolds number less than 2000, the flow will be laminar in nature.
  • the mobilities of ions in water are typically quite low, ⁇ 5 x 10 " m V " s " . Therefore, for the FD process the widths of the ducts will likely be limited to relatively small (centimeter or millimeter) size regimes to reduce the time required to separate the slow-moving ions. Furthermore, flows are preferably laminar on the input side, so the size of the flow channels should probably be small, e.g., 1 cm.
  • methods by which to increase output for the FD process generally include increasing the number of flow channels, decreasing the distance the ions must travel, increasing the travel time of the ions, and increasing the flow velocity. More specifically, these approaches can include decreasing the channel width, increasing the channel length, adding more channels in parallel, increasing the magnetic field strength, and increasing the relative motion between the magnetic field and the ions.
  • Ion selective membranes allow the passage of either positively charged ions (cations) or negatively charged ions (anions) while excluding the passage of ions of the opposite charge. This may be understood by referring again to FIG. 8. These semipermeable barriers are commonly known as ion-exchange, ion- selective, or electrodialysis membranes.
  • a moving magnetic field may be used that induces an MF based on the Faraday effect.
  • a rotating magnet can move the lines of flux through stationary or slowly (e.g. laminar flowing liquid) fluid.
  • a rotating magnet can give, e.g., a relative velocity between the magnetic field and ions in circular channel with a 1.5 meter circumference (a radius of about 9.4 inches) of about 90 meters/second, or about 360 times as fast.
  • the "last" ions might reach an exit wall in a little over 200 sec.
  • the time may be proportionally reduced by increasing the magnetic field (e.g. by a factor of four to reduce the time to about 50 seconds) or by increasing the radius (e.g. by a factor of four), or both (for a factor of 16 reduction to about 13.6 seconds).
  • a liquid traveling at the maximum velocity for laminar flow might be cleaned in a single pass.
  • flow may be slowed to about .06 meters per second and might be cleaned in a single pass around the smaller unit.
  • a channel width of about 3 to 5 mm may be used with fluid flow rates in the .08 to .05 meters per second range.
  • the fluid may also flow through fractional passes or multiple passes.
  • the fluid may flow in a non-circular path, including, e.g. a linear path, with the lines of flux moving through the fluid to move oppositely charged ions in opposite directions.
  • Fractional turns e.g,. half turns, can be convenient for units with more than one stage, and a unit may have a half turn first stage and a quarter turn second stage and a quarter turn third stage in the same rotating field.
  • One preferred design utilizes a constant flow cross-section, but in some embodiments, the flow volume decreases as concentrated brine is removed or some fluid is recycled.
  • the input stage capacity may be about twice the output volume, and the input flow velocity may be twice the output flow velocity.
  • ions may be separated in a fluid that is stationary stationary or moved at less than 1 meter per second with a magnetic field moved through the fluid at more than 1 00 meters per second. Also, ions may be separated from an ion-containing liquid that is stationary or moved at less than .25 meter per second with a magnetic field is moved through the fluid at more than 100 meters per second.
  • the magnetic field is rotating, and chambers with ion-containing fluid are stationary.
  • the magnetic field is provided by permanent magnets.
  • the magnetic field may be electro- magnetically provided.
  • a stationary energizing coil is preferred and the rotating magnetic element is preferably laminated. A pressure differential between the channels and inside the hollow walls and/or force from the relative motion between the ions and the magnetic field may assist the causing of the ions to pass into the walls.
  • the fluid in the channels may flow at a velocity such that the flow is laminar and turbulent flow is avoided.
  • the fluid in the chambers may be stationary.
  • channels are assembled into cylinder about a axis with an equal number of channels and walls, such that walls without channels on both sides are avoided.
  • ion-selective membranes may be used on one side of the walls and porous partitions are used on the other. In other embodiments, ion-selective membranes may be used on both sides of the walls and a sweep fluid is used within the walls.
  • the sweep fluid may be of the same type of fluid input into the channels.
  • the sweep fluid may be a portion of fluid output from the channels, which may be run as a counter-flow sweep.
  • air-core electromagnets, including superconducting magnets may be used.
  • ion-selective membranes may be used on both sides of the walls, and a sweep fluid may be used within the walls in a first stage with at least one later stage using ion-selective membranes on one side of the walls and porous partitions on the other.
  • porous partitions e.g., porous membranes or ricer shaped partitions
  • porous membranes or ricer shaped partitions can be used on both sides of the walls
  • the use of an ion-selective membrane on at least one side is preferred in at least on embodiment.
  • the fluid containing positive ions and negative ions may be, e.g., saline water, brackish water, seawater, ion-containing gas, or nuclear waste.
  • the fluid containing positive ions and negative ions is deionized and potable water is produced.
