US20180320963A1

US20180320963A1 - Process for Gas/Vapor Separation by Cryogenic Froth Flotation

Info

Publication number: US20180320963A1
Application number: US15/587,037
Authority: US
Inventors: Larry Baxter; Stephanie Burt; Christopher Hoeger; David Frankman; Aaron Sayre; Eric Mansfield; Skyler Chamberlain; Kyler Stitt; Nathan Davis
Original assignee: Individual
Current assignee: Sustainable Energy Solutions Inc
Priority date: 2017-05-04
Filing date: 2017-05-04
Publication date: 2018-11-08

Abstract

A process for separating a vapor from a gas is disclosed. A cryogenic liquid is provided to an inlet of a froth flotation device. A carrier gas is provided to a gas distributor of the froth flotation device. The carrier gas comprises a product vapor. Bubbles of the carrier gas are produced and passed through the cryogenic liquid in the froth flotation device. A portion of the product vapor desublimates, condenses, crystallizes, or a combination thereof to produce a solid product and a product-depleted carrier gas. Bubbles of the product-depleted carrier gas collect the solid product as a froth concentrate. The froth concentrate is removed by overflowing out of the froth flotation device.

Description

FIELD OF THE INVENTION

This invention relates generally to the field of solid-liquid separation. More particularly, we discuss application of froth floatation technologies to the field of cryogenic separations.

BACKGROUND

The art of froth flotation has been used in mineral processing since the 19^thcentury to separate different ore types from each other, leading to concentrates that can be processed economically in other processes. Froth flotation is still used extensively in mineral processing, and has found application in paper recycling and waste-water treatment. Typically, froth flotation is preceded by comminution, or crushing and grinding, which liberates the minerals as physically separate grains. The ore is then mixed with water to form a slurry, mixed with chemicals, and passed into the froth flotation units. The chemicals added depend on the mineral surface chemistry, but can include surfactants, collectors, or pH modifiers. Further chemicals are added at appropriate stages in the flotation process, including surfactants, collectors, pH modifiers, frothers, and other modifiers. Air is bubbled into the froth flotation cells. The bubbles collect minerals that are hydrophobic or chemically made to become hydrophobic, while hydrophilic minerals stay with the water. The froth overflows or is skimmed off the top, resulting in a froth concentrate, while the rest is removed as flotation tailings. Further stages of froth flotation can further concentrate the froth concentrate, scavenge desired minerals from the flotation tailings, or clean the froth concentrate of any leftover undesired minerals.
Froth flotation is most typically used for separation of solids from solids, but can be used for solid-liquid separations. In flotation separations, the particles to be separated from the liquid have a lower density than the liquid, allowing bubbles to easily elevate the particles to the top of the liquid for removal. When flotation separation is used for particles that are denser than the liquid and are hydrophilic, collectors and other chemicals are sometimes required to cause the particles to be collectable by the bubbles for removal. The present disclosure differs from typical froth flotation in that typical froth flotation is not conducted at cryogenic temperatures. Further, typical froth flotation does not separate vapors from gases.
Typically, froth flotation occurs in aqueous solutions. In some specific instances, organic solvents have been used in froth flotation. In one instance, an organic solution was used in density sorting against an aqueous solution to separate seed batches, as described in, “The Encyclopedia of Seeds: Science, Technology and Uses,” by Bewley, et al., on page 122. In another, U.S. Pat. No. 3,186,546 to Keen, teaches flotation separation of particulate materials in non-aqueous media. This patent from 1965 has not been adopted in any mineral processing application of which the inventors are aware. This is likely due to the use of hazardous organics such as fluorinated organic compounds as collectors and kerosene or aromatic hydrocarbons like benzene as solvents. The present disclosure differs from these disclosures in that density sorting is used, fluorinated organic compounds are used as collectors, aromatic hydrocarbons are used as solvents, and solids are directly separated from liquids. These disclosures are pertinent and may benefit from the processes disclosed herein and are hereby incorporated for reference in their entirety for all that they teach.
United States patent publication number 955,012 to Sulman teaches concentration of ores. A method for separating sulfidic ores from other ores is provided. The present disclosure differs from this disclosure in that solids are not created in the flotation cell and no cryogenic froth flotation is disclosed. This disclosure is pertinent and may benefit from the processes disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 2,990,958 to Greene, et al., teaches a froth flotation method using oils for separating ore types. The present disclosure differs from this disclosure in that solids are not created in the flotation cell and no cryogenic froth flotation is disclosed. This disclosure is pertinent and may benefit from the processes disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
U.S. Pat. No. 3,822,015 to Kornberg, et al., teaches separation of solids by varying the bulk density of a fluid separating medium. The present disclosure differs from this disclosure in that solids are not created in the flotation cell and no cryogenic froth flotation is disclosed. This disclosure is pertinent and may benefit from the processes disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.
Canadian patent publication number 2276473 to Coulter teaches cryogenic crushing of ore. The present disclosure differs from this disclosure in that no cryogenic froth flotation is disclosed. This disclosure is pertinent and may benefit from the processes disclosed herein and is hereby incorporated for reference in its entirety for all that it teaches.

