Method for thermo-chemical energy storage

Abstract

A method for thermo-chemical energy storage involves carrying out reversible chemical reactions for the storage of heat energy in the form of chemical energy in one or more chemical compounds for later re-release in the form of heat energy using chemical equilibrium reactions. Equilibrium reactions of ammine complexes of transition metal salts are carried out for the storage and re-release of the energy. Specifically, ammine complexes of transition metal salts are formed and decomposed according to the following reversible total reactions: [Me(NH3)n]X+ΔHR⇄MeX+n NH3, wherein Me represents at least one transition metal ion and X represents one or more counterion(s) in a quantity sufficient for charge equalizing the complex, according to the valence thereof and that of the transition metal ion. Also, one or more transition metal salt(s), carried on a carrier material that is inert with regard to the reaction, is/are used.

1 . A method for thermo-chemical energy storage by carrying out reversible chemical reactions for the storage of heat energy in the form of chemical energy in one or more chemical compounds for later re-release in the form of heat energy using chemical equilibrium reactions, wherein equilibrium reactions of ammine complexes of transition metal salts are carried out for the storage and re-release of the energy,
 wherein   a) ammine complexes of transition metal salts are formed and decomposed according to the following reversible total reactions:
   [Me(NH 3 ) n ]X+ΔH R   MeX+ n NH 3  
 
   wherein Me represents at least one transition metal ion and X represents one or more counterion(s) in a quantity sufficient for charge equalizing the complex, according to the valence thereof and that of the transition metal ion; and   b) one or more transition metal salt(s), carried on a carrier material that is inert with regard to the reaction, is/are used.   
     
     
         2 . The method according to  claim 1 , wherein the at least one transition metal is selected from Mn, Fe, Co, Ni, Cu, and Cd. 
     
     
         3 . The method according to  claim 2 , wherein the at least one transition metal is selected from Cu and Cd. 
     
     
         4 . The method according to  claim 1 , wherein a sulfate ion SO 4   2−  or two chloride ions Cl −  are used as the counterion(s) X. 
     
     
         5 . The method according to  claim 4 , wherein CuSO 4  or CdCl 2  is used as the transition metal salt. 
     
     
         6 . The method according to  claim 1 , wherein the carrier material is selected from vermiculite, porous aluminium silicates, and zeolites. 
     
     
         7 . The method according to  claim 6 , wherein a zeolite or expanded vermiculite is used as the carrier material. 
     
     
         8 . The method according to  claim 1 , wherein a particulate carrier having a grain size of 0.1 to 5 mm is used. 
     
     
         9 . The method according to  claim 1 , wherein the carrier material is loaded with about 10 to about 70 wt % of the transition metal salt. 
     
     
         10 . A method using ammine complexes of transition metal salts for thermo-chemical energy storage by carrying out chemical equilibrium reactions of the ammine complexes of transition metal salts for the storage and re-release of energy,
 wherein   a) ammine complexes of transition metal salts are formed and decomposed according to the following reversible total reactions:
   [Me(NH 3 ) n ]X+ΔH R   MeX+ n NH 3  
 
   wherein Me represents at least one transition metal ion and X represents one or more counterion(s) in a quantity sufficient for charge equalizing the complex, according to the valence thereof and that of the transition metal ion; and   b) one or more transition metal salt(s), carried on a carrier material that is inert with regard to the reaction, is/are used.   
     
     
         11 . The method according to  claim 2 , wherein the at least one transition metal is Cd. 
     
     
         12 . The method according to  claim 1 , wherein a particulate carrier having a grain size of 0.5 to 3 mm is used. 
     
     
         13 . The method according to  claim 1 , wherein a particulate carrier having a grain size of 1 to 2 mm is used. 
     
     
         14 . The method according to  claim 1 , wherein the carrier material is loaded with about 35 to about 65 wt % of the transition metal salt. 
     
     
         15 . The method according to  claim 1 , wherein the carrier material is loaded with about 40 to about 60 wt % of the transition metal salt.