  • the fluid containing positive ions and negative ions is partially deionized and further processed by reverse osmosis and potable water is produced.
  • more than one stage of de-ionization is used and the ion- concentrated fluid exiting a later stage is recycled to an earlier stage.
  • Electromagnets can be used instead of permanent magnets, as iron or steel core electromagnets can give 3 to 4 tesla (and more with special high-permeability magnetic steels), compared to the 1 tesla of permanent magnets.
  • the size reduction can lead to enough net cost reduction to out- weigh the minor operating cost of an electromagnet.
  • the magnets can be visualized as "C" magnets (akin to horseshoe magnets).
  • the gap in the C's could go radially out from a rotating shaft as shown in FIG. 11 , and this configuration is convenient for stages one-half arc or less.
  • configurations having the gap in the C's parallel to the shaft may be used, and a configuration with the gap pointing down is shown in FIG. 12.
  • a portion of the C magnets may be stationary, but the eddy current losses are generally minimized if the entire C rotates. Laminating it all produces lower losses and results in a cheaper design.
  • a circle of electromagnet laminations (with a stationary coil) can be used in place of permanent magnets in a similar configuration. Laminating into a circle requires either the laminations or the spacers between the laminations, or both, be wedge shaped. Wedged shaped spacers can be plastic and are generally easier to make than wedge shaped metallic portions.
  • the rotating magnetic field may possibly also be supplied by a multi-phase (e.g., 3-phase or 2- phase) motor-stator configuration where the field is magnetically biased to not reverse across the gap. Such a configuration might eliminate moving magnetic parts.
  • Magnet poles, electromagnet or permanent magnet, of a rotating magnet preferably are preferably laminated at least as deep as the gap between north and south poles, e.g., about 1 cm.
  • the laminations should be spaced far enough apart to keep flux lines from jumping from one lamination to the- next, e.g., about one mm.
  • the ions may remix in the hollow walls with brine exiting, flowing parallel to the magnetic line of flux, minimizing the separation of ions in hollow walls and reducing the load on a motor that drives the rotation.
  • a separation of ions in the hollow walls can, however, help transfer additional ions into the hollow walls. While the ring of channels may be rotated and the magnet C's held stationary
  • Wall Effects in FD One of the many unique features of the FD process is the affect of the walls of the duct.
  • electrostatic ionic separation processes the ions are attracted to the wall, and they are adsorbed onto the wall (high-surf ace-area electrode). Once absorbed, desorbing the ions from the electrode surface is a technical challenge.
  • the ions are magnetically forced to the wall.
  • the separated ions are not adsorbed onto the duct walls, but are instead relatively free to pass through the walls if conditions are right.
  • the wall is not the ion collection portal.
  • the ions are collected in ancillary concentrated/reject ports.
  • the wall need not be composed of impermeable materials to adsorb the ions nor to impede their relative motion.
  • the walls of the duct can be formulated as porous membranes on both sides (with relatively large pore sizes to allow ions to pass through, but to provide some flow resistance to the fluidic media), an ion-permeable membrane on one side and a porous membrane on the other, different ion-selective permeable membranes on both sides of the duct, with one side anion- selective and the other cation-selective.
  • the ions are removed almost as soon as they reach the walls, and their movement is very slow, then the ion distribution across most of the channel will be almost flat and will remain almost flat as the solution becomes more dilute as purification continues; the only major increase in ion density would be at the walls.
  • An important element is forcing the ions to flow from a region of lower concentration within the channel to a region of higher concentration within the wall.
  • the forces tending to make the ions flow into the wall include (1) the action of the generated EMF via the rotating magnetic field upon the ions, (2) the net electrostatic attraction from the counterions across or within the wall, and (3) a somewhat lower pressure within the wall that partially offsets the concentration gradient.
  • the phenomena above can limit the degree of practical purification achieved per stage. For example, if ions will only flow at practical speeds into a fluid with 0.2 molar (M) higher concentration, then the waste stream from a 0.6-M input could be 0.8 M.
  • the waste stream from a 0.4-M input stage could be 0.6 M, or equal to the original input stream. Therefore, the first stage can go from 0.6 Mto 0.4 M while the increased- concentration waste stream is discarded.
  • the second stage could go from 0.4 Mto 0.2 M while the increased-concentration waste stream is recycled back to the first stage.
  • the third stage could go from 0.2 Mto 0.05 while the increased-concentration waste stream is recycled back to the second stage.
  • FD removes the charge-carrier solutes from the solution rather than the solvent from the solution. That is, FD removes minority constituents, not the majority constituent. (Reverse osmosis removes the solvent.)
  • the high ion concentration reject ports are not only concentrated in ions, but because of the ion-separation process, they are also rich in one type t of ion. Therefore, as the fluid flows in these reject ports, it conducts an ionic current. This ionic current can be recovered to further improve the energy efficiency of the FD process.
