Ionic liquid solar ponds

Abstract

A solar pond includes a upper convection zone including an ionic liquid; a non-convection zone; and a lower convection zone. The ionic liquid may be an imidazolium salt, an ammonium salt, a pyridinium salt, a piperidium salt, or a phosphonium salt.

1 . A solar pond comprising:
 a upper convection zone comprising an ionic liquid;   a non-convection zone; and   a lower convection zone.   
     
     
         2 . The solar pond of  claim 1 , wherein the ionic liquid has a density that is less than a density of the non-convection zone and the lower convection zone, at an operating temperature of the upper convection zone of the solar pond. 
     
     
         3 . The solar pond of  claim 2 , wherein the density of the ionic liquid is from 0.80 g/ml to 1.25 g/ml, and the operating temperature of the upper convection zone is from about 0° C. to about 100° C. 
     
     
         4 . The solar pond of  claim 1  wherein the ionic liquid comprises an imidazolium ion, an ammonium ion, a pyridinium ion, a piperidium ion, or a phosphonium ion. 
     
     
         5 . The solar pond of  claim 1 , wherein the ionic liquid comprises 4-(2-hydroxy-propyl)-1-methyl-4H-imidazolium hexafluorophosphate; 3-methyl-1-(propan-2-ol)-imidazolium hexafluorophosphate; 3-methyl-1-(propan-2-01)-imidazolium chloride; 3-methyl-1-(propan-2-ol)-imidazolium nitrate; 3-methyl-1-(ethoxyethoxy)-imidazolium hexafluorophosphate; 3-hexyl-1-(2-diethylphosphonato-ethyl)-imidazolium tetrafluoroborate; 3-hexyl-1-(3-diethylphosphonato-propyl)-imidazolium tetrafluoroborate; 3-octyl-1-(2-diethylphosphonato-ethyl)-imidazolium tetrafluoroborate; 3-methyl-1-butyl-imidazolium tetrafluoroborate; 3-methyl-1-butyl-imidazolium chloride; 3-methyl-1-butyl-imidazolium octyl sulfate; 3-methyl-1-butyl-imidazolium fluorohydrogenate; 3-methyl-1-ethyl-imidazolium tricyanomethane; 3-methyl-1-ethyl-imidazolium fluorohydrogenate; 3-methyl-1-ethyl-imidazolium carborane; 3-methyl-1-ethyl-imidazolium methylcarborane; 3-methyl-1-ethyl-imidazolium ethyl carborane; 3-methyl-1-methyl-imidazolium fluorohydrogenate; 3-methyl-1-propyl-imidazolium fluorohydrogenate; 3-methyl-1-pentyl-imidazolium fluorohydrogenate; 3-methyl-1-hexyl-imidazolium fluorohydrogenate; 3-methyl-1-hexyl-imidazolium chloride; 3-methyl-1-octyl-imidazolium chloride; 3-methyl-1-octyl-imidazolium tetrafluoroborate; 3-methyl-1-methyl-imidazolium tetrafluoroborate; 3-methyl-2-ethyl-1-methyl-imidazolium carborate; tetraethylammonium tributyoctylborate; tetraethylammonium acetate; hexyl-triethyl-ammonium hexyl-triethylborate; hexyl-triethyl-ammonium tributyoctylborate; tetrapropylammonium tripropylhexylborate; tetrabutylammonium tributyhexylborate; hexyl-tri-butylammonium tributylhexylborate; hexyl-tri-butylammonium bis-trifluoromethanesulfonamide; heptyl-tri-butylammonium bis-trifluoromethanesulfonamide; tetrapentylammonium bis-trifluoromethanesulfonamide; octyl-tri-butylammonium bis-trifluoromethanesulfonamide; octyl-tri-butylammonium trifluoromethylsulfonate; tetrahexylammonium bis-trifluoromethanesulfonamide; tetrahexylammonium tributyhexylborate; tetraheptylammonium bis-trifluoromethanesulfonamide; tetraoctylammonium bis-trifluoromethanesulfonamide; tetradodecylammonium bis-trifluoromethanesulfonamide; N-methyl-N-propylpyrrolidine dicyanimide; N-methyl-N-butylpyrrolidine dicyanimide; N-methyl-N-hexylpyrrolidine dicyanimide; [bis-(N-butyl-N-ethyl-amino)-methylene]-dimethyl-ammonium tetrafluoroborate; [bis-(N-hexyl-N-hexyl-amino)-methylene]-dimethyl-ammonium tetrafluoroborate; [bis-(N-hexyl-N-hexyl-amino)-methylene]-dimethyl-ammonium hexafluorophosphate; [bis-(N-hexyl-N-hexyl-amino)-methylene]-dimethyl-ammonium chloride; [bis-(N-hexyl-N-hexyl-amino)-methylene]-dimethyl-ammonium bis-trifluoromethanesulfonamide; [bis-(N-octyl-N-octyl-amino)-methylene]-dimethyl-ammonium tetrafluoroborate; [bis-(N-octyl-N-octyl-amino)-methylene]-dimethyl-ammonium hexafluorophosphate; [bis-(N-octyl-N-octyl-amino)-methylene]-dimethyl ammonium chloride; methyl-tripropylphosphonium tosylate; methyl-tri-(iso-butyl)phosphonium tosylate; methyl-tri-(tert-butyl)phosphonium tosylate; methyl-di-(iso-butyl)-octylphosphonium tosylate; methyl-di-(iso-butyl)-tetradecylphosphonium tosylate; tetradecyl-tri-(hexyl)-phosphonium bromide; tetradecyl-tri-(hexyl)-phosphonium tetrafluoroborate; tetradecyl-tri-(hexyl)-phosphonium hexafluorophosphate; octylimidazolium salicylate; nonylimidazolium salicylate; dodecylimidazolium salicylate; or (butyoxymethyl)imidazolium salicylate. 
     
