Patent Publication Number: US-2023135067-A1

Title: Integrated desiccant-based cooling and dehumidification

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 62/859,432 filed Jun. 10, 2019 and U.S. Provisional Patent Application No. 62/986,908 filed Mar. 9, 2020, each of which is incorporated herein in its entirety by reference. 
    
    
     CONTRACTUAL ORIGIN 
     The United States Government has rights in this invention under Contract No. DE-AC36-08G028308 between the United States Department of Energy and Alliance for Sustainable Energy, LLC, the Manager and Operator of the National Renewable Energy Laboratory. 
    
    
     BACKGROUND 
     Air dehumidification is used around the world to provide comfortable and healthy indoor environments that are properly humidified. While being useful for conditioning supply air, conventional dehumidification systems are costly to operate as they use large amounts of energy (e.g., electricity). With the growing demand for energy, the cost of air dehumidification is expected to increase, and there is a growing demand for more efficient air dehumidification methods and technologies. Additionally, there are increasing demands for dehumidification technologies that do not use chemicals and materials, such as many conventional refrigerants, that may damage the environment if released or leaked. Maintenance is also a concern with many air dehumidification technologies, and, as a result, any new technology that is perceived as having increased maintenance requirements, especially for residential use, will be resisted by the marketplace. 
     State of the art vapor compression systems provide humidity control by first overcooling the air to remove humidity, and then reheating it to the desired temperature. This process is inefficient. Natural-gas-driven, open absorption systems offer an alternative, with better humidity control. But these are either inefficient (single-effect regeneration) or complex, expensive, and still require significant research (double-effect regeneration). 
     SUMMARY 
     Embodiments provided by the present disclosure can eliminate desiccant technologies&#39; weaknesses by providing an all-electric option and eliminating water consumption by reclaiming water from the air. 
     In a first aspect, the present disclosure provides a dehumidification system, comprising: a heat and mass exchanger; at least one electrodialysis stack; a high salt ion concentration liquid desiccant; and a low salt ion concentration liquid desiccant, wherein the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant are in a single, continuous stream that connects the heat and mass exchanger and the at least one electrodialysis stack. 
     In some embodiments, the high salt ion concentration liquid desiccant absorbs water from a process air stream in the heat and mass exchanger and rejects salt ions to the low salt ion concentration liquid desiccant in the at least one electrodialysis stack. 
     In some embodiments, the low salt ion concentration liquid desiccant desorbs water from a purge air stream in the heat and mass exchanger and accepts ions from the high salt ion concentration liquid desiccant in the at least one electrodialysis stack. 
     In some embodiments, the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant comprise the same salt solution. 
     In some embodiments, the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant comprise a salt solution selected from sodium chloride, potassium chloride, potassium iodide, lithium chloride, copper(II) chloride, silver chloride, calcium chloride, chlorine fluoride, bromomethane, iodoform, hydrogen chloride, lithium bromide, hydrogen bromide, potassium acetate, 1-Ethyl-3-methylimidazolium acetate, and combinations thereof. 
     In some embodiments, the salt solution is selected from lithium chloride and calcium chloride. 
     In some embodiments, the salt solution is lithium chloride. 
     In some embodiments, upon entry into the heat and mass exchanger, the difference in salt ion concentration between the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant is 20% by weight (wt %). 
     In some embodiments, upon entry into the at least one electrolysis stack, the difference in salt ion concentration between the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant is 10 wt %. 
     In some embodiments, upon entry into the heat and mass exchanger, the high salt ion concentration liquid desiccant has a salt ion concentration of 35 wt %. 
     In some embodiments, upon entry into the heat and mass exchanger, the low salt ion concentration liquid desiccant has a salt ion concentration of 15 wt %. 
     In some embodiments, in the at least one electrodialysis stack, the high salt ion concentration liquid desiccant is converted into the low salt ion concentration liquid desiccant, and the low salt ion concentration liquid desiccant is converted into the high salt ion concentration liquid desiccant. 
     In some embodiments, the system comprises two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen or twenty electrodialysis stacks arranged in series between a cathode and an anode. 
     In a second aspect, the present disclosure provides a method of dehumidifying air, comprising: absorbing water from a process air stream into a high salt ion concentration liquid desiccant in a heat and mass exchanger, dehumidifying the process air stream; desorbing water from a low salt ion concentration liquid desiccant into a purge air stream in the heat and mass exchanger; moving the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant to at least one electrodialysis stack; rejecting salt ions from the high salt ion concentration liquid desiccant to the low salt ion concentration liquid desiccant in the at least one electrodialysis stack, converting the high salt ion concentration liquid desiccant into the low salt ion concentration liquid desiccant; and accepting ions from the high salt ion concentration liquid desiccant into the low salt ion concentration liquid desiccant in the at least one electrodialysis stack, converting the low salt ion concentration liquid desiccant into the high salt ion concentration liquid desiccant; wherein: the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant flow in a single, continuous stream that connects the heat and mass exchanger and the at least one electrodialysis stack; and the converted high salt ion concentration liquid desiccant and the converted low salt ion concentration liquid desiccant are moved to the mass and heat exchanger. 
     In some embodiments, the method further comprises purging heat from the high salt ion concentration liquid desiccant into the low salt ion concentration liquid desiccant in the heat and mass exchanger, cooling the dehumidified process air stream. 
     In some embodiments, the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant comprise the same salt solution selected from sodium chloride, potassium chloride, potassium iodide, lithium chloride, copper(II) chloride, silver chloride, calcium chloride, chlorine fluoride, bromomethane, iodoform, hydrogen chloride, lithium bromide, hydrogen bromide, potassium acetate, 1-Ethyl-3-methylimidazolium acetate, and combinations thereof. 
     In some embodiments, the salt solution is selected from lithium chloride and calcium chloride. 
     In some embodiments, the salt solution is lithium chloride. 
     In some embodiments, when absorbing water from a process air stream into a high salt ion concentration liquid desiccant and desorbing water from a low salt ion concentration liquid desiccant, the difference in salt ion concentration between the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant is 20% by weight (wt %). 
     In some embodiments, when initiating the rejection of salt ions from the high salt ion concentration liquid desiccant to the low salt ion concentration liquid desiccant in the at least one electrodialysis stack, and when initiating the acceptance of ions from the high salt ion concentration liquid desiccant into the low salt ion concentration liquid desiccant in the at least one electrodialysis stack, the difference in salt ion concentration between the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant is 10 wt %. 
     In some embodiments, when absorbing water from the process air stream, the high salt ion concentration liquid desiccant has a salt ion concentration of 35 wt %. 
     In some embodiments, when desorbing water into the purge air stream, the low salt ion concentration liquid desiccant has a salt ion concentration of 15 wt %. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments are illustrated in the referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting. 
         FIG.  1    illustrates, in schematic form, a cooling and dehumidification system provided by embodiments of the present disclosure. The depicted embodiment comprises an integrated system of a single heat and mass exchanger  100  and three electrolysis stacks  102 ,  104  and  106 . 
         FIG.  2    illustrates, in schematic form, another cooling and dehumidification system provided by embodiments of the present disclosure. The depicted embodiment comprises an integrated system of a single heat and mass exchanger  200  and a single electrolysis stack  202 , wherein the electrolysis stack  202  contains a plurality of channels within a single stack where ion exchange may take place. 
         FIG.  3    illustrates, in schematic form, yet another cooling and dehumidification system provided by embodiments of the present disclosure. The embodiment depicted represents a general configuration of an integrated, continuous system comprising both a heat and mass exchanger and an electrolysis stack. 
         FIG.  4    illustrates, in schematic form, portions of a dehumidification system that perform water absorption, which occurs in a heat and mass exchanger, and ion separation/desiccant concentration, which occurs in an electrodialysis stack. 
         FIG.  5    illustrates, in schematic form, portions of a dehumidification system that perform cooling, that occur in a heat and mass exchanger, and ion separation/desiccant dilution, which occur in an electrodialysis stack. 
         FIG.  6    illustrates, in schematic form, a generalized heat and mass exchanger, demonstrating the flow of fluid simultaneously into a high salt solution concentration desiccant and out of a low salt solution concentration desiccant. 
         FIG.  7    illustrates, in schematic form, a generalized electrodialysis stack. 
         FIG.  8    shows concentrations of desiccant streams when using the absorber shown in the heat and mass exchanger of  FIG.  6   , for a range of ambient air humidity. The figure shows high efficiency dehumidification even when the concentration difference between the two liquid desiccant streams is small. 
         FIG.  9    illustrates heat transfer flows between different fluids of the model described in Example 2. LD=liquid desiccant, w=humidity ratio, q=heat transfer (sensible or latent), Jv=mass flux into desiccant. 
         FIG.  10    shows the estimate electrical input to concentrate a desiccant stream to 35%, for the minimum concentration of the dilute stream. 
     
    
    
