ABSTRACT
Abstract
A method of scrubbing a gas, such as flue gas or exhaust gas, comprising carbon dioxide to deplete the gas of carbon dioxide (CO 2 ), the method comprising the steps of:
scrubbing the gas in a scrubber ( 210 ) with a first alkaline, aqueous scrubbing liquid to dissolve carbon dioxide (CO 2 ) as hydrogen carbonate (HCO 3 â ) and/or as carbonate (CO 3 2â ) in the first alkaline, aqueous scrubbing liquid, thereby providing a first spent aqueous scrubbing liquid comprising hydrogen carbonate (HCO 3 â ) and/or carbonate (CO 3 2â ), the first spent aqueous scrubbing liquid having a pH from about 7 to about 9; feeding the first spent aqueous scrubbing liquid to an anode chamber of an electrolytic cell ( 310 ) comprising the anode chamber ( 313 ) and a cathode chamber ( 312 ) separated by a membrane ( 311 ); regenerating the first spent aqueous scrubbing liquid in the electrolytic cell ( 310 ) by electrolysis, the electrolysis increasing the pH of the first spent aqueous scrubbing liquid in the cathode chamber ( 312 ), the electrolysis further depleting the first spent aqueous scrubbing liquid of hydrogen carbonate (HCO 3 â ) and of carbonate (CO 3 2â ) in the anode chamber ( 313 ) by decreasing the pH, the regeneration further comprising generating gaseous hydrogen in the cathode chamber ( 312 ) and a gaseous mixture of oxygen and carbon dioxide (CO 2 ) in the anode chamber ( 313 ) by electrolysis; and withdrawing regenerated alkaline, aqueous scrubbing liquid from the cathode chamber ( 312 ) and re-circulating it to the scrubber ( 210 ); wherein: the gaseous hydrogen is withdrawn from the cathode chamber ( 312 ); and the gaseous mixture of oxygen and carbon dioxide is withdrawn from the anode chamber ( 313 ).
Description
This application claims priority to EP Patent Application No. 20206242.8 filed 6 Nov. 2020, the entire contents of which is hereby incorporated by reference.
TECHNICAL FIELD
The present invention relates to a method of scrubbing a gas, such as flue gas comprising carbon dioxide (CO 2 ), to deplete the gas of carbon dioxide, comprising regenerating spent aqueous scrubbing liquid. Further, the present invention relates to a system for such scrubbing of a gas, such as flue gas, comprising carbon dioxide.
BACKGROUND
Carbon dioxide (CO 2 ) is a gas that when emitted into the atmosphere is damaging to the climate as it contributes to the green-house effect and rise in global temperature. It is for example produced as a byproduct when fossil fuel, e.g. coal, gasoline or diesel, is burned. Coal- and gas-fired power plants accounts for a large share of CO 2 emissions. It is a goal for many sectors to lower carbon dioxide emissions.
Emitted gases resulting from combustion and comprising CO 2 are typically denoted flue gases or exhaust gases. Depleting such emitted gases of CO 2 by lowering the CO 2 content in the emitted gases, can be done by so called scrubbing of the gases, i.e. removing the CO 2 from the gas stream by absorbing/dissolving CO 2 in a liquid. The primary application for CO 2 scrubbing is for removal of CO 2 from the exhaust (i.e. flue gas) of coal- and gas-fired power plants, downstream of a power station, before the gas is released into the atmosphere. By using such a process, it would be possible to significantly lower the CO 2 emissions involved in coal-fired power generation. In the chemical industry, CO 2 scrubbing is used to separate CO 2 from natural gas, for use in, for example, the beverage or fertilizer sector.
In a CO 2 -scrubbing system, a scrubbing solution takes up the carbon dioxide from the flue gas, at low temperatures, in an absorber. Most common is scrubbing of the flue gas using a chemical absorption medium, such as an alkaline, aqueous liquid. In an alkaline, aqueous liquid, CO 2 will dissolve and partly be hydrolyzed into carbonic acid (H 2 CO 3 ). Given the alkaline pH, formed carbonic acid (H 2 CO 3 ) will be shifted into hydrogen carbonate (HCO 3 â ) and/or carbonate (CO 3 2â ), as outlined below.
CO 2 +H 2 O=>H 2 CO 3
H 2 CO 3 OH â =>HCO 3 â +H 2 O
HCO 3 â +OH â =>CO 3 2â +H 2 O
The technology being primarily developed for this process involves the use of aqueous amines, e.g. aqueous monoethanolamine, as absorption solvent. Amine scrubbing has been used to separate carbon dioxide (CO 2 ) from natural gas and hydrogen since 1930. However, it is not yet used on a larger scale for CO 2 capture from coal-fired power plants. The process is energy consuming and the technology has not been implemented in large scale because of the capital costs of installing the facility and the operating costs. Scrubbers using aqueous monoethanolamine as absorption solvent for example use large amounts of heat for regeneration of the solvent used in the scrubber. Presently, there are no other industrial applicable technologies that will provide energy-efficient or timely solutions to CO 2 emission from conventional coal-fired power plants.
Further key areas in development work on the carbon capture process include process integration and optimization for applications in large-scale power plants.
There is an imperative need for improved scrubbing systems that preferably require less heat for CO2 capture.
SUMMARY
Accordingly, there is, according to a first aspect, provided a method of scrubbing a gas comprising carbon dioxide (CO 2 ) to deplete the gas of carbon dioxide. The gas comprising carbon dioxide (CO 2 ) may typically be a result from combustion, such as flue gas or exhaust gas. However, also other gases comprising carbon dioxide (CO 2 ) may be scrubbed by the present method. An example would be to capture CO 2 from a power plant that generates heat and power from biomass.