     
         6 . The solar pond of  claim 2 , wherein the ionic liquid is a liquid at the operating temperature of the upper convection zone of the solar pond. 
     
     
         7 . The solar pond of  claim 6 , wherein the operating temperature is from about 0° C. to about 100° C. 
     
     
         8 . The solar pond of  claim 1 , wherein the ionic liquid is stable to electromagnetic radiation. 
     
     
         9 . The solar pond of  claim 8 , wherein the electromagnetic radiation is ultra-violet radiation. 
     
     
         10 . The solar pond of  claim 1 , wherein the upper convention zone comprises from 0.1% to 10% of a total depth of the solar pond. 
     
     
         11 . The solar pond of  claim 1 , wherein the non-convection zone comprises an aqueous salt solution. 
     
     
         12 . The solar pond of  claim 1 , wherein the non-convention zone comprises from 1% to 50% of a total depth of the solar pond. 
     
     
         13 . The solar pond of  claim 1 , wherein the lower convection zone comprises an aqueous salt solution, that is of a higher concentration than the non-convention zone. 
     
     
         14 . The solar pond of  claim 13 , wherein the aqueous salt solution comprises sodium chloride, potassium chloride, magnesium chloride, calcium chloride, sodium nitrate, potassium nitrate, ammonium nitrate, sodium sulfate, sodium carbonate, sodium bicarbonate, disodium phosphate, borax, or diammonium phosphate. 
     
     
         15 . The solar pond of  claim 1 , wherein the upper convention zone comprises from 0.1% to 10% of a total depth of the solar pond. 
     
     
         16 . A solar pond upper convection zone comprising an ionic liquid. 
     
     
         17 . The solar pond upper convection zone of  claim 16 , wherein a density of the ionic liquid is from 0.80 to 1.25 g/ml, and an operating temperature of the upper convection zone from about 0° C. to about 100° C. 
     
     
         18 . The solar pond upper convection zone of  claim 16 , wherein the ionic liquid comprises an imidazolium ion, an ammonium ion, a pyridinium ion, a piperidium ion, or a phosphonium ion. 
     