     DETAILED DESCRIPTION 
     The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods that are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements. 
     The phrases “inlet supply air,” “inlet supply airstream,” “process air,” and “process air stream” are used interchangeably herein. All refer to an airstream that is to be cooled and dehumidified by the systems and methods provided by the present disclosure. 
     The present disclosure provides systems and methods for the dehumidification and conditioning of air. This involves the use of liquid desiccants that flow through the systems in a closed loop, through a single, integrated system comprising one or more heat and mass exchangers and one or more electrodialysis stacks. The heat and mass exchangers transfer heat and humidity from process air (to be dehumidified) into a liquid desiccant stream that is high in salt ion concentration (i.e., a high concentration liquid desiccant stream). The transferred heat is then moved from the high concentration desiccant stream into a liquid desiccant stream that is low in salt ion concentration (i.e., a low concentration liquid desiccant stream). Thereafter, heat and humidity are moved from the low salt ion concentration desiccant stream into an exhaust air stream, which is purged from the system. In doing so, the heat and mass exchangers remove the process air from a space, for example a room in a building (home, office or otherwise), move the process air through the heat and mass exchangers where it is dehumidified and cooled, and then reintroduce that process air into the space from which it was removed. The end result being reintroduction of dehumidified and cooled air into the space from which it was originally removed. Removal of water from the process air dilutes the ion concentration of the high concentration liquid desiccant stream by adding water to it. Likewise, removal of water from the low concentration desiccant stream into the exhaust air concentrates the ions in the low concentration stream. In order to volumetrically reconstitute those desiccant streams, after the process air is dehumidified and cooled, the high concentration liquid desiccant stream and low concentration liquid desiccant stream are moved from a heat and mass exchanger to one or more electrodialysis stacks where the high concentration liquid desiccant stream is converted into the low concentration liquid desiccant stream and, likewise, the low concentration liquid desiccant stream is converted into the high concentration liquid desiccant stream, before being returned to the heat and mass exchanger for further dehumidification of air. 
     The systems provided by the present disclosure therefore comprise integrated functionality between one or more heat and mass exchangers and one or more electrodialysis stacks. The disclosed systems serve to dehumidify and/or cool a process air flow in order to maintain environmental comfort in an enclosed space. Unlike other such systems known in the art, such as liquid desiccant air conditioning units, no heating steps are required in the embodiments provided by the present disclosure. Such steps can be expensive and require significant energy input, depending on the temperature and humidity of the process air flow. Given that, it is anticipated that the new systems and methods disclosed herein will provide significant cost and energy savings for both manufacturers and consumers. 
     Dehumidification of process air is achieved via the use of one or more mass and heat exchangers (or transfer assemblies) as indirect evaporative coolers and/or heat exchangers. Each mass and heat exchanger is formed of alternating stacks, each, in some embodiments, including a first (or upper) layer or sheet of membrane material, a separation wall, and a second (or lower) layer or sheet of membrane material. The upper and lower membranes are permeable to water molecules in the vapor state while the separation wall is impermeable to water but allows heat transfer (i.e., is a thin layer and/or is made of materials that conduct heat). In each mass and heat exchanger, a high concentration liquid desiccant flows between the first membrane layer and the separation wall and a low concentration liquid desiccant flows between the separation wall and the second membrane layer. In some embodiments, when one or more mass and heat exchangers are used in tandem, the flow order of the air streams is reversed, such that they are flowing in opposite directions to each other. When more than two mass and heat exchangers are used in tandem, this reversal of flow ordering is repeated to form alternating supply and exhaust air flow channels or chambers. Process air (or air to be dehumidified and cooled) is directed through a first channel along a first side of the first water permeable membrane while a portion of the pre-cooled exhaust air (e.g., a fraction of the process air that has already been dehumidified and cooled by previous flow through one or more mass and heat exchanger(s)) is directed through a second channel along a second side of a second water permeable membrane, typically in a counterflow arrangement relative to the flow of the incoming process air. Thus, the high concentration liquid desiccant flow is on the other side of the first water permeable membrane from the process air, while the low concentration liquid desiccant flow is on the other side of the second water permeable membrane from the exhaust airflow (i.e., the fraction of previously processed air directed to be exhausted). As noted above, the flow of the exhaust, or purge, air can be counter to that of the process air flow, or in the same direction, depending on the desired arrangement of mass and heat exchangers, as follows: 
     First Chamber:
         →Process air intake→   First water permeable membrane   →High ion concentration liquid desiccant→       

     Water impermeable, heat permeable plate 
     Second chamber:
         →Low ion concentration fluid desiccant→   Second water permeable membrane   ←Exhaust air←—or—→Exhaust air→
 
Such an arrangement can be seen in, for example,  FIG.  2   . In various embodiments, the supply air inlet airflow, supply outlet airflow, exhaust airflow, and both liquid desiccant flows are plumbed such as via one or more manifold assemblies into a heat and mass exchanger, which can be provided in a housing as a single unit such as, for example, an indirect evaporative cooler.
       