The method comprises the steps of scrubbing the gas in a scrubber with a first alkaline, aqueous scrubbing liquid to dissolve carbon dioxide (CO 2 ) as hydrogen carbonate (HCO 3 â ) and/or as carbonate (CO 3 2â ) in the first alkaline, aqueous scrubbing liquid, thereby providing a first spent aqueous scrubbing liquid comprising hydrogen carbonate (HCO 3 â ) and/or carbonate (CO 3 2â ). The first spent aqueous scrubbing liquid has a pH from about 7 to about 9, in order to optimize the subsequent regeneration.
The method further comprises the step of feeding the first spent aqueous scrubbing liquid to an anode chamber of an electrolytic cell with an anode and a cathode. The anode and the cathode of the electrolytic cell are separated by a membrane to provide the anode chamber and a cathode chamber. The membrane is permeable to alkali metals, such as lithium, sodium and potassium, but has no or low permeability to hydrogen carbonate (HCO 3 â ) and/or to carbonate (CO 3 2 ). Typically, the membrane is permeable only to cations. The membrane may be a cation-exchange membrane. In the electrolytic cell, the first spent aqueous scrubbing liquid is regenerated by electrolysis. In regenerating the spent aqueous scrubbing liquid, a number of electrolytic cells connected in parallel may be used. Before being fed to the anode chamber, the spent aqueous scrubbing liquid may be filtered to remove particulate matter.
In electrolysis, water is converted into oxygen and hydronium ions (H 3 O + ) at the anode, whereas water is converted into hydrogen and hydroxide ions (OH â ) at the cathode. The electrolysis thus increases the pH of the first spent aqueous scrubbing liquid in the cathode chamber and depletes the first spent aqueous scrubbing liquid of hydrogen carbonate (HCO 3 â ) and of carbonate (CO 3 2â ) in the anode chamber, by decreasing the pH to shift the equilibrium towards carbonic acid in turn shifted into carbon dioxide. The regeneration further comprises generating gaseous hydrogen in the cathode chamber and a gaseous mixture of oxygen and carbon dioxide in the anode chamber by electrolysis. The chemical reactions and description of the operation of the processes are further described in the Detailed Description herein further below.
The method further comprises the step of withdrawing regenerated alkaline, aqueous scrubbing liquid from the cathode chamber and re-circulating it to the scrubber.
One key difference from the set-up of commercially available amine scrubbers is that the scrubbing liquid in the present method is regenerated by electrochemistry, while scrubbers in the art typically use large amounts of heat for regeneration of the scrubbing liquid used in the scrubber.
According to the present method, in regenerating the scrubbing liquid its pH is increased. Further, the regeneration, as already explained, also generates carbon dioxide and hydrogen, which may be used downstream for synthesis of organic compounds, such as methanol, thus adding further value to the process. The process is ideal for processes such as downstream Power-to-X processes.
The gaseous hydrogen is withdrawn from the cathode chamber and the gaseous mixture of oxygen and carbon dioxide is withdrawn from the anode chamber.
Withdrawing hydrogen, oxygen and carbon dioxide from the regeneration process is advantageous as hydrogen and oxygen can be used to generate electricity, e.g. by a fuel cell, to operate the process partly. Further, hydrogen and carbon dioxide (CO 2 ) can be used for synthesis of organic compounds, e.g. methanol, thereby compensating for the cost of running the process.
The carbon capture reaction in the scrubbing step takes place automatically. The operation of the scrubber is thereby an automatic process and requires no power apart from one needed to circulate the liquids. The regeneration process that takes place in the cathode and anode chambers of the electrolytic cell are electrochemical reactions, which inherently require electrical power. The electrochemical process regenerates the solvent, produces hydrogen at the cathode and a mixture of carbon dioxide (CO 2 ) and oxygen at the anode.
The actual power consumption will depend on the technical implementation of the process. Overall, the process requires a large amount of electrical energy rather than heat. This is positive, as electrification of the regeneration in carbon capture processes is highly desired. Further, some of the energy may be recovered as heat for district heating. Regeneration of amine-based scrubbing liquids reduces the overall efficiency of a power plant as some of the heat generated rather than being distributed, has to be used to re-generate the scrubbing liquid. Regeneration of alkaline scrubbing liquids comprising dissolved metal hydroxides may be regenerated electrical energy thus not affecting the overall efficiency of a power plant.
In order to dissolve carbon dioxide and shift the equilibrium towards hydrogen carbonate (HCO 3 â ) and of carbonate (CO 3 2â ), the first aqueous scrubbing liquid needs to be alkaline, i.e. have a pH exceeding 7, such as 8 or higher.
Thus, the first alkaline, aqueous scrubbing liquid may comprise a metal hydroxide. According to an embodiment of the method, the first alkaline, aqueous scrubbing liquid comprises one or more of dissolved potassium hydroxide (KOH), dissolved sodium hydroxide (NaOH) and dissolved lithium hydroxide (LiOH). The first alkaline, aqueous scrubbing liquid may comprise potassium hydroxide (KOH). Given its high solubility in water, potassium hydroxide (KOH) is a preferred metal hydroxide.
In the anode chamber, a gaseous mixture of oxygen and carbon dioxide is formed. The method may thus further comprise a step of separating this gaseous mixture of oxygen and carbon dioxide into a first stream, rich in oxygen and/or depleted of carbon dioxide, and a second stream, rich in carbon dioxide and/or depleted of oxygen. The gaseous mixture of oxygen and carbon dioxide may be compressed to provide for separation of liquid carbon dioxide (CO 2 ) from gaseous (O 2 ). According to one embodiment of the method, carbon dioxide (CO 2 ) and/or oxygen (O 2 ) withdrawn from the anode chamber is compressed into liquid carbon dioxide and/or compressed oxygen (O 2 ).