     
         19 . The solar pond upper convection zone of  claim 16 , wherein the ionic liquid comprises 4-(2-hydroxy-propyl)-1-methyl-4H-imidazolium hexafluorophosphate; 3-methyl-1-(propan-2-01)-imidazolium hexafluorophosphate; 3-methyl-1-(propan-2-ol)-imidazolium chloride; 3-methyl-1-(propan-2-ol)-imidazolium nitrate; 3-methyl-1-(ethoxyethoxy)-imidazolium hexafluorophosphate; 3-hexyl-1-(2-diethylphosphonato-ethyl)-imidazolium tetrafluoroborate; 3-hexyl-1-(3-diethylphosphonato-propyl)-imidazolium tetrafluoroborate; 3-octyl-1-(2-diethylphosphonato-ethyl)-imidazolium tetrafluoroborate; 3-methyl-1-butyl-imidazolium tetrafluoroborate; 3-methyl-1-butyl-imidazolium chloride; 3-methyl-1-butyl-imidazolium octyl sulfate; 3-methyl-1-butyl-imidazolium fluorohydrogenate; 3-methyl-1-ethyl-imidazolium tricyanomethane; 3-methyl-1-ethyl-imidazolium fluorohydrogenate; 3-methyl-1-ethyl-imidazolium carborane; 3-methyl-1-ethyl-imidazolium methylcarborane; 3-methyl-1-ethyl-imidazolium ethylcarborane; 3-methyl-1-methyl-imidazolium fluorohydrogenate; 3-methyl-1-propyl-imidazolium fluorohydrogenate; 3-methyl-1-pentyl-imidazolium fluorohydrogenate; 3-methyl-1-hexyl-imidazolium fluorohydrogenate; 3-methyl-1-hexyl-imidazolium chloride; 3-methyl-1-octyl-imidazolium chloride; 3-methyl-1-octyl-imidazolium tetrafluoroborate; 3-methyl-1-methyl-imidazolium tetrafluoroborate; 3-methyl-2-ethyl-1-methyl-imidazolium carborate; tetraethylammonium tributyoctylborate; tetraethylammoniurn acetate; hexyl-triethyl-ammonium hexyl-triethylborate; hexyl-triethyl-ammonium tributyoctylborate; tetrapropylammonium tripropylhexylborate; tetrabutylammonium tributyhexylborate; hexyl-tri-butylammonium tributylhexylborate; hexyl-tri-butylammonium bis-trifluoromethanesulfonamide; heptyl-tri-butylammonium bis-trifluoromethanesulfonamide; tetrapentylammonium bis-trifluoromethanesulfonamide; octyl-tri-butylammonium bis-trifluoromethanesulfonamide; octyl-tri-butylammonium trifluoromethylsulfonate; tetrahexylammonium bis-trifluoromethanesulfonamide; tetrahexylammonium tributyhexylborate; tetraheptylammonium bis-trifluoromethanesulfonamide; tetraoctylammonium bis-trifluoromethanesulfonamide; tetradodecylammonium bis-trifluoromethanesulfonamide; N-methyl-N-propylpyrrolidine dicyanimide; N-methyl-N-butylpyrrolidine dicyanimide; N-methyl-N-hexylpyrrolidine dicyanimide; [bis-(N-butyl-N-ethyl-amino)-methylene]-dimethyl-ammonium tetrafluoroborate; [bis-(N-hexyl-N-hexyl-amino)-methylene]-dimethyl-ammonium tetrafluoroborate; [bis-(N-hexyl-N-hexyl-amino)-methylene]-dimethyl-ammonium hexafluorophosphate; [bis-(N-hexyl-N-hexyl-amino)-methylene]-dimethyl-ammonium chloride; [bis-(N-hexyl-N-hexyl-amino)-methylene]-dimethyl-ammonium bis-trifluoromethanesulfonamide; [bis-(N-octyl-N-octyl-amino)-methylene]-dimethyl-ammonium tetrafluoroborate; [bis-(N-octyl-N-octyl-amino)-methylene]-dimethyl-ammonium hexafluorophosphate; [bis-(N-octyl-N-octyl-amino)-methylene]-dimethyl-ammonium chloride; methyl-tripropylphosphonium tosylate; methyl-tri-(iso-butyl)phosphonium tosylate; methyl-tri-(tert-butyl)phosphonium tosylate; methyl-di-(iso-butyl)-octylphosphonium tosylate; methyl-di-(iso-butyl)-tetradecylphosphonium tosylate; tetradecyl-tri-(hexyl)-phosphonium bromide; tetradecyl-tri-(hexyl)-phosphonium tetrafluoroborate; tetradecyl-tri-(hexyl)-phosphonium hexafluorophosphate; octylimidazolium salicylate; nonylimidazolium salicylate; dodecylimidazolium salicylate; or (butyoxymethyl)imidazolium salicylate. 
     
     
         20 . A geothermal system comprising a solar pond comprising an upper convection zone comprising an ionic liquid.