SUMMARY

A process for separating a vapor from a gas is disclosed. A cryogenic liquid is provided to an inlet of a froth flotation device. A carrier gas is provided to a gas distributor of the froth flotation device. The carrier gas comprises a product vapor. The solid product is cryogenic liquidphobic. Bubbles of the carrier gas are produced and passed through the cryogenic liquid in the froth flotation device. A portion of the product vapor desublimates, condenses, crystallizes, or a combination thereof to produce a solid product and a product-depleted carrier gas. Bubbles of the product-depleted carrier gas collect the solid product as a froth concentrate. The froth concentrate is removed by overflowing out of the froth flotation cell. The froth concentrate comprises the solid product, the product-depleted carrier gas, and a first portion of the cryogenic liquid.
A second portion of the cryogenic liquid may be removed from the froth flotation device as a used cryogenic liquid. The second portion of the cryogenic liquid is substantially larger than the first portion of the cryogenic liquid. In this manner, the product vapor is separated from the carrier gas.
The product vapor may comprise carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, hydrogen cyanide, water, hydrocarbons, mercury, other heavy metals, condensed organics, salts, water ice, particulates, soot, dust, or combinations thereof.
The cryogenic liquid may comprise any compound or mixture of compounds with a freezing point above the temperature at which the solid melts. The cryogenic liquid may comprise mercaptans, ionic liquids, salt solutions, hydrocarbons, or a combination thereof.
The carrier gas may comprise combustion flue gas, syngas, producer gas, natural gas, steam reforming gas, light gases, hydrocarbons with a freezing point above the temperature of the cryogenic liquid, or combinations thereof. The product-depleted carrier gas may be passed from the froth concentrate through further froth flotation.
A frother, a collector, a modifier, or a combination thereof may be provided to the froth flotation device.
The froth flotation device may be enclosed and maintained at an elevated pressure.
A controller may be provided to receive inputs from instruments and output commands to drives and valves. The gas distributor may comprise an agitator. The agitator may be driven with a variable frequency drive. The froth flotation device may comprise a skimmer. The froth flotation device may comprise a level sensor. The froth flotation device may comprise a turbidity meter. A flow rate of the carrier gas may be controlled with a control valve and a flow rate of the cryogenic liquid may be controlled with a variable frequency drive on a pump.
The gas distributor may comprise a cryogenically-stable material. The cryogenically-stable material may comprise sintered ceramics, polytetrafluoroethylene, polychlorotrifluoroethylene, natural diamond, man-made diamond, chemical-vapor deposition diamond, polycrystalline diamond, or combinations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through use of the accompanying drawings, in which:

FIG. 1 shows a process for separating a product vapor from a gas.

FIG. 2 shows a process for separating carbon dioxide vapor from a combustion flue gas.

FIG. 3 shows a flotation cell for separating a vapor from a gas.

FIG. 4 shows an enclosed flotation cell for separating a vapor from a gas.

FIG. 5 shows a flotation cell for separating a vapor from a gas.

FIG. 6 shows a bank of flotation cells for separating a vapor from a gas.