Further, hydrogen formed in the cathode chamber is withdrawn. Hydrogen withdrawn from the cathode chamber may be used as a fuel to provide electricity, either internally or externally. Hydrogen and oxygen may be used to fuel a fuel cell. The electricity formed may optionally be used to operate the electrolytic cell regenerating the spent aqueous scrubbing liquid. This is advantageous as it at least partly compensates for the electricity consumption of running the process. Further, it may also be of interest to sell hydrogen on the open market.
The anode chamber is typically not operated such that all hydrogen carbonate (HCO 3 â ) is converted to carbon dioxide. The method may thus further comprise withdrawing an aqueous stream still comprising some hydrogen carbonate (HCO 3 â ) from the anode chamber. This stream may be concentrated, such as by reversed osmosis. The resulting concentrated stream comprising hydrogen carbonate (HCO 3 â ) may be re-circulated to the electrolytic cell, thus facilitating further removal of hydrogen carbonate (HCO 3 â ).
Typically, the gas comprising carbon dioxide and the scrubbing liquid are fed in contraflow manner to the scrubber to provide for efficient removal of carbon dioxide.
According to one embodiment of the method, the scrubbing of the gas comprising carbon dioxide is performed in at least a first stage and in a second stage. This provides for efficient removal of carbon dioxide, while still providing for optimizing the pH of the spent scrubbing liquid to be regenerated. The scrubbing may be performed in more than two stages.
In scrubbing the gas comprising carbon dioxide in a first stage and in a second stage, the regenerated alkaline, aqueous scrubbing liquid, withdrawn from the cathode chamber, is fed as a second alkaline, aqueous scrubbing liquid to the second stage of scrubbing downstream of the first stage of scrubbing. A second spent scrubbing liquid, resulting from the second stage of scrubbing, is at least partly, fed as the first alkaline, aqueous scrubbing liquid to the first stage of scrubbing upstream of the second stage of scrubbing.
In scrubbing the gas comprising carbon dioxide in several stages, spent scrubbing liquid, resulting from a downstream stage of scrubbing, may be, at least partly, fed as the alkaline, aqueous scrubbing liquid to an upstream stage of scrubbing. Further, the regenerated alkaline, aqueous scrubbing liquid, withdrawn from the cathode chamber, may be fed as an aqueous scrubbing liquid to the last stage of scrubbing downstream. Furthermore, spent scrubbing liquid from the first stage of scrubbing may be fed to the electrolytic cell to be regenerated.
In scrubbing the gas comprising carbon dioxide in a first stage and in a second stage, the pH of the second alkaline, aqueous scrubbing liquid is preferably higher than the pH of the first alkaline, aqueous scrubbing liquid in order to remove carbon dioxide efficiently. The pH of the second alkaline, aqueous scrubbing liquid may be in the range 12 to 14, such as about 13.5. Further, the pH of the first alkaline, aqueous scrubbing liquid may be in the range 8 to 10, such as about 9.
In scrubbing the gas comprising carbon dioxide in several stages, the pH of the aqueous scrubbing liquid will be lower in up-stream stages than in down-stream stages.
In embodiments according to which the scrubbing of the gas comprising carbon dioxide is performed in a first stage and in a second stage, regenerated alkaline, aqueous scrubbing liquid withdrawn from the cathode chamber may be mixed with a part of the second spent scrubbing liquid to provide the second alkaline, aqueous scrubbing liquid. By mixing these liquids, the pH of the second alkaline, aqueous scrubbing liquid is lower than the pH of the regenerated alkaline, aqueous scrubbing liquid withdrawn from the cathode chamber. The pH of the second alkaline, aqueous scrubbing li
This application claims priority to EP Patent Application No. 20206242.8 filed 6 Nov. 2020, the entire contents of which is hereby incorporated by reference.
TECHNICAL FIELD
The present invention relates to a method of scrubbing a gas, such as flue gas comprising carbon dioxide (CO 2 ), to deplete the gas of carbon dioxide, comprising regenerating spent aqueous scrubbing liquid. Further, the present invention relates to a system for such scrubbing of a gas, such as flue gas, comprising carbon dioxide.
BACKGROUND
Carbon dioxide (CO 2 ) is a gas that when emitted into the atmosphere is damaging to the climate as it contributes to the green-house effect and rise in global temperature. It is for example produced as a byproduct when fossil fuel, e.g. coal, gasoline or diesel, is burned. Coal- and gas-fired power plants accounts for a large share of CO 2 emissions. It is a goal for many sectors to lower carbon dioxide emissions.
Emitted gases resulting from combustion and comprising CO 2 are typically denoted flue gases or exhaust gases. Depleting such emitted gases of CO 2 by lowering the CO 2 content in the emitted gases, can be done by so called scrubbing of the gases, i.e. removing the CO 2 from the gas stream by absorbing/dissolving CO 2 in a liquid. The primary application for CO 2 scrubbing is for removal of CO 2 from the exhaust (i.e. flue gas) of coal- and gas-fired power plants, downstream of a power station, before the gas is released into the atmosphere. By using such a process, it would be possible to significantly lower the CO 2 emissions involved in coal-fired power generation. In the chemical industry, CO 2 scrubbing is used to separate CO 2 from natural gas, for use in, for example, the beverage or fertilizer sector.
