EP3411139A1 - Integrated process for capturing carbon dioxide - Google Patents
Integrated process for capturing carbon dioxideInfo
- Publication number
- EP3411139A1 EP3411139A1 EP17748275.9A EP17748275A EP3411139A1 EP 3411139 A1 EP3411139 A1 EP 3411139A1 EP 17748275 A EP17748275 A EP 17748275A EP 3411139 A1 EP3411139 A1 EP 3411139A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- solution
- substance
- atm
- soluble
- integrated process
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/77—Liquid phase processes
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/1456—Removing acid components
- B01D53/1475—Removing carbon dioxide
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
- B01D53/229—Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption)
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/62—Carbon oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/75—Multi-step processes
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/58—Multistep processes
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
- B01D2252/20—Organic absorbents
- B01D2252/202—Alcohols or their derivatives
- B01D2252/2023—Glycols, diols or their derivatives
- B01D2252/2026—Polyethylene glycol, ethers or esters thereof, e.g. Selexol
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
- B01D2252/20—Organic absorbents
- B01D2252/202—Alcohols or their derivatives
- B01D2252/2023—Glycols, diols or their derivatives
- B01D2252/2028—Polypropylene glycol, ethers or esters thereof
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/50—Carbon oxides
- B01D2257/504—Carbon dioxide
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/40—Capture or disposal of greenhouse gases of CO2
Definitions
- CCU post-combustion C0 2 capture and utilization
- the present invention pertains to a new highly efficient, low energy, and low cost system and methods to capture C0 2 from one or more C0 2 containing gas mixtures.
- C0 2 is absorbed from a gas mix containing C0 2 , such as flue gas, by a C0 2 - lean solution comprising one or more C0 2 absorbents.
- a soluble substance is added to the resulting C0 2 rich solution, eliciting the desorption of gaseous carbon dioxide.
- the resultant solution following the aforementioned C0 2 desorption is separated into the soluble substance and the C0 2 -lean absorption solution.
- the C0 2 -lean absorption solution is transferred to the absorption step and the soluble substance is transferred to the C0 2 desorption step, making the process regenerable.
- the soluble substance and the C0 2 -lean absorption solution recovery is characterized by one or more or a combination of the following:
- the invention pertains to an integrated process for capturing C0 2 .
- the process comprises desorbing gaseous C0 2 from a C0 2 containing aqueous solution comprising carbonate, bicarbonate, sesquicarbonate, carbamate, or a mixture thereof.
- the desorbing of gaseous C0 2 is conducted in the presence of a suitable water soluble substance.
- the invention pertains to an integrated process for capturing C0 2 .
- the process comprises capturing C0 2 to form a C0 2 containing solution comprising carbonate, bicarbonate, sesquicarbonate, carbamate, or a mixture thereof.
- Gaseous C0 2 is desorbed from the C0 2 containing solution comprising carbonate, bicarbonate, sesquicarbonate, carbamate, or a mixture thereof.
- the desorbing of gaseous C0 2 is conducted in the presence of a suitable soluble substance.
- the soluble substance is at least partially recovered by employing (1) a membrane with a molecular weight cutoff of greater than about 80 daltons or (2) distillation or (3) a combination thereof.
- the soluble substance may comprise water, organic solvent, siloxanes, ionic liquids, water soluble polymer, soluble polymer, glycol, polyethylene glycol, polypropylene glycol, ethers, glycol ethers, glycol ether esters, triglyme, polyethylene glycols of multiple geometries, including, branched polyethylene glycols, star polyethylene glycols, comb polyethylene glycols, methoxypolyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic Acid, diol polymers, 1,2 propanediol, 1,2 ethanediol, 1,3 propanediol, cellulose ethers, methylcellulose, cellosize, carboxymethylcellulose, hydroxyethylcellulose, sugar alcohol, sugars, alcohols, ketones, aldehydes, esters, organosilicon compounds, halogenated solvents, non-volatile solvents, a substance with a vapor pressure less
- FIG 1 illustrates an embodiment of a C0 2 capture system with C0 2 desorption in the presence of a soluble substance and membrane-based recovery.
- FIG 2 illustrates an embodiment of a C0 2 capture system with C0 2 desorption in the presence of a volatile soluble substance and distillation recovery.
- FIG 3 illustrates an embodiment of a C0 2 capture system with C0 2 desorption in the presence of a C0 2 switchable solvent and thermal C0 2 switching recovery.
- FIG 4 illustrates an embodiment of a C0 2 capture system with C0 2 desorption in the presence of a C0 2 switchable solvent and air-contacting C0 2 switching recovery.
- FIG 5 illustrates an embodiment of a C0 2 capture system with C0 2 desorption in the presence of a thermally switchable solvent and thermal switching recovery.
- FIG 6 illustrates an embodiment of a C0 2 capture system with C0 2 desorption in the presence of a soluble substance and hybrid 'salting-out' and membrane recovery.
- FIG 7 illustrates an embodiment of a C0 2 capture system with C0 2 desorption in the presence of an ultra-low boiling point water soluble substance and mechanical vapor compression distillation.
- FIG 8 illustrates an embodiment of a C0 2 capture system with C0 2 desorption in the presence of an ultra-low boiling point water soluble substance and mechanical vapor compression distillation wherein heat is exchanged between the distillation and absorption stages, chilling the absorption stage.
- FIG 9 illustrates an embodiment of a C0 2 capture system with C0 2 desorption in the presence of a soluble substance and nanofiltration membrane recovery, wherein the nanofiltration stage is heated.
- FIG 10 shows rate of C0 2 desorption in specific experiments.
- FIG 11 shows C0 2 desorbed in specific experiments.
- FIG 12 shows C0 2 generated at different ammonium bicarbonate solution concentrations.
- FIG 13 shows a plateau in C0 2 generations at high ammounium carbonate and solvent concentrations.
- FIG 14 shows C0 2 release as a function of final solvent mole fraction.
- FIG 15 shows reboiler temperature requirement for acetone and DMM.
- the instant invention generally pertains to an integrated process for capturing C0 2 .
- the process comprises desorbing gaseous C0 2 from a C0 2 containing solution comprising carbonate, bicarbonate, sesquicarbonate, carbamate, or a mixture thereof.
- the desorbing of gaseous C0 2 is usually conducted in the presence of a suitable soluble substance.
- the C0 2 containing solution may be formed in any convenient manner. Generally, any solution capable of dissolving C0 2 in desirable amounts may be employed.
- the components and amounts of such solutions may vary depending upon factors such as, for example, the amount of C0 2 to be dissolved, the source and state of C0 2 and any impurities therewith, the specific desorbing steps, any subsequent processing steps, and other factors.
- the C0 2 containing solution may be derived from or comprise a C0 2 absorbent that is capable of capturing C0 2 from the desired source at the desired parameters.
- Such absorbents may vary widely depending upon the source and desired characteristics of the C0 2 containing solution to be formed.
- the C0 2 absorbent may comprise, for example, water, ammonia, ammonium, amine, azine, amino ethyl ethanol amine, 2-amino-2- methylpropan-l-ol (AMP), MDEA, MEA, primary amine, secondary amine, tertiary amine, low molecular weight primary or secondary amine, metal-ammine complex, metal-ammonia complex, metal-ammonium complex, sterically hindered amine, imines, azines, piperazine, alkali metal, lithium, sodium, potassium, rubidium, caesium, alkaline earth metal, calcium, magnesium, ionic liquid, thermally switchable compounds, C0 2 switchable compounds, enzymes, metal - organic frameworks, quaternary ammonium, quaternary ammonium cations, quaternary ammonium cations embedded in polymer, or mixtures thereof.
- AMP 2-amino-2- methylpropan-l-ol
- MEA 2-amin
- the amounts of C0 2 to be captured from the source will vary. Typically, it is desired to capture at least about any of the following percentages (%) from the total C0 2 in the source: 40, or 50, or 60, or 70, or 80, or 90, or substantially 100.
- the C0 2 may be captured from any convenient source using any convenient manner.
- the C0 2 source may be treated, e.g., scrubbed, before being subjected to the absorbent and/or forming the C0 2 containing solution.
- Such treating methods may be particularly advantageous if the source has impurities that may deleteriously affect subsequent processing steps, e.g., recovery steps employing a membrane or distillation.
- impurities include, but are not limited to, NOx, SOx, oils, particulate matter, heavy metals, and heavy compounds, etc. Conventional treating methods may be employed for this purpose.
- the C0 2 source may be left untreated or only partially treated before being subjected to the absorbent and/or forming the C0 2 containing solution.
- Such an instance may be particularly advantageous if the source does not have impurities or has impurities which are benign or have ameliorable affects.
- Such an example may include a C0 2 source containing NOx or SOx, which may be subjected to a C0 2 absorbent comprising of aqueous ammonia.
- the NOx or SOx may react with said ammonia, forming salable products, such as ammonium nitrate, ammonium sulfate, ammonium sulfite, ammonium bisulfite, ammonium metabisulfite or ammonium nitrite.
- Said salable byproducts may be removed by any convenient manner, including, but not limited to, ion exchange, ion exchange membrane, electrodialysis, or removal or replacement of the absorbent and/or C0 2 containing solution.
- Convenient sources from which to capture C0 2 for the C0 2 containing solution include sources selected from the group consisting of flue gas; combustion emissions; manufacturing emissions; refining emissions or a combination thereof.
- sources may include, for example, from combustion of one or more hydrocarbons; emissions from the combustion of natural gas, coal, oil, petcoke, gasoline, diesel, biofuel, or municipal waste; emissions from waste water treatment gases, or landfill gases, from air, from metal production/refining, from the production of Iron, Steel, Aluminum or Zinc, from cement production, from quicklime production, from Glass production, oil and gas refineries, steam reforming, hydrogen production, HVAC, refrigeration, transportation vehicles (ships, boats, cars, buses, trains, trucks, airplanes), natural gas, biogas, alcohol fermentation, volcanic activity, decomposing leaves/biomass, septic tank, respiration, manufacturing facilities, fertilizer production, geothermal wells, and combinations thereof.
- the C0 2 containing solution may typically comprise carbonate, bicarbonate, sesquicarbonate, carbamate, or a mixture thereof.
- the solution may also comprise suitable cations such as ammonium and other species such as described above that may remain from any C0 2 absorbent.
- the C0 2 containing solution may be aqueous, but, of course, it may take other forms as well depending upon the embodiment employed.
- the desorbing of gaseous C0 2 may be conducted in any convenient manner. Such manner will vary depending upon the specific amount, composition, and nature of the C0 2 containing solution. Typically, the desorbing is conducted in the presence of a suitable soluble substance, for example, water soluble substance. Useful substances and potentially useful concentrations vary depending upon the reactants, amounts, and desired outcomes.
- a suitable soluble substance for example, water soluble substance.
- Useful substances and potentially useful concentrations vary depending upon the reactants, amounts, and desired outcomes.
- the specific manner of combining the suitable soluble substance and C0 2 containing solution is not particularly critical in most instances. That is, the suitable soluble substance may be added to the C0 2 containing solution, the C0 2 containing solution may be added to the suitable soluble substance, or one or the other could even be formed in situ or combined in some other manner.
- the amounts of C0 2 to be desorbed will vary. Typically, it is desired to desorb at least about any of the following percentages (%) from the total C0 2 in the source: 40, or 50, or 60, or 70, or 80, or 90, or substantially 100%.
- the soluble substance employed may vary depending upon, for example, whether it is to be at least partially recovered, and, if so, in what manner.
- at least partially recovered it is meant from at least about 50%, or at least about 60%, or at least about 70%, or at least about 80%, or at least about 90%, or at least about 95%, or at least about 99% up to nearly 100% of the soluble solvent is recovered for re-use in the process or something else.
- the manner of at least partially recovering the soluble substance is not particularly critical and will vary depending upon such factors as the specific composition, the desired outcome, and equipment available.
- the separation mechanism used for at least partially recovering the soluble substance may include one or more or a combination of the following: membrane, reverse osmosis, hot reverse osmosis, nanofiltration, organic solvent nanofiltration, hot nanofiltration, ultrafiltration, hot ultrafiltration, microfiltration, filtration, distillation, membrane distillation, multi-effect distillation, mechanical vapor compression distillation, binary distillation, azeotrope distillation, hybrid separation devices, flash distillation, multistage flash distillation, extractive distillation, switchable solvent, 'salting- out,' or centrifuge, or combinations thereof.
- the soluble substance may be at least partially recovered by employing a membrane that is, for example, capable of at least partially rejecting said soluble substance while allowing substantial passage of C0 2 containing aqueous solution or vice versa.
- C0 2 containing solution or "C0 2 containing aqueous solution” simply refers to the subsequently obtained solution after desorbing of C0 2 .
- C0 2 containing aqueous solution or C0 2 containing solution may have various amounts of C0 2 or even no C0 2 depending upon the amount of C0 2 desorbed in the desorbing step.
- This subsequently obtained solution typically comprises the solution components less any C0 2 desorbed while any soluble substance is at least partially recovered by virtue of being rejected by the membrane.
- the soluble substance may comprise, for example, water, organic solvent, water soluble polymer, soluble polymer, glycol, polyethylene glycol, polypropylene glycol, ethers, glycol ethers, glycol ether esters, triglyme, polyethylene glycols of multiple geometries, including, branched polyethylene glycols, star polyethylene glycols, comb polyethylene glycols, methoxypolyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic Acid, diol polymers, 1,2 propanediol, 1 ,2 ethanediol, 1,3 propanediol, cellulose ethers, methylcellulose, cellosize, carboxymethylcellulose, hydroxyethylcellulose, sugar alcohol, sugars, alcohols, ketones, aldehydes, esters, organosilicon compounds, halogenated solvents, non-volatile solvents, a substance with a vapor pressure less than 0.01 atm
- Useful membranes for at least partial recovery may include, for example, any membrane capable of at least partially rejecting said soluble substance while allowing substantial passage of C0 2 containing aqueous solution or vice versa.