FIG. 7 shows a process flow diagram of two banks of flotation cells in series for separating a vapor from a gas.

DETAILED DESCRIPTION

It will be readily understood that the components of the present invention, as generally described and illustrated in the Figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the invention, as represented in the Figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention.
Referring to FIG. 1, a process for separating a product vapor from a gas is shown at 100, as per one embodiment of the present invention. A cryogenic liquid is provided to an inlet of a froth flotation device 101. A carrier gas is provided to a gas distributor of the froth flotation device, the carrier gas comprising a product vapor 102. Bubbles of the carrier gas are produced and passed through the cryogenic liquid in the froth flotation device 103. This causes a portion of the product vapor to desublimate, condense, crystallize, or a combination thereof to produce a solid product and a product-depleted carrier gas 104. The solid product is cryogenic liquidphobic. Liquidphobic has similar meaning to terms like, “hydrophobic,” or “organophobic,” but is more general. Rather than tending to repel or fail to mix with water or organics, respectively, liquidphobic compounds will tend to repel or fail to mix with whatever liquid is disclosed. Stating something is cryogenic liquidphobic should not be implied to mean that the solid product will tend to repel or fail to mix with all liquids at cryogenic temperatures. Rather, the cryogenic liquid must be chosen such that the solid product will be liquidphobic towards it. A solid product that is liquidphobic towards one cryogenic liquid may be completely soluble, or liquidphilic, in a different cryogenic liquid. Due to this liquidphobicity, bubbles of the product-depleted carrier gas collect the solid product as a froth concentrate 105. The froth concentrate is removed by overflowing out of the froth flotation cell 106. The froth concentrate comprises the solid product, the product-depleted carrier gas, and a first portion of the cryogenic liquid. A second portion of the cryogenic liquid is removed from the froth flotation device as a used cryogenic liquid 107.
Referring to FIG. 2, a process for separating carbon dioxide vapor from a combustion flue gas is shown at 200, as per one embodiment of the present invention. A cryogenic liquid at a cryogenic temperature that is lower than the frost point of the combustion flue gas is provided to an inlet of a froth flotation device 201. The combustion flue gas, comprising carbon dioxide vapor and other light gases, is provided to a gas distributor of the froth flotation device 202. Bubbles of the combustion flue gas pass through the cryogenic liquid in the froth flotation device 203. This causes a portion of the carbon dioxide vapor to desublimate, condense, crystallize, or a combination thereof to produce a solid carbon dioxide and a CO2-depleted combustion flue gas 204. The solid carbon dioxide is cryogenic liquidphobic. Due to this cryogenic liquidphobicity, bubbles of the CO2-depleted combustion flue gas collect the solid carbon dioxide as a froth concentrate 205. The froth concentrate is removed by overflowing out of the froth flotation cell 206. A second portion of the cryogenic liquid is removed from the froth flotation device as a used cryogenic liquid 207.
Referring to FIG. 3, a flotation cell for separating a vapor from a gas is shown at 300, as per one embodiment of the present invention. Cryogenic liquid 330 is provided to cell 302 through liquid inlet 304. Carrier gas 332 is passed through gas inlet 306 and bubbler 312 and enters cell 302 as carrier gas bubbles 340. Carrier gas 332 comprises a product vapor. A portion of the product vapor is desublimated, condensed, crystallized, or a combination thereof to form a solid product and product-depleted carrier gas 338. Cryogenic liquid 330 is selected such that the solid product is liquidphobic towards cryogenic liquid 330. Due to this liquidphobicity, product-depleted carrier gas bubbles 342 collect the solid product and form froth concentrate 336. Froth concentrate 336 overflows into overflow weir 308, product-depleted carrier gas 338 is removed as bubbles 342 rupture, and the cryogenic liquid and solid product left from froth concentrate 336 are