  • the cation-rich and anion-rich ionic currents can be connected to an external load (e.g., capacitor plates).
  • Dissolving a solute involves three processes, (1) breaking ionic forces, (2) expanding the solvent cage, and (3) stabilizing the ions. Each of these steps has an associated enthalpy change ( ⁇ H): ⁇ H so ⁇ u te, always positive; ⁇ H so ivent, always positive, and ⁇ H m i X i ⁇ g , always negative.
  • ⁇ H SO iutio n The heat of solution ⁇ H SO iutio n is the sum of these three terms.
  • FD does not involve breaking ionic forces, stabilizing ions, nor expanding the solvent cage. It is a process that simply separates the ions already in the solution into regions of relatively higher and lower concentrations, but never takes them out of solution. Therefore, the process requires relatively low energy.
  • the embodiments of FD uses a minimal amount of external energy.
  • the sources of external energy may include a pump to move the water and an external motor to rotate the magnetic field as shown in FIGS. 1 1 and 12.
  • the FD water purification technology has many attributes. For example, it requires little or no water pretreatment. In principle, it has very low energy consumption and incorporates energy recovery. Also, it does not require the use of harmful chemicals. It has minor logistics issues for deionization operation. Its total costs (capital plus operating) are estimated to be highly cost-effective per unit of flow. Since the water pressures used can be relatively low, 50-100 psi (340-690 kPa), low- cost plumbing and seals can be used. This is not the case with high-pressure RO systems. It is a simple design, It is simple to operate. It can remove any charged species from any fluid medium. In principle, it can be constructed without membranes subject to fouling. Its design can be applied on many scales. It can purify water of any charged or chargeable contaminant, including both biological (viruses, bacteria), and chemical (radioactive nuclides) species. Integration ofFD and RO Technologies
  • FD may be used upstream of an RO unit. This would significantly reduce the duty requirements on both systems in handling copious amounts of total dissolved solids; therefore, it could reduce the total energy consumption of the integrated hybrid system.
  • FD is better able to handle radioactive elements and heavy metals, with the additional benefit of being able to dispose of them in a safer manner during a concentrated discharge process, it can improve the effectiveness of a downstream RO unit.
  • An upstream FD could also be used to significantly reduce the salt concentration in saltwater feeding into an RO unit, in which case the water flux through the RO membranes will increase substantially because the concentration polarization of salt near the membrane surface is reduced, leading to an overall more efficient system.
  • a FD could also be used to feed into a forward or direct osmosis (FO) configuration. Examples
  • the use of a pair of ion selective membranes on the sides of a hollow wall and a sweep stream within the wall can give a high ion extraction rate.
  • the combination of magnetic field induced molarity buildup at wall and mutual attraction of ions on opposite faces provides force that could transfer ions through the pair of ion selective membranes into the sweep fluid that has, e.g., a 0.15 to 0.20 higher molarity than the process fluid.
  • an additional .05 to .10 rise is available from the 100 to 200 psi higher pressure of the process fluid compared to the waste siteam, and thus the ions can be transferred into a higher molarity sweep stream, with, e.g., a total of .20 to .30 molarity rise, or even .40 with 400 psi.
  • the molarity rise of waste above the process fluid is also the amount the process fluid can be reduced in that stage, thus the first stage can reduce the molarity of the process stream from, e.g., the .4 of brackish water to a .2 or .1 stream.
  • the .6 of seawater can be reduced to a .4 or .3 or even a .2 stream.
  • Further stages of magnetic purification can use one ion selective membrane and a porous partition as sides of the wall.
  • Ion buildup on opposite sides wall from the combination of ion movement due to magnetic forces and mutual attraction of ions on opposite faces provide ion buildup to give a recycle stream of at least a .15 to .20 higher molarity than the average process fluid in the waste fluid stream.
  • Fluid is transferred through a porous partition on one side while combination of molarity buildup at wall, and mutual attraction of ions on opposite side of ion selective membrane, provide force to transfer ions through the ion selective membrane.
  • part of output may be used as recycle in a counterflow flush in the further stages and pump the recycle back into the inlet and use sets of opposite ion selective membranes throughout (a flush of saline of the same salinity as input saline, would still be used for stage I). If flowing opposite direction to main flow, ions in recycle will tend to move in a direction to pull ions through the membranes, but flow may be turbulent in the recycle stream.
  • Example 1 Stage I, saline sweep waste stream input pressure 200 psi, input molarity; .4 molar (brackish water) waste molarity; up to -.1 above that of input saline process fluid to waste, molarity rise: low at entrance, .3 max product stream molarity; goes from .4 to .1 output molarity; .1 molar uses 2 ion selective membranes
  • the process fluid volume out of Stage I is only slightly less than the Stage I process volume input, and sweep volume may be between 5 and 20 times the product volume Stage II, reverse osmosis booster pump to 400 psi input molarity; .1 molar input waste molarity; about .2 product stream; goes from.