- Such membranes may comprise a membrane selected from the group consisting of Reverse Osmosis, Nanofiltration, Organic Solvent Nanofiltration, Ultrafiltration, Microfiltration, and Filtration membranes.
- the membrane may have a molecular weight cutoff of greater than about 80 daltons. That is, the membrane allows passage of a substantial or majority amount of components with a molecular weight of less than about 80 daltons while rejecting a substantial or majority amount of components with a molecular weight of greater than about 80 daltons up to about 600 daltons.
- molecular weight cut-off may refer to the lowest molecular weight solute (in daltons) in which 90% of the solute is retained by the membrane, or the molecular weight of the molecule that is 90% retained by the membrane.
- Membranes with a molecular weight cutoff of less than 1 ,000 daltons, or less than 10,000 daltons, or less than 50,000 daltons, or less than 100,000 daltons, or less than 200,000 daltons, or less than 500,000 daltons, or less than 1 ,000,000 daltons may also be useful depending upon the circumstances and components employed.
- the membrane may be comprised of any useful material and such useful material may vary depending upon the components to be separated, their molecular weight, viscosity, and/or other properties.
- Useful membranes may include, for example, membranes comprised of a material selected from a thin film composite; a polyamide; a cellulose acetate; a ceramic membrane; other materials and combinations thereof.
- any at least partial recovery step(s) involving one or more membranes may be conducted at a temperature of less than or equal to about 50, or less than or equal to 40, or less than or equal to about 35, or less than or equal to about 30°C.
- the at least partial recovery step(s) temperature may be at a temperature of from about 18°C to about 32°C.
- the pressure employed during any at least partial recovery may be any convenient pressure, e.g., elevated, reduced, or substantially atmospheric.
- the step(s) may be conducted at a pressure of from about 0.75 to about 1.25 atmospheres.
- the at least partial recovery conditions employing one or more membranes are substantially room temperature and pressure.
- the at least partially recovering said soluble substance may be accomplished by distillation or some equivalent thereof.
- the soluble substance may comprise, for example, one or more or a combination of the following: volatile organic solvents, soluble substances with a molecular weight less than 600 daltons, soluble substances with a molecular weight less than 200 daltons, dimethoxymethane, acetone, acetaldehyde, methanol, dimethyl ether, THF, ethanol, isopropanol, propanal, methyl formate, azeotropes, alcohols, ketones, aldehydes, esters, organosilicon compounds, halogenated solvents, a substance with a vapor pressure greater than than 0.01 aim at 20°C, or a mixture thereof.
- the integrated process wherein C0 2 volatilizes may occur in the presence of a low C0 2 partial pressure gas, in the presence of air, with the application of heat, or a combination thereof.
- distillation is to be employed then often the distillation of the substance to be at least partially received depends upon the components and may occur at a temperature of less than about 1 10°C, or less than about 100°C, or less than about 90°C, or less than about 80°C, or less than about 70°C, or less than about 60°C, or less than about 50°C, or less than about 40°C, or less than about 30°C.
- the soluble substance may comprise a thermally switchable substance, a C0 2 switchable substance, or a non-ionic carbon containing compound.
- a switchable substance is one which substantially separates from other materials depending upon, for example, a property or other ingredients of a combined composition. That is, a thermally switchable substance may precipitate from a given solution when subjected to temperatures above or below a certain threshold, e.g., cloud point.
- Useful thermally switchable substances may include, for example, those that substantially precipitate, separate, or have a cloud point at or above 30, or 40, or 50, or 60, or 70, or 80, or 90, or 100, or 110°C.
- the integrated process may be conducted with a C0 2 -switchable substance as the soluble substance.
- a C0 2 -switchable substance may be soluble in solutions such as aqueous solutions when sufficient C0 2 is dissolved but separate and become insoluble upon release of sufficient gaseous C0 2 .
- the switchable solvent may be hydrophobic upon volatilization of substantial amounts, e.g., a majority, of dissolved C0 2 .
- concentration of the soluble substance(s) and any C0 2 absorbent employed in the integrated process may vary depending upon the substance, other substances, and desired results.
- each may have a concentration of from about 1M to about 18M. That is, the concentration of each may be independent or dependent of the other and be, for example, greater or less than 1M, or less than 2M, or less than 3M, or less than 4M, or less than 5M, or less than 6M or less than 10M up to as high as 18M.
- the specific desorbing conditions may vary depending upon the amount of C0 2 present, the soluble substance employed and its concentration, the absorbent precursor or residual, if any, and its concentration, the presence and type of any impurities, the desired partial recovery steps, if any, and other factors. Generally, it may be preferred to select substances and conditions such that the desorbing step may be conducted at a temperature of less than or equal to about 50, or less than or equal to 40, or less than or equal to about 35, or less than or equal to about 30°C. In other embodiments the desorbing temperature may be at a temperature of from about 18°C to about 32°C. Similarly, the pressure employed may be any convenient pressure. For example, the C0 2 may be desorbed at a pressure of from about 0.75 to about 1.25 atmospheres. In another embodiment the desorbing conditions are substantially room temperature and pressure.
- the integrated process of the present invention may involve further comprising making additional useful compounds from the solution, C0 2 , or both. That is, further processing steps may comprise producing ammonium carbamate, urea, or a derivative thereof.
- stage 1 Flue gas enters one or more absorption columns and carbon dioxide is absorbed in a C0 2 -lean aqueous C0 2 absorbent - carbon dioxide solution, forming a C0 2 -rich aqueous solution. Any remaining inert gases from the flue gas, such as N 2 , 0 2 , Ar, low concentrations of C0 2 , may be released from the absorption column and may undergo further treatment. The C0 2 -rich solution created in the absorption stage can be transferred to the C0 2 desorption stage (stage 2).
- C0 2 Desorption stage 2: A soluble substance, such as an organic solvent or water soluble polymer as described above, is added and mixed with the C0 2 -rich solution under, for example, room temperature and pressure conditions. C0 2 (g) is desorbed from the solution and may undergo compression or other treatment prior to utilization or conversion. After C0 2 desorption, the C0 2 -lean solution comprising the soluble substance can be transferred to soluble substance and C0 2 absorption solution recovery stage (stage 3).
- a soluble substance such as an organic solvent or water soluble polymer as described above
- stage 3 Soluble Substance and C0 2 Absorbing Solution Recovery
- the C0 2 - lean solution containing the soluble substance is separated into the C0 2 -lean absorption solution and the soluble substance using one or more separation mechanisms or devices.
- the C0 2 -lean absorption solution can be circulated to stage 1 and the soluble substance can be circulated to stage 2.
- Stage 3 allows the integrated process to be as regenerable as desired.
- Carbon dioxide absorption with examples employing aqueous ammonia or amine species solutions involve absorbing C0 2 from C0 2 (g) containing gas streams in a lean solution to create a rich solution.
- the lean solution may have a C0 2 loading comprising between 0.2 - 0.67 and the rich solution may have a C0 2 loading comprising between 0.45 - 1.
- the molar ratio may differ depending on the embodiment and C0 2 absorbent or absorbents employed.
- Greater C0 2 loading in the C0 2 rich solution may be achieved by, including, but not limited to, changing the temperature, increasing pressure, increasing C0 2 partial-pressure, increasing contact time, increasing residence time, increasing packing surface area, and/or the addition of a catalyst that accelerates C0 2 absorption.
- the absorption tower may be chilled to reduce absorbent volatilization, such as 'ammonia-slip' or the volatilization of other components of the absorption media. Absorbent volatilization may also be reduced by operating the absorption solutions at a greater C0 2 loading, although this may result in lower absorption rates and C0 2 absorption capacity. C0 2 loading may be optimized to maximize reaction kinetics and solution capacity.
- the absorption column may absorb less than or equal to any of the following: 5%, or 10% or 20%, or 30%, or 40%, or 50%, or 60%, or 70%, or 80% or 90%, or 99%, or 99.9%, or 100% of the C0 2 from the C0 2 containing gas stream.
- the absorption stage may include any absorption setup known in the art and may be composed of one or more absorption columns or vessels or other devices.
- the absorption column may include, but is not limited to, continuous absorption, continuous stirred absorption, batch column, packed column, plate column, hybrid absorption processes and other absorption processes known in the art.
- the absorption column or absorption solution may be chilled, wherein cooling may be conducted via any means including, but not limited to, ambient source, water bodies, cooling tower, industrial evaporative chiller and other chilling or cooling processes known in the art. It may be desirable for the C0 2 concentration in the C0 2 lean solution to be less than the C0 2 concentration in the C0 2 rich solution.
- a C0 2 (g) containing gas stream including but not limited to flue gas, synthesis gas, steam- reforming gas, methane reforming gas, hydrogen production gases, air, concentrated, membrane concentrated gas stream, membrane concentrated flue gas, upstaged air (as would be created from the moisture swing C0 2 upstaging processes described by Klaus Lackner http://pubs.acs.org/doi/abs/10.1021/es201 180v, incorporated herein by reference), biogas, landfill gas, or anaerobic digester gas.
- the C0 2 containing gas stream may be treated, used as an enthalpy, heat or cold source, or otherwise used prior to the absorption stage.
- the remaining gas stream after at least a portion of the C0 2 (g) is absorbed, or 'inert gases' may undergo further treatment or utilization, including but not limited to, thermal exchange with incoming C0 2 lean solution, water wash to remove trace gases, such as ammonia or organic solvent, removal process for trace gases, additional C0 2 scrubbing method, including, but not limited to, amines, solid sorbent, SELEXOL, UCARSOL, membrane or strong base, separation, purification, or use of constituents, such as hydrogen, carbon monoxide, nitrogen, oxygen and/or argon.
- additional C0 2 scrubbing method including, but not limited to, amines, solid sorbent, SELEXOL, UCARSOL, membrane or strong base, separation, purification, or use of constituents, such as hydrogen, carbon monoxide, nitrogen, oxygen and/or argon.
- the remaining gas stream following the absorption column such as the 'inert gases,' which may contain a lower concentration of C0 2 than the entering C0 2 containing gas stream, may be advantageously used in a C0 2 conversion process that benefits from a relatively lower concentration of C0 2 , such as biological processes and certain cement production processes.
- C0 2 such as biological processes and certain cement production processes.
- cement production processes that use C0 2 as a reagent, the oxide or silicate or calcium oxide or calcium silicate or magnesium oxide or magnesium silicate containing reactants may initially require only low C0 2 concentrations due to the highly exothermic nature of the reaction to form carbonates.
- the unreacted reagents require an increasingly greater concentration of C0 2 .
- This higher purity C0 2 may be supplied by the integrated C0 2 capture process.
- the absorption column may absorb a smaller percentage of the C0 2 in the C0 2 containing gas stream, such as less than any of the following: 20%, or 30%, or 40% or 50% or 60%, or 70%, or 80%, or 90%, or 99%. This may further reduce energy requirements, including due to the ability for the C0 2 lean and rich solutions to a higher C0 2 loading.
- the substance addition C0 2 desorption stage may work more efficiently when the C0 2 -rich and C0 2 -lean solutions are at a relatively higher C0 2 -loading. This may also may reduce capital costs by decreasing the require dimensions of the absorption column.
- the C0 2 -rich solution may exit the absorption column and may be transferred to Step 2. It may be advantageous to heat exchange this C0 2 -rich solution with the C0 2 -lean solution entering the absorption column. This may include a countercurrent heat exchange, resulting in a cooler/pre-cooled C0 2 lean stream and a warmer/pre-heated C0 2 rich stream.
- the C0 2 containing gas stream Prior to entering the C0 2 absorption column, the C0 2 containing gas stream may, if advantageous, be treated, via methods, including but not limited to, chilling and removal of contaminants, such as hydrogen sulfide, NO x , SO x , particulates and metals.
- the gas stream may be further concentrated with a gas membrane C0 2 concentrator or moisture-swing C0 2 concentrator.
- the entering gas stream may be used as an energy source to supplement energy requirements, including, but not limited to, heating or cooling in the integrated process or components of connecting infrastructure, such as piping.
- This gas stream may be thermally exchanged by means including, but not limited to, a heat exchanger or direct contacting.
- the absorption solution includes any aqueous or nonaqueous solution which absorbs C0 2 .
- C0 2 absorbents include, but are not limited to, one or more or a combination of the following: water, ammonia, ammonium amine, primary amine, secondary amine, tertiary amine, methylamine (MEA), methylethanolamine, aminoethylethanolamine, azine, imine, strong base, hydroxide, sodium hydroxide, potassium hydroxide, sodium oxide, potassium oxide, organic solvent, commercial C0 2 capture absorbents, quaternary ammonium compound, Selexol, Rectisol, KS-1 , UCARSOL, metal - organic framework, solid adsorbent, high surface area compounds, activated carbon, zeolites, carbon nanotubes, graphene, graphene oxide, amine, amino ethyl ethanol amine, 2-Amino-2- methylpropan-l-ol (AMP), MDEA, MEA
- C0 2 may be present in solution as one or more species throughout the integrated process, including, but not limited to, one or more or a combination of the following: bicarbonate, carbonate, carbamate, sesquicarbonate, free C0 2 , or dissolved C0 2 .
- the absorption solution may contain a desorption, absorption, or adsorption rate promoter, including, but not limited to, piperazine, diethanolamine, diglycolamine, and diisopropanolamine.
- Rate promoters may be used to, including, but not limited to, influence one or more of the following: C0 2 absorption, C0 2 desorption, soluble substance regeneration or reaction kinetics.
- the C0 2 loading of the C0 2 -lean solution may be dependent on the amount of C0 2 desorbed during the substance addition C0 2 desorption and the regeneration stages. Therefore, C0 2 loading of C0 2 -lean solution may be adjusted through, including, but not limited to, changing one or more or a combination of the following: residence time, added substance type or types, soluble substance concentration in the mixed C0 2 desorption solution, concentration of the soluble substance in the added substance solution, temperature, application of heating or cooling, C0 2 loading in the C0 2 rich solution, pressure, or C0 2 loading in the in the added substance solution.
