Patent Publication Number: US-9403686-B2

Title: Methods for associating or dissociating guest materials with a metal organic framework, systems for associating or dissociating guest materials within a series of metal organic frameworks, thermal energy transfer assemblies, and methods for transferring thermal energy

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 13/410,804 which was filed Mar. 2, 2012, now U.S. Pat. No. 8,795,412, entitled “Methods for Associating or Dissociating Guest Materials with a Metal Organic Framework, Systems for Associating or Dissociating Guest Materials Within a Series of Metal Organic Frameworks, Thermal Energy Transfer Assemblies, and Methods for Transferring Thermal Energy”, which claims priority to U.S. Provisional Patent Application No. 61/448,965 which was filed on Mar. 3, 2011, entitled “Methods for Associating or Dissociating Guest Materials with a Metal Organic Framework, Systems for Associating or Dissociating Guest Materials Within a Series of Metal Organic Frameworks, Thermal Energy Transfer Assemblies, and Methods for Transferring Thermal Energy”, the entirety of each of which is incorporated by reference herein. 
    
    
     STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT 
     This invention was made with Government support under Contract DE-AC0576RLO1830 awarded by the U.S. Department of Energy. The Government has certain rights in the invention. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to the use of metal organic frameworks. 
     BACKGROUND 
     Recently, metal organic frameworks have been proposed for use in various capacities. These capacities include but are not limited to the separation of molecules or materials from mixtures that include the molecules or materials. As an example, in various applications, metal organic frameworks have been proposed for use as materials that can be used to separate carbon dioxide from methane, for example. 
     In accordance with other applications, metal organic frameworks have also been utilized to retain certain molecules in higher density than they would be retained at when super pressurized. As an example, metal organic frameworks have been proposed for use as hydrogen storage tanks. 
     In these applications, in the past, the metal organic frameworks have been configured to selectively adsorb or desorb or associate or dissociate certain materials. As an example, the temperature and/or pressure of the metal organic framework can be manipulated, as well as the chemical and/or geometric structure of the metal organic framework, to facilitate either the association or adsorption, or the dissociation or desorption of the specific materials. 
     The present disclosure provides methods for using metal organic frameworks as well as systems that include metal organic frameworks and assemblies that include metal organic frameworks. 
     SUMMARY 
     Methods for releasing associated guest materials from a metal organic framework are provided with example methods including altering the oxidation state of at least a portion of the metal of the metal organic framework to dissociate at least a portion of the guest materials from the framework. Example methods for associating guest materials with a metal organic framework are also provided with example methods including altering the oxidation state of at least a portion of the metal of the metal organic framework to associate at least a portion of the guest materials with the framework. 
     Methods are provided for selectively associating or dissociating guest materials with a metal organic framework. Example methods can include altering the oxidation state of at least a portion of the metal of the metal organic framework to associate or dissociate at least a portion of the guest materials with the framework. 
     Systems for associating or dissociating guest materials within a series of metal organic frameworks are provided. Example systems can include at least two individual metal organic frameworks, with one of the individual metal organic frameworks configured to dissociate guest materials, and the other configured to associate guest materials. One framework can include at least some metals of one oxidation state and the other framework can include the same metals of another oxidation state. 
     Thermal energy transfer assemblies are provided. Example assemblies can include a metal organic framework electrically coupled to a power source; and a heat transfer assembly associated with the metal organic framework. 
     Methods for transferring thermal energy are also provided. Example methods can include adsorbing or desorbing guest materials to or from a metal organic framework, the adsorbing or desorbing facilitated by changing an oxidation state of at least some of the metal within the metal organic framework. The methods can also include providing thermal communication between a fluid and one or both of the metal organic framework or the guest materials, with the fluid changing temperature upon communication with the one or both of the metal organic framework or the guest materials. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the disclosure are described below with reference to the following accompanying drawings. 