     In several embodiments, dehumidification and evaporative cooling of the process air are accomplished by separation of the process air and the high concentration liquid desiccant by a water-permeable membrane. The membrane is formed of one or more substances or materials to be permeable to water molecules in the vapor state. The permeation of the water molecules through the membrane enables/is a driving force behind dehumidification and evaporative cooling of the process air stream. As described above, multiple air streams can be arranged to flow through the chambers of a single heat and mass exchanger such that a secondary (exhaust) air stream, which in several embodiments is an exhaust airflow of pre-cooled air, is humidified and absorbs enthalpy from the process air stream. The process air stream is cooled and simultaneously dehumidified by flowing a high concentration liquid desiccant along the opposite side of the water permeable membrane, allowing water to move across the membrane. 
     The same type of membrane is also used to separate the flow of a low concentration liquid desiccant from the exhaust airflow channel or chamber, such that the membrane separates the low concentration liquid desiccant from the exhaust air stream. Wicking materials/surfaces or other devices may be used to contain or control water flow (e.g., direct-contact wicking surfaces could be used in combination with the use of the liquid desiccant containment by a membrane), but membrane liquid control facilitates fabrication of the stacks or manifold structure useful for the heat and mass exchanger configurations disclosed herein that provide cooling and dehumidification of a process airflow. In such configurations, the air streams can be arranged in counter-flow, counter-flow with pre-cooled exhaust air, cross-flow, parallel flow, and impinging flow to perform desired simultaneous heat and mass exchange in a single evaporative cooling units containing more than one heat and mass exchanger. 
     The embodiments disclosed herein generally use one continuous stream of liquid desiccant, which can be described as a stream with portions of high and low salt concentration. The portions of the stream that are high in salt contain from about 20% to about 45% salt by weight. The portions of the stream that are low in salt concentration contain from about 3% to about 30% salt by weight. The concentrations are controlled by the amount of water absorbed into the high concentration liquid desiccant stream which, in some embodiments, matches the water desorbed from the low concentration stream. 
     The salt ion concentration of the high concentration liquid desiccant can vary in order to influence the target humidity of the process air stream. As the desired level of humidity of the process air stream decreases, the salt ion concentration of the high concentration liquid desiccant can increase. Increasing the salt ion concentration of the high concentration liquid desiccant allows it to remove more water from the process air stream. 
     The salt ion concentration of the low concentration liquid desiccant can also vary in order to influence the target humidity and/or temperature of the process air stream. The low concentration liquid desiccant desorbs water into the exhaust, or purge, air stream which, in some embodiments, reflects the ambient environment. Lower ambient humidity will allow for higher concentrations in this low concentration desiccant, meaning it will still be able to desorb enough water to maintain the integrity of the disclosed systems. At ambient humidity, the concentration of the low concentration liquid desiccant can be reduced in order to maintain a rate of water desorption. 
     As a person skilled in the art will appreciate, the salt ion concentrations of both the low and high concentration liquid desiccants can also vary based on the salt solution used. Some salt solutions will serve to dehumidify a process air stream more efficiently than others, and those that are less efficient may require a higher salt ion concentration in order to achieve a target outlet humidity. 
     Some embodiments also include a second heat and mass exchanger, wherein the first heat and mass exchanger receives inlet process air from an airstream, for example from ambient air or air return from a building, and the second heat and mass exchanger receives as the exhaust or purge air a stream of process air that has been dehumidified. The dehumidified process air that serves as the exhaust or purge air for the second heat and mass exchanger is produced by and flows from the first heat and mass exchanger. 
     A separation wall, also referred to herein as a plate, separates the first and second chambers described above. The wall is formed from a material (such as plastic) that is impermeable to the high concentration and low concentration liquid desiccants but that conducts or allows heat removed from the process air supply to be moved to the low concentration liquid desiccant. 
     In various embodiments, the low concentration liquid desiccant and high concentration liquid desiccant comprise a halide salt solution. As described herein, the flow of the desiccant streams overlap, or move through the disclosed systems in a continuous quasi-figure-8 pattern, with the low concentration desiccant stream being processed to become the high concentration desiccant stream, and vice versa. Because of that, both desiccant streams are made of the same solution, often a halide salt solution, with the difference between the two being the concentration of ions in the particular desiccant flow stream. The desiccant solution can be a halide salt can be selected from sodium chloride (NaCl), potassium chloride (KCl), potassium iodide (KI), lithium chloride (LiCl), copper(II) chloride (CuCl 2 ), silver chloride (AgCl), calcium chloride (CaCl 2 ), chlorine fluoride (CIF), bromomethane (CH 3 Br), iodoform (CHI 3 ), hydrogen chloride (HCl), lithium bromide (LiBr), hydrogen bromide (HBr), and combinations thereof. In some embodiments, the halide salt solution is selected from LiCl and CaCl 2 . In some embodiments, the halide salt solution is LiCl. The desiccant can also be potassium acetate or 1-Ethyl-3-methylimidazolium acetate (CAS number 143314-17-4). 
     The disclosed systems are integrated systems comprising both i) one or more heat and mass exchangers and ii) one or more electrolysis stacks. As stated briefly above, and in detail below, water is removed from the process air stream. This provides two advantages to the disclosed systems. First, the process air is dehumidified before it is returned to an enclosed space, helping to effect climate control in that enclosed space. Second, the water removed from the process air stream is moved directly into the high concentration desiccant stream. In contrast, water is removed from the low concentration desiccant stream into the exhaust or purge air stream, which is them removed from the system. The flow of the desiccant streams overlap, or operate in a quasi-figure-8 pattern, with the low concentration desiccant stream being processed via electrolysis to become the high concentration desiccant stream, and vice versa. By bringing water into the disclosed systems via the high concentration desiccant stream, the disclosed systems reclaim water from the air for use in cooling and dehumidifying more process air. Doing so allows the systems to utilize less water from municipal sources, easing environmental impacts. 
     The inventors have surprisingly determined that an integrated system comprising both i) heat and mass exchange systems and ii) electrolysis stacks, can be operated to cool and dehumidify air with great efficiency using two streams of salt solutions as liquid desiccants. In the heat and mass exchange systems, the concentration difference between the high concentration liquid desiccant and the low concentration liquid desiccant can be as much as 20 wt % wherein, in some embodiments, the high concentration liquid desiccant entering the heat and mass exchanger has a salt ion concentration of about 35 wt % and the low concentration liquid desiccant entering the heat and mass exchanger has a salt ion concentration of about 15 wt %. A desiccant stream of pure water is not used. 
     Electrodialysis has not been explored previously between high concentration (about 35 wt %) and low concentration (about 15 wt %) fluid desiccants; the present disclosure provides systems utilizing fluid desiccant streams having these concentrations. Namely, the present disclosure provides systems comprising i) a heat and mass exchange system whereby high concentration and low concentration fluid desiccants are used to dehumidify and/or cool air, and ii) an electrodialysis system that transfers ions from the spent high concentration liquid desiccant leaving the exchanger into the spent low concentration liquid desiccant, effectively converting one fluid flow to the other. This is achieved using multi-stage electrochemical deionization systems, which lower the concentration gradients across the membrane by distributing this gradient across several ion transport stages. The use of two streams of the same halide salt solution at differing ion concentrations as liquid desiccants has not been disclosed in the literature in an integrated system such as those disclosed herein. 
     In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions. 
     In a first embodiment, the present disclosure provides the system for dehumidifying a process air removed from and then resupplied to a space depicted in  FIG.  1   . The system is a single, integrated system comprising a heat and mass exchanger  100  directly coupled to multiple electrodialysis stacks ( 102 ,  104 ,  106 ). The heat and mass exchanger  100  contains: a first flow channel  1100  for through which a stream of inlet supply air  180  flows; a second flow channel  196  adjacent to the first flow channel  1100 , for receiving and outputting a high concentration liquid desiccant  150 ; a third flow channel  1104  adjacent to the second flow channel  196  for receiving and outputting a low concentration liquid desiccant  158 ; and a fourth flow channel  1102  adjacent to the third flow channel  1104  through which a stream of exhaust air  199  flows. The first and second flow channels are defined in part by a first vapor permeable membrane  198  that separates the first and second flow channels, wherein humidity (water vapor)  176  moves across the first vapor permeable membrane  198  from the stream of inlet supply air  180  to the high concentration liquid desiccant  150 . The third and fourth flow channels are defined in part by a second vapor permeable membrane  186  that separates the third and fourth flow channels. Humidity  178  flows across the second vapor permeable membrane  186  from the low concentration liquid desiccant  158  to the stream of exhaust air  199 . The second and third flow channels are defined in part by a separation wall  182  that separates the second  196  and third  1104  flow channels. The separation wall  182  allows transfer heat  184  to be transferred from the second flow channel  196  to the third flow channel  1104 . 
     In this embodiment, the high concentration liquid desiccant  150  enters the second flow channel  196  with a salt ion concentration of about 35 wt %, and the low concentration liquid desiccant  158  enters the third channel  1104  with a salt ion concentration of about 15 wt %—a difference of about 20 wt % in salt ion concentration. It is as this point in the disclosed system where the salt ion concentration between the two desiccants is at its maximal point. As the two desiccants move through the heat and mass exchanger, the high concentration liquid desiccant  150 , having gained water from the inlet supply air  180 , has its salt concentration drop from 35 wt % to 30 wt %; it is at 30 wt % concentration when it is moved from the heat and mass exchanger to the third electrolysis stack  106 . Additionally, the low concentration liquid desiccant  158  loses water to the exhaust air  199 , causing its salt concentration to increase from 15 wt % to 20 wt % when it is moved to the first electrolysis stack  102 . 
     The embodiment depicted in  FIG.  1    also comprises three electrodialysis stacks  102 ,  104 ,  106 . The first electrodialysis stack  102  includes a first electrodialysis flow channel  190  defined in part by a first cation permeable membrane  171 , into which a second stream of intermediate low concentration liquid desiccant  156 , having a salt concentration of 20 wt %, flows and out of which the first stream of low concentration liquid desiccant  158 , having a salt concentration of 15 wt %, flows, the desiccant  156  having lost 5 wt % of its salt ions during electrolysis in the first stack  102 . The first electrodialysis stack  102  also includes a second electrodialysis flow channel  191  defined in part by the first cation permeable membrane  171 , into which the low concentration liquid desiccant  158 , having just left the heat and mass exchanger with an ion concentration of 20 wt %, flows and out of which a first stream of intermediate high concentration liquid desiccant  162 , having a salt concentration of 25 wt %, flows, the desiccant  158  having gained 5 wt % of salt ions during electrolysis in the first stack  102 . Cations  170  flow from the low concentration liquid desiccant  158  across the first cation permeable membrane  171  into the second stream of intermediate low concentration liquid desiccant  156 . The cation content of the low concentration liquid desiccant  158  increases, or becomes more concentrated, by addition of cations  170 , thereby producing a first stream of intermediate high concentration liquid desiccant  162 . The cation concentration of the second stream of intermediate low concentration liquid desiccant  156  decreases, or becomes more dilute, by removal of cations  170 , thereby regenerating the low concentration liquid desiccant  158 . 
     The second electrodialysis stack  104  includes a third electrodialysis flow channel  192  defined in part by a second cation permeable membrane  173 , into which a first stream of intermediate low concentration liquid desiccant  154 , having a salt ion concentration of 25 wt %, flows and out of which the second stream of intermediate low concentration liquid desiccant  156 , having a salt ion concentration of 20 wt %, flows, the desiccant  154  having lost 5 wt % of its salt ions during electrolysis in the second stack  104 . The second electrodialysis stack  104  also includes a fourth electrodialysis flow channel  193  defined in part by the second cation permeable membrane  173 , into which the first stream of intermediate high concentration liquid desiccant  162 , having a salt ion concentration of about 25 wt %, flows, and out of which a second stream of intermediate high concentration liquid desiccant  164 , having a salt ion concentration of 30 wt %, flows, the desiccant  162  having gained 5 wt % in salt ions during electrolysis in the second stack  104 . Cations  172  flow from the first stream of intermediate low concentration liquid desiccant  154  across the second cation permeable membrane  173  into the first stream of intermediate high concentration liquid desiccant  162 . The cation concentration of the first stream of intermediate low concentration liquid desiccant  154  is decreased, or diluted, by removal of the cations  172 , thereby producing the second stream of intermediate low concentration liquid desiccant  156 . The cation concentration of the first stream of intermediate high concentration liquid desiccant  162  is concentrated by the addition of the cations  172 , thereby producing the second stream of intermediate high concentration liquid desiccant  164 . 
     The third electrodialysis stack  106  includes a fifth electrodialysis flow channel  194  defined in part by a third cation permeable membrane  175 , into which the high concentration liquid desiccant  152 , having a salt ion concentration of 30 wt %, flows and out of which the first stream of intermediate low concentration liquid desiccant  154 , having a salt ion concentration of 25 wt %, flows, the desiccant  152  having lost 5 wt % of its salt ions during electrolysis in the third stack  106 . The third electrodialysis stack  106  also includes a sixth electrodialysis flow channel  195  defined in part by the third cation permeable membrane  175 , into which the second stream of intermediate high concentration liquid desiccant  164 , having a salt ion concentration of 30 wt %, flows and out of which the high concentration liquid desiccant  150 , having a salt ion concentration of 35 wt %, flows, the desiccant  164  having gained 5 wt % of salt ions during electrolysis in the third stack  106 . Cations  174  flow from the high concentration liquid desiccant  150  across the third cation permeable membrane  175  into the second stream of intermediate high concentration liquid desiccant  164 . The cation concentration of the high concentration liquid desiccant  150  is decreased, or diluted, by removal of cations  174  to produce the first stream of intermediate low concentration liquid desiccant  154 . The cation concentration of the second stream of intermediate high concentration liquid desiccant  164  is increased, or concentrated, by the addition of the cations  174  to regenerate the high concentration liquid desiccant  150 . 
     In each of the three electrodialysis stacks  102 ,  104  and  106 , cations move across the cation permeable membranes  171 ,  173 ,  175  according to an electric field applied to each of the three electrodialysis stacks  102 ,  104 ,  106 . Briefly, cations, which are positively charged, will move away from a cathode (not shown), or positively charged component of an electrochemical cell, toward a negatively charged component, or anode (not shown). In the embodiment depicted in  FIG.  1   , the cathode(s) would be located to the left of each of the of the three electrodialysis stacks  102 ,  104 ,  106 , causing the cations  170 ,  172 ,  174  to move away from it, across the cation permeable membranes  171 ,  173 ,  175 . The anode(s) would be located to the right of each of the three electrodialysis stacks  102 ,  104 ,  106 , causing the cations  170 ,  172 ,  174  to move toward it. Because the cation permeable membranes  171 ,  173 ,  175  are only permeable to cations, anions present in the salt solutions will not move. The net effect being that the desiccant streams  162 ,  164  and  150  become increasingly concentrated with ions as they flow through the three electrodialysis stacks  102 ,  104 ,  106 . Similarly, the ion concentrations of desiccant streams  154 ,  156  and  158  decrease, becoming increasingly dilute as cations  174 ,  172  and  170  are removed from them. The depicted embodiment can be a single electrochemical cell, having a single cathode on one side (to the left in  FIG.  1   ) and a single anode on the other side (to the right in  FIG.  1   ). Alternatively, in the depicted embodiment each of the three electrodialysis stacks  102 ,  104 ,  106  can be its own electrochemical cell, having its own cathode and anode; in such an alternative embodiment, the arrangement of the cathodes and anodes will be the same as described above relative to  FIG.  1   , with the cathode to the left and anode to the right, allowing the depicted movement of cations  170 ,  172 ,  174 . 
     In this embodiment, the low concentration liquid desiccant  158  and high concentration liquid desiccant  150  are each the same halide salt solution. As shown in  FIG.  1   , the flow of the desiccant streams  150  and  158  overlap, or move through the disclosed system depicted in  FIG.  1    in a continuous quasi-figure-8 pattern, with the low concentration desiccant stream  158  being processed to become the high concentration desiccant stream  150 , and vice versa. Because of that, both desiccant streams are made of the same solution, often a halide salt solution, with the difference between the two being the concentration of ions in the particular desiccant flow stream—the high concentration liquid desiccant  150  having a salt ion concentration of 35 wt %, and the low concentration liquid desiccant  158  having a salt ion concentration of 15 wt %, when both desiccants enter the heat and mass exchanger. The halide salt can be selected from sodium chloride (NaCl), potassium chloride (KCl), potassium iodide (KI), lithium chloride (LiCl), copper(II) chloride (CuCl 2 ), silver chloride (AgCl), calcium chloride (CaCl 2 ), chlorine fluoride (CIF), bromomethane (CH 3 Br), iodoform (CHI 3 ), hydrogen chloride (HCl), lithium bromide (LiBr) hydrogen bromide (HBr), and combinations thereof. In some embodiments, the halide salt solution is selected from LiCl and CaCl 2 . In some embodiments, the halide salt solution is LiCl. The desiccant can also be potassium acetate or 1-Ethyl-3-methylimidazolium acetate (CAS number 143314-17-4). 
     In this embodiment, the water  176  removed from the inlet supply air  180  moves directly into the high concentration desiccant stream  150 . In contrast, water  178  is removed from the low concentration desiccant stream  158  into the exhaust or purge air stream  199 , which is them removed from the integrated system. As shown in  FIG.  1   , the flow of the desiccant streams  150  and  158  overlap, or operate in a quasi-figure-8 pattern, with the low concentration desiccant stream  158  being processed via electrolysis to become the high concentration desiccant stream  150 , and vice versa. By bringing water  176  into the system of this embodiment via the high concentration desiccant stream  150 , the disclosed system reclaims water from the inlet supply air  180  for use in cooling and dehumidifying more inlet supply air  180  in subsequent operational cycles. Doing so allows the system of this embodiment to utilize less water from municipal sources, easing environmental impacts. 
     The embodiment depicted in  FIG.  1    includes three electrodialysis stacks. One of skill in the art will recognize that the number of electrodialysis stacks can vary and that a sufficient number of electrodialysis stacks can be used in order to generate a low concentration liquid desiccant  158  and a high concentration liquid desiccant  150  with a desired cation concentration. More than one heat and mass exchanger can also be used. Also, while only two liquid desiccant streams are shown, the skilled artisan will recognize that there can also be multiple repeating pairs of channels with additional solution flows. The modifications to the system to accommodate fewer or more than three electrodialysis stacks, multiple solution flows in repeating pairs of channels, and more than one heat and mass exchanger would be known to one of skill in the art. 
     In a second embodiment, the present disclosure provides the system for dehumidifying air supplied to a space depicted in  FIG.  2   , and related methods of use.  FIG.  2    depicts a single, integrated system comprising a heat and mass exchanger  200  and a single, multilayer electrodialysis stack  202 . The heat and mass exchanger  200  includes a first flow channel  290  through which a stream of inlet supply air  270 , a second flow channel  292  adjacent to the first flow channel  290  through which a stream of high concentration liquid desiccant  210  flows, a third flow channel  294  adjacent to the second flow channel  292  through which a stream of low concentration liquid desiccant  224  flows, and a fourth flow channel  296  adjacent to the third flow channel  294  through which a stream of exhaust air  282  flows. The first and second flow channels  290  and  292  are defined in part by a first vapor permeable membrane  274  that separates the first and second flow channels  290  and  292 , wherein humidity  272  (water vapor) flows from the stream of inlet supply air  270  into the high concentration liquid desiccant  210 , wherein the high concentration liquid desiccant  210  increases in volume with the addition of water from the inlet supply air  270 . Similarly, the third and fourth flow channels  294  and  296  are defined in part by a second vapor permeable membrane  278  that separates the third and fourth flow channels  294  and  296 . Humidity  280  (water vapor) flows from the low concentration liquid desiccant  224  into the exhaust air  282 . The low concentration liquid desiccant  224  decreases in volume as water is removed from it into the exhaust air  282 . The second and third flow channels are defined in part by a separation wall  276  that separates the second and third flow channels  292  and  294 , wherein the separation wall  276  is impermeable to the flow of water or water vapor, but made of a material capable of transferring heat  278  from the second flow channel  292  to the third flow channel  294 . The movement of heat  278  reduces the temperature of the inlet supply air  270  as it flows through the first flow channel  290 . 
     As shown in  FIG.  2   , the low concentration liquid desiccant  224  and the high concentration liquid desiccant  210  then move from the heat and mass exchanger  200  to the integrated, multilayer electrodialysis stack  202 . The electrodialysis stack  202  depicted in  FIG.  2    includes seven flow channels. A first flow channel, which receives a stream of a first electrolyte solution  242 , is defined in part by an anode plate  250  and in part by a first cation exchange membrane  252 . A second flow channel, adjacent to the first flow channel, is defined in part by the first cation exchange membrane  252  and in part by a first anion exchange membrane  254 ; this second flow channel receives a first portion  230  of the low concentration liquid desiccant  224  and outputs a first portion  236  of the high concentration liquid desiccant  210 . A third flow channel, adjacent to the second flow channel, is defined in part by the first anion exchange membrane  254  and in part by a second cation exchange membrane  256 ; this third flow channel receives a first portion  216  of the high concentration liquid desiccant  210  and outputs a first portion  220  of the low concentration liquid desiccant  224 . A fourth flow channel, adjacent to the third flow channel, is defined in part by the second cation exchange membrane  256  and in part by a second anion exchange membrane  258 ; this fourth flow channel receives a second portion  232  of the low concentration liquid desiccant  224  and outputs a second portion  238  of the high concentration liquid desiccant  210 . A fifth flow channel, adjacent to the fourth flow channel, is defined in part by the second anion exchange membrane  258  and in part by a third cation exchange membrane  260 ; this fifth flow channel receives a second portion  218  of the high concentration liquid desiccant  210  and outputs a second portion  222  of the low concentration liquid desiccant  224 . A sixth flow channel, adjacent to the fifth flow channel, is defined in part by the third cation exchange membrane  260  and in part by a third anion exchange membrane  262 ; this sixth flow channel receives a third portion  234  of the low concentration liquid desiccant  224  and outputs a third portion  240  of the high concentration liquid desiccant  210 . A seventh flow channel, which receives a stream of a second electrolyte solution  244 , is defined in part by the third anion exchange membrane  262  and in part by a cathode plate  264 . Some embodiments include additional electrodialysis stacks similar to the electrodialysis stack described above. 
     As shown in  FIG.  2   , after leaving the heat and mass exchanger  200 , the high concentration liquid desiccant  210  is moved to the electrodialysis stack  202 , where it is split into two parts  216  and  218 , which enter the third and fifth channels, respectively. Additionally, after leaving the heat and mass exchanger  200 , the low concentration liquid desiccant  224  is moved to the electrodialysis stack  220 , where it is split into three parts  230 ,  232  and  234 , which enter the second, fourth, and sixth channels, respectively. Electrodialysis is then performed in the depicted channels, with cations moving away from cathode plate  264  toward anode plate  250 , and anions moving away from anode plate  250  and toward cathode plate  264 . As the liquid desiccants move through the channels, ions move across the ion permeable membranes  252 ,  254 ,  256 ,  258 ,  260  and  262  in the directions shown. The result of electrodialysis is that the concentration of ions in the liquid desiccant moving through the second, fourth and sixth channels increases; fractions  236 ,  238  and  240  are then pooled to become the high concentration liquid desiccant  224  that is recycled to the heat and mass exchanger  200 . Concomitantly, the concentration of ions in the liquid desiccant moving through the third and fifth channels decreases; fractions  220  and  222  are then pooled to become the low concentration liquid desiccant  224  that is recycled to the heat and mass exchanger  200 . 
     In this embodiment, the low concentration liquid desiccant  224 , after leaving the heat and mass exchanger  200 , is moved to the electrodialysis stack  202  where it is subjected to electrodialysis. The result of that electrodialysis is that the low concentration liquid desiccant  224  is then converted into the high concentration liquid desiccant  210  and moved back to the heat and mass exchanger  200 . Likewise, the high concentration liquid desiccant  210 , after leaving the heat and mass exchanger  200 , is moved to the electrodialysis stack  202  where it is subjected to electrodialysis. The result of that electrodialysis is that the high concentration liquid desiccant  210  is then converted into the low concentration liquid desiccant  224  and moved back to the heat and mass exchanger  200 . The integration of the heat and mass exchanger  200  with the electrodialysis stack  202  allows for the two liquid desiccant streams to be exchanged for one another during the processing of the inlet supply air  270 . This allows for repeated reuse of both desiccant streams, as volume and ionic content are moved back and forth between the liquid desiccant streams, while using less electricity. The end result is an integrated system that is more energy efficient than indirect evaporative cooling and dehumidification systems currently on the market. 
     Additionally, in this embodiment the low concentration liquid desiccant  224  and high concentration liquid desiccant  210  are each the same halide salt solution. As shown in  FIG.  2   , the flow of the desiccant streams  210  and  224  overlap, or move through the disclosed system depicted in  FIG.  2    in a continuous quasi-figure-8 pattern, with the low concentration desiccant stream  224  being processed to become the high concentration desiccant stream  210 , and vice versa. Because of that, both desiccant streams are made of the same solution, often a halide salt solution, with the difference between the two being the concentration of ions in the particular desiccant flow stream—the high concentration liquid desiccant  210  having a salt ion concentration of 35 wt %, and the low concentration liquid desiccant  224  having a salt ion concentration of 15 wt %, when both desiccants enter the heat and mass exchanger. The halide salt can be selected from sodium chloride (NaCl), potassium chloride (KCl), potassium iodide (KI), lithium chloride (LiCl), copper(II) chloride (CuCl 2 ), silver chloride (AgCl), calcium chloride (CaCl 2 ), chlorine fluoride (CIF), bromomethane (CH 3 Br), iodoform (CHI 3 ), hydrogen chloride (HCl), lithium bromide (LiBr), hydrogen bromide (HBr), and combinations thereof. In some embodiments, the halide salt solution is selected from LiCl and CaCl 2 . In some embodiments, the halide salt solution is LiCl. The desiccant can also be potassium acetate or 1-Ethyl-3-methylimidazolium acetate (CAS number 143314-17-4). 
     In this embodiment, the water  272  removed from the inlet supply air  270  moves directly into the high concentration desiccant stream  210 . In contrast, water  280  is removed from the low concentration desiccant stream  224  into the exhaust or purge air stream  282 , which is them removed from the integrated system. As shown in  FIG.  2   , the flow of the desiccant streams  210  and  224  overlap, or operate in a quasi-figure-8 pattern, with the low concentration desiccant stream  224  being processed via electrolysis to become the high concentration desiccant stream  210 , and vice versa. By bringing water  272  into the system of this embodiment via the high concentration desiccant stream  210 , the disclosed system reclaims water from the inlet supply air  270  for use in cooling and dehumidifying more inlet supply air  270  in subsequent operational cycles. Doing so allows the system of this embodiment to utilize less water from municipal sources, easing environmental impacts. 