In a CO 2 -scrubbing system, a scrubbing solution takes up the carbon dioxide from the flue gas, at low temperatures, in an absorber. Most common is scrubbing of the flue gas using a chemical absorption medium, such as an alkaline, aqueous liquid. In an alkaline, aqueous liquid, CO 2 will dissolve and partly be hydrolyzed into carbonic acid (H 2 CO 3 ). Given the alkaline pH, formed carbonic acid (H 2 CO 3 ) will be shifted into hydrogen carbonate (HCO 3 â ) and/or carbonate (CO 3 2â ), as outlined below.
CO 2 +H 2 O=>H 2 CO 3
H 2 CO 3 OH â =>HCO 3 â +H 2 O
HCO 3 â +OH â =>CO 3 2â +H 2 O
The technology being primarily developed for this process involves the use of aqueous amines, e.g. aqueous monoethanolamine, as absorption solvent. Amine scrubbing has been used to separate carbon dioxide (CO 2 ) from natural gas and hydrogen since 1930. However, it is not yet used on a larger scale for CO 2 capture from coal-fired power plants. The process is energy consuming and the technology has not been implemented in large scale because of the capital costs of installing the facility and the operating costs. Scrubbers using aqueous monoethanolamine as absorption solvent for example use large amounts of heat for regeneration of the solvent used in the scrubber. Presently, there are no other industrial applicable technologies that will provide energy-efficient or timely solutions to CO 2 emission from conventional coal-fired power plants.
Further key areas in development work on the carbon capture process include process integration and optimization for applications in large-scale power plants.
There is an imperative need for improved scrubbing systems that preferably require less heat for CO2 capture.
SUMMARY
Accordingly, there is, according to a first aspect, provided a method of scrubbing a gas comprising carbon dioxide (CO 2 ) to deplete the gas of carbon dioxide. The gas comprising carbon dioxide (CO 2 ) may typically be a result from combustion, such as flue gas or exhaust gas. However, also other gases comprising carbon dioxide (CO 2 ) may be scrubbed by the present method. An example would be to capture CO 2 from a power plant that generates heat and power from biomass.
The method comprises the steps of scrubbing the gas in a scrubber with a first alkaline, aqueous scrubbing liquid to dissolve carbon dioxide (CO 2 ) as hydrogen carbonate (HCO 3 â ) and/or as carbonate (CO 3 2â ) in the first alkaline, aqueous scrubbing liquid, thereby providing a first spent aqueous scrubbing liquid comprising hydrogen carbonate (HCO 3 â ) and/or carbonate (CO 3 2â ). The first spent aqueous scrubbing liquid has a pH from about 7 to about 9, in order to optimize the subsequent regeneration.
The method further comprises the step of feeding the first spent aqueous scrubbing liquid to an anode chamber of an electrolytic cell with an anode and a cathode. The anode and the cathode of the electrolytic cell are separated by a membrane to provide the anode chamber and a cathode chamber. The membrane is permeable to alkali metals, such as lithium, sodium and potassium, but has no or low permeability to hydrogen carbonate (HCO 3 â ) and/or to carbonate (CO 3 2 ). Typically, the membrane is permeable only to cations. The membrane may be a cation-exchange membrane. In the electrolytic cell, the first spent aqueous scrubbing liquid is regenerated by electrolysis. In regenerating the spent aqueous scrubbing liquid, a number of electrolytic cells connected in parallel may be used. Before being fed to the anode chamber, the spent aqueous scrubbing liquid may be filtered to remove particulate matter.
In electrolysis, water is converted into oxygen and hydronium ions (H 3 O + ) at the anode, whereas water is converted into hydrogen and hydroxide ions (OH â ) at the cathode. The electrolysis thus increases the pH of the first spent aqueous scrubbing liquid in the cathode chamber and depletes the first spent aqueous scrubbing liquid of hydrogen carbonate (HCO 3 â ) and of carbonate (CO 3 2â ) in the anode chamber, by decreasing the pH to shift the equilibrium towards carbonic acid in turn shifted into carbon dioxide. The regeneration further comprises generating gaseous hydrogen in the cathode chamber and a gaseous mixture of oxygen and carbon dioxide in the anode chamber by electrolysis. The chemical reactions and description of the operation of the processes are further described in the Detailed Description herein further below.
The method further comprises the step of withdrawing regenerated alkaline, aqueous scrubbing liquid from the cathode chamber and re-circulating it to the scrubber.
One key difference from the set-up of commercially available amine scrubbers is that the scrubbing liquid in the present method is regenerated by electrochemistry, while scrubbers in the art typically use large amounts of heat for regeneration of the scrubbing liquid used in the scrubber.
According to the present method, in regenerating the scrubbing liquid its pH is increased. Further, the regeneration, as already explained, also generates carbon dioxide and hydrogen, which may be used downstream for synthesis of organic compounds, such as methanol, thus adding further value to the process. The process is ideal for processes such as downstream Power-to-X processes.
The gaseous hydrogen is withdrawn from the cathode chamber and the gaseous mixture of oxygen and carbon dioxide is withdrawn from the anode chamber.
Withdrawing hydrogen, oxygen and carbon dioxide from the regeneration process is advantageous as hydrogen and oxygen can be used to generate electricity, e.g. by a fuel cell, to operate the process partly. Further, hydrogen and carbon dioxide (CO 2 ) can be used for synthesis of organic compounds, e.g. methanol, thereby compensating for the cost of running the process.