removed. Warmed cryogenic liquid 334 passes out liquid outlet 310. In some embodiments, product-depleted carrier gas 338 is collected and passed through further froth flotation cells to remove all product vapor. In some embodiments, warmed cryogenic liquid 334 is cooled and returned as cryogenic liquid 330. In other embodiments, a series of froth flotation cells are provided in series, the carrier gas passing through each in turn. In these embodiments, the warmed cryogenic liquid 334 is sent to the previous froth flotation cell and used as the cryogenic liquid in that cell. In this manner, a temperature profile is created, where the carrier gas passes through the warmest cryogenic liquid first and progressively colder cryogenic liquids in later stages, maximizing efficiency and product vapor removal.
Referring to FIG. 4, an enclosed flotation cell for separating a vapor from a gas is shown at 400, as per one embodiment of the present invention. Cryogenic liquid 430 is provided to cell 402 through liquid inlet 404. Carrier gas 432 is passed through gas inlet 406 and bubbler 412 and enters cell 402 as carrier gas bubbles 440. Carrier gas 432 comprises a product vapor. A portion of the product vapor is desublimated, condensed, crystallized, or a combination thereof to form a solid product and product-depleted carrier gas 438. Cryogenic liquid 430 is selected such that the solid product is liquidphobic towards cryogenic liquid 430. Due to this liquidphobicity, product-depleted carrier gas bubbles 442 collect the solid product and form froth concentrate 436. Froth concentrate 436 overflows into overflow weir 408, product-depleted carrier gas 438 is removed as bubbles 442 rupture, and the cryogenic liquid and solid product left from froth concentrate 436 are removed. Warmed cryogenic liquid 434 passes out liquid outlet 410. Product-depleted carrier gas 438 is removed through gas outlet 414. In some embodiments, product-depleted carrier gas is passed through further froth flotation cells to remove all product vapor. In some embodiments, warmed cryogenic liquid 434 is cooled and returned as cryogenic liquid 430. In other embodiments, a series of froth flotation cells are provided in series, the carrier gas passing through each in turn. In these embodiments, the warmed cryogenic liquid 434 is sent to the previous froth flotation cell and used as the cryogenic liquid in that cell. In this manner, a temperature profile is created, where the carrier gas passes through the warmest cryogenic liquid first and progressively colder cryogenic liquids in later stages, maximizing efficiency and product vapor removal.
Referring to FIG. 5, a flotation cell for separating a vapor from a gas is shown at 500, as per one embodiment of the present invention. Cryogenic liquid 530 is provided to cell 502 through liquid inlet 504. Carrier gas 532 is passed through gas inlet 506, down drive shaft 514, through impeller/diffuser 512, and enters cell 502 as carrier gas bubbles 540. Drive shaft 514 and impeller/diffuser 512 are rotated by a v-belt drive, including pulley 516. Carrier gas 532 comprises a product vapor. A portion of the product vapor is desublimated, condensed, crystallized, or a combination thereof to form a solid product and product-depleted carrier gas 538. Cryogenic liquid 530 is selected such that the solid product is liquidphobic towards cryogenic liquid 530. Due to this liquidphobicity, product-depleted carrier gas bubbles 542 collect the solid product and form froth concentrate 536. Froth concentrate 536 overflows into overflow weir 508, product-depleted carrier gas 538 is removed as bubbles 542 rupture, and the cryogenic liquid and solid product left from froth concentrate 536 are removed. Warmed cryogenic liquid 534 passes out liquid outlet 510. In some embodiments, product-depleted carrier gas 538 is collected and passed through further froth flotation cells to remove all product vapor. In some embodiments, product-depleted carrier gas is passed through further froth flotation cells to remove all product vapor. In some embodiments, warmed cryogenic liquid 534 is cooled and returned as cryogenic liquid 530. In other embodiments, a series of froth flotation cells are provided in series, the carrier gas passing through each in turn. In these embodiments, the warmed cryogenic liquid 534 is sent to the previous froth flotation cell and used as the cryogenic liquid in that cell. In this manner, a temperature profile is created, where the carrier gas passes through the warmest cryogenic liquid first and progressively colder cryogenic liquids in later stages, maximizing efficiency and product vapor removal.
