Abstract: Provided are methods for recovering a rare earth metal from an aqueous solution containing at least two metals. The methods entail: providing an aqueous solution containing rare earth metal ions from a rare earth metal and base metal ions from a base metal that is a transition metal; adding to the aqueous solution a solvent to capture carbon dioxide; and recovering the rare earth metal by: introducing a source of (bi)carbonate or carbamate anion into the solution, thereby forming a rare earth metal carbonate; forming a soluble base metal complex which enables separation of the rare earth element; and precipitating the rare earth metal carbonate from the aqueous solution, thereby forming a rare earth metal-depleted aqueous solution.

Abstract: Provided are methods for recovering calcium carbonate (CaCO3) and magnesium hydroxide (Mg(OH)2) from an aqueous solution containing Ca2+ and Mg2+ ions. The method includes: introducing the aqueous solution into an electrochemical cell having a chamber with a photoactive cathode and an anode therein; and then performing process (a) and process (b). Process (a) entails introducing a source of (bi) carbonate anion into the cell, providing a voltage across the cell, resulting in a process (a) water reduction reaction at the cathode, and precipitating solid CaCO3 from the solution, facilitated by hydroxide ions generated from the process (a) water reduction reaction. Process (b) entails providing a voltage across the cell, resulting in a process (b) water reduction reaction at the cathode, and precipitating solid Mg(OH)2 from the solution, facilitated by hydroxide ions generated from the process (b) water reduction reaction.

Abstract: The present disclosure includes a method of producing solid inorganic carbonate compounds by capturing, converting, and storing carbon dioxide comprising providing one or more precursor compound; providing one or more carbon dioxide capture solvent or capture additive; and reacting said one or more precursor compound with said one or more carbon dioxide capture solvent or capture additive under conditions effective to produce one or more solid inorganic carbonate compound. Also disclosed is a method of producing solid inorganic bicarbonate compounds by capturing, converting, and storing carbon dioxide comprising providing one or more precursor compound; providing one or more carbon dioxide capture solvent or capture additive; and reacting said one or more precursor compound with said one or more carbon dioxide capture solvent or capture additive under conditions effective to produce one or more solid inorganic bicarbonate compound.

Abstract: The present disclosure relates to methods for producing hydrogen and calcium- or magnesium-bearing carbonates by capturing, converting, and storing carbon dioxide. The methods may include providing one or more calcium- or magnesium-bearing compounds; providing one or more water-soluble oxygenates; providing a plurality of catalysts; and reacting one or more calcium- or magnesium-bearing compounds and one or more water-soluble oxygenates with plurality of catalysts under conditions to produce hydrogen and calcium- or magnesium-bearing carbonates. The methods may include providing one or more calcium- or magnesium-bearing silicates; providing carbon monoxide; providing water vapor; and reacting one or more calcium- or magnesium-bearing silicates, carbon monoxide, and water vapor.

Abstract: Methods and systems for capturing and storing carbon dioxide are disclosed. In some embodiments, the methods include the following: mixing materials including magnesium or calcium with one or more acids and chelating agents to form a magnesium or calcium-rich solvent; using the organic acids derived from biogenic wastes as acids or chelating agents; generating carbonate ions by reacting a gas including carbon dioxide with a carbonic anhydrase biocatalyst; reacting the solvent with the carbonate ions to form magnesium or calcium carbonates; recycling a solution containing the biocatalyst after forming magnesium or calcium carbonates for re-use in the generating step; using the magnesium and calcium carbonates as carbon neutral filler materials and using the silica product as green filler materials or inexpensive absorbents.

Abstract: Methods and systems for capturing and storing carbon dioxide are disclosed. In some embodiments, the methods include the following: mixing materials including magnesium or calcium with one or more acids and chelating agents to form a magnesium or calcium-rich solvent; using the organic acids derived from biogenic wastes as acids or chelating agents; generating carbonate ions by reacting a gas including carbon dioxide with a carbonic anhydrase biocatalyst; reacting the solvent with the carbonate ions to form magnesium or calcium carbonates; recycling a solution containing the biocatalyst after forming magnesium or calcium carbonates for re-use in the generating step; using the magnesium and calcium carbonates as carbon neutral filler materials and using the silica product as green filler materials or inexpensive absorbents.

Abstract: Methods and systems for capturing and storing carbon dioxide are disclosed. In some embodiments, the methods include the following: mixing materials including magnesium or calcium with one or more acids and chelating agents to form a magnesium or calcium-rich solvent; using the organic acids derived from biogenic wastes as acids or chelating agents; generating carbonate ions by reacting a gas including carbon dioxide with a carbonic anhydrase biocatalyst; reacting the solvent with the carbonate ions to form magnesium or calcium carbonates; recycling a solution containing the biocatalyst after forming magnesium or calcium carbonates for re-use in the generating step; using the magnesium and calcium carbonates as carbon neutral filler materials and using the silica product as green filler materials or inexpensive absorbents.