The carbon capture reaction in the scrubbing step takes place automatically. The operation of the scrubber is thereby an automatic process and requires no power apart from one needed to circulate the liquids. The regeneration process that takes place in the cathode and anode chambers of the electrolytic cell are electrochemical reactions, which inherently require electrical power. The electrochemical process regenerates the solvent, produces hydrogen at the cathode and a mixture of carbon dioxide (CO 2 ) and oxygen at the anode.
The actual power consumption will depend on the technical implementation of the process. Overall, the process requires a large amount of electrical energy rather than heat. This is positive, as electrification of the regeneration in carbon capture processes is highly desired. Further, some of the energy may be recovered as heat for district heating. Regeneration of amine-based scrubbing liquids reduces the overall efficiency of a power plant as some of the heat generated rather than being distributed, has to be used to re-generate the scrubbing liquid. Regeneration of alkaline scrubbing liquids comprising dissolved metal hydroxides may be regenerated electrical energy thus not affecting the overall efficiency of a power plant.
In order to dissolve carbon dioxide and shift the equilibrium towards hydrogen carbonate (HCO 3 â ) and of carbonate (CO 3 2â ), the first aqueous scrubbing liquid needs to be alkaline, i.e. have a pH exceeding 7, such as 8 or higher.
Thus, the first alkaline, aqueous scrubbing liquid may comprise a metal hydroxide. According to an embodiment of the method, the first alkaline, aqueous scrubbing liquid comprises one or more of dissolved potassium hydroxide (KOH), dissolved sodium hydroxide (NaOH) and dissolved lithium hydroxide (LiOH). The first alkaline, aqueous scrubbing liquid may comprise potassium hydroxide (KOH). Given its high solubility in water, potassium hydroxide (KOH) is a preferred metal hydroxide.
In the anode chamber, a gaseous mixture of oxygen and carbon dioxide is formed. The method may thus further comprise a step of separating this gaseous mixture of oxygen and carbon dioxide into a first stream, rich in oxygen and/or depleted of carbon dioxide, and a second stream, rich in carbon dioxide and/or depleted of oxygen. The gaseous mixture of oxygen and carbon dioxide may be compressed to provide for separation of liquid carbon dioxide (CO 2 ) from gaseous (O 2 ). According to one embodiment of the method, carbon dioxide (CO 2 ) and/or oxygen (O 2 ) withdrawn from the anode chamber is compressed into liquid carbon dioxide and/or compressed oxygen (O 2 ).
Further, hydrogen formed in the cathode chamber is withdrawn. Hydrogen withdrawn from the cathode chamber may be used as a fuel to provide electricity, either internally or externally. Hydrogen and oxygen may be used to fuel a fuel cell. The electricity formed may optionally be used to operate the electrolytic cell regenerating the spent aqueous scrubbing liquid. This is advantageous as it at least partly compensates for the electricity consumption of running the process. Further, it may also be of interest to sell hydrogen on the open market.
The anode chamber is typically not operated such that all hydrogen carbonate (HCO 3 â ) is converted to carbon dioxide. The method may thus further comprise withdrawing an aqueous stream still comprising some hydrogen carbonate (HCO 3 â ) from the anode chamber. This stream may be concentrated, such as by reversed osmosis. The resulting concentrated stream comprising hydrogen carbonate (HCO 3 â ) may be re-circulated to the electrolytic cell, thus facilitating further removal of hydrogen carbonate (HCO 3 â ).
Typically, the gas comprising carbon dioxide and the scrubbing liquid are fed in contraflow manner to the scrubber to provide for efficient removal of carbon dioxide.
According to one embodiment of the method, the scrubbing of the gas comprising carbon dioxide is performed in at least a first stage and in a second stage. This provides for efficient removal of carbon dioxide, while still providing for optimizing the pH of the spent scrubbing liquid to be regenerated. The scrubbing may be performed in more than two stages.
In scrubbing the gas comprising carbon dioxide in a first stage and in a second stage, the regenerated alkaline, aqueous scrubbing liquid, withdrawn from the cathode chamber, is fed as a second alkaline, aqueous scrubbing liquid to the second stage of scrubbing downstream of the first stage of scrubbing. A second spent scrubbing liquid, resulting from the second stage of scrubbing, is at least partly, fed as the first alkaline, aqueous scrubbing liquid to the first stage of scrubbing upstream of the second stage of scrubbing.
In scrubbing the gas comprising carbon dioxide in several stages, spent scrubbing liquid, resulting from a downstream stage of scrubbing, may be, at least partly, fed as the alkaline, aqueous scrubbing liquid to an upstream stage of scrubbing. Further, the regenerated alkaline, aqueous scrubbing liquid, withdrawn from the cathode chamber, may be fed as an aqueous scrubbing liquid to the last stage of scrubbing downstream. Furthermore, spent scrubbing liquid from the first stage of scrubbing may be fed to the electrolytic cell to be regenerated.
In scrubbing the gas comprising carbon dioxide in a first stage and in a second stage, the pH of the second alkaline, aqueous scrubbing liquid is preferably higher than the pH of the first alkaline, aqueous scrubbing liquid in order to remove carbon dioxide efficiently. The pH of the second alkaline, aqueous scrubbing liquid may be in the range 12 to 14, such as about 13.5. Further, the pH of the first alkaline, aqueous scrubbing liquid may be in the range 8 to 10, such as about 9.
In scrubbing the gas comprising carbon dioxide in several stages, the pH of the aqueous scrubbing liquid will be lower in up-stream stages than in down-stream stages.