Referring to FIG. 6, a bank of flotation cells for separating a vapor from a gas is shown at 600, as per one embodiment of the present invention. Cryogenic liquid 630 is provided to bank 602, consisting of four cells. Carrier gas 632 is passed through gas pipe 606, passes down drive shafts 614, through impellers/diffusers (not shown), and enters each cell in bank 602 as carrier gas bubbles. Drive shafts 614 and the impellers/diffusers are rotated by a v-belt drive, including pulley 616. Carrier gas 632 comprises a product vapor. A portion of the product vapor is desublimated, condensed, crystallized, or a combination thereof to form a solid product and product-depleted carrier gas 638. Cryogenic liquid 630 is selected such that the solid product is liquidphobic towards cryogenic liquid 630. Due to this liquidphobicity, product-depleted carrier gas bubbles collect the solid product and form a froth concentrate (not shown). The froth concentrate overflows into overflow weir 608, product-depleted carrier gas 638 is removed as the bubbles rupture, and the cryogenic liquid and solid product left from the froth concentrate are removed as concentrate 636. Warmed cryogenic liquid 634 passes out liquid outlet 610. In some embodiments, product-depleted carrier gas 638 is collected and passed through further froth flotation banks to remove all product vapor. In some embodiments, product-depleted carrier gas is passed through further froth flotation cells to remove all product vapor. In some embodiments, warmed cryogenic liquid 634 is cooled and returned as cryogenic liquid 630. In other embodiments, a series of froth flotation banks are provided in series, the carrier gas passing through each in turn. In these embodiments, the warmed cryogenic liquid 634 is sent to the previous froth flotation bank and used as the cryogenic liquid in that bank. In this manner, a temperature profile is created, where the carrier gas passes through the warmest cryogenic liquid first and progressively colder cryogenic liquids in later stages, maximizing efficiency and product vapor removal.
Referring to FIG. 7, a process flow diagram of two banks of flotation cells in series for separating a vapor from a gas are shown at 700, each bank of cells consisting of the bank of cells in FIG. 6, as per one embodiment of the present invention. Cryogenic liquid 731, from bank 706, is provided to bank 704. Carrier gas 732, comprising a product vapor, is provided to bank 704 through the distributors of each cell in bank 704. A first portion of the product vapor desublimates, condenses, crystallizes, or a combination thereof to produce a first solid product and product-depleted carrier gas 733. The first solid product is cryogenic liquidphobic. Bubbles of product-depleted carrier gas 733 collect the solid product as a first froth concentrate. The froth concentrate overflows out of each cell in bank 704 and product-depleted carrier gas 733 is collected as bubbles rupture, leaving a mixture of a portion of cryogenic liquid 731 and the first solid product as product slurry 735. Product-depleted carrier gas 733 is passed to bank 706. Warmed cryogenic liquid 734 has make-up liquid added, is cooled, and is recycled as cryogenic liquid 730, which is provided to bank 706. A second portion of the product vapor desublimates, condenses, crystallizes, or a combination thereof in bank 706 to produce a second solid product and product-depleted carrier gas 738. The second solid product is cryogenic liquidphobic. Bubbles of product-depleted carrier gas 738 collect the second solid product as a froth concentrate, product-depleted carrier gas 738 is removed as bubbles rupture, leaving a mixture of a portion of cryogenic liquid 730 and the second solid product as a product slurry. This product slurry combines with product slurry 735 to produce final product slurry 736. In some embodiments, this final product slurry is separated such that a final solid product is produced while the portions of cryogenic liquid 730 and 731 are recycled as make-up liquid.