- Small concentrations of soluble substance may persist or be present in the C0 2 absorption solution.
- Low concentrations of soluble substances, such as organic solvents may reduce ammonia slip or other C0 2 absorbent volatilization in the absorption column and reduce energy consumption during regeneration. Additionally, low concentrations of soluble substances, such as organic solvents, may increase C0 2 uptake and inhibit unintended C0 2 volatilization.
- the maximum said low concentration is dependent on the type of substance and includes, but is not limited to, vol / vol% concentrations of less than any of the following: 0.001%, or 0.1%, or 0.5%, or 1%, or 1.5%, or 2%, or 2.5%, or 3%, or 3.5%, or 4%, or 4.5%, or 5%, or 5.5%, or 6%, or 6.5%, or 7%, or 7.5%, or 8%, or 8.5%, or 9%, or 9.5%, or 10%, or 10.5%, or 11%, or 11.5%, or 12%, or 12.5%, or 13%, or 13.5%, or 14%, or 14.5%, or 15%.
- Carbon Dioxide Sources Any process or resource producing or containing carbon dioxide.
- C0 2 sources include, but are not limited to, the following: Power Plant (Natural gas, coal, oil, petcoke, biofuel, municipal waste), Waste Water Treatment, Landfill gas, Air, Metal production/refining (such as Iron, Steel, Aluminum, etc.), Glass production, Oil refineries, HVAC, Transportation vehicles (ships, boats, cars, buses, trains, trucks, airplanes), Natural Gas, Biogas, Alcohol fermentation, Volcanic Activity, Decomposing leaves/biomass, Septic tank, Respiration, Manufacturing facilities, Fertilizer production, or Geothermal processes where C0 2 (g) releases from a well or wells.
- Non-Aqueous Embodiment The integrated process may be aqueous or nonaqueous.
- a non-aqueous process may use a non-aqueous solution media as part of the C0 2 containing solution.
- Media include, for example, polar organic solvents, including, but not limited to, ethylene carbonate, propylene carbonate, ethylene glycol, propylene glycol, DMSO, water and acetonitrile or inorganic solvents, such as liquid ammonia or liquid amines and mixtures thereof.
- the non-aqueous system may use a solution media containing of one or more C0 2 absorbents, such as ammonia, ammonium, amines or amine functionalized polymers.
- C0 2 absorbents may be at a wide range of concentrations.
- the absorbent concentration may be as a low as 0.000001 M or as great as pure absorbent.
- the concentration of the C0 2 absorbent may be as low as 0.00001M or less than any of the following: 0.01 M, or 0.05M, or 0.1M, or 0.3M, or 0.5M, or 0.8 M, or 1M, or 1.3M, or 1.5M, or 1.8M, or 2M, or 2.3M, or 2.5M, or 2.8M, or 3M, or 3.3M, or 3.5M, or 3.8M, or 4M, or 5M, or 6M, or 7M, or 8M, or 9M, or 10M, or 12M, or 15M, or 18M, or even pure absorbent.
- the C0 2 absorbent concentration range may be as low as 0.0001% to as great as 99.99999%.
- the concentration of the C0 2 absorbent may be as low as 0.001%, or any of the following: 0.01%, or less than 0.1%, or 0.5%, or 1%, or 1.5% or 2%, or 2.5%, or 3%, or 3.5%, or 4%, or 4.5% or 5%, or 5.5%, or 6%, or 6.5%, or 7%, or 7.5%, or 8%, or 8.5%, or 9%, or 9.5%, or 10%, or 10.5%, or 11%, or 11.5%, or 12%, or 12.5%, or 13%, or 13.5%, or 14%, or 14.5%, or 15%, or 15.5%, or 16%, or 16.5%, or 17%, or 17.5% or 18%, or 18.5%, or 19%, or 19.5%, or 20%, or 20.5%, or 21%, or 21.5%, or 22%, or 22.5%, or 23%, or 23
- the specific absorbent : C0 2 species molar ratios in the C0 2 rich and C0 2 lean solutions may be from as great as pure absorbent to as low as pure C0 2 . It may be desirable for the C0 2 rich solution to comprise a greater molar ratio of absorbent : C0 2 species than the C0 2 lean solution.
- the C0 2 rich solution absorbent : C0 2 species molar ratios include but are not limited to, less than 2:1, or less than 10: 1 or any of the following: 8: 1, or 6: 1, or 4: 1, or 2:1, or 1.9:1, or 1.85:1, or 1.8:1, or 1.75:1, or 1.7:1, or 1.65:1 , 1.6:1, or 1.55:1, or 1.5:1 , or 1.45: 1, or 1.4: 1, or 1.35: 1, or 1.3: 1, or 1.25: 1, or 1.2: 1, or 1.15: 1, or 1.1 : 1, or 1.05: 1 or 1 :1 , or 0.95: 1, or 0.9: 1.
- the C0 2 lean solution absorbent : C0 2 species molar ratios include but are not limited to, greater than 1.5: 1, or greater than any of the following: 100: 1, or 50: 1, or 10: 1, or 8: 1, or 6: 1, or 4:1, or 2:1, or 1.95:1, or 1.9:1, or 1.85: 1, or 1.8: 1, or 1.75: 1, or 1.7: 1, or 1.65:1 , 1.6:1, or 1.55:1 , or 1.5:1 , or 1.45:1 , or 1.4: 1 , or 1.35:1, or 1.3 :1 , or 1.25: 1 , or 1.2: 1 , or 1.15:1, or 1.1 : 1, or 1.05: 1 or 1 : 1, or 0.95: 1, or 0.9:1.
- the C0 2 rich solution enters the C0 2 desorption setup.
- the C0 2 rich solution may be a liquid solution or a liquid-solid slurry.
- a soluble substance and/or soluble substance containing solution is added to a C0 2 rich aqueous solution and C0 2 (g) is subsequently desorbed, while the C0 2 absorbent, such as ammonia or an amine or other absorbents known in the art, predominantly remain in solution, such as less than 2% or less than any of the following: or 1%, or 0.5%, or 0.1% absorbent volatilization.
- the C0 2 desorption mechanism may include, but is not limited to, the soluble substance interfering with the interactions between C0 2 species' and the C0 2 absorbent or C0 2 absorbents.
- Said interferences may include, but are not limited to, one or more or a combination of the following: reducing of solution dielectric constant, decrease in C0 2 species solubility, decrease in absorbent solubility, decrease in absorbent - C0 2 species compound solubility, decrease in absorbent - C0 2 species salt solubility, weakening of hydration shells surrounding dissolved C0 2 species, weakening of hydration shells surrounding C0 2 absorbent, weakening of hydration shells in absorbent - C0 2 species compound, weakening of hydration shells absorbent - C0 2 species salt, formation of a trimer, formation of an adduct, formation of a complex, formation of a complex ion, formation of a zwitterion, reaction with C0 2 absorbent, reversible reaction
- the interaction of the soluble substance with the C0 2 absorbent - carbon dioxide salt may not involve a metathesis reaction or a single displacement reaction. It may be desirable for no chemical reaction to occur between the soluble substance and the C0 2 absorbent. It may be desirable for the C0 2 desorption to be entirely due to changes in solution media properties, such as changes in solution dielectric constant, changes in solution polarity, and changes in hydration shell stability.
- the soluble substance may be preheated or cooled before injection into the mixing apparatus.
- the mixing apparatuses and methods include, but are not limited to, batch mixers, continuous stirred-tank reactors, CSTRs, distillation column, packed column, electrospray, spray column, countercurrent spray column, and/or other apparatuses and/or methods.
- the apparatus may be heated using waste heat or other heat source for, including, but not limited to, promoting C0 2 desorption, reducing viscosity and/or increasing the rate of solvent mixing.
- the C0 2 may pressurize, by any means, including but not limited to, closing and opening a release valve to allow the system to pressurize, utilizing a smaller gas release valve, temperature change, or using external compression.
- a release valve to allow the system to pressurize, utilizing a smaller gas release valve, temperature change, or using external compression.
- the exiting gas stream may contain predominantly C0 2 .
- this desorbed C0 2 may be used for, including, but not limited to, one or more or a combination of the following: enhanced oil recovery, methanol production, syngas production, fuel production, urea production, fertilizer production, carbonate, bicarbonate production, carbamate production, beverage production, greenhouse, agricultural applications, welding gas, turbine working fluid, laser gas, food production, inert gas, cement production, C0 2 conversion processes, and other existing and future applications.
- This gas stream may be further treated by, including, but not limited to, water wash down, aqueous wash down, non-aqueous wash down, changes in pressure, changes in temperature, compression, vacuum, and an additional carbon capture process.
- Additives may be added to this gas stream prior, during or after treatment or in the absence of treatment.
- additives include, but are not limited to, ammonia, electricity, light, hydrogen, amine, oxygen, methane, methanol, carbon monoxide, hydrogen sulfide, haloalkanes, chlormethane, dimethylether, hydrogen cynide, sulfur, acid or acid gas, hydroxide, oxide, carbonate, carbamate, and bicarbonate.
- Maintaining C0 2 (g) in Headspace Measures may be taken to ensure the gas stream or headspace contains a high concentration of C0 2 (g), especially during the first instance of use or after construction. This may be achieved by, including, but not limited to, purging the C0 2 (g) generation vessel with pure C0 2 (g) before the first run of the process. Self-purging may also be employed by using the C0 2 (g) desorbed during solvent addition in initial runs to displace or dilute the other gases present in the vessel.
- the added soluble substance may include, but is not limited to, one or more or a combination of the following: organic solvents, concentrated soluble substance solutions, water soluble polymers, combinations of soluble substances, solvent mixtures, emulsions, pure substance, pure solvent, aqueous solvent, surfactant containing solvents, zwitterions, solids, soluble solids, gases, liquid-solid mixtures, soluble gases, aerosols, suspended solids, solid-gas mixtures, super critical fluids, and fluid mixtures.
- Precipitate during Solvent Addition C0 2 Desorption When a soluble substance is added to a C0 2 rich solution, such as 2M aqueous ammonium bicarbonate, in addition to the desorption of C0 2 (g), a portion of the C0 2 containing salt may precipitate as a solid. This precipitate may dissolve back into solution, including, but not limited to, as C0 2 (g) desorption occurs. This may be due to ammonium carbonate or carbamate (NH 3 : C0 2 of 2: 1) being more soluble than ammonium bicarbonate (NH 3 : C0 2 of 1 :1) in the water - soluble substance solution. In some embodiments there is no substantial precipitate formed.
- a C0 2 rich solution such as 2M aqueous ammonium bicarbonate
- Heating or cooling may be incorporated throughout the integrated process.
- heating or cooling may be beneficial during C0 2 desorption to increase C0 2 (g) yield and soluble substance solubility.
- Polyethylene glycols (PEGs) and polypropylene glycols (PPGs) for example, have higher Gibbs free energy of mixing and osmotic pressure at lower temperatures.
- Cooling may enhance C0 2 (g) desorption, including, but not limited to, due to the greater Gibbs free energy of mixing and osmotic pressure of PEGs and PPGs at cooler temperatures and the decreased solubility of the CO2 containing salts, such as ammonium bicarbonate or carbonate, at lower temperatures.
- Heating may enhance C0 2 (g) desorption, including, but not limited to, due to greater reaction kinetics and lower C0 2 species solubility.
- the soluble substance may be added to the C0 2 rich solution as a concentrated aqueous or non-aqueous solution or in a pure form.
- Said concentrated solution of the soluble substance may contain a vol / vol % concentration of soluble substance as low as 0.0001% to as great as 99.99999%).
- Vol / vol% concentrations of the soluble substance or concentrated soluble substance solution may be practically greater than any of the following: 1%>, or 5%, or 10%, or 11%, or 12%, or 13%, or 14%, 15%, or 16%, or 17%, or 18%, or 19%, or 20%, or 21%, or 22%, or 23%, or 24%, or 25%, or 26%, or 27%, or 28%, or 29%, or 30%, or 31%, or 32%, or 33%, or 34%, or 35%, or 36%, or 37%, or 38%, or 39%, or 40%, or 41%, or 42%, or 43%, or 44%, or 45%, or 46%, or 47%, or 48%, or 49%, or 50%, or 51%, or 52%, or 53%, or 54%, or 55%, or 56%, or 57%, or 58%, or 59%, or 60%, or 65%, or 70%, or 75%, or 80%, or 85%, or 90%, or
- the resulting concentration of the soluble substance in the C0 2 desorption / mixing step may be a vol / vol % concentration of soluble substance as low as 0.0001%) to as great as 99.99999%.
- Vol / vol% concentrations of the soluble substance in the C02 desorption / mixing step or resulting mixed solution may be practically greater than any of the following: 0.1%, or 1%, or 2%, or 3%, or 4%, or 5%, or 5.5%, or 6%, or 6.5%, or 7%, or 7.5%, or 8%, or 8.5%, or 9%, or 9.5%, or 10%, or 10.5%, or 1 1%, or 1 1.5%, or 12%, or 12.5%, or 13%, or 13.5%, or 14%, or 14.5%, or 15%, or 15.5%, or 16%, or 16.5%, or 17%, or 17.5% or 18%, or 18.5%, or 19%, or 19.5%, or 20%, or 20.5%, or 21%, or 21.5%, or 22%, or 22.5%,
- the maximum solubility of the soluble substance in the C0 2 desorption / mixing step may be a vol / vol % concentration of soluble substance as low as insoluble to as great as completely miscible.
- Vol / vol% solubility of the soluble substance may be practically greater than any of the following: 0.001%, 0.01%, 0.1%, or 1%, or 2%, or 3%, or 4%, or 5%, or 6%, or 7%, or 8%, or 9%, or 10%, or 1 1%, or 12%, or 13%, or 14%, or 15%, or 16%, or 17%, or 18%, or 19%, or 20%, or 21%, or 22%, or 23%, or 24%, or 25%, or 26%, or 27%, or 28%, or 29%, or 30%, or 31%, or 32%, or 33%, or 34%, or 35%, or 36%, or 37%, or 38%, or 39%, or 40%, or 41 %, or 42%, or 43%
- the purity of C0 2 may desirably by greater than 90%.