     In a third embodiment, with reference to  FIG.  2   , the present disclosure provides a method of cooling and dehumidifying inlet supply air  270 , comprising: 
     in the heat and mass exchanger  200 , moving humidified inlet supply air  270  through a first flow channel  290  and a high concentration fluid desiccant  210  through a second flow channel  292  along opposite sides of a first vapor permeable membrane  274 ; 
     in the heat and mass exchanger  200 , moving a low concentration fluid desiccant  224  through a third flow channel  294  and an exhaust air stream  282  through a fourth flow channel  296  along opposite sides of a second vapor permeable membrane  278 , wherein a vapor impermeable separation wall  276  separates the second  292  and third  294  flow channels; 
     outputting the inlet supply air  270  from the heat and mass exchanger  200 ; 
     moving the high concentration fluid desiccant  210  and the low concentration fluid desiccant  224  out of the heat and mass exchanger  200  and into the electrodialysis stack  202 ; and 
     recycling the high concentration fluid desiccant  210  and the low concentration fluid desiccant  224  for further use in the second flow channel  292  and third flow channel  294 , respectively; 
     wherein: 
     water vapor  272  moves from the humidified inlet supply air  270  across the first membrane  274  into the high concentration fluid desiccant  210 , dehumidifying the inlet supply air  270 ; 
     heat  278  moves across the separation wall  276  from the high concentration fluid desiccant  210  into the low concentration fluid desiccant  224 , cooling the inlet supply air  270 ; 
     water vapor  280  moves from the low concentration fluid desiccant  224  across the second water-permeable membrane  278  into the exhaust air stream  282 ; and 
     in the electrolysis stack  202 , prior to recycling, the high concentration fluid desiccant  210  is processed to become the low concentration fluid desiccant  224  and the low concentration fluid desiccant  224  is processed to become the high concentration fluid desiccant  210 . 
     In this embodiment, in the electrolysis stack  202 , processing of the high concentration fluid desiccant  210  comprises: 
     splitting the high concentration fluid desiccant  210  stream into two streams of high concentration fluid desiccant  216  and  218 ; 
     moving cations away from the two streams of high concentration fluid desiccant  216  and  218  across two cation permeable membranes  256  and  260  via electrolysis, and moving anions away from the two streams of high concentration fluid desiccant  216  and  218  across two anion permeable membranes  254  and  258 , creating two streams of low concentration fluid desiccant  220  and  224 ; and 
     combining the two streams of low concentration fluid desiccant  220  and  224 , creating the low concentration fluid desiccant  224  stream. 
     In this embodiment, in the electrolysis stack  202 , processing of the low concentration fluid desiccant  224  comprises: 
     splitting the low concentration fluid desiccant  224  stream into three streams of low concentration fluid desiccant  230 ,  232  and  234 ; 
     moving cations into the three streams of low concentration fluid desiccant  230 ,  232  and  234  across three cation permeable membranes  252 ,  256  and  260  via electrolysis, and moving anions into the three streams of low concentration fluid desiccant  230 ,  232  and  234  across three anion permeable membranes  254 ,  258  and  262  via electrolysis, creating three streams of high concentration fluid desiccant  236 ,  238  and  240 ; and 
     combining the three streams of high concentration fluid desiccant  236 ,  238  and  240 , creating the high concentration fluid desiccant  210  stream. 
     In this embodiment, in the electrodialysis stack  202  prior to recycling, the two streams of high concentration fluid desiccant  216  and  218  are intercalated between the three streams of low concentration fluid desiccant  230 ,  232  and  234 , along opposite sides of a series of alternating cation and anion permeable membranes. In some embodiments, the order of the alternating cation and anion permeable membranes is cation permeable membrane  252 , anion permeable membrane  254 , cation permeable membrane  256 , anion permeable membrane  258 , cation permeable membrane  260  and anion permeable membrane  262 . 
     As shown in  FIG.  2   , cations and anions move from the two streams of high concentration fluid desiccant  216  and  218 , across the ion-permeable membranes, into the three streams of low concentration fluid desiccant  230 ,  232  and  234 , via electrolysis as described above. The concentration of ions in the two streams of high concentration fluid desiccant  216  and  218  become reduced and the concentration of ions in the three streams of low concentration fluid desiccant  230 ,  232  and  234  increase. The result of the electrodialysis is that the high concentration liquid desiccant  210 , after leaving the second flow channel  292  is converted into the low concentration liquid desiccant  224  via electrolysis and moved back to the third flow channel  294 . The integration of the heat and mass exchanger  200  with the electrodialysis stack  202  allows for the two liquid desiccant streams to be exchanged for one another during the processing of the inlet supply air  270 . This allows for repeated reuse of both desiccant streams, as volume and ionic content are moved back and forth between the liquid desiccant streams, while using less electricity. The end result is an integrated system that is more energy efficient than indirect evaporative cooling and dehumidification systems currently on the market. 
     Additionally, in this embodiment the low concentration liquid desiccant  224  and high concentration liquid desiccant  210  are each the same halide salt solution. As shown in  FIG.  2   , the flow of the desiccant streams  210  and  224  overlap, or move through the disclosed system depicted in  FIG.  2    in a continuous quasi-figure-8 pattern, with the low concentration desiccant stream  224  being processed to become the high concentration desiccant stream  210 , and vice versa. Because of that, both desiccant streams are made of the same solution, often a halide salt solution, with the difference between the two being the concentration of ions in the particular desiccant flow stream—the high concentration liquid desiccant  210  having a salt ion concentration of 35 wt %, and the low concentration liquid desiccant  224  having a salt ion concentration of 15 wt %, when both desiccants enter the heat and mass exchanger. The halide salt can be selected from sodium chloride (NaCl), potassium chloride (KCl), potassium iodide (KI), lithium chloride (LiCl), copper(II) chloride (CuCl 2 ), silver chloride (AgCl), calcium chloride (CaCl 2 ), chlorine fluoride (CIF), bromomethane (CH 3 Br), iodoform (CHI 3 ), hydrogen chloride (HCl), lithium bromide (LiBr), hydrogen bromide (HBr), and combinations thereof. In some embodiments, the halide salt solution is selected from LiCl and CaCl 2 . In some embodiments, the halide salt solution is LiCl. The desiccant can also be potassium acetate or 1-Ethyl-3-methylimidazolium acetate (CAS number 143314-17-4). 
     In this embodiment, the water  272  removed from the inlet supply air  270  moves directly into the high concentration desiccant stream  210 . In contrast, water  280  is removed from the low concentration desiccant stream  224  into the exhaust or purge air stream  282 , which is them removed from the integrated system. As shown in  FIG.  2   , the flow of the desiccant streams  210  and  224  overlap, or operate in a quasi-figure-8 pattern, with the low concentration desiccant stream  224  being processed via electrolysis to become the high concentration desiccant stream  210 , and vice versa. By bringing water  272  into the system of this embodiment via the high concentration desiccant stream  210 , the disclosed system reclaims water from the inlet supply air  270  for use in cooling and dehumidifying more inlet supply air  270  in subsequent operational cycles. Doing so allows the system of this embodiment to utilize less water from municipal sources, easing environmental impacts. 
     In a fourth embodiment, the present disclosure provides yet another system for cooling and dehumidifying air as provided in  FIG.  3   . In this embodiment, a process air stream  300  is moved through a heat and mass exchanger along a first side of a vapor permeable membrane  304 . A high concentration liquid desiccant  320  is also moved through the heat and mass exchanger, along a second side of the vapor permeable membrane  304 . The process air stream  300  and the high concentration liquid desiccant  320  are separated by the first vapor permeable membrane  304 . Water vapor  302  flows across the first vapor permeable membrane  304  from the process air stream  300  into the high concentration liquid desiccant  320 . The high concentration liquid desiccant  320  is thereby diluted by water vapor  302  from the first process air stream  300 , where it is then moved from the heat and mass exchanger to an electrolysis stack. The result is that the process airstream is dehumidified. 
     A purge air stream  314  is received and flows through the heat and mass exchanger along a first side of a second water vapor permeable membrane  310 . A low concentration liquid desiccant  332  also flows through the heat and mass exchanger, along a second side of the second water vapor permeable membrane  310 . The coolant air stream  314  and the low concentration liquid desiccant  332  are separated by the second vapor permeable membrane  310 . Water vapor  312  flows across the second vapor permeable membrane  310  from the low concentration liquid desiccant  332  into the purge air stream  314 . The low concentration liquid desiccant  332  therefore becomes more concentrated by evaporation of water vapor  312  from the low concentration liquid desiccant  332  into the purge air stream, where it is then moved to an electrodialysis stack. 
     In the heat and mass exchanger, the high concentration liquid desiccant  320  and the low concentration liquid desiccant  332  are separated by a water vapor impermeable barrier  306 . Heat  308  from the high concentration fluid desiccant  320  moves across the barrier  306  into the low concentration fluid desiccant  332 . The result is the cooling of the inlet air  300 . 
     At the electrolysis stack, the high concentration liquid desiccant  320  from the heat and mass exchanger is split into two high concentration streams,  324  and  326 , and flowed into separate channels of the electrodialysis stack  344  and  352 . During electrodialysis, the electrodialysis stack removes ions from the high concentration streams  324  and  326 , producing streams  328  and  330 , which contain low concentrations of ions. Low concentration streams  328  and  330  are then combined to generate the low concentration liquid desiccant  332 , which is recycled back to the heat and mass exchanger. 
     Additionally, at the electrolysis stack the low concentration liquid desiccant  332  from the heat and mass exchanger is flowed into a single, central channel  348  of the electrodialysis stack that is located between channels  344  and  352 . During electrolysis, the electrodialysis stack moves ions into the central channel  348 , generating the high concentration liquid desiccant  320 , which is recycled back to the heat and mass exchanger. 
     Ions move out of channels  344  and  352 , and into channel  348 , by passing across ion permeable membranes  342 ,  346 ,  350  and  354 . In electrolysis, ions will move in accordance with the electrical current imparted into the stack—with cations moving away from the cathode and toward the anode, anions moving away from the anode and toward the cathode. In the depicted embodiment, structure  340  can be either the cathode or the anode, depending upon the desired configuration of the electrodialysis stack. Similarly, structure  356  can be either the cathode or the anode. As a person of skill in the art will know, when structure  340  is a cathode, structure  356  is an anode. Similarly, when structure  340  is an anode, structure  356  is a cathode. Additional electrodialysis flow channels and membranes can be placed between the anode and cathode, and multiple electrodialysis stacks can be arranged in series. For example, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, or more electrodialysis stacks can be arranged in series. 
     In this embodiment, the low concentration liquid desiccant  332 , after leaving the heat and mass exchanger, is moved to the electrodialysis stack where it is subjected to electrodialysis. The result of that electrodialysis is that the low concentration liquid desiccant  332  is then converted into the high concentration liquid desiccant  320  and moved back to the heat and mass exchanger. Likewise, the high concentration liquid desiccant  320 , after leaving the heat and mass exchanger, is moved to the electrodialysis stack where it is subjected to electrodialysis. The result of that electrodialysis is that the high concentration liquid desiccant  320  is then converted into the low concentration liquid desiccant  332  and moved back to the heat and mass exchanger. The integration of the heat and mass exchanger with the electrodialysis stack allows for the two liquid desiccant streams to be exchanged for one another during the processing of the inlet supply air  300 . This allows for repeated reuse of both desiccant streams, as volume and ionic content are moved back and forth between the liquid desiccant streams, while using less electricity. The end result is an integrated system that is more energy efficient than indirect evaporative cooling and dehumidification systems currently on the market. 
     Additionally, in this embodiment the low concentration liquid desiccant  332  and high concentration liquid desiccant  320  are each the same halide salt solution. As shown in  FIG.  3   , the flow of the desiccant streams  320  and  332  overlap, or move through the disclosed system depicted in  FIG.  3    in a continuous quasi-figure-8 pattern, with the low concentration desiccant stream  332  being processed to become the high concentration desiccant stream  320 , and vice versa. Because of that, both desiccant streams are made of the same solution, often a halide salt solution, with the difference between the two being the concentration of ions in the particular desiccant flow stream—the high concentration liquid desiccant  320  having a salt ion concentration of 35 wt %, and the low concentration liquid desiccant  332  having a salt ion concentration of 15 wt %, when both desiccants enter the heat and mass exchanger. The halide salt can be selected from sodium chloride (NaCl), potassium chloride (KCl), potassium iodide (KI), lithium chloride (UCI), copper(II) chloride (CuCl 2 ), silver chloride (AgCl), calcium chloride (CaCl 2 ), chlorine fluoride (CIF), bromomethane (CH 3 Br), iodoform (CHI), hydrogen chloride (HCl), hydrogen bromide (HBr), lithium bromide (LiBr), and combinations thereof. In some embodiments, the halide salt solution is selected from LiCl and CaCl 2 . In some embodiments, the halide salt solution is LiCl. The desiccant can also be potassium acetate or 1-Ethyl-3-methylimidazolium acetate (CAS number 143314-17-4). 
     In this embodiment, the water  302  removed from the inlet supply air  300  moves directly into the high concentration desiccant stream  320 . In contrast, water  312  is removed from the low concentration desiccant stream  332  into the exhaust or purge air stream  314 , which is them removed from the integrated system. As shown in  FIG.  3   , the flow of the desiccant streams  320  and  332  overlap, or operate in a quasi-figure-8 pattern, with the low concentration desiccant stream  332  being processed via electrolysis to become the high concentration desiccant stream  320 , and vice versa. By bringing water  302  into the system of this embodiment via the high concentration desiccant stream  320 , the disclosed system reclaims water from the inlet supply air  300  for use in cooling and dehumidifying more inlet supply air  300  in subsequent operational cycles. Doing so allows the system of this embodiment to utilize less water from municipal sources, easing environmental impacts. 
       FIGS.  4  and  5    depict a fifth embodiment of a dehumidification system provided by the present disclosure, illustrating yet other examples of water absorption (occurring in a heat and mass exchanger) and ion separation (occurring in an electrodialysis stack). In this embodiment, the processes depicted in  FIG.  4    can occur apart from the processes depicted in  FIG.  5   . Such processes may be split between distinct structures within a closed, integrated system. The depicted embodiments of  FIGS.  4  and  5    do not occur in a continuous loop with each other, though they could be adjusted for such operation. Rather, the depicted embodiments of  FIGS.  4  and  5    are performed in two complimentary but distinct loops. 
     In the portion of this embodiment provided in  FIG.  4   , the process of water absorption involves the movement of humidity  402 , in the form of water vapor, from process air  400 , across a vapor permeable membrane  404 , to a liquid desiccant  420  and heat  408  from the liquid desiccant  420  moves across a water vapor impermeable barrier  406 , to a coolant side (such as that depicted, for example, in  FIG.  5   ). 
     Process air  400  flows along one side of a vapor permeable membrane  404  that separates the air from a desiccant stream  420  flowing on the other side of the membrane  404 . In some embodiments, the desiccant stream  420  contains a high concentration of salt ions, making it a high concentration desiccant stream  420 . Humidity (water vapor)  402  flows across the membrane  404  from the process air  400  to the high concentration desiccant stream  420 . On the opposite side of the flow channel containing the high concentration liquid desiccant  420  is a barrier  406  that is impermeable to water vapor, but that will allow for the free transfer of energy in the form of heat. In the depicted embodiment, heat  408  flows across the barrier  406  from the high concentration desiccant stream  420  to a coolant side. Once the water  402  is moved from the process air  400  into the high concentration liquid desiccant  420 , the desiccant  420  is moved from the heat and mass exchanger to the electrodialysis stack. 
     In this embodiment, water  402  is removed from the inlet supply air  400  and moved into the high concentration desiccant stream  420 . The disclosed system is therefore capable of claiming water directly from the inlet supply air  400  for use in cooling and dehumidifying more inlet supply air  400  in subsequent operational cycles. Doing so allows the system of this embodiment to utilize less water from municipal sources, easing environmental impacts. 
     At the electrodialysis stack, the high concentration desiccant stream  420  is split into high concentration streams  424  and  426  that flow into channels  444  and  452 . A flow of a fluid desiccant containing a low concentration of salt ions  434  is brought from another location (not shown) and moved into central channel  448 , located between channels  444  and  452 . During electrolysis, the electrodialysis stack moves ions into the central channel  448 , generating the high concentration liquid desiccant  420 , which is recycled back to the heat and mass exchanger. 
     Ions move out of channels  444  and  452 , and into channel  448 , by passing across ion permeable membranes  442 ,  446 ,  450  and  454 , in the directions depicted by the curved arrows. In electrolysis, ions will move in accordance with the electrical current imparted into the stack—with cations moving away from the cathode and toward the anode, anions moving away from the anode and toward the cathode. In the depicted embodiment, structure  440  can be either the cathode or the anode, depending upon the desired configuration of the electrodialysis stack. Similarly, structure  456  can be either the cathode or the anode. As a person of skill in the art will know, when structure  440  is a cathode, structure  456  is an anode. Similarly, when structure  440  is an anode, structure  456  is a cathode. Additional electrodialysis flow channels and membranes can be placed between the anode and cathode, and multiple electrodialysis stacks can be arranged in series. For example, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, or more electrodialysis stacks can be arranged in series. 
     In this embodiment, the fluid desiccant containing a low concentration of salt ions  434  becomes highly concentrated with salt ions as a result of electrodialysis, becoming the high concentration liquid desiccant  420  that is moved back to the heat and mass exchanger for subsequent processing cycles. 
     High concentration streams  424  and  426  lose salt ions during electrolysis, becoming low concentration streams  428  and  430 , which are combined into a low concentration fluid desiccant  432  that is moved to another part of the system for use as a low concentration liquid desiccant in another portion of the integrated system. 
     Additionally, in this embodiment the fluid desiccant containing a low concentration of salt ions  434  and the high concentration liquid desiccant  420  are each the same halide salt solution. The system depicted in  FIG.  4    represents a portion of a closed system whereby the fluid desiccant containing a low concentration of salt ions  434  is processed to become the high concentration desiccant stream  420 . To ensure consistent operability, the salt solutions must be the same solution, often a halide salt solution, with the difference between the two being the concentration of ions in the particular desiccant flow stream—the high concentration liquid desiccant  420  having a salt ion concentration of 35 wt %, and the low concentration liquid desiccant  432  having a salt ion concentration of 15 wt %, when both desiccants enter a heat and mass exchanger. The halide salt can be selected from sodium chloride (NaCl), potassium chloride (KCl), potassium iodide (KI), lithium chloride (LiCl), copper(II) chloride (CuCl 2 ), silver chloride (AgCl), calcium chloride (CaCl 2 ), chlorine fluoride (ClF), bromomethane (CH 3 Br), iodoform (CHI 3 ), hydrogen chloride (HCl), lithium bromide (LiBr), hydrogen bromide (HBr), and combinations thereof. In some embodiments, the halide salt solution is selected from LiCl and CaCl 2 . In some embodiments, the halide salt solution is LiCl. The desiccant can also be potassium acetate or 1-Ethyl-3-methylimidazolium acetate (CAS number 143314-17-4). 
     In the portion of this embodiment provided in  FIG.  5   , the process of water cooling involves the movement of heat  500 , across a water vapor impermeable barrier  502 , into a liquid desiccant  520 . Water vapor  506  from the liquid desiccant  520  moves across a vapor permeable membrane  504 , to a flow of purge or coolant air  508 . The heat  500  can come from a water absorption process, such as that depicted in  FIG.  4   . 
     In some embodiments, the desiccant stream  520  contains a low concentration of salt ions, making it a low concentration desiccant stream  520 . The low concentration fluid desiccant  520  flows along one side of the vapor permeable membrane  504  that separates the desiccant stream  520  from a flow of purge or coolant air  508  flowing on the other side of the membrane  504 . Humidity (water vapor)  506  flows across the membrane  504  from the low concentration fluid desiccant  520  to the purge or coolant air  508 . On the opposite side of the flow channel containing the low concentration liquid desiccant  520  is a barrier  502  that is impermeable to water vapor, but that will allow for the free transfer of energy in the form of heat. In the depicted embodiment, heat  500  flows across the barrier  502  from a water absorption side into the low concentration desiccant stream  520 . Once the water  402  is moved from the low concentration liquid desiccant  520 , the desiccant  520  is moved from the heat and mass exchanger to the electrodialysis stack. 
     At the electrodialysis stack, a first flow of fluid desiccant containing a high concentration of salt ions  526  is brought from another location (not shown) and split into high concentration streams  528  and  530  that flow into channels  544  and  552 . The low concentration fluid desiccant  520  coming from the heat and mass exchanger is moved into central channel  548 , located between channels  544  and  552 . During electrolysis, the electrodialysis stack moves ions into the central channel  548 , generating a second flow of fluid desiccant containing a high concentration of salt ions  524 , which is moved to another portion of the closed, integrated system. 
     During electrolysis, high concentration streams  528  and  530  lose salt ions, becoming low concentration streams  532  and  534 . Those streams are combined to form the low concentration fluid desiccant  520 , that is then recycled to the heat and mass exchanger for further processing rounds. 
     Ions move out of channels  544  and  552 , and into channel  548 , by passing across ion permeable membranes  542 ,  546 ,  550  and  554 , in the directions depicted by the curved arrows. In electrolysis, ions will move in accordance with the electrical current imparted into the stack—with cations moving away from the cathode and toward the anode, anions moving away from the anode and toward the cathode. In the depicted embodiment, structure  540  can be either the cathode or the anode, depending upon the desired configuration of the electrodialysis stack. Similarly, structure  556  can be either the cathode or the anode. As a person of skill in the art will know, when structure  540  is a cathode, structure  556  is an anode. Similarly, when structure  540  is an anode, structure  556  is a cathode. Additional electrodialysis flow channels and membranes can be placed between the anode and cathode, and multiple electrodialysis stacks can be arranged in series. For example, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, or more electrodialysis stacks can be arranged in series. 
     Additionally, in this embodiment the fluid desiccant containing a high concentration of salt ions  526  and the low concentration liquid desiccant  520  each contain the same halide salt solution. To ensure consistent operability, the salt solutions must be the same solution, often a halide salt solution, with the difference between the two being the concentration of ions in the particular desiccant flow stream—the high concentration liquid desiccant  524  having a salt ion concentration of 35 wt %, and the low concentration liquid desiccant  520  having a salt ion concentration of 15 wt %, when both desiccants enter a heat and mass exchanger. The halide salt can be selected from sodium chloride (NaCl), potassium chloride (KCl), potassium iodide (KI), lithium chloride (LiCl), copper(II) chloride (CuCl 2 ), silver chloride (AgCl), calcium chloride (CaCl 2 ), chlorine fluoride (ClF), bromomethane (CH 3 Br), iodoform (CHI 3 ), hydrogen chloride (HCl), lithium bromide (LiBr), hydrogen bromide (HBr), and combinations thereof. In some embodiments, the halide salt solution is selected from LiCl and CaCl 2 . In some embodiments, the halide salt solution is LiCl. The desiccant can also be potassium acetate or 1-Ethyl-3-methylimidazolium acetate (CAS number 143314-17-4). 
     EXPERIMENTAL EXAMPLES 
     Experimental Example 1 
       FIG.  6    depicts a heat and mass exchanger consistent with embodiments provided by the present disclosure.  FIG.  6    shows, on the left hand side of the “plate,” how water vapor can diffuse through a membrane and be absorbed into a concentrated salt solution desiccant stream. On the right hand side of the “plate,” water is evaporated from the diluted salt solution desiccant stream through a membrane into a separate airstream. The salt solution with the lower concentration (right hand side of the “plate”) has a higher vapor pressure, and therefore can evaporate water into the coolant air stream while water vapor is removed from the process air stream and absorbed into the high-concentration salt solution. The absorption and evaporation occur simultaneously and setup a strong driving force for heat transfer from the high-concentration solution to the low-concentration solution. As provided herein, a heat and mass exchanger such as that depicted in  FIG.  6    can serve as a part of an integrated system, that also includes one or more electrolysis stacks for electrochemical regeneration using ion transfer to concentrate the desiccant, wherein the mass and heat exchanger provides a 4-fluid absorber to reject water from the diluted desiccant stream. The four fluids being a process air stream, a high concentration salt solution fluid desiccant, a low concentration salt solution fluid desiccant, and a purge or coolant air stream. 
     Experimental Example 2 
     Electrodialysis or other ion-separation technologies are a promising regeneration method, where salt ions and water molecules are separated without energy intensive liquid/vapor phase change. The process removes ions from an already-dilute desiccant stream and transports the ions, across ion exchange membranes, to further concentrate a strong desiccant stream. Both streams can be stored for later use. Electrodialysis is common for desalination and waste-water treatment, but not for high-concentration desiccants useful in the systems and methods provided by the present disclosure. Existing research has looked solely at energy to drive moisture from one concentration to another, but not how to integrate electrodialysis into a liquid-desiccant cycle. 
     Electrochemical regeneration as it was known to occur prior to the filing of the instant application is shown in  FIG.  7   , where positive and negative ions move across a cation and anion membrane to create concentrated and diluted liquid streams. However, to discharge the diluted stream from prior art electrochemical regeneration methods requires very low concentration desiccants, such that they can be disposed of down the drain (nearly pure water), like condensate is for standard vapor compression air conditioners. However, the performance of electrodialysis and other electrochemical processes degrade when working over large concentration gradients, particularly when the diluted stream is at very low concentrations. This is needed for desiccant regeneration, which produces 35% (by wt.) liquid desiccant. 
     In contrast, the approach disclosed herein generates a low-concentration desiccant stream ( ˜ 15% by wt.), rather than pure water. The water is removed by directing the low-concentration solution to the cooling side of a 4-fluid dehumidifier (shown in  FIG.  6   ) where it evaporates and cools the concentrated desiccant stream, removing the heat of absorption from the desiccant. Electrodialysis has not been explored previously between high ( ˜ 35% by wt.) and moderate ( ˜ 15% by wt.) concentration fluid desiccants; the present disclosure provides systems utilizing fluid desiccant streams having these concentrations. As set forth above, this can be achieved using multi-stage electrochemical deionization systems, which lower the concentration gradients across the membrane by distributing this gradient across several ion transport stages. 
     A model of the absorber was created, showing how the difference in concentration can be lowered for this process. The results of the modeling are shown in  FIG.  8   . Depending on the ambient humidity, the concentration difference can be very small, drastically increasing efficiency. Even at high ambient air humidity, the diluted stream is still far from pure water (which would be required for discharge down the drain), and allows for a more efficient electrochemical process, with much fewer stages. 
     To predict the required concentration of the desiccant streams, a model of the four fluids shown in  FIG.  2    was built: two airstreams and two desiccants streams. The two air channels are approximately 3 mm wide, and the desiccant channels are approximately 0.5 mm wide. A 20-micron porous membrane is used between the desiccant and air. The model assumes a crossflow geometry with the following flow directions:
         High-concentration desiccant—vertical downward   Low-concentration desiccant—vertical downward   Process air stream—horizontal   Coolant air stream—vertical downward       