In some embodiments, the product vapor comprises carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, hydrogen cyanide, water, hydrocarbons, mercury, other heavy metals, condensed organics, salts, water ice, particulates, soot, dust, or combinations thereof.
In some embodiments, the cryogenic liquid comprises any compound or mixture of compounds with a freezing point above the temperature at which the solid melts. In other embodiments, the cryogenic liquid comprises mercaptans, ionic liquids, salt solutions, hydrocarbons, or a combination thereof.
In some embodiments, the carrier gas comprises combustion flue gas, syngas, producer gas, natural gas, steam reforming gas, light gases, hydrocarbons with a freezing point above the temperature of the cryogenic liquid, or combinations thereof.
In some embodiments, the product-depleted carrier gas is separated from the froth concentrate. In some embodiments, the product-depleted carrier gas is passed through further froth flotation devices. In some embodiments, the solid product is separated from the first portion of the cryogenic liquid and the first portion of the cryogenic liquid is passed to combine with the used cryogenic liquid. In some embodiments, the used cryogenic liquid is reconstituted by heat exchange to produce the cryogenic liquid.
In some embodiments, a frother, a collector, a modifier, or a combination thereof are provided to the froth flotation device.
In some embodiments, a controller is provided to receive inputs from instruments and output commands to drives and valves. In some embodiments, a gas distributor comprising an agitator is provided. In some embodiments, the agitator comprises a variable frequency drive. In some embodiments, the froth flotation device further comprises a skimmer, a level sensor, a turbidity meter, or combinations thereof. In some embodiments, a flow rate of the carrier gas is controlled with a control valve and a flow rate of the cryogenic liquid is controlled with a variable frequency drive on a pump.
In some embodiments, the gas distributor comprises a cryogenically-stable material. In some embodiments, the cryogenically-stable material comprises sintered ceramics, polytetrafluoroethylene, polychlorotrifluoroethylene, natural diamond, man-made diamond, chemical-vapor deposition diamond, polycrystalline diamond, or combinations thereof.
Combustion flue gas consists of the exhaust gas from a fireplace, oven, furnace, boiler, steam generator, or other combustor. The combustion fuel sources include coal, hydrocarbons, and biomass. Combustion flue gas varies greatly in composition depending on the method of combustion and the source of fuel. Combustion in pure oxygen produces little to no nitrogen in the flue gas. Combustion using air leads to the majority of the flue gas consisting of nitrogen. The non-nitrogen flue gas consists of mostly carbon dioxide, water, and sometimes unconsumed oxygen. Small amounts of carbon monoxide, nitrogen oxides, sulfur dioxide, hydrogen sulfide, and trace amounts of hundreds of other chemicals are present, depending on the source. Entrained dust and soot will also be present in all combustion flue gas streams. The method disclosed applies to any combustion flue gases. Dried combustion flue gas has had the water removed.
Syngas consists of hydrogen, carbon monoxide, and carbon dioxide.
Producer gas consists of a fuel gas manufactured from materials such as coal, wood, or syngas. It consists mostly of carbon monoxide, with tars and carbon dioxide present as well.
Steam reforming is the process of producing hydrogen, carbon monoxide, and other compounds from hydrocarbon fuels, including natural gas. The steam reforming gas referred to herein consists primarily of carbon monoxide and hydrogen, with varying amounts of carbon dioxide and water.
Light gases include gases with higher volatility than water, including hydrogen, helium, carbon dioxide, nitrogen, and oxygen. This list is for example only and should not be implied to constitute a limitation as to the viability of other gases in the process. A person of skill in the art would be able to evaluate any gas as to whether it has higher volatility than water.
Refinery off-gases comprise gases produced by refining precious metals, such as gold and silver. These off-gases tend to contain significant amounts of mercury and other metals.