         FIG. 1  is a configuration of a metal organic framework according to an embodiment of the disclosure. 
         FIG. 2  represents configurations of metal organic frameworks according to an embodiment of the disclosure. 
         FIG. 3  represents configurations of metal organic framework and mixtures that include guest materials depicted according to an embodiment of the disclosure. 
         FIG. 4  represents a system including metal organic framework according to an embodiment of the disclosure. 
         FIG. 5  represents a system including metal organic framework according to an embodiment of the disclosure. 
     
    
    
     DESCRIPTION 
     This disclosure is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8). 
     The methods, systems, and assemblies of the present disclosure will be described with reference to  FIGS. 1-5 . Referring first to  FIG. 1 , a metal organic framework configuration  10  is shown that includes metal organic framework  12  conductively coupled via contact  16  and conductive conduit  18  to power source  20 . Framework  12  can include metals coupled to organic components. Framework  12  may be configured to define open sites designed to receive guest materials. The open sites may be defined by more than one metal organic complex, for example. At least a portion of the metals of the metal organic framework should be electrically responsive, and more than one metal may be included in metal organic complex  13  having organic portion  14  and metal portion  15 . 
     Metal portion  15  of complex  13  can include metals and, according to example implementations, the oxidation state of at least some of the metals will change upon application of differing voltages to the framework. The metals can include transition state metals. Example metals can include Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Mn, Tc, Re, Bh, Fe, Ru, Os, Hs, Co, Rh, Os, Hs, Co, Rh, Ir, Mt, Ni, pd, Pt, Ds, Cu, Ag, Au, Zn, and Rg. At least a portion of framework  12  can include one or more of these metals in a charged state. 
     For example metal portion  15  can include mixed valence metals (M 2+ /M 3+ ) complexed with the organic portion; M 2+ =Fe, Cd, Co, Cu, Mn, Ni, and Zn; and M 3+ =Fe or Co, for example. According to specific implementations, the metal portion can include (Fe 2+ /Fe 3+ ), and this metal may be complexed as Fe 3   2+ [Fe 3+ (CN) 6 ] 2  or Fe 3   3+ [Fe 3+ (CN) 6 ], with the former being a different oxidation state than the latter under differing electrical conditions. These mixed valence metal complexes may include tetrakis[4-(pyridyl)oxamethyl]methane as an organic component, for example. 
     In accordance with example implementations, the organic portion  14  may be referred to as a ligand that coordinates the metal of the framework. The ligand may be multidentate, for example. The organic portion can be a conductive organic portion. Example organic portions can include but are not limited to straight chain hydrocarbon and/or aromatic rings. The metal organic complex can include metallocenes or calixarenes for example. In accordance with example implementations, the ligand of the metal organic complex can be substantially conductive. Example organic portions of the metal organic complex can include but are not limited to tetrakis[4-(pyridyl)oxamethyl]methane or p-tert-butylcalix[4]arene. 
     Contact  16  can be in electrical communication with at least a portion of the metal of the metal organic framework. In accordance with example implementations, contact  16  may be in electrical communication with the organic portion of the metal organic framework and the organic portion can provide electrical communication to at least a portion of the metal of the metal organic framework. Electrical input to contact  16  from power source  20  may be controlled with a controller (not shown). The controller may be programmable and/or may be coupled to a computer operating system (not shown). In accordance with example implementations, the controller may be manipulated to provide a desired voltage to framework  12 , the voltage corresponding to the association/dissociation of guest materials. Utilizing the power source and the controller voltammetry as well as cyclic voltammetry can be applied to framework  12 . 
     Framework  12  of  FIG. 1  is depicted without a substrate. In accordance with example implementations, framework  12  may be associated with a substrate. In specific implementations, framework  12  may be bond to a substrate and/or supported by or within a substrate. In accordance with example configurations, framework  12  may be within a housing, such as a conduit, including tubular conduits. In accordance with other configurations, framework  12  may be supported by a substrate with the substrate being a substantially open support such as a platform, or in other configurations, framework  12  may be supported by the exterior of a conduit, such as tubular conduit configured to contain framework and/or other materials therein. In accordance with example implementations, framework  12  can be applied to or within a substrate as a thin film. 