     The model is a finite-difference model that calculates the heat and mass transfer between the four fluids at each node within the device. There are 15 nodes in the horizontal direction, and 8 nodes in the vertical direction. Heat and mass transfer coefficients are calculated for each fluid based on correlations from the literature, including for water vapor diffusion across the membrane. Membranes can be included on both liquid desiccant streams, neither, or some combination. 
     To The heat and mass transfer flows between the different streams is shown in  FIG.  9   , along with the temperature, humidity, and concentration profiles. The low vapor pressure of the desiccant on the process side sets up a humidity driving potential from the air to the desiccant. The absorption of the water vapor into the desiccant releases the enthalpy of vaporization, heating the desiccant. The heat in that desiccant is then transferred to the process airstream and across the plate into the low-concentration liquid desiccant. Water vapor is evaporating from this second desiccant stream, which absorbs heat. This cools the coolant airstream and also the high-concentration desiccant across the plate. Concentration polarization within the desiccant film is also calculated using an estimate for the mass transfer coefficient for water molecules to diffuse inside the desiccant film. 
     The model calculates the outlet temperature and the outlet concentration or humidity using an iterative solver in the Engineering Equation Solver program. The model has the following independent variables:
         flow rate of liquid desiccant (4 L/min)   desiccant inlet temperature (30 C)   Return air temperature (27 C)   Return air inlet humidity ratio (11.1 g/kg)   Process and coolant side airflow rates (3400 m 3 /hr)   Inlet coolant air temperature (35 C)   Inlet coolant air humidity ratio (ranging from 10 g/kg to 20 g/kg)   Note: the process side inlet temperature and humidity is calculated assuming 30% ventilation air (30% outdoor air (which matches the coolant air) and 70% return air).       