- the C0 2 concentration range may be as low as 0.0001%) to as great as 99.99999%.
- the purity or concentration of the desorbed C0 2 may be as low as any of the following: 0.1% or greater than 0.1%, or 1%, or 2%, or 3%, or 4%, or 5%, or 6%, or 7%, or 8%, or 9%, or 10%, or 11%, or 12%, or 13%, or 14%, or 15%, or 16%, or 17%, or 18%, or 19%, or 20%, or 21%, or 22%, or 23%, or 24%, or 25%, or 26%, or 27%, or 28%, or 29%, or 30%, or 31%, or 32%, or 33%, or 34%, or 35%, or 36%, or 37%, or 38%, or 39%, or 40%, or 41%, or 42%, or 43%, or 44%, or
- Partial Pressure of C0 2 Desorbed The partial pressure of C0 2 may be greater than 0.5 atm or 1 atm.
- the C0 2 partial pressure range may be as low as 0.001 atm to as great as 100,000 atm, liquid C0 2 , supercritical C0 2 , or solid C0 2 .
- the partial pressure of C0 2 may be as low as any of the following: 0.001 atm, or 0.01 atm, or greater than or less than 0.05 atm, or 0.1 atm, or 0.2 atm, or 0.3 atm, or 0.4 atm, or 0.5 atm or 0.6 atm, or 0.7 atm, or 0.8 atm, or 0.9 atm, or 1 atm, or 1.1 atm, or 1.2 atm, or 1.3 atm, or 1.4 atm, or 1.5 atm, or 1.6 atm, or 1.7 atm, or 1.8 atm, or 1.9 atm, or 2 atm, or 2.1 atm, or 2.2 atm, or 2.3 atm, or 2.4 atm, or 2.5 atm, or 2.6 atm, or 2.7 atm, or 2.8 atm, or 2.9 atm, or 3 atm, or 3.5 atm, or 4 atm, or 4.5 atm, or 5 atm, or 5.5 atm, or 6 atm, or 6.5 atm, or
- the purity or concentration of the desorbed C0 2 or final C0 2 produced may be dependent on the application.
- the setup may contain other gases than C0 2 (g).
- the other gas or gases present in with this C0 2 may be dependent on the application.
- hydrogen may be added as a headspace gas during C0 2 desorption. This example may reduce C0 2 capture energy requirements, including, but not limited to, due to the requirement of a lower partial pressure of C0 2 (g) desorbed and lower final solvent concentration required.
- the substance or substances may be recovered via one or more separation mechanisms.
- This stage involves separating the solution produced by the C0 2 desorption stage into two main streams: 1) the C0 2 -lean absorption solution; 2) the soluble substance.
- the absorption solution is recycled back to the C0 2 absorption stage and the soluble substance is recycled back to the substance C0 2 desorption stage.
- Separation devices and mechanisms employed are dependent on the type or types of added substances. Separation devices and mechanisms include, but are not limited to, one or more or a combination of the following: semi-permeable membrane, nanofiltration, organic solvent nanofiltration, reverse osmosis, ultrafiltration, microfiltration, hot nanofiltration, hot ultrafiltration, distillation, membrane distillation, flash distillation, multi- effect distillation, mechanical vapor compression distillation, switchable solvent, hybrid systems, thermally switchable solvent, centrifuge, or filter or combinations thereof.
- Example embodiments include, but are not limited to, FIG 1. and FIG 9.
- C0 2 Desorption A concentrated soluble substance solution or 'concentrate', such as 30% PEG, 70% C0 2 lean aqueous ammonia-carbon dioxide, is added and mixed with the C0 2 rich solution at a preset vol / vol% ratio under room temperature and pressure conditions. C0 2 (g) is desorbed from the C0 2 rich solution and may undergo compression or other treatment prior to utilization. The C0 2 -lean mixed solution containing the added substance, is transferred to stage 3.
- a concentrated soluble substance solution or 'concentrate' such as 30% PEG, 70% C0 2 lean aqueous ammonia-carbon dioxide
- Two aqueous streams are generated: 1) a 'concentrate' stream (30% PEG(l) in diagram), which contains a high concentration of the soluble substance, such as PEG or PPG; 2) a 'permeate' stream (C0 2 lean in diagram) which contains less, minimal concentrations, or none of the added substance, such as PEG or PPG. Additional C0 2 may be desorbed from the 'concentrate' side and may be used as additional captured C0 2 (not shown in diagram). The 'concentrate' stream is transferred to stage 2 (C0 2 desorption) and the 'permeate' stream is transferred to stage 1 (flue gas C0 2 absorption).
- Ultra-low cost and widely available reagents including, but not limited to - soluble polymer (including, but not limited to, PEG, PPG, or other
- the embodiment is composed of three main steps: 1) The addition/contacting of a gas containing C0 2 to convert aqueous ammonia, ammonium or amine containing C0 2 lean solution to a C0 2 rich solution. The remaining inert gases may undergo further purification, treatment or compression; 2) The addition of a large molecular weight (MW) water soluble substance or substances to the C0 2 rich solution to desorb C0 2 (g), creating a C0 2 lean solution + added substance + C0 2 (g). This C0 2 (g) stream may undergo further purification, treatment or compression; 3) The recovery of the added substance or substances using a separation mechanism.
- MW molecular weight
- the C0 2 lean aqueous soluble substance - C0 2 absorbent - carbon dioxide solution formed in the second stage is fed into a membrane module and may be separated using pressurization.
- the separation mechanism may include, but is not limited to, one or more or combination of the following: microfiltration, ultrafiltration, nanofiltration organic solvent nanofiltration and reverse osmosis.
- the membrane rejects the organic solvent or soluble substance, while allowing the C0 2 lean aqueous ammonia-carbon dioxide salt to pass through the membrane.
- the solution that passes through the membrane, or the permeate stream, is then transferred to the C0 2 absorption column.
- the solution rejected by the membrane, which contains a higher concentration of the soluble substance is recycled to the C0 2 desorption stage as the soluble substance containing solution.
- the type of membrane or filter employed may be dictated by the molecular weight of the soluble substance added, which may be advantageously larger than the molecular weight cut-off of the membrane.
- the molecular weight cut-off of the membrane or filter may be sufficiently large to allow aqueous ammonia-carbon dioxide species to pass though or to be minimally rejected.
- the power source of the pump is not of particular importance, however it may be powered by electricity, pressure exchanger, turbocharger, hydraulic pressure, heat, pressure retarded osmosis, or forward osmosis.
- energy can be recovered by both or either the permeate (the absorption solution) and the concentrate (the soluble substance containing solution).
- energy recovery devices include, but are not limited to, pressure exchangers and turbochargers.
- the embodiment may be heated or cooled where advantageous.
- the solvent addition and mixing step may be heated or cooled for various purposes, including, but not limited to, increasing C0 2 (g) yield, decreasing timeframe of C0 2 (g) generation, increasing solvent solubility, reducing energy consumption in the membrane or filtration module or a combination thereof.
- Energy consumption in the membrane or filtration module may be reduced from solution or module heating due to, but not limited to, the one or more of the following: 1) reduction of osmotic pressure (which decreases with increasing temperature in PEGs, PPGs and other water soluble polymers), reduction in concentration polarization, reduction in viscosity and change in solubility. Any portion of the process may be heated or cooled.
- Heat sources may include, but are not limited to, waste heat, power plant waste heat, steam, heat, pump or compressor waste heat, industrial process waste heat, steel waste heat, metal refining and production waste heat, paper mill waste heat, cement production waste heat, calcination waste heat, factory waste heat, petroleum refining waste heat, solar heat, solar pond, air conditioner waste heat, combustion heat, geothermal heat, ocean or water body thermal heat, stored heat, and C0 2 (g) absorption solution heat.
- Temperatures of heating or cooling for any of the embodiments disclosed include, but are not limited to, less than any of the following: -20 °C, or -10 °C, or 0 °C, or 10 °C, or 20°C, or 25°C, or 30°C, or 35 °C, or 40°C, or 41.5 °C, or 41.5°C, or 41.5°C - 60 °C, or 45°C, or 50°C, or 55°C, or 60°C, or 60 - 100°C, or 110°C, or 150°C.
- power plant condenser waste heat is generally abundant at ⁇ 41.5°C and may be employed.
- Relatively lower molecular weight solvents may be employed if advantageous, including, but not limited to, polyethylene glycols 150 - 2000, polypropylene glycols 425 - 4000 and glycol ethers, such as triglyme.
- relatively lower molecular weight solvents or soluble substances such as polyethylene glycols 150— 2000, may have a higher osmotic pressure for a given volume / volume % concentration, these may be advantageous due to including, but not limited to, one or more of the following: 1) exhibit lower viscosity, 2) higher solubility, 3) less prone to degradation, 4) less expensive, 5) lower concentration polarization, 6) higher mole fraction per given vol / vol %, 7) greater Gibbs free energy of mixing and 8) greater influence on dielectric constant.
- Relatively larger molecular weight solvents may be advantageous due to one or more of the following: 1) lower osmotic pressure, 2) greater reduction of osmotic pressure with heat, 3) allow for the use of a larger pore size membrane or filter, 4) allow for the use of a higher permeability membrane, 4) may possess an LCST or UCST phase change with temperature and 5) may decrease in solubility with changes in temperature.
- the process may be constructed for large scale, stationary C0 2 capture.
- the process may also be constructed and transported in smaller scale modules or as a unit, such as in shipping containers and transported and used in other locations. This may facilitate the ability to capture carbon dioxide in remote locations, in applications including, but not limited to, oil and gas production, cement production, mining and air C0 2 capture.
- the process may also be constructed as a stationary process.
- the added concentrate which may be a solution with a high concentration of the large molecular weight soluble substance, may comprise one or more or a combination of the following: a solid, a liquid, an aqueous solution containing the recovered substance, an aqueous solution containing the recovered solvent and C0 2 absorption species, an aqueous solution containing the recovered solvent and C0 2 absorption species and C0 2 species or a combination thereof.
- Heating prior or during membrane recovery may reduce energy consumption due to, including, but not limited to, lower osmotic pressure and lower concentration polarization. Chilling may be useful in the absorption column to reduce ammonia slip.
- C0 2 (g) may be desorbed during Step 3 with or without heating. This C0 2 (g) and other C0 2 (g) desorbed at or between stages 1 , 2 or 3 of this process may undergo the same use or treatment as the C0 2 (g) desorbed from the desorption stage (stage 2), including use as captured C0 2 (g).
- C0 2 (g) may be desorbed due to, including, but not limited to, one or more or a combination of the following: increase in soluble substance concentration, a further decrease in the dielectric constant in the solution, weakening of the hydration shells solvating the aqueous ammonia (or other C0 absorbent molecule or molecule combination) - carbon dioxide compound, or changes in temperature or pressure.
- the pressure of the C0 2 (g) generated may supplement the pressurization energy requirements of the pump or other pressurization method.
- the regeneration portion of this embodiment may employ, including, but not limited to one, or more or a combination of the following: reverse osmosis, nanofiltration, organic solvent nanofiltration, ultrafiltration, microfiltration or switchable solvent.
- the embodiment may employ a reverse osmosis membrane with a low molecular weight cut-off, including but not limited to, less than any of the following: 250 da, or 200 da, or 150 da, or 125 da, or 100 da, or 95 da, or 90 da, or 85 da, or 80 da, or 75 da, or less than the hydration radius of ammonium bicarbonate.
- this embodiment may employ aqueous ammonia as the C0 2 absorbent.
- Ionic aqueous ammonia (or ammonium) - carbon dioxide species may become free dissolved ammonia or carbon dioxide under these conditions.
- the hydration radius of free ammonia or carbon dioxide is significantly smaller than the hydration radius of ionic species of ammonia (ammonium) and carbon dioxide (bicarbonate or carbonate or carbamate).
- the ammonia - carbon dioxide may more freely pass through a relatively small molecular weight cut-off reverse osmosis or forward osmosis membrane.
- This may allow for the use of lower molecular weight added substances, such as ethylene glycol, ethylene carbonate, propylene glycol, propylene carbonate, and polyethylene glycol (PEG) 200, which may be advantageous due to, including, but not limited to, one or more or a combination of the following: greater solubility, lower viscosity, lower cost, exhibit a greater Gibbs free energy of mixing, exhibit a greater influence on solution dielectric constant, less prone to degradation, and exhibit less concentration polarization during membrane solvent recovery. Additionally, it may allow for appreciably complete recovery or removal of the added solvent, including when a relatively larger molecular substance is employed.
- PEG polyethylene glycol
- Multicomponent separation devices or multistage separation devices may be employed.
- Said device or devices may include, but are not limited to, one or more or a combination of the following: binary distillation, azeotrope distillation, membrane distillation, mechanical vapor compression, hybrid systems, flash distillation, multistage flash distillation, multieffect distillation, extractive distillation, switchable solvent, reverse osmosis, nanofiltration, organic solvent nanofiltration, ultrafiltration, and microfiltration.
- such a hybrid system may involve at least partially recovering the soluble substance using nanofiltration and then further concentrating the soluble substance using membrane distillation.
- Another example of such a hybrid system may be a process wherein a switchable solvent 'switches' out of solution due to the presence of a stimulant, such as a change in temperature, then nanofiltration is employed to further concentrate the switchable solvent or remove remaining switchable solvent in the C0 2 lean solution.
- the switchable solvent or other substance dissolved in solution may be further recovered or concentrated or even removed from the one or more layers or separate solutions that are formed.
- the osmotic pressure range of the resulting water soluble substance solution may be as low as 0.001 atm to as great as 1,000,000 atm.
