Process for Gas/Vapor Separation by Cryogenic Froth Flotation

A process for separating a vapor from a gas comprising:

• providing n froth flotation banks in series, a bank B1 being associated with a first bank and a bank Bn being associated with an nth bank, n representing the number of banks, wherein each bank comprises one or more flotation cells;
• providing a cryogenic liquid to the banks Bn through B1 in reverse series, passing the cryogenic liquid through the one or more flotation cells;
• providing a carrier gas to the banks B1 through Bn in series, passing the carrier gas through gas distributors in the one or more flotation cells of the banks, producing bubbles of the carrier gas and passing the bubbles of the carrier gas through the cryogenic liquid in the froth flotation device, wherein:
• the product vapor desublimates, condenses, crystallizes, or a combination thereof to produce a solid product and a product-depleted carrier gas, wherein the solid product is cryogenic liquidphobic;
• and,
• bubbles of the product-depleted carrier gas collect the solid product as a froth concentrate;
• removing the froth concentrate by overflow out of the banks B1 through Bn, wherein the froth concentrate comprises the solid product, the product-depleted carrier gas, and a first portion of the cryogenic liquid;
• separating froth concentrate into the product-depleted carrier gas, the solid product, and the first portion of the cryogenic liquid, removing the product-depleted carrier gas and the solid product as a final gas product and a final solid product, respectively;
• removing a second portion of the cryogenic liquid from the bank B1, combining the second portion of the cryogenic liquid with the first portion of the cryogenic liquid to form a used cryogenic liquid, wherein the second portion of the cryogenic liquid is substantially larger than the first portion of the cryogenic liquid;
• and,
• reconstituting the used cryogenic liquid by heat exchange to produce the cryogenic liquid;
• whereby the product vapor is separated from the carrier gas.