     The outlet humidity ratio is specified in the model (8 g/kg), and then it is run for different inlet humidity ratios. The model solves for the required concentrations on the strong and weak side to deliver the required outlet humidity ratio, and so that the water evaporation rate on the coolant airstream matches the water vapor absorption rate on the process side. This ensures a mass balance on the water coming into and going out of the system. 
     The modeling results are shown in  FIG.  8   . This shows how the concentration is much higher than that required for disposing of the diluted stream down the drain (mass fraction &lt;0.0002). The higher the mass fraction of the diluted stream, the less energy the electrodialysis regenerator will use. 
     Experimental Example 3 
       FIG.  1    shows how three electrodialysis stacks integrate with a heat and mass exchanger so that desiccant flows in a continuous stream. As shown at the top of  FIG.  1   , the high concentration liquid desiccant  150  is at the most concentrated state when it is entering the second flow channel  196 , where the concentrations mass of salt per mass of solution is about 35% salt concentration by weight. The process continues as follows:
         On the process side/left side of plate  182 , the high concentration fluid desiccant  150  absorbs water from the process air  180 , dropping in concentration from 35% salt concentration by weight to 30% salt concentration by weight when it leaves the second flow channel  196 .   In electrodialysis stack  106 , the high concentration fluid desiccant  150 , as it moves through the fifth electrodialysis flow channel  194 , gives up ions  174  across membrane  175 , further dropping in salt concentration from 30% salt by weight (as it enters channel  194 ) to 25% salt by weight as it leaves channel  194 , leaving as a first stream of intermediate low concentration liquid desiccant  154 ; and   In contrast, second intermediate high concentration liquid desiccant stream  164 , moving in the sixth electrodialysis flow channel  195  increases in salt concentration from 30% when it enters the channel  195  to 35% when it exits flow channel  195  as the now recycled high concentration liquid fluid desiccant stream  150 .   In electrodialysis stack  104 , the intermediate/low concentration fluid desiccant  154 , as it moves through the third electrodialysis flow chamber  192 , gives up ions  172  across membrane  173 , further dropping in salt concentration from 25% salt by weight (as it enters channel  192 ) to 20% salt by weight as it leaves channel  192 , leaving as a second stream of intermediate low concentration liquid desiccant  156 ; and   In contrast, first intermediate high concentration liquid desiccant stream  162 , moving in the fourth electrodialysis flow channel  193  increases in salt concentration from 25% when it enters the channel  193  to 30% when it exits flow channel  193  as the second intermediate high concentration liquid desiccant  164 .   In electrodialysis stack  102 , the second stream of intermediate low concentration liquid desiccant  156 , as it moves through flow chamber  190 , gives up ions  170  across membrane  171 , further dropping in salt concentration from 20% salt by weight (as it enters channel  190 ) to 15% salt by weight as it leaves channel  190 , leaving as the now recycled low concentration fluid desiccant stream  158 ; and   In contrast, the low concentration fluid desiccant stream  158  that left the third flow channel  1104  of the heat and mass exchanger  100  and is now moving through the second electrodialysis flow channel  191  increases in salt concentration from 20% when it enters flow channel  191  to 25% when it exits flow channel  191  as first intermediate high concentration liquid desiccant stream  162 .   The recycled low concentration fluid desiccant  158  is moved back to the heat and mass exchanger  100 , where it enters the third flow channel  1104 . Water evaporates from the desiccant  158  into a coolant or exhaust airstream  199 , which is then exhausted outside, concentrating the fluid desiccant  158  from 15% to 20% salt concentration by weight. This step also removes water from the system that was absorbed by the high concentration desiccant  150  in flow channel  196  of the heat and mass exchanger.       