In embodiments according to which the scrubbing of the gas comprising carbon dioxide is performed in a first stage and in a second stage, regenerated alkaline, aqueous scrubbing liquid withdrawn from the cathode chamber may be mixed with a part of the second spent scrubbing liquid to provide the second alkaline, aqueous scrubbing liquid. By mixing these liquids, the pH of the second alkaline, aqueous scrubbing liquid is lower than the pH of the regenerated alkaline, aqueous scrubbing liquid withdrawn from the cathode chamber. The pH of the second alkaline, aqueous scrubbing liquid may thus be adjusted by changing the ratio of regenerated alkaline, aqueous scrubbing liquid withdrawn from the cathode chamber to the second spent scrubbing liquid. Further, part of the second spent scrubbing liquid may be mixed with a part of a first spent scrubbing liquid, resulting from the first stage of scrubbing, to provide the first alkaline, aqueous scrubbing liquid. By mixing these liquids, the pH of the first alkaline, aqueous scrubbing liquid will be higher than the pH the first spent scrubbing liquid, and the first spent scrubbing liquid may be partly re-cycled.
In order to further optimize the pH within the electrolytic cell, part of the regenerated alkaline, aqueous scrubbing liquid may be re-circulated to the cathode chamber. The regenerated alkaline, aqueous scrubbing liquid may be diluted by an aqueous stream before re-circulating it to the cathode chamber. This aqueous stream may be provided by withdrawing an aqueous stream still comprising some hydrogen carbonate (HCO 3 â ) from the anode chamber and concentrating it, such as by reversed osmosis, to provide an aqueous stream depleted of hydrogen carbonate (HCO 3 â ) and a concentrated stream comprising hydrogen carbonate (HCO 3 â ).
According to a second aspect, there is in corresponding manner provided a system for scrubbing a gas, such as flue gas or exhaustive gas, comprising carbon dioxide to deplete the flue gas of carbon dioxide. The system comprises a scrubber arrangement for scrubbing a gas with an alkaline, aqueous scrubbing liquid to dissolve carbon dioxide as hydrogen carbonate (HCO 3 â ) and/or as carbonate (CO 3 2â ) in the alkaline, aqueous scrubbing liquid. The system further comprises a regeneration arrangement for regenerating spent aqueous scrubbing liquid by electrolysis.
The scrubber arrangement comprises a scrubber. The scrubber has an inlet for the gas to be scrubbed and an outlet for a gas depleted of carbon dioxide. The scrubber further has an inlet for receiving the alkaline, aqueous scrubbing liquid and an outlet for withdrawing spent aqueous scrubbing liquid. Preferably, the inlets and outlets are arranged to provide for scrubbing in a counterflow manner.
The regeneration arrangement comprises an electrolytic cell, or a number of electrolytic cells connected in parallel. The electrolytic cell comprises an anode chamber and a cathode camber separated by a membrane. The membrane is permeable to alkali metals, such as lithium, sodium and potassium, but has no or low permeability to hydrogen carbonate (HCO 3 â ) and/or carbonate (CO 3 2 ). Typically, the membrane is permeable only to cations. The membrane may be a cation-exchange membrane. The anode chamber comprises an anode inlet for receiving the spent aqueous scrubbing liquid from the scrubber arrangement and an anode outlet for withdrawing oxygen and carbon dioxide. The regeneration arrangement may further comprise a filter for filtering spent aqueous scrubbing liquid to be fed to the anode inlet of the anode chamber. Further, the cathode chamber comprises an outlet for withdrawing regenerated aqueous scrubbing liquid and hydrogen. The outlet for spent aqueous scrubbing liquid of the scrubber is in flow communication with the inlet for the spent aqueous scrubbing liquid of the anode chamber. Similarly, the outlet for regenerated aqueous scrubbing liquid of the cathode chamber is flow communication with the inlet for the alkaline, aqueous scrubbing liquid of the scrubber.
An advantage of this system is that it comprises both a scrubber arrangement and a regeneration arrangement where output from the scrubber arrangement can be regenerated by electrolysis and reused in the scrubber arrangement, enabling and optimizing a complete, energy and cost efficient system of depleting gas of carbon dioxide, driven by electrical power.
According to one embodiment, the scrubber arrangement comprises a first and a second buffer tank for alkaline, aqueous scrubbing liquid. Further, the scrubber comprises at least a first and a second absorber. It may comprise more than two absorbers. Further, a number of scrubbers may be used. A number of scrubbers may be either connected in series or in parallel.
The first absorber comprises an inlet for receiving alkaline, aqueous scrubbing liquid from the first buffer tank. Further, the first absorber comprises an outlet for withdrawing spent aqueous scrubbing liquid from first absorber to feed to an inlet of the first buffer tank. Thus, alkaline, aqueous scrubbing liquid may be circulated between the first absorber and the first buffer tank. While the presence of the first buffer tank is preferred, it may according to some embodiments be dispensed with and the alkaline, aqueous scrubbing liquid may be re-circulated over the first absorber by a first pipe system connecting the inlet and the outlet of the first absorber. Further, the first buffer tank is in flow communication with the inlet for the spent aqueous scrubbing liquid of the anode chamber.
The second absorber comprises an inlet for receiving alkaline, aqueous scrubbing liquid from the second buffer tank. Further, the second absorber comprises an outlet for withdrawing spent aqueous scrubbing liquid from second absorber to feed to an inlet of the second buffer tank. Thus, alkaline, aqueous scrubbing liquid may be circulated between the second absorber and the second buffer tank. While the presence of the second buffer tank is preferred, it may according to some embodiments be dispensed with and the alkaline, aqueous scrubbing liquid may be re-circulated over the second absorber by a first pipe system connecting the inlet and the outlet of the second absorber. Further, the outlet for regenerated aqueous scrubbing liquid of the cathode chamber is in flow communication with the inlet of the second absorber. Furthermore, the outlet of the second absorber is in flow communication with the inlet of the first absorber.