  • Example 1 2 ion selective membranes are used along with a saline sweep of same salinity as the input saline and a sweep flow of between 5 and 20 times the product flow.
  • Product fluid volume out is about 50% of the volume in Stage I, thus the first stage needs to have 2 times the capacity of product output.
  • Example 2 Stage I, with saline sweep waste stream input molarity; .4 molar input waste molarity; barely above that of input saline molarity rise: initially about 0 goes up to .2 rise at stage end product stream molarity; goes from .4 to .3 output molarity; .3 molar output uses, e.g., 2 ion selective membranes
  • the first stage needs to have a volume capacity of 8 times the product volume.
  • Example 2 has almost the same product output as new saline in, and thus avoids doing any extra pretreatment to the fluid.
  • Example 2 uses more relaxed requirements for molarity rise than example 1, and thus reduces needed residence time in the field and further reduces Hall voltage effects. Note also that the ion drift velocity near the porous partition can be the same order of magnitude as the velocity of the flow through the partition, but velocity of flow is much smaller near the opposite wall.
  • Example 3 Stage I, saline sweep waste stream input pressure 220 psi input molarity; .4 molar input waste molarity; barely above that of input saline molarity rise: approximately 0 goes up to .1 rise at stage end product stream molarity; goes from .4 to .3 output molarity; .3 molar output uses, e.g., 2 ion selective membranes
  • Stage II exhaust stream recycled to Stage I input molarity; .3 molar input recycle molarity; goes from .45 to .35 (average .4) molarity rise: .15 rise product stream molarity; goes from .3 to .2 output molarity; .2 molar output uses, e.g., 1 ion selective membrane and one porous partition
  • Stage III exhaust stream recycled to Stage II input molarity; .2 molar input recycle molarity; goes from .35 to .25 (average .3) molarity rise: .15 rise product stream molarity; goes from .2 to .1 output molarity; .1 molar output uses, e.g., 1 ion selective membrane and one porous partition
  • Stage IV exhaust stream recycled to Stage III input molarity; .1 molar input recycle molarity; about .25 to about .15 (average .2) molarity rise: about .15 product stream molarity; goes from .1 to .05 output molarity; .05 molar output uses, e.g., 1 ion selective membrane and one porous partition
  • Example 3 is similar to example 2, but uses a low pressure RO polishing at the end.
  • Example 4 Stage I, seawater input and sweep input pressure 400 psi, input molarity; .6 molar (seawater) waste molarity; up to about.1 above that of input saline molarity rise: up to .4 rise product stream molarity; goes from .6 to .2 output molarity; .2 molar uses 2 ion selective membranes
  • Process fluid volume out of Stage I is only slightly less than the Stage I process volume input, and sweep volume may be between 5 and 20 times the product volume
  • Stage II, reverse osmosis, booster pump to 500 psi input molarity; .2 molar input waste molarity; about .25 product stream; goes from .2 molarity to ⁇ 500 ppm output; ⁇ 500 ppm uses RO membranes product volume 1/5 of RO input volume, approximately 1/5 of input volume
  • Example 4 is a higher pressure system (although still much lower than a conventional RO system).
  • Example 5 Stage I, saline sweep waste stream input molarity; .6 molar seawater input waste molarity; barely above that of input seawater molarity rise: about 0 goes up to .4 rise at stage end product stream molarity; goes from .6 to .4 output molarity; .4 molar output uses, e.g., 2 ion selective membranes
  • Example 5 has a seawater input, has counterflow recycling, and uses a moderate- pressure RO polishing at the end.
  • a method and apparatus hag been developed for deionizing any fluid medium based on the Faraday Effect.
  • the Faraday induced MF forces are used to separate the charged species from any fluid.
  • porous partitions, Ion-selective membranes; and/or variations thereof may be used.
  • discharged ionic current that is comprised of mostly one ionic species may be used.
  • magnetically ion separation is made practical by multiple channels with hollow separator walls, ion-selective membranes, and those of a moving magnetic field.
  • an ion-selective membrane allows removal of ions of one type, while avoiding the counter-productive removal of fluid with lower- than average content of the other type of ion, thus the effectiveness of ion removal is greatly increased.
  • the magnetic field moves hundreds of times faster than the maximum, laminar-flow-restricted, fluid movement, and the size of the unit is dramatically reduced.
  • the process also uses the ability for energy recovery of the separated ions that form an "ionic current" that can be harvested to operate ancillary devices, or be feed back into the rotating motors, pumps, etc.
  • Performance improvements using a counterflow sweep (or, equivalently, a countercurrent flow) design may be derived through a reduction in osmotic pressure differentials across the membranes.
  • the lowest ionic strength DI solution e.g., the "cleanest" portion of the product water stream
  • the highest ionic strength concentrate solution e.g., the
  • Osmotic pressure differences across a membrane may be expressed as a function of the difference in solution concentration according to the following:
  • ⁇ is the osmotic pressure difference
  • ⁇ (nN) is the difference in solute molarity across the membrane
  • n/V is the quantity moles per liter, or molarity, M
  • R is the ideal gas constant (0.0821 L aten mol "1 K “1 ”
  • T is the absolute temperature (303 K in this example).
  • CO,DI Co.b ⁇ ne - 35,000 ppm