     From the mass and heat exchanger  100 , the low concentration fluid desiccant  158  enters electrodialysis stack  102  and is progressively concentrated as it progresses through the three electrodialysis stacks  102 ,  104  and  106  until it becomes the high concentration liquid desiccant  150 . 
     The process can be modified to lower the concentration of the low concentration desiccant  158  to below 15% by adding more electrodialysis stacks. 
     Desiccant storage tanks can also be added at stream  150  (highest concentration) and stream  158  (lowest concentration). This allows the system to use electricity at times separate from the cooling demand and to store the two desiccant concentrations for later use. It also allows for changes in the average water content of the desiccant, such that the system volume can increase and decrease as the concentration changes. 
     The configuration in  FIG.  1    reduces the concentration change across each electrodialysis stack. In the depicted embodiment, a 5% concentration change for the two streams is shown, with both streams entering at the same concentration. The maximum delta concentration across each electrodialysis stack is then only 5%, while the total change in concentration is 20% (35% to 15%). The change could also be reduced by expanding the number of electrodialysis stacks with the same total concentration change (e.g., 6 ED stacks over 20% would have a delta concentration of only 2.5% per ED stack). 
     Without the integration of the low concentration liquid desiccant stream  158  in channel  1104  into the heat and mass exchanger, which removes water from the desiccant stream  158  without added energy, an electrodialysis-based system using a liquid desiccant would need to dispose of the desiccant down the drain. This requires a very low concentration such that the salt ions do not contaminate the waste-water stream and is not depleted by removing ions from the system. Drinking water thresholds are ˜0.2 parts per thousand, which also corresponds to about 1-2 kg of salt dumped into the wastewater stream per year, or about 6% of the total salt ions of the system lost per year. As such, the disclosed embodiments significantly advance the state of the art. 
     Experimental Example 4 
     To understand the energy impact of the disclosed integrated systems, it is useful to estimate the energy required to regenerate the desiccant from 30% mass fraction back to 35% mass fraction after absorbing water from the airstream. This was done using the calculations described below, with the results shown in  FIG.  10   . 
     The total power, in kW, is shown in  FIG.  10    for a 1 L/min desiccant flow. Operating the disclosed systems uses between 0.5 and 1.5 kW, depending on the minimum concentration, whereas reducing the desiccant concentration to 0.2 parts per thousand, as required by the prior art systems, requires 4 kW. Thus, the disclosed systems use only 12-38% of the energy as a set of electrodialysis stacks alone. 
     In addition to the electricity savings, the disclosed systems improve the performance of the electrodialysis process for concentrating desiccant by:
         Eliminating the disposal of LiCl (or other desiccant) ions into the municipal wastewater stream;   Eliminating loss of this desiccant from the system, which would need to be replaced;   Reducing the capital cost of the electrodialysis stacks by reducing the number of electrodialysis stacks required; and   Providing cooling to the dehumidified airstream inherently in the process, through evaporation, which minimizes the cooling required to maintain desired outlet temperatures from the disclosed systems.       