If the scrubber arrangement comprises more than two absorbers, they may be arranged such that the outlet of a downstream absorber is in flow communication with the inlet of an upstream absorber. Further, an inlet of the last absorber (i.e. the most downstream absorber close to an outlet for scrubbed gas) is in flow communication with the outlet for regenerated aqueous scrubbing liquid of the cathode chamber. Furthermore, an outlet of the first absorber (i.e. the most upstream close to an inlet for the gas to be scrubbed) is in flow communication with an inlet for the spent aqueous scrubbing liquid of the anode chamber. Typically, the alkaline, aqueous scrubbing liquid may be re-circulated over each absorber by means of a pipe system connecting the inlet and the outlet of the respective absorber. Similar to the first and second absorber, any further absorbers may be in flow communication with a corresponding buffer tank.
To further provide for adjusting flows independently, the scrubber arrangement may further comprise a third buffer tank for regenerated aqueous scrubbing liquid. The third buffer tank is in flow communication with the outlet for regenerated aqueous scrubbing liquid of the cathode chamber and with the inlet of the second absorber. Further, the scrubber arrangement may comprise a fourth buffer tank for spent aqueous scrubbing liquid. The fourth buffer tank is in flow communication with the first buffer tank and with an inlet for the spent aqueous scrubbing liquid of the anode chamber.
This design enables regenerated aqueous scrubbing liquid of the cathode chamber to be reused in the scrubbing process and enables optimization of the pH of the liquids before being recycled into the scrubber.
The regeneration arrangement may further comprise a first compressor unit for compressing hydrogen withdrawn from the cathode chamber and/or a second compressor unit for compressing oxygen and carbon dioxide withdrawn from the anode chamber. Further, regeneration arrangement may comprise a first gas separator for separating oxygen and carbon dioxide withdrawn from the anode chamber from each other. Typically, the first gas separator is arranged downstream the second compressor unit to separate liquid carbon dioxide from gaseous oxygen.
This way the system can provide compressed hydrogen, compressed oxygen and carbon dioxide, as well as separated oxygen and carbon dioxide, for commercial exploration.
According to one embodiment, the regeneration arrangement further comprises a concentrator, such as a filter, for concentrating an aqueous stream comprising some hydrogen carbonate (HCO 3 â ) withdrawn from the anode chamber to provide a concentrated stream comprising hydrogen carbonate (HCO 3 â ) and an aqueous stream depleted of hydrogen carbonate (HCO 3 â ). The concentrator is arranged in flow communication, typically by pipes, with the electrolytic cell such that:
the aqueous stream comprising some hydrogen carbonate (HCO 3 â ) may be withdrawn from the anode chamber and fed to the concentrator; the concentrated stream comprising hydrogen carbonate (HCO 3 â ) may be withdrawn from the concentrator and fed to the anode chamber; and/or the aqueous stream depleted of hydrogen carbonate (HCO 3 â ) may be withdrawn from the concentrator and fed to the cathode chamber.
The regeneration arrangement may further comprise a first balance tank for regenerated alkaline, aqueous scrubbing liquid. The first balance may be arranged in flow communication, typically by pipes, with the electrolytic cell and it may have:
a first inlet for receiving regenerated alkaline, aqueous scrubbing liquid from the cathode chamber; a second inlet for receiving the aqueous stream depleted of hydrogen carbonate (HCO 3 â ) withdrawn from the concentrator; and/or an outlet for feeding diluted regenerated alkaline, aqueous scrubbing liquid to the cathode chamber of electrolytic cell.
Further, the regeneration arrangement may comprise a second balance tank for spent aqueous scrubbing liquid. The second balance may be arranged in flow communication, typically by pipes, with the electrolytic cell and it may have:
a first inlet for receiving spent aqueous scrubbing liquid from the scrubber arrangement; a second inlet for receiving the concentrated stream comprising hydrogen carbonate (HCO 3 â ) from the concentrator; and/or an outlet for feeding spent aqueous scrubbing liquid to the anode chamber of the electrolytic cell.
In scrubbing flue gas in a power plant, the scrubbing and the regeneration are typically run continuously at the plant. It is however possible to run the scrubbing separately from the regeneration. As an example, the scrubbing may be operated in a vehicle, whereas the regeneration takes place at a central unit, which may serve several vehicles. The vehicle may be provided with a scrubber arrangement comprising a third buffer tank for regenerated aqueous scrubbing liquid and a fourth buffer tank for spent aqueous scrubbing liquid. By providing the vehicle with such a scrubber arrangement, it may be run independently of the rearrangement until the third buffer tank runs empty and/or the fourth buffer tank becomes full.