- the osmotic pressure may be as low as less than any of the following: 0.001 atm, or 0.01 atm, or greater than or less than 0.05 atm, or 0.1 atm, or 0.2 atm, or 0.3 atm, or 0.4 atm, or 0.5 atm or 0.6 atm, or 0.7 atm, or 0.8 atm, or 0.9 atm, or 1 atm, or 1.1 atm, or 1.2 atm, or 1.3 atm, or 1.4 atm, or 1.5 atm, or 1.6 atm, or 1.7 atm, or 1.8 atm, or 1.9 atm, or 2 atm, or 2.1 atm, or 2.2 atm, or 2.3 atm, or 2.4 atm, or 2.5 atm, or 2.6 atm, or 2.7 atm, or 2.8 at
- Organic Solvent and CO lean absorbing solution recovery employs a nanofiltration membrane with a pore size sufficiently small to reject the large molecular weight organic solvent and sufficiently large to allow aqueous ammonia-carbon dioxide salts to pass through the membrane.
- An effective membrane for this process may have molecular weight cutoff of above 200 Daltons to allow hydrated ammonia or amine and carbon dioxide to pass through the membrane and below the molecular weight of the organic solvent or soluble substance, such as PEG 600.
- Energy for separation is supplied by pressurization, which may be accomplished using electricity and pumps used in commercial reverse osmosis desalination and nanofiltration process. Energy requirements in commercial aqueous membrane-based separation processes can approach the minimum thermodynamic energy requirement, exponentially improving the efficiency of C0 2 capture.
- Embodiments may include:
- non-volatile solvents including, but not limited to, Polyethylene glycols
- Embodiment Tested (1) C0 2 is absorbed in the C0 2 lean aqueous ammonia in the absorption column, forming C0 2 rich aqueous ammonia; (2) PEG concentrate is added and mixed with the C0 2 rich aqueous ammonia, desorbing C0 2 and forming a C0 2 lean solution; (3) PEG concentrate and C0 2 lean aqueous ammonia are separated using nanofiltration and recycled. Nanofiltration membranes reject PEG, while ammonia, water and carbon dioxide species pass through the membranes.
- C0 2 Desorption stage of this embodiment involves adding the substance, such as a concentrated aqueous PEG solution, to the C0 2 rich aqueous C0 2 absorbent - carbon dioxide solution, such as ammonia - carbon dioxide, from the absorption column. Pure C0 2 (g) is desorbed at room temperature and pressure (RTP) conditions.
- substance such as a concentrated aqueous PEG solution
- C0 2 rich aqueous C0 2 absorbent - carbon dioxide solution such as ammonia - carbon dioxide
- the graph at Fig 11 shows the total C0 2 generation in respect to final PEG concentration and time.
- Optimization may involve, including, but not limited to, changing mixing rate, soluble substance type, soluble substance concentration, C0 2 absorbent solution, C0 2 absorbent concentration, C0 2 absorbent combination and temperature.
- Optimization of solvent type may involve determining the most effective molecular weights and molecular structures of each soluble substance type and making most effective use of each soluble substances' properties.
- PPGs aqueous propylene glycols
- the osmotic pressure of a 50% PPG 425 vol/vol solution is -75% less at 40°C than 20°C (pg.
- An example of making optimal use of this property may involve preheating the solution produced in the C0 2 desorption mixer prior to the nanofiltration soluble substance recovery stage. This may reduce regeneration energy requirements by reducing osmotic pressure, viscosity and concentration polarization.
- a separation device such as a filter, may be employed, for purposes, including but limited to, preventing the buildup of solids in the substance regeneration component.
- Solubility of ammonium bicarbonate increases with temperature until it begins to decompose at 40°C - 60 °C.
- higher concentrations than 2.7M may be still contain no solids, including, but not limited to, if the temperature is raised.
- ammonium bicarbonate, carbonate or sesquicarbonate precipitate may form in the absorption column, including, but not limited to, because the absorption column may operate at near or below room temperature to prevent ammonia slip.
- Maximizing concentration may be useful as it may, including, but not limited to, increase the C0 2 absorption - desorption capacity.
- Nanofiltration PEG 600 Energy Requirement Calculations This stage employs nanofiltration membranes with a pore size sufficiently small to reject the large molecular weight organic solvent, such as polyethylene glycol, or other soluble substance and sufficiently large to allow aqueous ammonia-carbon dioxide salts, or other C0 2 absorbent - C0 2 species, to pass through the membrane.
- An effective membrane for this process may have a molecular weight cutoff of above 200 Daltons to allow hydrated ammonia and carbon dioxide to pass through the membrane and below the molecular weight of the organic solvent (e.g. PEG 600).
- Aqueous PEGs are commonly employed to evaluate the molecular weight cutoff of standard reverse osmosis and nanofiltration membranes. PEG is nontoxic and inert, and may pose little threat of degradation, fouling or other unintended interaction with nanofiltration membranes. The process may use standard industrial nanofiltration membrane modules and setups known in the art.
- Energy for separation may be supplied by pressurization, which may be accomplished using electricity and pumps used in commercial reverse osmosis desalination and nanofiltration processes known in the art. Energy requirements in commercial aqueous membrane-based separation processes may approach the minimum thermodynamic energy requirement, exponentially improving the efficiency of C0 2 capture.
- the nanofiltration setup may be designed based on optimized solution flow rates and PEG concentration in the 'PEG-concentrate' added solution and the mixed solution. These parameters may be determined based on the absorption column and C0 2 desorption stages.
- Desired properties There are a wide range of substances capable of being added to an aqueous solution containing ammonia, ammonium, amine or bicarbonate, carbonate or carbamate species that would desorb C0 2 can be subsequently recovered using membrane or filter based processes (e.g. Microfiltration, Ultrafiltration, Nanofiltration, Reverse Osmosis). The following is a list of potentially desirable properties for these added substances. Desired substances may include one or more of the following, although the properties are not limited to those described herein and added substances may or may not exhibit any of these properties.
- Solvents that meet the properties thereof include, but are not limited to, a wide range of glycols (such as polyethylene glycols [PEG] and polypropylene glycols [PPG]).
- glycols such as polyethylene glycols [PEG] and polypropylene glycols [PPG]).
- Embodiments described include the embodiment shown in FIG. 2.
- the system is composed of three main steps: 1) Gas containing C0 2 enters the absorption column and C0 2 is absorbed in a C0 2 -lean aqueous absorbent - carbon dioxide solution, forming a C0 2 -rich aqueous absorbent - carbon dioxide solution. The remaining inert gases from the flue gas (N 2 , 0 2 , Ar, low concentrations of C0 2 ) are released from the absorption column. 2) The addition of a water-soluble solvent to a C0 2 rich solution, resulting in the formation of gaseous C0 2 (g) and a C0 2 -lean solution.
- the gaseous C0 2 (g) may undergo further purification or treatment to remove solvent, water vapors, or traces of absorbent vapor, which may be recycled in the process; 3)
- the distillation and condensation of the low boiling point solvent from the remaining C0 2 lean solution which may include using ultra low grade heat (less than any of the following: -42 °C, or 60 °C, or 80 °C, or 100 °C).
- the C0 2 lean solution which now contains an appreciably lower concentration of organic solvent, is circulated to the absorption column, while the condensed organic solvent is circulated to the substance addition desorption stage.
- distillation may be conducted by exploiting the high vapor pressure of the solvent via one or more or a combination of the following: multi-effect distillation, membrane distillation, a lower temperature condenser, vapor compression, or mechanical vapor compression distillation.
- the C0 2 -lean solution after the recovery of the solvent, may be recycled to the first step of the process.
- C0 2 (g) lean aqueous ammonia - carbon dioxide solution may be composed of predominantly aqueous ammonium carbonate and ammonium carbamate at an NH 3 : C0 2 molar ratio that may be greater than 1.5 : 1 and may be near 2 : 1.
- C0 2 (g) is absorbed in the C0 2 lean aqueous ammonia to form aqueous ammonium bicarbonate at an NH 3 : C0 2 molar ratio, such as less than 1.5 : 1 and near 1 : 1.
- Dilute C0 2 (g) is absorbed in a C0 2 lean aqueous ammonia - carbon dioxide solution according to the following chemical reaction:
- C0 2 is desorbed by adding one or more water soluble, low cost organic solvents under moderate conditions to the C0 2 rich aqueous ammonia-carbon dioxide solution, such as room temperature and pressure conditions.
- a low boiling point organic solvent such as acetone, dimethoxymethane, acetaldehyde, methyl formate, or dimethyl ether is employed.
- C0 2 (g) is desorbed under substantially room temperature and pressure (RTP) conditions according to the following chemical reaction:
- C0 2 (g) is desorbed from solution due to the organic solvent reducing the solution dielectric constant. It may be theorized that aqueous ammonia catalyzes and fosters the hydration of C0 2 into carbonic acid, thus enabling C0 2 to dissolve at a significantly greater concentration than it would without the presence of ammonia.
- the addition of an organic solvent may weaken the aqueous ammonia catalyzed hydration shells surrounding the dissolved C0 2 due to reduction of the solution dielectric constant, thus prompting the generation of C0 2 (g) owing to the significantly lower solubility of aqueous phase C0 2 when uncatalyzed by ammonia.
- Significant pure C0 2 (g) yields were achieved under room temperature and pressure conditions in a relatively short timeframe.
- C0 2 desorption or absorbent - C0 2 salt decomposition unintended or intended, may occur during this stage.
- Desorbed C0 2 may be separated from the organic solvent vapor and treated similarly to the captured C0 2 produced in the desorption or mixing step.
- the C0 2 absorbent may be recycled, including, but not limited to, by dissolving in the added organic solvent or other added substance in the C0 2 desorption step.
- a multi-substance solvent may be used. Said solutions or mixtures may be desired to be azeotropes due to their property to function with a uniform boiling point. However, solvent mixtures do not have to be azeotropes, and may be mixtures of solvents that may or may not each boil at different temperatures. Mixtures may be composed of a combination of substances for any one or more reasons that may include, but are not limited to, improving properties, such as lower temperature boiling point, lower enthalpy of vaporization, greater solubility and lower dielectric constant or a solvent may be added to prevent an unfavorable reaction between the C0 2 absorbent salt and a substance.
- C0 2 may be desorbed during the distillation step. This C0 2 and other gases that may be present, including, but not limited to, C0 2 absorbent, solvent vapor, and water vapor, may be separated and / or treated. C0 2 released in the distillation column and any other stage of the process may be utilized or treated by any methods or means, including those described for Stage 2.
- the particular mechanism used to separate the added solvent from the solution may include, but is not limited to, one or more or a combination of the following: binary distillation, azeotrope distillation, mechanical vapor compression, membrane distillation, hybrid systems, flash distillation, multistage flash distillation, multieffect distillation, extractive distillation, switchable solvent, reverse osmosis, nanofiltration, organic solvent nanofiltration, ultrafiltration, and microfiltration.
- the headspace gases may self-pressurize or pressurize. This may be advantageous due to, including, but not limited to, reductions in compression energy requirements and less energy demands for water wash down or other organic solvent and C0 2 absorbent separation process.
- Water wash-downs or other treatment processes may be applied at any stage of the process, including to some or all entering and exiting fluid streams. This includes, but is not limited to: o Purification or removal of one or more or a combination of the following from the gas stream exiting the C0 2 absorber or 'inert gases: organic solvent, ammonia, other C0 2 absorbent, other impurity, other chemical or water o Purification or removal of one or more or a combination of the following from the gas stream exiting the C0 2 desorption stage: organic solvent, ammonia, other C0 2 absorbent, other impurity, other chemical or water
- Larger molar mass water soluble molecules such as soluble molecules with a molecular weights greater than 200 daltons, may be included in solution to reduce total quantity of moles and increase the added organic solvent mole fraction, which may reduce temperature requirements during distillation in accordance with Raoult's Law.
- the solvent may be desired to possess, including, but not limited to, a low boiling point, low dielectric constant, low enthalpy of vaporization, no azeotrope with water (or an azeotrope with a higher mole fraction of the added solvent than water), low toxicity and high solubility in water.
- a low boiling point low dielectric constant
- low enthalpy of vaporization no azeotrope with water (or an azeotrope with a higher mole fraction of the added solvent than water)
- low toxicity and high solubility in water may react or interact with the C0 2 absorbent in potentially unfavorable ways within the process unless additional measures are taken.
- Solvents that have a greater likelihood of reaction with ammonia or ammonium salts include those in the categories of Amines, Ketones, Aldehydes, Esters, and Carboxylic Acids.
- solvents are used from these categories, it may be desirable for them to, include, but not be limited to, react to form a useful chemical, react slowly, react reversibly, or not react at all with C0 2 absorbents and C0 2 absorbent containing compounds.
- acetone is a ketone, however its reaction with Ammonia sometimes requires months of continuous contact time, which may be unlikely or undesirable in the system.
- solvents do react with Ammonia, other substances may be added to prevent an unfavorable reaction.
- Methyl Formate a solvent with a very low boiling point, high water solubility and low dielectric constant, reacts with ammonia to formamide (an acid amide) and methanol.
- Methyl Formate does form an azeotrope with Methanol, http://pubs.acs.org/doi/abs/10.1021/je200140m incorporated herein by reference. Therefore, the two solvents, if at the appropriate ratio to form the azeotrope, may boil at a uniform temperature.
- Solvents that typically do not react with ammonia include those in the categories of Ethers and low molecular weight Alcohols. These substances rarely form unfavorable reactions with ammonia.
- the solvent may be distilled at or below 85°C without appreciable volatilization of ammonia from solution at atmospheric pressure.
- C0 2 (g) or NH 3 (g) are released from solution, these may re-dissolve in solution when the solvent is recycled.
- C0 2 (g) may be released in significant excess to NH 3 (g), and may be removed as captured C0 2 (g).
- Raoult's law may be useful for the solvent distillation step of this embodiment.
- Raoult's Law describes the relationship between the mole fraction of a liquid in solution and the liquid's vapor pressure (ex. Mole fraction * Partial pressure of liquid at temperature - Partial pressure in system).
- traces of added solvent may continue to remain in the C0 2 absorption solution.