Landscapes

  • Engineering & Computer Science (AREA)
  • Water Supply & Treatment (AREA)
  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Urology & Nephrology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Electrochemistry (AREA)
  • Molecular Biology (AREA)
  • Hydrology & Water Resources (AREA)
  • Organic Chemistry (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Water Treatment By Electricity Or Magnetism (AREA)

Abstract

La présente invention concerne un procédé et un dispositif de filtration de fluide. En l'occurrence, pour séparer du fluide une espèce chargée, on utilise notamment la force de Lorentz ou les forces mécaniques induites par l'effet Faraday.
PCT/US2002/038858 2001-12-05 2002-12-05 Production d'eau potable par separation ionique et desionisation Ceased WO2003048050A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
AU2002357785A AU2002357785A1 (en) 2001-12-05 2002-12-05 Water purification: ion separation and deionization
AU2003291651A AU2003291651A1 (en) 2002-10-24 2003-10-24 Applications of an ion bridge and a countercurrent flow design for use in water purification
PCT/US2003/033843 WO2004037727A1 (fr) 2002-10-24 2003-10-24 Applications d'un pont d'ions et d'une conception d'ecoulement a contre-courant dans la purification d'eau

Applications Claiming Priority (10)

Application Number Priority Date Filing Date Title
US33559201P 2001-12-05 2001-12-05
US33601901P 2001-12-05 2001-12-05
US60/336,019 2001-12-05
US60/335,592 2001-12-05
US42134002P 2002-10-24 2002-10-24
US60/421,340 2002-10-24
US30183002A 2002-11-21 2002-11-21
US10/301,550 US20040007452A1 (en) 2001-12-05 2002-11-21 Water purification: ion separation
US10/301,830 2002-11-21
US10/301,550 2002-11-21

Publications (1)

Publication Number Publication Date
WO2003048050A1 true WO2003048050A1 (fr) 2003-06-12

Family

ID=27540872

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2002/038858 Ceased WO2003048050A1 (fr) 2001-12-05 2002-12-05 Production d'eau potable par separation ionique et desionisation

Country Status (2)