     Referring next to  FIG. 2 , configurations of metal organic frameworks according to an embodiment of the disclosure are shown. Referring first to  2 (A), framework  12  is depicted having a metal portion  15  (M X ), representing complex  13  having an M X  oxidation state. Framework  12  has a voltage V 1  being applied thereto to maintain the M X  oxidation state. Referring next to  2 (B), framework  22  is shown having complex  13  with metal portion  25  (M y ), representing the M y  oxidation state. Framework  22  has a voltage V 2  being applied thereto to maintain the M y  oxidation state. In accordance with example implementations, the M X  oxidation state is different than the M y  oxidation state. The change in oxidation state can be facilitated by altering the voltage applied to the framework. As an example, frameworks  12  and  22  can be substantially the same, but with application of V 1  the oxidation state is M X , and with application of V 2  the oxidation state is M y . In accordance with example implementations, the metal of the metal organic framework can be electrochemically altered. According to example implementations the oxidation state of at least some of the metals of the metal organic framework can be changed by altering the voltage applied to the metal and/or the metal organic framework. In example implementations V 1  would be different than V 2 . Referring next to  2 (C), at least a portion of the framework  12  is shown having complexes  13  including portion  15  (M X ) having voltage V 1  being applied thereto. In accordance with example implementations, framework  22  of  2 (B) can be altered to reflect framework  12  of  2 (C) by altering V 2  to V 1 . According to specific implementations, by transitioning from  2 (A)- 2 (C), framework  12  can transition from having metal portions  15  through metal portions  25  to metal portions  15  again. 
     Referring next to  FIG. 3 , configurations of metal organic framework and mixtures that include guest materials are depicted according to an embodiment of the disclosure. Referring first to  3 (A), framework  12  is shown having V 1  applied thereto to maintain M X  oxidation states of at least some of metal portions  15  of complexes  13 . 
     In accordance with example implementations, mixture  30  can be exposed or provided to framework  12 . Mixture  30  can include guest material  32  (*). Material  32  can be a material that is desired to be separated from mixture  30 . Example materials include but are not limited to carbon dioxide, and mixture  30  may include components other than carbon dioxide being represented as a remainder of the mixture  34  (#). In accordance with other implementations, guest material  32  may be exposed or provided to framework  12  in substantially pure form. For example, carbon dioxide, hydrofluorocarbons (HFC&#39;s), refrigerants, N 2 , He, butane, propane, pentane, ammonia, and freon may be desired as a guest material and metal organic frameworks having dynamically modifiable metal portions may be configured to associate with or adsorb same. 
     In accordance with  3 (A), mixture  30  is provided to framework  12  and at least some of material  32  is retained while material  34  is not. Accordingly, methods for associating guest materials with a metal organic framework are provided with the method including altering the oxidation state of at least a portion of the metal of the metal organic framework to associate at least a portion of the guest materials with the framework. Further, methods for exposing a mixture to the metal organic framework are provided with the mixture comprising the guest materials and other materials, and at least a portion of the other materials not being associated with the metal organic framework upon the exposing. Referring to  3 (B), V 2  can be applied to form framework  22  from framework  12  with framework  22  including complexes  13  having metal portions  25  (M y ). Upon changing at least some of the oxidation state of M X  to M y , at least some of guest material  32  dissociates or desorbs from framework  22  as substantially pure guest material  32 . Accordingly, a method for releasing associated guest materials from a metal organic framework is provided with the method including altering the oxidation state of at least a portion of the metal of the metal organic framework to dissociate at least a portion of the guest materials from the framework. Referring to  3 (C), V 1  can be applied to again substantially form framework  12  from framework  22  with framework  12  including complexes  13  having metal portions  15  (M X ). Upon returning the oxidation state of M y  to M X , mixture  30  can be exposed to framework  12  to associate or adsorb guest material  32  with or to framework  12 . 