- the timeframe of distillation may need to be lengthened. Distillation may be optimized to minimize energy demand, while achieving optimal solvent concentrations in the C0 2 absorber and C0 2 desorber.
- This embodiment generates high purity C0 2 via the addition of a water soluble organic solvent to a C0 2 rich aqueous ammonia-carbon dioxide solution, such as would be generated from the absorption of flue gas C0 2 in aqueous ammonia.
- the organic solvent is subsequently distilled using low temperature heat, resulting in recovery of the solvent and remaining C0 2 lean aqueous ammonia-carbon dioxide solution.
- Pure C0 2 is desorbed under room temperature pressure (RTP) conditions and employs only low cost, abundant reagents.
- RTP room temperature pressure
- MATERIALS AND METHODS Measurements were acquired using a gas flow setup with on-line mass spectrometry. An Omega mass flow controller was used to control the flow rate of the carrier gas (ultra-high purity helium, 50 mL/min). The outlet line was heated to prevent solvent condensation. For each experiment, an appropriate amount of ammonium bicarbonate (>99.5%, Sigma Aldrich) was dissolved in deionized (DI) water to form 100 mL of total solution at a desired molarity (1.0, 1.5 M, or 2.0 M). A 250 mL glass media bottle containing the solution was attached to a three-port cap containing helium carrier gas inflow port, gas mixture outlet port, and organic solvent injection port.
- DI deionized
- a needle valve connected to a vacuum chamber with an SRS 100 residual gas analyzer was used to sample the outlet gas and obtain the C0 2 partial pressure.
- C0 2 partial pressures were converted to molar flow rates using a calibration curve derived from previous measurements of mass flow controlled ultrahigh purity C0 2 and by normalizing the signal intensity to the helium carrier gas. Integration of C0 2 flow rates over one hour yielded the values for total pure C0 2 generation.
- Total C0 2 generation was determined by extrapolating results from 1 hour experiments with an ExpConvExp fitting function using the Multi-peak Fit package in Igor Pro (WaveMetrics Inc.). During long timeframe experiments with 20 mL of organic solvent added, C02 generation tapered off after a three-hour period. Correspondingly, C02 generation from 1 hour experiments were extrapolated to three hours. Three-hour extrapolations deviated less than 12.5% from experimental results.
- the feed solution was distilled to the operational organic solvent mole fraction ( ⁇ 3 ⁇ 4) in the regenerated solution (0.0216 for acetone, 0.0181 for dimethoxymethane, and 0.0279 for acetaldehyde).
- the operational organic solvent mole fraction was experimentally determined by adding small amounts of organic solvent at RTP conditions to a 100 mL 2 M aqueous ammonium bicarbonate solution until the injection of additional organic solvent resulted in C0 2 generation ( Figure S2).
- the C0 2 absorption column, C0 2 in flue gas is absorbed by a C0 2 lean aqueous ammonia-carbon dioxide solution (NH 3 : C0 2 molar ratio >1.5), forming a C0 2 rich solution (NH 3 : C0 2 molar ratio ⁇ 1).
- the remaining gases after the C0 2 is absorbed are released from the absorption column ('Inert Gases' in Figure 1). Similar C0 2 absorption columns are currently employed in the chilled ammonia process.
- the solvent mixer In the second stage, the solvent mixer, the C0 2 rich ammonia-carbon dioxide solution from the C0 2 absorption column is mixed with an organic solvent (acetone, acetaldehyde, or dimethoxymethane) under mild temperatures and pressures, such as RTP conditions, generating high purity C0 2 .
- the solution becomes C0 2 lean as pure C0 2 is generated.
- the solvent distillation column the solution formed in the solvent mixer enters a distillation column, where the organic solvent is distilled from the C0 2 lean aqueous solution.
- the aqueous solution is recirculated to the C0 2 absorption column and the organic solvent is recirculated to the solvent mixer.
- C0 2 was desorbed by adding acetone, dimethoxymethane (DMM), or acetaldehyde to aqueous ammonium bicarbonate solutions under RTP conditions.
- the graph shows the amount of pure C0 generated over 1 hour (experimentally observed) and 3 hour (extrapolated) periods when 20 mL of acetone and DMM were added to 100 mL of 1, 1.5, or 2 M aqueous ammonium bicarbonate solutions at RTP conditions.
- C0 2 desorbed per 20 mL of organic solvent increased with ammonium bicarbonate concentration.
- Fig 12 shows: C0 2 generated at different ammonium bicarbonate solution concentrations with different organic solvents injected. Experiments were conducted using an online mass spectrometry setup and 20 mL of solvent added to a 100 mL aqueous ammonium bicarbonate solution. The control was the C0 2 (g) desorbed from solution with no organic solvent injected under room-temperature and -pressure (RTP) conditions. Solid bars represent C0 2 generated over 1 h, determined experimentally, and hatched bars represent the additional C0 2 generation during 3 h of operation, from extrapolation. The C0 2 capacity for dimethoxymethane and acetaldehyde added to a 2 M solution is similar to those of current MEA and chilled ammonia processes.
- aqueous ammonia performs multiple roles as a reactant, catalyst, base, and product controller, thus enabling aqueous phase C0 2 to dissolve at a significantly greater concentration than it would without the presence of ammonia.
- the addition of an organic solvent may weaken the hydration shells surrounding the dissolved C0 2 due to reduction of the solution dielectric constant, thus prompting the generation of C0 2 (g) owing to the significantly lower solubility of aqueous phase C0 2 when its interaction with ammonia is inhibited.
- Acetaldehyde reacts with ammonia under anhydrous conditions to form a trimer. Under aqueous conditions, the acetaldehyde-ammonia trimer is stable at pH above 10, forms the acetaldehyde-ammonia adduct ion at a pH less than 10 and greater than 7, and reversibly dissociates into acetaldehyde and free ammonia at a pH below 7.
- aqueous acetaldehyde-ammonia adduct ion which forms at the pH of aqueous ammonia-carbon dioxide solutions (C0 2 rich pH ⁇ 8; C0 2 lean pH ⁇ 9), decomposes into acetaldehyde vapor and aqueous ammonia upon the volatilization of acetaldehyde.
- acetaldehyde desorbed more C0 2 than DMM and acetone and was effectively recovered from the aqueous ammonia-carbon dioxide solution during low temperature distillation.
- Negligible C0 2 generation occurs at low solvent concentrations.
- FIG. 14 C0 2 release (moles) as a function of final solvent mole fraction and solvent type for: A) 2 M ammonium bicarbonate, B) 1.5 M ammonium bicarbonate, and C) 1 M ammonium bicarbonate.
- the reboiler temperature requirement for acetone and DMM was 49°C and 55°C less, respectively, than the MEA process, and 30°C and 36°C less, respectively, than the chilled ammonia process.
- the heat duty for acetaldehyde was 1.39 MJ per kg of C0 2 , or. less than quarter the heat duty of a pilot chilled ammonia process.
- the reboiler temperature requirement for acetaldehyde was 68°C, which is 72°C and 53 °C lower, respectively, than the temperature requirements of the MEA and chilled ammonia processes.
- Reboiler temperature requirements for all three organic solvents investigated were significantly less than current C0 2 capture technologies and within the temperature range of low grade waste heat.
- aqueous ammonia - carbon dioxide salt decomposition may occur under substantially room temperature and pressure (RTP) conditions using the addition of a water soluble organic solvent to a C0 2 rich aqueous ammonia - carbon dioxide solution (stage 2).
- RTP room temperature and pressure
- the energy consumed in the distillation section of this embodiment may be dependent on the relative volatility of the organic solvent to the aqueous solution and the enthalpy of vaporization of the organic solvent.
- Water soluble solvents with low boiling points, such as acetaldehyde require significantly lower temperature heat in the distillation and less reflux. Additionally, at these lower temperatures, less water is vaporized, further reducing energy consumption.
- the embodiment uses the addition of a soluble substance or substances to a solution containing C0 2 absorbent - carbon dioxide species, such as ammonia, ammonium, amine, bicarbonate, carbonate, carbon dioxide or carbamate species, to trigger the release of carbon dioxide gas from solution.
- C0 2 absorbent - carbon dioxide species such as ammonia, ammonium, amine, bicarbonate, carbonate, carbon dioxide or carbamate species.
- the added substance recovered from solution via a change in one or more or a combination of system conditions, including, but not limited to, changes in temperature, light, pressure, magnetic field, kinetic energy or a change in the presence of one or more compounds, such as changes in humidity or carbon dioxide concentration.
- the added substance can be separated and recovered by one or more techniques, including, but not limited to, filtration, centrifuge, decanting, distillation and membrane based process, such as nanofiltration, organic solvent nanofiltration, reverse osmosis, ultrafiltration, membrane distillation, and other membrane based separation devices described herein.
- the embodiment may be composed of three main steps: 1) The absorption of C0 2 in a C0 2 lean solution, resulting in the formation of a C0 2 rich solution; 2) The addition of a water-soluble substance or substances to decompose the C0 2 rich solution to a C0 2 lean solution + C0 2 (g).
- This C0 2 gas stream may undergo further purification or treatment to remove water vapor or traces of ammonia or other substances, which may be recycled in the process; 3) The recovery of the added substance or substances using one or more or a combination of changes in system conditions, which may be followed by or integrated with a physical separation mechanism.
- Changes in system conditions include, but are not limited to changes in temperature, light, pressure, magnetic field, kinetic energy, favorable reaction or a change in the presence of one or more compounds, such changes in the concentration of water vapor or humidity or changes in the presence or headspace concentration of C0 2 .
- the added substance may be physically separated and recovered by one or more techniques, including, but not limited to, filtration, centrifuge, decanting, distillation, magnetism, and/or membrane based process, such as reverse osmosis, forward osmosis, electrodialysis, nanofiltration, organic solvent nanofiltration ultrafiltration, membrane distillation, integrated electric-field nanofiltration, hot nanofiltration, or hot ultrafiltration.
- the C0 2 lean solution, after the recovery of the added substance or substances may be recycled to the first step of the process.
- the recovered substance or substances may be recycled to the second step of the process.
- a switchable solvent may be employed instead of a low boiling point solvent to reduce energy consumption and eliminate the need for a conventional distillation column.
- Switchable solvents specifically Switchable Hydrophilicity Solvents (SHS)
- SHS Switchable Hydrophilicity Solvents
- C0 2 may be added to the switchable solvent to make it hydrophilic.
- the hydrophilic version of the solvent is then added to the C0 2 rich solution to decompose it into C0 2 (g) and C0 2 -lean hydrophilic solvent aqueous solution.
- the switchable solvent is then converted to its hydrophobic form through the application of low grade heat or the use of a non-reactive gas to reduce the partial pressure of C0 2 (g) in the headspace and is separated from solution.
- C0 2 (g) may be separated from the non-reactive gas through one or more processes, including, but not limited to, the following: gas membrane separation and/or condensation.
- the non-reactive gas is desired to be insoluble in water, have a much larger molecule size than C0 2 or have a higher boiling point than C0 2 .
- the hydrophobic version of the switchable solvent can be recovered various separation methods described herein including, but not limited to, decanting, centrifuge or membrane.
- FIG. 4 Switchable solvent without waste heat or recycled inert gas that uses less valuable energy input in recovering the switchable solvent.
- This embodiment is different from the embodiment shown in FIG. 3 in its process for converting the switchable solvent from its hydrophilic form back to its hydrophobic form. Air is passed through the headspace above the switchable solvent, resulting in the evaporation of C0 2 (g) due to the low C0 2 (g) partial pressure. As C0 2 in the switchable solvent is desorbed, the solvent switches from its hydrophilic form to its hydrophobic form, forming a two-layer solution.
- This embodiment doesn't capture the carbon dioxide added to the switchable solvent, which may be absorbed into the switchable solvent in the form of flue gas or other C0 2 (g) containing source. However, this embodiment captures large portion of the power plant's C0 2 (g), without valuable energy input.
- a large body of water or ultra-low grade heat source may be applied as a heat source.
- the heat generated during C0 2 absorption may be applied to the switchable solvent regeneration stage, allowing for advantageous cooling of the absorber while supplying heat to the switchable solvent recovery stage. This allows for the only energy input to be the difference in partial pressure between the C0 2 (g) in flue gas and in the air. In cases where waste heat is utilized, lower surface area and energy consumption would be required in this system.
- Desired properties may include one or more of the following, although the properties are not limited to those described and added substances may or may not exhibit any up to all of these properties.
- Polypropylene glycol 425 is thermally switchable
- Non-toxic, inexpensive thermally switchable substances includes random or sequential copolymers of low molecular weight diols such as 1,2 propanediol, 1 ,2 ethanediol, and/or 1,3 propanediol. These switchable substances have a cloud point temperature of between 40° C to 90°C and a molecular weight high enough to allow for further separation of the substance using nanofiltration. These solutes are used in forward osmosis for desalination. These thermally switchable substances, and other thermally switchable substances, are further described in https://www.google.com/patents/US20120267308, incorporated herein by reference.
- Thermally responsive compounds include, but are not limited to, Lower Critical Solution Temperature (LCST) and Upper Critical Solution Temperature (UCST) compounds, thermo sensitive magnetic nanoparticles, thermally responsive polyelectrolytes and thermally responsive ionic liquids.
- LCST Lower Critical Solution Temperature
- UST Upper Critical Solution Temperature
- LCST compounds are soluble or have a higher solubility below a certain threshold temperature, the lower critical solution temperature.
- thermosensitive poly(N-isopropylacrylamide) (PNIPAM) hydrogel s can absorb water below the volume phase transition temperature (VPTT, ⁇ 32C) and expel water at temperatures above the VPTT.
- Other examples of these hydrogel substances include polyacrylamide (PAM), PNIPAM, and poly(Nisopropylacrylamide-co-acrylic acid) and sodium (P(NIPAM-co-SA)).
- Non-hydrogel LCST compounds include, but are not limited to, Methylcellulose and triethylamine.
- Substances may also exhibit a UCST, a temperature which the solution must be above to exhibit more solubility.