     Energy Consumption Calculation: 
     The total energy consumption of the electrodialysis components of the manifold shown above is calculated by determining the power required for each unit, then summing these values. In each electrodialysis stack, a current of: 
     
       
         
           
             
               i 
               ideal 
             
             = 
             
               
                 QF 
                 NA 
               
               ⁢ 
               
                 ( 
                 
                   
                     c 
                     out 
                   
                   - 
                   
                     c 
                     in 
                   
                 
                 ) 
               
             
           
         
       
     
     must be applied, where Q is the volumetric flow rate, F is Faraday&#39;s Constant, N is the number of CEM/AEM pairs in the stack, A is the cross-sectional surface area, and 
     
       
         
           
             
               c 
               in 
             
             = 
             
               
                 
                   ω 
                   LiCl 
                   in 
                 
                 ⁢ 
                 
                   ρ 
                   
                     
                       H 
                       2 
                     
                     ⁢ 
                     O 
                   
                 
               
               
                 M 
                 LiCl 
               
             
           
         
       
       
         
           
             
               c 
               out 
             
             = 
             
               
                 
                   ω 
                   LiCl 
                   out 
                 
                 ⁢ 
                 
                   ρ 
                   
                     
                       H 
                       2 
                     
                     ⁢ 
                     O 
                   
                 
               
               
                 M 
                 LiCl 
               
             
           
         
       
     
     are the inlet and (desired) outlet salt concentrations. 
     Assuming that most of the voltage drop arises due to ohmic losses (i.e., neglecting all junction potentials), the voltage input required can be found as: 
     
       
         
           
             
               
                 ∑ 
                 k 
               
               
                 Δ 
                 ⁢ 
                 
                   V 
                   
                     ohm 
                     , 
                     k 
                   
                 
               
             
             = 
             
               
                 
                   ∑ 
                   k 
                 
                 
                   IR 
                   k 
                 
               
               = 
               
                 
                   ∑ 
                   k 
                 
                 
                   i 
                   ⁢ 
                   
                     
                       L 
                       k 
                     
                     
                       σ 
                       k 
                     
                   
                 
               
             
           
         
       
     
     The conductivity of each layer will change as a function of the salt stream concentrations, with lower concentrations leading to lower conductivities. Note that these results use dilute solution theory, which neglects ion-ion interactions, which could be considered when calculating the ohmic losses. Concentrated solution theory would predict a slight benefit of reducing the salt concentrations, as ion-ion “friction” would be reduced. However, this effect should be small compared to the concentration effect. 
     The ionic conductivity is a function of the local salt concentration and the species&#39; diffusion coefficients: 
     
       
         
           
             
               σ 
               k 
             
             = 
             
               
                 ∑ 
                 k 
               
               
                 
                   
                     F 
                     2 
                   
                   RT 
                 
                 ⁢ 
                 
                   ( 
                   
                     z 
                     k 
                     2 
                   
                   ) 
                 
                 ⁢ 
                 
                   D 
                   k 
                 
                 ⁢ 
                 
                   c 
                   k 
                 
               
             
           
         
       
     
     If we assume local electroneutrality in the rinses, the total ionic conductivity becomes: 
     
       
         
           
             
               σ 
               tot 
             
             = 
             
               
                 
                   
                     F 
                     2 
                   
                   ⁢ 
                   c 
                 
                 RT 
               
               ⁢ 
               
                 ( 
                 
                   
                     D 
                     
                       Li 
                       + 
                     
                   
                   + 
                   
                     D 
                     
                       Cl 
                       - 
                     
                   
                 
                 ) 
               
             
           
         
       
     
     where c refers to the bulk rinse concentration, i.e., it can refer to c in  or c out . 
     Plugging in the conductivities to the voltage expression allows us to calculate the different potential drops required by each electrodialysis stack (A, B, and C in Table 1, below). Assuming N=20 for each stack, separation distances of 1 mm, and using a constant flow rate Q=1 L/min and area A=25 cm 2 , the potentials required by each unit are: 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Stack ID 
                 ΔV (V) 
                 P (kW) 
               
               
                   
                   
               
             
            
               
                   
                 A 
                 1.34 
                 0.127 
               
               
                   
                 B 
                 1.58 
                 0.150 
               
               
                   
                 C 
                 1.94 
                 0.184 
               
               
                   
                   
               
            
           
         
       
     
     Thus, the total power required will be 0.461 kW for the example shown in the data of Table 1 (ω max =0.35, ω min =0.15). The units with more dilute streams require a higher applied voltage due to the lower conductivities. Assuming different number of modules can be used to calculate the power for different minimum concentrations, which provides the curve in  FIG.  9   . 
     Stated Examples 
     The following stated examples refer to embodiments of the systems and methods provided by the present disclosure:
 
Example 1. A dehumidification system, comprising:
 
     a heat and mass exchanger; 
     at least one electrodialysis stack; 
     a high salt ion concentration liquid desiccant; and 
     a low salt ion concentration liquid desiccant; 
     wherein: 
     the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant are in a single, continuous stream that connects the heat and mass exchanger and the at least one electrodialysis stack; 
     the high salt ion concentration liquid desiccant absorbs water from a process air stream in the heat and mass exchanger and rejects salt ions to the low salt ion concentration liquid desiccant in the at least one electrodialysis stack; and 
     the low salt ion concentration liquid desiccant desorbs water from a purge air stream in the heat and mass exchanger and accepts ions from the high salt ion concentration liquid desiccant in the at least one electrodialysis stack. 
     Example 2. The dehumidification system of Example 1, wherein the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant comprise the same salt solution.
 
Example 3. The dehumidification system of Example 1 or Example 2, wherein the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant comprise a salt solution selected from sodium chloride, potassium chloride, potassium iodide, lithium chloride, copper(II) chloride, silver chloride, calcium chloride, chlorine fluoride, bromomethane, iodoform, hydrogen chloride, lithium bromide, hydrogen bromide, potassium acetate, 1-Ethyl-3-methylimidazolium acetate, and combinations thereof.
 
Example 4. The dehumidification system of Example 2 or Example 3, wherein the salt solution is selected from lithium chloride and calcium chloride.
 
Example 5. The dehumidification system of any one of Examples 2-4, wherein the salt solution is lithium chloride.
 
Example 6. The dehumidification system of any one of Examples 1-5, wherein, upon entry into the heat and mass exchanger, the difference in salt ion concentration between the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant is 20% by weight (wt %).
 
Example 7. The dehumidification system of any one of Examples 1-6, wherein, upon entry into the at least one electrolysis stack, the difference in salt ion concentration between the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant is 10 wt %.
 
Example 8. The dehumidification system of any one of Examples 1-7, wherein, upon entry into the heat and mass exchanger, the high salt ion concentration liquid desiccant has a salt ion concentration of 35 wt %.
 
Example 9. The dehumidification system of any one of Examples 1-8, wherein, upon entry into the heat and mass exchanger, the low salt ion concentration liquid desiccant has a salt ion concentration of 15 wt %.
 
Example 10. The dehumidification system of any one of Examples 1-9, wherein, in the at least one electrodialysis stack, the high salt ion concentration liquid desiccant is converted into the low salt ion concentration liquid desiccant, and the low salt ion concentration liquid desiccant is converted into the high salt ion concentration liquid desiccant.
 
Example 11. The dehumidification system of any one of Examples 1-10, wherein the system comprises two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen or twenty electrodialysis stacks arranged in series between a cathode and an anode.
 
Example 12. A method of dehumidifying air, comprising:
 
     absorbing water from a process air stream into a high salt ion concentration liquid desiccant in a heat and mass exchanger, dehumidifying the process air stream; 
     desorbing water from a low salt ion concentration liquid desiccant into a purge air stream in the heat and mass exchanger; 
     moving the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant to at least one electrodialysis stack; 
     rejecting salt ions from the high salt ion concentration liquid desiccant to the low salt ion concentration liquid desiccant in the at least one electrodialysis stack, converting the high salt ion concentration liquid desiccant into the low salt ion concentration liquid desiccant; and 
     accepting ions from the high salt ion concentration liquid desiccant into the low salt ion concentration liquid desiccant in the at least one electrodialysis stack, converting the low salt ion concentration liquid desiccant into the high salt ion concentration liquid desiccant; 
     wherein: 
     the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant flow in a single, continuous stream that connects the heat and mass exchanger and the at least one electrodialysis stack; and 
     the converted high salt ion concentration liquid desiccant and the converted low salt ion concentration liquid desiccant are moved to the mass and heat exchanger. 
     Example 13. The method of Example 12, further comprising purging heat from the high salt ion concentration liquid desiccant into the low salt ion concentration liquid desiccant in the heat and mass exchanger, cooling the dehumidified process air stream.
 
Example 14. The method of Example 12 or Example 13, wherein the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant comprise the same salt solution selected from sodium chloride, potassium chloride, potassium iodide, lithium chloride, copper(II) chloride, silver chloride, calcium chloride, chlorine fluoride, bromomethane, iodoform, hydrogen chloride, lithium bromide, hydrogen bromide, potassium acetate, 1-Ethyl-3-methylimidazolium acetate, and combinations thereof.
 
Example 15. The method of Example 14, wherein the salt solution is selected from lithium chloride and calcium chloride.
 
Example 16. The method of Example 14 or Example 15, wherein the salt solution is lithium chloride.
 
Example 17. The method of any one of Examples 12-16, wherein, when absorbing water from a process air stream into a high salt ion concentration liquid desiccant and desorbing water from a low salt ion concentration liquid desiccant, the difference in salt ion concentration between the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant is 20% by weight (wt %).
 
Example 18. The method of any one of Examples 12-16, wherein:
 
     when initiating the rejection of salt ions from the high salt ion concentration liquid desiccant to the low salt ion concentration liquid desiccant in the at least one electrodialysis stack, and 
     when initiating the acceptance of ions from the high salt ion concentration liquid desiccant into the low salt ion concentration liquid desiccant in the at least one electrodialysis stack, the difference in salt ion concentration between the high salt ion concentration liquid desiccant and the low salt ion concentration liquid desiccant is 10 wt %. 
     Example 19. The method of any one of Examples 12-18, wherein, when absorbing water from the process air stream, the high salt ion concentration liquid desiccant has a salt ion concentration of 35 wt %.
 
Example 20. The method of any one of Examples 12-19, wherein, when desorbing water into the purge air stream, the low salt ion concentration liquid desiccant has a salt ion concentration of 15 wt %.