Regenerable adsorbent gels and the method of their preparation

Claim 1

A REGENERABLE ADBORBENT FOR CARBON DIOXIDE GAS WHICH COMPRISES THE OXIDE OF A FIRST METAL SELECTED FROM THE GROUP CONSISTING OF LITHIUM, ZINC, BIVALENT IRON, NICKEL, COPPER, COBALT, MANGANESE, MAGNESIUM, CALCIUM, BARIUM, CADMIUM, AND MIXTURES OF THE FOREGOING, IN COMBINATION WITH AN OXIDE OF A TRIVALENT METAL SELECTED FROM THE GROUP CONSISTING OF IRON, ALUMINUM AND CHROMIUM, THE MOLAR RATIO OF SAID FIRST METAL TO SAID RIVALENT METAL BEING IN THE RANGE OF 0.25 TO 5 TO 99.75 TO 95, AND ABSORBENT HAVING A SPECIFIC SURFACE FOR ADSORPTION OF PURE CARBON DIOXIDE AT 1 ATMOSPHERE PRESSURE AND 0*C. OF AT LEAST ABOUT 100M.2/GM. AND BEING CAPABLE OF DESORBING AT LEAST ABOUT 30 PERCENT BY VOLUME OF THE CARBON DIOXIDE ADSORBED AT 0*C. AND 1 ATMOSPHERE PRESSURE WHEN EXPOSED TO A VACUUM OF 10**-4 ATMOSPHERE AT 25*C.

Claim 3

A METHOD FOR PREPARING A REGENERABLE CARBON DIOXIDE ADSORBENT WHICH COMPRISES ESTABLISHING AN AQUEOUS SOLUTION COMPRISING BETWEEN ABOUT 0.1 AND 4.0 MOLES PER LITER OF A SOLUTION COMPRISING A CARONATE OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND AMMONIUM, ADDING THERETO AT LEAST ONE SALRT OF A FIRST METAL SELECTED FROM THE GROUP CONSISTING OF LITHIUM, ZINC, BIVALENT IRON, NICKEL, COPPER, COBALT, MANGANESE, MAGNESIUM, CALCIUM, BARIUM, CADMIUM, INCLUDING MIXTURES OF THE FOREGOING, AND ONE SALT OF A TRIVALENT METAL SELECTED FROM THE GROUP CONSISTING OF ALUMINUN, IRON AND CHROMIUM, INCLUDING MIXTURES OF THE FOREGOING, CONTINUING ADDITION OF SAID SALTS UNTIL THERE HS BEEN ADDED AN AMOUNT OF SALT WHICH IS 0 TO 10 PERCENT LESS THAN THE AMOUNT STOICHIOMETRICALLY REQUIRED TO REACT WITH THE CARBONATE IONS IN THE SOLUTION, MAINTAINING THE TEMPERATURE OF THE SOLUTION BETWEEN ABOUT 0* AND 35*C., BUT HIGH ENOUGH TO SUSTAIN EVOLUTION OF CARBON DIOXIDE, SEPARATING THE GEL FROM THE RESULTING SOLUTION AND DEHYDRATING THE GEL AT A TEMPERATURES LESS THAN 110*C.

Claim 4

A METHOD FOR PREPARING A REGENERABLE CARBON DIOXIDE ADSORBENT WHICH COMPRISES ESTABLISHING AN AQUEOUS SOLUTION COMPRISING BETWEEN ABOUT 0.1 AND 4.0 MOLES PER LITER OF A SOLUTION COMPRISING A CARONATE OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL AND AMMONIUM, ADDING THERETO AT LEAST ONE SALRT OF A FIRST METAL SELECTED FROM THE GROUP CONSISTING OF LITHIUM, ZINC, BIVALENT IRON, NICKEL, COPPER, COBALT, MANGANESE, MAGNESIUM, CALCIUM, BARIUM, CADMIUM, INCLUDING MIXTURES OF THE FOREGOING, AND ONE SALT OF A TRIVALENT METAL SELECTED FROM THE GROUP CONSISTING OF ALUMINUN, IRON AND CHROMIUM, INCLUDING MIXTURES OF THE FOREGOING, CONTINUING ADDITION OF SAID SALTS UNTIL THERE HS BEEN ADDED AN AMOUNT OF SALT WHICH IS 0 TO 10 PERCENT LESS THAN THE AMOUNT STOICHIOMETRICALLY REQUIRED TO REACT WITH THE CARBONATE IONS IN THE SOLUTION, MAINTAINING THE TEMPERATURE OF THE SOLUTION BETWEEN ABOUT 0* AND 35*C., BUT HIGH ENOUGH TO SUSTAIN EVOLUTION OF CARBON DIOXIDE, SEPARATING THE GEL FROM THE RESULTING SOLUTION AND DEHYDRATING THE GEL AT A TEMPERATURES LESS THAN 110*C.