- Many water soluble, non-ionic compounds exhibit both an LCST and a UCST, such as the nicotine-water system.
- thermosensitive magnetic nanoparticles include, but are not limited to those described in the following article http://pubs.rsc.org/en/content/articlelanding/201 l/cc/clccl3944d#!divAbstract which is incorporated herein by reference. These nanoparticles are typically hydrophilic and are coated with various functional groups to allow them to generate osmotic pressure in solution.
- Thermally responsive ionic liquids include, but are not limited to those described in the following article http://pubs.rsc.org/en/Content/ ArticleLanding/2015/EW/c4ew00073k#!div Abstract which is incorporated herein by reference. Light:
- Substances showing magnetic field based change in solubility or other form of recovery via changes in magnetic field may be useful. These include, but are not limited to, magnetic nanoparticles with added functional groups (such as those described in http://pubs.acs.org/doi/abs/10.1021/iel00438x, incorporated herein by reference), and magnetic or inductive heating of nanoparticles in solution.
- Substances that change solubility or other recovery method due to pressure or a combination of pressure and temperature may also be useful. These include, but are not limited to, PSA, polyacrylamide (PAM), PNIPAM, and poly(Nisopropylacrylamide-co- acrylic acid sodium (P(NIPAM-co-SA)) hydrogels.
- Changes in solution kinetic energy can act as a stimulus to change or promote a change in the solubility or other form of recovery of an added substance.
- Kinetic energy can be of various forms, including, but not limited to, mixing and sonication. Ultrasonic sonication may either increase or decrease solubility and to promote precipitation and crystal nucleation. Ultrasonic sonication may be used to increase the rate of C0 2 desorption.
- Mixing may be employed for, including, but not limited to, facilitating the dissolution of the added substance and increase the rate of C0 2 gas desorption.
- the general substance embodiment may not involve the added substance chemically reacting with the C0 2 absorbent or C0 2 species. However, if the substance does react with C0 2 , the following may be some favorable properties for these reactions:
- Properties of a favorable reaction include, but are not limited to one or more or a combination of the following:
- An example of a potentially favorable reversible reaction includes the formation of reversible ammonia-metal complexes. These complexes may reduce the affinity of ammonia to the carbon dioxide in solution, resulting in a release or a low temperature release of carbon dioxide from solution.
- the reagents may function as catalysts. Instances may also exist where the favorable reaction does not involve reversibility. In the instance where the reaction is irreversible, it may be advantageous for one or more byproducts to have a value-added application, such as use in forward osmosis desalination or fertilization.
- a water-soluble substance such as an organic solvent
- a C0 2 rich aqueous ammonia - carbon dioxide solution may generally initiate and foster C0 2 desorption independently of temperature.
- heat including heat above the decomposition temperature of the absorbent - carbon dioxide, may be applied to the C0 2 desorption and substance regeneration stages.
- This may, include, but not be limited to, increase C0 2 desorption rate, increase solution capacity, reduce C0 2 loading, improve the properties of the C0 2 absorption solution to maximize C0 2 uptake, improve the properties of the C0 2 absorption solution to maximize the rate of C0 2 uptake, help overcome enthalpy of desorption or overcome activation energy, which may be especially useful for C0 2 absorbents with high enthalpies of reaction relative to ammonia.
- the presence of the soluble substance, such as PEG or PPG may reduce the temperature and energy requirements of C0 2 desorption during thermal desorption in comparison to existing ammonia or amine thermal desorption processes.
- Example 1 A water soluble substance is added at a moderate or cool temperature, such as at room temperature, in the C0 2 desorption stage and gaseous C0 2 is desorbed. After at least a significant portion, such as less than any of the following: 5%, or 10%, or 15%, or 20%, or 25%, or 30%, or 35%, or 40%, or 45%, or 50% of the C0 2 in solution, is desorbed, heat may be applied to the mixed desorption solution in a separate or the same reactor or reactors.
- a moderate or cool temperature such as at room temperature
- heat may also be desirable for heat to be applied when the C0 desorption rate due to the presence of the soluble substance has appreciably subsided, such as the C0 2 desorption rate subsiding to less than any of the following: 95%, or 90%, or 75%, or 60%, or 50% or 40%), or 30%), or 20%>, or 10%) of the maximum C0 2 desorption rate after soluble substance injection.
- the application of heat may enhance C0 2 (g) desorption.
- the temperature and energy requirements for thermal desorption may be significantly less than conventional thermal desorption processes due to the presence of the water-soluble substance.
- the added substance in this example may be non-volatile, such as a vapor pressure at 20°C at less than 0.1 atm, or any of the following: 0.05 atm, or 0.03 atm, or 0.01 atm, or 0.001 atm, or 0.0001 atm, and minimally prone to thermal degradation.
- Such substances include, but are not limited to, PEG and PPG.
- This embodiment may allow for significant reductions in energy requirements for C0 2 capture, while allowing for, including, but not limited to, one or more or a combination of the following: greater C0 2 desorption rates, greater C0 2 solution capacity, lower precipitate formation, lower C0 2 loading in the C0 2 lean solution, and greater C0 2 uptake in the C0 2 absorption column.
- Example 2 The water-soluble substance is added to the C0 2 -rich solution in the C0 2 desorption stage and heat is applied to the solution during most the C0 2 desorption timeframe.
- the initial C0 2 desorption may be primarily due to the influence of the soluble substance.
- the heat may, include, but not be limited to, increase the rate of C0 2 desorption or facilitate C0 2 desorption.
- the influence of heat application on C0 2 desorption may increase over time and the influence of the added substance may subside.
- Example 3 In embodiments where the added substance is recovered using heat, such as embodiments with various forms of distillation or switchable solvent, or where heat is applied during soluble substance recovery, such as may be the case in membrane-based recovery embodiments, C0 2 (g) may be desorbed. This C0 2 desorption may be in part due to thermal decomposition. This C0 2 may be recovered and utilized in a similar manner to the C0 2 desorption during the C0 2 desorption stage.
- C0 2 (g) is generated until the NH 3 : C0 2 molar ratio in the aqueous solution is sufficient to prompt 'salting-out' or the formation of a multi-layer solution.
- This NH 3 : C0 2 molar ratio may be greater than 1.5: 1.
- the presence of aqueous ammonium carbamate species may facilitate the formation of a two layer solution.
- the layer with a lower concentration of large molecular weight solvent is fed into a separation mechanism, which includes those described in FIGURE 1.
- the layer with a higher concentration of solvent may also be fed into one or more of these separation mechanisms if desired.
- the layer with a higher concentration of solvent is combined with the concentrate formed during the separation mechanism, forming a high concentration solvent solution.
- the process requires less energy due to separating solvent from a smaller volume of solution.
- the layers may be separated via various processes, including, but not limited to, decanting or centrifugation.
- no separation mechanism is employed after the two or more layers are separated.
- the layer or layers with a lower concentration of the soluble substance may be transferred to the absorption column as the absorption solution.
- the layers with a higher concentration of the soluble substance are transferred to the C0 2 desorption step.
- a distillation process may be used to recover the solvent in one or more of the solvent layers.
- a membrane may be used to concentrate or recover the substance or purify the C0 2 lean or C0 2 -rich solutions in one or of the substance containing layers.
- This embodiment is composed of three main steps: 1) The contacting of a gas containing C0 2 to convert a C0 2 lean solution to a C0 2 rich solution. The remaining inert gases may undergo further purification, treatment or compression; 2) The addition of low boiling point soluble substance or substances, such as dimethyl ether, to the C0 2 rich solution to generate C0 2 (g), creating a C0 2 lean solution + added substance + C0 2 (g). The substance may be added in the gas phase, liquid phase or a combination of gas and liquid phases. This C0 2 (g) stream may undergo further purification, treatment or compression.
- Any remaining or residual solvent vapor in the C0 2 (g) stream may be separated and recovered; 3) The recovery of the added substance or substances using ultra-low temperature distillation.
- Heat or enthalpy sources include, but are not limited to, ultra-low temperature waste heat sources, ambient temperature enthalpy sources, and chilling fluids.
- the process may replace or greatly minimize the need for evaporative cooling towers, as the distillation column can cool the condenser fluids in an open or closed loop. Higher temperature heat may be used if desired.
- the process may be conducted without a vapor compressor and may condense the solvent with lower temperatures or only condense a portion of the pure solvent to the liquid phase before solvent addition.
- the process may be conducted under a higher pressure, allowing for the solvent to condense under more moderate conditions without a compressor.
- a vapor compressor or mechanical vapor compression distillation the solvent may condense at a greater temperature and residual solvent vapors may be easier to recover.
- Heat may be recovered or removed during to solvent vapor condensation or compression.
- the C0 2 (g) may need to be separated from the low boiling point solvent vapor during C0 2 desorption. This may involve various treatment methods, including, but not limited, water wash-down, condenser, compression or other systems and methods described herein.
- the enthalpy or heat source is a fluid exchanged with the C0 2 (g) absorption column.
- the fluid or chilling fluid may be an external fluid heat exchanged with the absorption and distillation columns or the solutions within either or both the absorption or distillation columns. Additional heat or enthalpy may be recovered from the residual vapor separator and the vapor compressor.
- C0 2 (g) absorption is known in the art to perform more advantageously at ambient or lower than ambient temperatures.
- an external refrigeration, chilling or evaporative cooling unit is used to cool the solution, increasing energy load and capital and operator costs.
- This chilling is generally required due to the exothermic nature of C0 2 (g) absorption reaction.
- the embodiment shown in FIG. 8 allows for the heat energy generated in C0 2 (g) absorption to be recovered or used to power the solvent distillation. Additionally, heat or enthalpy sources may be used, however, it may be advantageous to integrate and balance the energy demands in the process, including those from the C0 2 (g) absorption and solution regeneration stages.
- Desired substances may include one or more of the following, although the properties are not limited to those described and added substances may or may not exhibit any of these properties.
- Dimethyl ether exhibits high solubility in water, even above its boiling point, is essentially non-toxic and is a low cost, commodity chemical.
- Dimethyl Ether may be sufficiently soluble in water for this application under moderate conditions (see graph below). Based on its molar mass and dielectric constant, the process may require a mole fraction of 0.04 - 0.06 to prompt C0 2 desorption, which may be achieved under moderate conditions (http://www.pet.hw.ac.uk/icgh7/papers/icgh201 1Final00008.pdf, incorporated herein by reference).
- the solvent distillation is used for chilling an external medium.
- This may include, but is not limited to, cooling condenser fluid from power generation, HVAC systems, ice skating rinks, datacenters, manufacturing, industrial processes, solar thermal or photovoltaic and mining and natural resource extraction.
- Natural heat sinks may also be used as enthalpy or heat sources including, but not limited to, water bodies, air, geothermal sources, and solar thermal sources.
- Substance is added to a C0 2 adsorbent, such as quaternary ammonium cation containing material, to desorb C0 2 .
- a C0 2 adsorbent such as quaternary ammonium cation containing material
- the adsorbents may exhibit any range of surface areas or surface morphologies.
- C0 2 capture adsorbents and hybrid adsorbents - absorbents may exhibit properties, including, but not limited to, one or more or a combination of the following:
- Distilled solvent or solvent vapor may be contacted with the second stage of the embodiment shown in FIG. 2, as a means of added the solvent to desorb C0 2 (g).
- the vapor may dissolve and condense, adding solvent to the solution, while increasing the solution temperature, which may improve C0 2 (g) desorption yield and recover heat or a portion of the enthalpy of vaporization.
- any C0 2 (g) released from solution during the distillation is combined with the C0 2 (g) released during the second stage. This may reduce energy consumption in preheating the solution prior to distillation and lower capital costs by minimizing or eliminating the need for a condenser.
- Ammonium Carbonate may have an ammonia to carbon dioxide molar ratio of > 1.5 : 1 to ⁇ 100:1
- Ammonium Bicarbonate or Ammonium Sesquicarbonate may have an ammonia to carbon dioxide molar ratio of 0.25:1 to 1.5: 1
- Solvent or substance may be substance or combination of substances that when added to a carbon dioxide species containing solution, such as an ammonia-carbon dioxide solution, prompts the release of carbon dioxide.
- the solvent or substance may include, but is not limited to, one or more of the following: a soluble substance, a water soluble substance, an organic solvent, an organic substance, a soluble organic substance, a water soluble organic solvent, a soluble polymer, a water soluble organic substance, a substance containing carbon, a substance containing carbon and hydrogen, a substance containing carbon, hydrogen and oxygen, or a substance containing hydrogen and nitrogen, a non-ionic substance, a non-reactive substance, a non-ionic water soluble substance, non-reactive water soluble substance, inert soluble substance, inert water soluble substance, or inert substance.
- Switchable Solvent Include substances with Switchable Hydrophilicity (SHS), Switchable Polarity (SPS), Switchable Water (SW). Further information is incorporated herein by reference:
- Substance(s) may be added or included at any component in the system to enhance performance. These improvements in performance may include, but are not limited to, enhancing C0 2 absorption, enhancing C0 2 desorption, prevention of ammonia reaction with solvent and preventing ammonia slip.
- absorption and desorption catalysts known in the art include, but are not limited to, HZSM-5, ⁇ - A1 2 0 3 , HY, silica-alumina, or combinations thereof.
- Waste Heat/Low Grade Heat Heat energy that can be utilized in the systems and methods described herein.
- the temperature me be less than 200 °C, or less than 100 °C, or less than 50 °C. It may be advantageous for the heat source to be an untapped byproduct of another process.
- waste heat sources include, but are not limited to, the following: Power Plant (Natural gas, coal, oil, petcoke, biofuel, municipal waste), Condensing water, Flue Gas, Steam, Oil refineries, Metal production/refining (Iron, Steel, Aluminum, etc.), Glass production, Manufacturing facilities, Fertilizer production, Transportation vehicles (ships, boats, cars, buses, trains, trucks, airplanes), Waste Water Treatment, Solar thermal, Solar pond, Solar photovoltaic, Geothermal (Deep Well), Biofuel powered vehicles,
- Power Plant Natural gas, coal, oil, petcoke, biofuel, municipal waste
- Condensing water Flue Gas, Steam, Oil refineries, Metal production/refining (Iron, Steel, Aluminum, etc.)