Claims

1. A process for separating a vapor from a gas comprising:

providing a cryogenic liquid to an inlet of a froth flotation device;

providing a carrier gas to a gas distributor of the froth flotation device, the carrier gas comprising a product vapor;

producing bubbles of the carrier gas and passing the bubbles of the carrier gas through the cryogenic liquid in the froth flotation device, wherein:

a portion of 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; and,

removing the froth concentrate by overflow out of the froth flotation device, wherein the froth concentrate comprises the solid product, the product-depleted carrier gas, and a first portion of the cryogenic liquid;

whereby the product vapor is separated from the carrier gas.

2. The process of claim 1, further comprising removing a second portion of the cryogenic liquid from the froth flotation device as a used cryogenic liquid, wherein the second portion of the cryogenic liquid is substantially larger than the first portion of the cryogenic liquid

3. The process of claim 1, providing the product vapor comprising carbon dioxide, nitrogen oxide, sulfur dioxide, nitrogen dioxide, sulfur trioxide, hydrogen sulfide, hydrogen cyanide, water, hydrocarbons, mercury, other heavy metals, condensed organics, salts, water ice, particulates, soot, dust, or combinations thereof.

4. The process of claim 1, providing the cryogenic liquid comprising any compound or mixture of compounds with a freezing point below the temperature at which the solid melts.

5. The process of claim 1, providing the cryogenic liquid comprising mercaptans, ionic liquids, salt solutions, hydrocarbons, or a combination thereof.

6. The process of claim 5, providing the hydrocarbons comprising 1,1,3-trimethylcyclopentane, 1,4-pentadiene, 1,5-hexadiene, 1-butene, 1-methyl-1-ethylcyclopentane, 1-pentene, 3,3,3,3-tetrafluoropropene, 3,3-dimethyl-1-butene, 3-chloro-1,1,1,2-tetrafluoroethane, 3-methylpentane, 3-methyl-1,4-pentadiene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-methylpentane, 5-methyl-1-hexene, 5-methyl-1-pentene, 5-methylcyclopentene, 5-methyl-trans-2-pentene, bromochlorodifluoromethane, bromodifluoromethane, bromotrifluoroethylene, chlorotrifluoroethylene, cis 3-hexene, cis-1,3-pentadiene, cis-2-hexene, cis-2-pentene, dichlorodifluoromethane, difluoromethyl ether, trifluoromethyl ether, dimethyl ether, ethyl fluoride, ethyl mercaptan, hexafluoropropylene, isobutane, isobutene, isobutyl mercaptan, isopentane, isoprene, methyl isopropyl ether, methylcyclohexane, methylcyclopentane, methylcyclopropane, n,n-diethylmethylamine, octafluoropropane, pentafluoroethyl trifluorovinyl ether, propane, sec-butyl mercaptan, trans-2-pentene, trifluoromethyl trifluorovinyl ether, vinyl chloride, bromotrifluoromethane, chlorodifluoromethane, dimethyl silane, ketene, methyl silane, perchloryl fluoride, propylene, vinyl fluoride, methanol, ethanol, 1-propanol, 2-propanol, aqueous mixtures thereof, or combinations thereof.

7. The process of claim 1, providing the carrier gas comprising combustion flue gas, syngas, producer gas, natural gas, steam reforming gas, light gases, hydrocarbons with a freezing point above the temperature of the cryogenic liquid, or combinations thereof.

8. The process of claim 1, further comprising separating the product-depleted carrier gas from the froth concentrate.

9. The process of claim 8, further comprising passing the product-depleted carrier gas through further froth flotation devices.

10. The process of claim 8, further comprising separating the solid product from the first portion of the cryogenic liquid and passing the first portion of the cryogenic liquid to combine with the used cryogenic liquid.

11. The process of claim 10, further comprising reconstituting the used cryogenic liquid by heat exchange to produce the cryogenic liquid.

12. The process of claim 1, further comprising providing a frother, a collector, a modifier, or a combination thereof to the froth flotation device.

13. The process of claim 1, further comprising providing a controller to receive inputs from instruments and output commands to drives and valves.

14. The process of claim 13, providing the gas distributor further comprising an agitator.

15. The process of claim 14, further comprising driving the agitator with a variable frequency drive.

16. The process of claim 15, providing the froth flotation device further comprising a skimmer, a level sensor, a turbidity meter, or combinations thereof.

17. The process of claim 16, providing the froth flotation device further comprising controlling a flow rate of the carrier gas with a control valve and a flow rate of the cryogenic liquid with a variable frequency drive on a pump.

18. The process of claim 1, providing the gas distributor comprising a cryogenically-stable material.

19. 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.

20. The process of claim 19, further comprising:

providing a controller to receive inputs from instruments and output commands to drives and valves;

providing the gas distributors further comprising agitators, the agitators comprising variable frequency drives; and,

providing the banks B1 through Bn with skimmers, level sensors, turbidity meters, control valves for controlling flow rates of the carrier gas, and variable frequency drives on pumps for controlling flow rates of the cryogenic liquid.