In-situ reactive absorption for equilibrium-shifting of non-condensable gases

Abstract

The invention is directed to a salt composition for use in a thermochemical energy storage device, said salt composition comprising a base and a hygroscopic salt that can produce a gas by reacting with an acid. In further aspects the invention is directed to ab energy storage compartment and a thermochemical energy storage device comprising the salt composition.

1 . Salt composition for use in a thermochemical energy storage device, said salt composition comprising a base and a hygroscopic salt that can produce a gas by reacting with an acid. 
     
     
         2 . Salt composition in accordance with  claim 1 , wherein said hygroscopic salt comprises a metal salt comprising an anion selected from the group consisting of chlorides, sulfides, sulfates, sulfites, carbonates, sulfonates and combinations thereof. 
     
     
         3 . Salt composition in accordance with  claim 1 , wherein said hygroscopic salt comprises a metal salt comprising a metal ion selected from the group consisting of alkali metals, alkaline earth metals and combinations thereof, preferably selected from the group consisting of sodium, potassium, calcium, strontium, magnesium and combinations thereof. 
     
     
         4 . Salt composition in accordance with  claim 1 , wherein the base comprises a basic salt that comprises a metal ion selected from the group consisting of alkali metals, alkaline earth metals and combinations thereof, preferably selected from the group consisting of sodium, potassium, calcium, strontium, magnesium and combinations thereof. 
     
     
         5 . Salt composition in accordance with  claim 1 , wherein the base is a basic salt that comprises an anion selected from the group consisting of hydroxide, carbonate, bicarbonate acetate, sulfide, silicate, preferably hydroxide. 
     
     
         6 . Salt composition in accordance with  claim 1 , wherein the base and the hygroscopic salt are based on a common metal ion. 
     
     
         7 . Salt composition in accordance with  claim 1 , that is obtainable by providing a melt comprising the hygroscopic salt and the base, followed by solidifying said melt. 
     
     
         8 . Salt composition in accordance with  claim 1 , wherein the hydroscopic salt has a theoretical energy storage density of more than 0.5 GJ/m 3 , preferably more than 1 GJ/m 3 , more preferably more than 2 GJ/m, most preferably more than 2.5 GJ/m 3 . 
     
     
         9 . Salt composition in accordance with  claim 1 , wherein the hygroscopic salt comprises one or more salts selected from the group consisting of LiCl, CrCl 2 , CuCl 2 , CaCl 2 , FeCl 2 , LaCl 3 , MgCl 2 , EuCl 3 , GdCl 3 , LiBr, CsF, LiI, MnI 2 , LiNO 2 , Mg(NO 3 ) 2 , Al 2 (SO 4 ) 3 , KAl(SO 4 ) 2 , VOSO 4 , Na 3 PO 4 , K 2 CO 3 , Na 2 CO 3 , Na 2 S, preferably Na 2 S. 
     
     
         10 . Salt composition in accordance with  claim 1 , wherein the base comprises NaOH. 
     
     
         11 . Energy storage compartment for a thermochemical heat storage device, said energy storage compartment comprising the salt composition according to  claim 1 . 
     
     
         12 . Thermochemical energy storage device comprising an energy storage compartment according to  claim 11 . 
     
     
         13 . Thermochemical energy storage device according to  claim 12 , further comprising a liquid storage compartment comprising a condenser and/or evaporator unit and an energy storage compartment comprising the salt composition and a heat exchanger that is thermally connected to the salt composition. 
     
     
         14 . Thermochemical energy storage device according to  claim 13 , further comprising a restricted gas flow passage, preferably closable by a valve, between the water storage compartment and the energy storage compartment. 
     
     
         15 . Method for providing the salt composition in accordance with  claim 1  comprising providing a melt comprising the hygroscopic salt and the base, followed by solidifying said melt.