Country Link
AU (1) AU2002357785A1 (fr)
WO (1) WO2003048050A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004033086A1 (fr) * 2002-10-11 2004-04-22 Richard Gordon L Procede et appareil pour separer les ions contenus dans un flux de fluide
FR2859989A1 (fr) * 2003-09-23 2005-03-25 Sci Rhodes Innovation Dispositif de desionisation de solutions salines
FR2859990A1 (fr) * 2003-09-23 2005-03-25 Sci Rhodes Innovation Dispositif de desionisation de solutions salines
GR20040100125A (el) * 2004-04-08 2005-11-30 Εμμανουηλ Αντωνιου Καλης Ηλεκτρονικη συσκευη μονου καλωδιου για την ηλεκτροχημικη μεταβολη της υφης των αλατων του υδατος
CN112062233A (zh) * 2020-08-28 2020-12-11 林洪钧 一种海水化淡系统
CN114178051A (zh) * 2021-11-24 2022-03-15 南京极速优源感光材料研究院有限公司 一种杂质剔除装置及杂质剔除方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3693792A (en) * 1971-05-05 1972-09-26 John F Sylvester Electrodynamic particle separator
US4935122A (en) * 1986-12-22 1990-06-19 Dreyfuss William C Mineral separator system
US6460974B1 (en) * 2001-07-27 2002-10-08 Hewlett-Packard Company Micro-pump and method for generating fluid flow

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3693792A (en) * 1971-05-05 1972-09-26 John F Sylvester Electrodynamic particle separator
US4935122A (en) * 1986-12-22 1990-06-19 Dreyfuss William C Mineral separator system
US6460974B1 (en) * 2001-07-27 2002-10-08 Hewlett-Packard Company Micro-pump and method for generating fluid flow

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6783687B2 (en) 2002-02-13 2004-08-31 Gordon L. Richard Method and apparatus for separating ions from a fluid stream
WO2004033086A1 (fr) * 2002-10-11 2004-04-22 Richard Gordon L Procede et appareil pour separer les ions contenus dans un flux de fluide
FR2859989A1 (fr) * 2003-09-23 2005-03-25 Sci Rhodes Innovation Dispositif de desionisation de solutions salines
FR2859990A1 (fr) * 2003-09-23 2005-03-25 Sci Rhodes Innovation Dispositif de desionisation de solutions salines
WO2005030650A1 (fr) * 2003-09-23 2005-04-07 Sci Rhodes Innovation Dispositif de desionisation de solutions salines
GR20040100125A (el) * 2004-04-08 2005-11-30 Εμμανουηλ Αντωνιου Καλης Ηλεκτρονικη συσκευη μονου καλωδιου για την ηλεκτροχημικη μεταβολη της υφης των αλατων του υδατος
CN112062233A (zh) * 2020-08-28 2020-12-11 林洪钧 一种海水化淡系统
CN114178051A (zh) * 2021-11-24 2022-03-15 南京极速优源感光材料研究院有限公司 一种杂质剔除装置及杂质剔除方法

Also Published As

Publication number Publication date
AU2002357785A1 (en) 2003-06-17

Similar Documents

Publication Publication Date Title
US20040007452A1 (en) Water purification: ion separation
Yan et al. Multistage-batch electrodialysis to concentrate high-salinity solutions: Process optimisation, water transport, and energy consumption
US8377280B2 (en) Microscale capacitive deionization apparatus
US20220380235A1 (en) Electrochemical separation systems and methods
EP3000789B1 (fr) Appareil et procédé de purification d'un fluide
JP7382072B2 (ja) 電解質が溶解した供給液を少なくとも部分的に脱イオンするための脱イオンデバイスおよび方法と、そのようなデバイスを用いる装置
Semmens et al. An evaluation of continuous electrodeionization as an in‐line process for plating rinsewater recovery
Alwan et al. Recent advances in the application of magnetic/electromagnetic field for water desalination
WO2003048050A1 (fr) Production d'eau potable par separation ionique et desionisation
EP2778140B1 (fr) Dispositif de purification d'un fluide et procédé de purification d'un fluide, en particulier en utilisant le dispositif mentionné
US9878927B2 (en) Apparatus for purifying a fluid and method for purifying a fluid, in particular by means of the aforesaid apparatus
US20070034514A1 (en) Device for deionizing saline solutions
US20040262234A1 (en) Desalinization using a moving magnetic field
WO2011132477A1 (fr) Procédé de concentration de solution électrolytique
WO2020112719A1 (fr) Séparateur d'ions à plusieurs étages avec recirculation
CN103011354A (zh) 海水淡化器
JP2005118645A (ja) 海水淡水化方法とその装置
WO2004037727A1 (fr) Applications d'un pont d'ions et d'une conception d'ecoulement a contre-courant dans la purification d'eau

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ OM PH PL PT RO RU SC SD SE SG SK SL TJ TM TN TR TT TZ UA UG UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR IE IT LU MC NL PT SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP

DPE2 Request for preliminary examination filed before expiration of 19th month from priority date (pct application filed from 20040101)