- Glass production Manufacturing facilities
- Fertilizer production Transportation vehicles (ships, boats, cars, buses, trains, trucks, airplanes), Waste Water Treatment, Solar thermal, Solar pond, Solar photovoltaic, Geothermal (Deep Well), Biofuel powered vehicles,
- Biofuel/Biomass/Municipal Waste Power Plants Desulfurization, Alcohol production, hydrogen sulfide treatment, acid (e.g. sulfuric) production, Renewable fertilizer production, Ocean Thermal, Space heating, Grey water, Diurnal temperature variation, Geothermal (Shallow well/loop), or respiration.
- acid e.g. sulfuric
- Renewable fertilizer production Ocean Thermal, Space heating, Grey water, Diurnal temperature variation, Geothermal (Shallow well/loop), or respiration.
- Carbon Dioxide Sources Any process or resource producing or containing carbon dioxide. Examples of C0 2 sources include, but are not limited to, the following:
- Heat or cooling may be applied at any point in the process.
- heat may be applied in the substance addition and mixing stage (Stage 2) for various purposes, including, but not limited to, promoting C0 2 (g) generation and increasing mixing rate and cooling may be applied in the absorption column.
- Heat exchangers and recovery devices may be employed where advantageous. For example, heat may be recovered from the streams exiting the distillation column by preheating the solution entering the distillation column.
- the gases considered “inert” may not react with the ammonia or carbon dioxide in unfavorable ways. These gases may not be universally “inert,” as they may react with other substances or under other or similar conditions. These “inert gases” may include, but are not limited to, nitrogen, oxygen, hydrogen, argon, methane, carbon monoxide, low concentrations of C0 2 (g) volatile hydrocarbons, such as ethane, butane, propane.
- the "flue gas” or carbon dioxide containing gas stream may include any gas stream that at least partially comprises carbon dioxide.
- Degradation or oxidation of the C0 2 absorbent may occur due to, including, but not limited to, one or more or a combination of the following: thermal degradation, light, UV light, or reaction with oxygen, NO x , SO x , C0 2 or the added substance. Degradation or oxidation is known in the art to be most prevalent in amine and azine C0 2 absorbents.
- Degradation or Oxidation inhibitors include, but are not limited to, one or more or a combination of the following: antioxidants, sulfites, bisulfite, metabisulfites, nitrites, hydroxyethylidene diphosphonic acid (HEDP), diethylene triamine penta acetic acid (DPTA), diethylenetriamine penta (methylene phosphonic acid) (DTPMP), ethylenediamine tetra (methylene phosphonic acid) (EDTMP), citric acid, or absorbent combinations that inhibit degradation or oxidation,
- antioxidants sulfites, bisulfite, metabisulfites, nitrites, hydroxyethylidene diphosphonic acid (HEDP), diethylene triamine penta acetic acid (DPTA), diethylenetriamine penta (methylene phosphonic acid) (DTPMP), ethylenediamine tetra (methylene phosphonic acid) (EDTMP), citric acid, or absorbent combinations that inhibit
- the added substance may exhibit oxidation or degradation. Measures may be employed to prevent degradation and oxidation. Degradation or oxidation of the added substance may occur due to, including, but not limited to, one or more or a combination of the following: thermal degradation, light, UV light, or reaction with oxygen, NO x , SO x , C0 2 , or the C0 2 absorbent.
- Degradation or Oxidation inhibitors include, but are not limited to, one or more or a combination of the following: antioxidants, sulfites, bisulfite, metabisulfites, nitrites, or added substance combinations that inhibit unfavorable reactions, such as degradation or oxidation.
- Corrosion resistant materials may include, but is not limited to, one or more or a combination of the following: Teflon, polyethylene, polypropylene, PVC, stainless - steel, metals non-reactive with ammonia, metals non-reactive with aqueous ammonium, and materials not reactive with the C0 2 absorbent or absorbents employed.
- Mixing devices include, but are not limited to, on or more or a combination of the following:
- Heat sources may include, but are not limited to, waste heat, power plant waste heat, steam, heat, pump or compressor waste heat, industrial process waste heat, steel waste heat, metal refining and production waste heat, paper mill waste heat, factory waste heat, petroleum refining waste heat, solar heat, solar pond, air conditioner waste heat, combustion heat, geothermal heat, ocean or water body thermal heat, stored heat, and C0 2 (g) absorption solution heat.
- the solution may comprise one or more or a combination of the following phases throughout the integrated process: liquid, solid, liquid-solid slurry, liquid-solid mixture, gas, two-phase solution, three-phase solution, two-layer solution, or supercritical
- the C0 2 rich compound or C0 2 may be captured or absorbed prior to the integrated process.
- the C0 2 desorption stage may be directly fed a C0 2 rich solution by a device or stage other than an absorption column.
- the C0 2 may have been absorbed in a separate location and the resulting C0 2 rich feed is transported to the C0 2 desorption stage.
- the C0 2 in the C0 2 rich compound may not have been captured from a gas source.
- the C0 2 instead may be sourced from a solid or liquid, which may be directly fed into the process or undergo methathesis or displacement reaction to remove extract this C0 2 species into a form with which C0 2 can be desorbed with substance addition.
- An example of this may include C0 2 species derived from a metathesis reaction with limestone or a metathesis reaction in the production of another C0 2 containing compound.
- Another example may be C0 2 species present in compounds in waste water, such as Urea or ammonium carbonate or ammonium bicarbonate.
- Water soluble substances may include, but are not limited to, the substances detailed below:
- Aqueous solution Water soluble polymer, Soluble polymer, Glycol Polyethylene Glycol, Polypropylene Glycol Ethers, Glycol Ethers, Glycol ether esters, Triglyme.
- Polyethylene Glycols of multiple geometries Methoxypolyethylene Glycol, Polyvinyl Alcohol Polyvinylpyrrolidone, Polyacrylic Acid, Diol polymers, 1,2 propanediol, 1,2 ethanediol, 1,3 propanediol, Cellulose Ethers, Methylcellulose, Cellosize,
- Carboxymethylcellulose Hydroxyethylcellulose, Sugar Alcohol, Sugars, Alcohols Ketones, Aldehydes, Esters, Organosilicon compounds, Halogenated solvents
- PNIPAM Poly(N-isopropylacrylamide)
- PAM Polyacrylamide
- Natural water-soluble polymers Starches, Sugars, Polysaccharides, Agar, Alginates, Carrageenan, Furcellaran, Casein and caseinates, Gelatin, Guar gum and derivatives, Gum arabic, Locust bean gum, Pectin, Cassia gum, Fenugreek gum, Psyllium seed gum, Tamarind gum, Tara gum, Gum ghatti, Gum karaya, Gum tragacanth, Xanthan gum, Curdlan, Diutan gum, Gellan gum, Pullulan, Scleroglucan (sclerotium gum)
- PEGs are available with different geometries, including, but not limited to, the following:
- Branched PEGs have three to ten PEG chains emanating from a central core group.
- Star PEGs have 10 to 100 PEG chains emanating from a central core group.
- Comb PEGs have multiple PEG chains normally grafted onto a polymer backbone.
- Organic solvent with a molecular weight including, but not limited to, greater than 100 da or any of the following: 125 da, or 150 da, or 175 da, or 200 da, or 225 da, or 250 da, or 275 da, or 300 da, or 325 da, or 350 da, or 375 da, or 400 da, or 425 da, or 450 da, or 475 da, or 500 da, or 525 da, or 550 da, or 575 da, or 600 da
- Polymer with a molecular weight including, but not limited to, greater than 100 da or greater than any of the following: 125 da, or 150 da, or 175 da, or 200 da, or 225 da, or 250 da, or 275 da, or 300 da, or 325 da, or 350 da, or 375 da, or 400 da, or 425 da, or 450 da, or 475 da, or 500 da, or 525 da, or 550 da, or 575 da, or 600 da
- Substance with a molecular weight including, but not limited to, greater than 100 da or greater than any of the following: 125 da, or 150 da, or 175 da, or 200 da, or 225 da, or 250 da, or 275 da, or 300 da, or 325 da, or 350 da, or 375 da, or 400 da, or 425 da, or 450 da, or 475 da, or 500 da, or 525 da, or 550 da, or 575 da, or 600 da
- Organic solvent with a hydration radius including, but not limited to, greater than 100 da, or greater than any of the following: 125 da, or 150 da, or 175 da, or 200 da, or 225 da, or 250 da, or 275 da, or 300 da, or 325 da, or 350 da, or 375 da, or 400 da, or 425 da, or 450 da, or 475 da, or 500 da, or 525 da, or 550 da, or 575 da, or 600 da
- Polymer with a hydration radius including, but not limited to, greater than 100 da, or or greater than any of the following: 125 da, or 150 da, or 175 da, or 200 da, or 225 da, or 250 da, or 275 da, or 300 da, or 325 da, or 350 da, or 375 da, or 400 da, or 425 da, or 450 da, or 475 da, or 500 da, or 525 da, or 550 da, or 575 da, or 600 da
- Substance with a hydration radius including, but not limited to, greater than 100 da, or or greater than any of the following: 125 da, or 150 da, or 175 da, or 200 da, or 225 da, or 250 da, or 275 da, or 300 da, or 325 da, or 350 da, or 375 da, or 400 da, or 425 da, or 450 da, or 475 da, or 500 da, or 525 da, or 550 da, or 575 da, or 600 da
- Solvent trope (2nd Weight of 1st (2nd Azeotrope with Solvent) alone) Solvent) AzeoSolvent Solvent trope Water?
- amines and other C0 2 reactive compounds may be employed, however, it may be desirable for the amines to not react with the C0 2 absorbent - C0 2 , such as in a metathesis reaction.
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Abstract
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PCT/US2017/016512 WO2017136728A1 (en) | 2016-02-03 | 2017-02-03 | Integrated process for capturing carbon dioxide |
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WO2019113513A1 (en) | 2017-12-08 | 2019-06-13 | Baker Hughes, A Ge Company, Llc | Ionic liquid based well asphaltene inhibitors and methods of using the same |
EA202091413A1 (en) | 2018-07-11 | 2020-09-24 | Бейкер Хьюз Холдингз Ллк | WELL ASPHALTEN INHIBITORS BASED ON IONIC LIQUID AND METHODS OF THEIR APPLICATION |
CN110448994B (en) * | 2019-08-16 | 2022-08-05 | 北京化工大学 | Process method for trapping NO by using renewable amino functional eutectic solvent |
US11452974B2 (en) | 2020-06-19 | 2022-09-27 | Honda Motor Co., Ltd. | Unit for passive transfer of CO2 from flue gas or ambient air |
CN111871159A (en) * | 2020-07-15 | 2020-11-03 | 中石化南京化工研究院有限公司 | Membrane separation coupling alcohol amine solution for capturing flue gas CO2Apparatus and method |
CN114558549B (en) * | 2020-11-27 | 2023-03-21 | 北京驭碳科技有限公司 | Use of carboxylate compounds as absorbents for capturing carbon dioxide |
CN112892587B (en) * | 2021-01-22 | 2022-07-05 | 华东师范大学 | Method for preparing ethylene glycol by efficiently catalyzing hydration reaction of ethylene oxide |
CN113533125B (en) * | 2021-03-11 | 2022-09-09 | 华润水泥技术研发有限公司 | Cementing material carbon absorption reaction device |
CN114644535B (en) * | 2021-06-28 | 2023-03-14 | 石河子大学 | Carbon dioxide fertilizer for regulating and controlling plant photosynthesis and preparation method and application thereof |
CN116351265B (en) * | 2022-01-17 | 2024-06-07 | 中国科学院过程工程研究所 | Preparation and application of high-performance mixed matrix gas separation membrane based on ionic liquid coordination |
CN114452779B (en) * | 2022-03-09 | 2022-09-27 | 清华大学 | Carbon dioxide capture system based on phase change absorbent |
CN114768777A (en) * | 2022-04-18 | 2022-07-22 | 济宁九德半导体科技有限公司 | Application of polyether polyol or derivatives thereof as adsorbent and gas adsorption device |
CN114984727B (en) * | 2022-07-28 | 2022-10-28 | 北京百利时能源技术股份有限公司 | Low-temperature cryogenic CO 2 Trapping device and trapping method |
WO2024033942A1 (en) * | 2022-08-10 | 2024-02-15 | Prerna Goradia | Regenerable gas absorption material and device |
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GB0502227D0 (en) * | 2005-02-03 | 2005-03-09 | Thermal Energy Systems Ltd | Gas separation and compresssion device |
EP2210656A1 (en) * | 2009-01-27 | 2010-07-28 | General Electric Company | Hybrid carbon dioxide separation process and system |
WO2012030630A1 (en) * | 2010-09-02 | 2012-03-08 | The Regents Of The University Of California | Method and system for capturing carbon dioxide and/or sulfur dioxide from gas stream |
MX336817B (en) * | 2010-09-09 | 2016-02-02 | Exxonmobil Res & Eng Co | High co2 to amine adsorption capacity co2 scrubbing processes. |
EP2433700A1 (en) * | 2010-09-23 | 2012-03-28 | Alstom Technology Ltd | Trace component removal in CO2 removal processes by means of a semipermeable membrane |
CA2773724C (en) * | 2010-10-29 | 2013-08-20 | Co2 Solutions Inc. | Enzyme enhanced co2 capture and desorption processes |
US20130200291A1 (en) * | 2012-01-27 | 2013-08-08 | Queen's University At Kingston | Tertiary Amine-Based Switchable Cationic Surfactants and Methods and Systems of Use Thereof |
US9321004B2 (en) * | 2013-04-30 | 2016-04-26 | Uop Llc | Mixtures of physical absorption solvents and ionic liquids for gas separation |
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