     Referring to  FIG. 4 , assembly  120  is shown that can be configured to transfer thermal energy. In accordance with example implementations, framework  22  can be configured to dissociate or desorb guest material  32 . Guest material  32  can be such a material that when it expands from the associated or adsorbed state it consumes energy in the form of heat from its surroundings. Accordingly, guest material  32  can be provided to a heat transfer assembly such as a mass of coils  122  being configured to be exposed to fluid  124 . Accordingly, temperature T 1  of guest material  32  can be less than temperature T 2  of guest material  32  after it passes through exchanger  122 . Further, fluid  124  can have a temperature T 3  that is greater than temperature T 4  after being exposed to coils  122 . In accordance with example implementations, framework  22  can include associated or adsorbed guest material such as a refrigerant or carbon dioxide; V 1  can be altered to change the oxidation state of the metal of the metal organic framework thereby dissociating or desorbing guest material from the framework. Upon dissociation the guest material can be allowed to expand via valve  126 , such as a throttling valve, and be provided to coils  122  wherein the guest material cools fluid  124 , such as air or water, for example. In accordance with example implementations, guest material  32  upon passing through exchanger  122  may be provided to another metal organic framework configured to associate or adsorb the guest material. 
     Accordingly, thermal energy transfer assemblies of the present disclosure can include a metal organic framework electrically coupled to a power source, and a heat transfer assembly associated with the metal organic framework. In accordance with specific implementations, the assemblies can further include a controller (not shown) operatively coupled to the metal organic framework and the power source. Additionally, the assembly can include another metal organic framework coupled to the heat transfer assembly, with the metal of one organic framework having an oxidation state different than the metal of the other organic framework. 
     Referring to  FIG. 5 , system  130  is shown generally depicting components of an adsorption chiller. Referring first to (A), guest materials  32  such as a carbon dioxide can be dissociated or desorbed upon providing V 2  to framework  22 . During this dissociation or desorption fluid  124  can be exposed to the thermal energy of framework  22 . In accordance with example implementations, framework  22  can be supported by a thermally conductive material and configured along the outside of a conduit containing fluid  124 . Fluid  124  can be cooled as it passes through this conduit and utilized as desired. Further, guest material  32  can be allowed to condense. 
     Referring next to (B), guest material  32  can be allowed to at least partially evaporate and associate or adsorb to framework  12  at V 1 . During adsorption, framework  12  can increase in temperature and this thermal energy may be provided to fluid  130  as it is exposed to framework  12 . In accordance with example implementations, framework  12  can be configured along the outside of a conduit containing fluid  130  to facilitate the heat transfer. Accordingly, the temperature of fluid  130  upon being exposed to framework  12  can be greater than before it was exposed to framework  12 . Accordingly, assembly  130  can be configured as an adsorption chiller. In accordance with example implementations, the adsorption chiller of assembly  130  includes an electrochemically driven desorption and/or adsorption cycle. 
     Accordingly, methods for transferring thermal energy are provided with the methods including adsorbing or desorbing guest materials to or from a metal organic framework. The adsorbing or desorbing can be facilitated by changing an oxidation state of at least some of the metal within the metal organic framework. The methods can include providing thermal communication between a fluid and one or both of the metal organic framework or the guest materials. The fluid can change temperature upon communication with the one or both of the metal organic framework or the guest materials. According to example implementations, the providing thermal communication between the metal organic framework and the liquid can include providing a conduit having an exterior in thermal contact with the metal organic framework, and providing the fluid within the conduit. 
     In compliance with the statute, embodiments of the invention have been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the entire invention is not limited to the specific features and/or embodiments shown and/or described, since the disclosed embodiments comprise forms of putting the invention into effect.