According to a third aspect, there is thus provided scrubber arrangement for scrubbing a gas, such as flue gas, comprising carbon dioxide to deplete the flue gas of carbon dioxide. As already described above, the scrubber arrangement comprises a scrubber having an inlet for the gas to be scrubbed and an outlet for gas depleted of carbon dioxide. The scrubber further has an inlet for receiving the alkaline, aqueous scrubbing liquid and an outlet for withdrawing spent aqueous scrubbing liquid. The scrubber arrangement comprises a first and a second buffer tank for alkaline, aqueous scrubbing liquid, and the scrubber at least comprises a first and a second absorber. The first absorber comprises an inlet for receiving alkaline, aqueous scrubbing liquid from the first buffer tank and an outlet for withdrawing spent aqueous scrubbing liquid and feed it to an inlet of the first buffer tank. Thus, alkaline, aqueous scrubbing liquid may be circulated between the first absorber and the first buffer tank. While the presence of the first buffer tank is preferred, it may according to some embodiments be dispensed with and the alkaline, aqueous scrubbing liquid may be re-circulated over the first absorber by a first pipe system connecting the inlet and the outlet of the first absorber. The second absorber comprises an inlet for receiving alkaline, aqueous scrubbing liquid from the second buffer tank and an outlet for withdrawing spent aqueous scrubbing liquid from the second absorber to feed to an inlet of the second buffer tank. Thus, alkaline, aqueous scrubbing liquid may be circulated between the second absorber and the second buffer tank. While the presence of the second buffer tank is preferred, it may according to some embodiments be dispensed with and the alkaline, aqueous scrubbing liquid may be re-circulated over the second absorber by a second pipe system connecting the inlet and the outlet of the first absorber. The outlet of the second absorber is in flow communication with the inlet of the first absorber.
If the scrubber arrangement comprises more than two absorbers, they may be arranged such that the outlet of a downstream absorber is in flow communication with the inlet of an upstream absorber. Further, an inlet of the last absorber (i.e. the most downstream absorber close to an outlet for scrubbed gas) is in flow communication with the outlet for regenerated aqueous scrubbing liquid of the cathode chamber. Furthermore, an outlet of the first absorber (i.e. the most upstream close to an inlet for the gas to be scrubbed) is in flow communication with an inlet for the spent aqueous scrubbing liquid of the anode chamber. Typically, the alkaline, aqueous scrubbing liquid may be re-circulated over each absorber by means of a pipe system connecting the inlet and the outlet of the respective absorber. Similar to the first and second absorber, any further absorbers may be in flow communication with a corresponding buffer tank.
According to one embodiment, the scrubber arrangement further comprises a third buffer tank for regenerated aqueous scrubbing liquid. The third buffer tank has an inlet for receiving regenerated aqueous scrubbing liquid, such that the third buffer tank may be filled up with regenerated aqueous scrubbing liquid. Further, the third buffer tank is in flow communication with the inlet of the second absorber. Furthermore, the scrubber arrangement may comprise a fourth buffer tank for spent aqueous scrubbing liquid. The fourth buffer tank is in flow communication with the first buffer tank, such that the fourth buffer tank may be filled up with regenerated aqueous scrubbing liquid in operating the scrubber arrangement. The fourth buffer tank further has an outlet for withdrawing spent aqueous scrubbing liquid, such that the fourth buffer tank may be emptied.
By providing such a scrubber arrangement, it can be utilized without being directly connected to any regeneration arrangement. It may for example be installed in a vehicle for scrubbing an exhaust gas obtained in the operation of the vehicle. The third buffer tank can be filled with alkaline, aqueous scrubbing liquid to be used in the scrubbing process. Spent aqueous scrubbing liquid can be withdrawn from the fourth buffer tank to empty it at a convenient time point, such as when re-fueling the vehicle, for it to be emptied after being filled up during the process.
Correspondingly, there is, according to a fourth aspect, provided a regeneration arrangement for regenerating a spent aqueous scrubbing liquid comprising hydrogen carbonate (HCO 3 â ) and/or carbonate (CO 3 2â ) used in electrolysis to provide alkaline, aqueous scrubbing liquid. The regeneration arrangement has already been described herein above. It comprises an electrolytic cell. The electrolytic cell comprises an anode chamber and a cathode camber separated by a membrane. The anode is present within the anode chamber and the cathode is present within the cathode chamber. The anode chamber comprises an anode inlet for receiving the spent aqueous scrubbing liquid and an anode outlet for withdrawing oxygen and carbon dioxide. The regeneration arrangement may further comprise a filter for filtering spent aqueous scrubbing liquid to be fed to the anode inlet of the anode chamber. The cathode chamber comprises an outlet for withdrawing regenerated aqueous scrubbing liquid and hydrogen. The regeneration arrangement further comprises a concentrator for concentrating an aqueous stream comprising some hydrogen carbonate (HCO 3 â ) withdrawn from the anode chamber to provide a concentrated stream comprising hydrogen carbonate (HCO 3 â ) and an aqueous stream depleted of hydrogen carbonate (HCO 3 â ). The concentrator is arranged in flow communication with the electrolytic cell such that the aqueous stream comprising some hydrogen carbonate (HCO 3 â ) may be withdrawn from the anode chamber and fed to the concentrator, the concentrated stream comprising hydrogen carbonate (HCO 3 â ) may be withdrawn from the concentrator and fed to the anode chamber, and the aqueous stream depleted of hydrogen carbonate (HCO 3 â ) may be withdrawn from the concentrator and fed to the cathode chamber.
The regeneration arrangement may further comprise a first balance tank for regenerated alkaline, aqueous scrubbing liquid. The first balance tank has a first inlet for receiving regenerated alkaline, aqueous scrubbing liquid, and a second inlet for receiving the aqueous stream depleted of hydrogen carbonate (HCO 3 â ) withdrawn from the concentrator. Further, the first balance tank has an outlet for feeding diluted regenerated alkaline, aqueous scrubbing liquid to the cathode chamber of electrolytic cell. Furthermore, regeneration arrangement may comprise a third buffer tank for storing regenerated aqueous scrubbing liquid. The third buffer tank has an inlet for receiving regenerated aqueous scrubbing liquid, such that the third buffer tank may be filled up with regenerated aqueous scrubbing liquid. Further, the third buffer tank has an outlet for withdrawing regenerated aqueous scrubbing liquid in filling up a corresponding buffer tank of the scrubbing system.
The regeneration arrangement may further comprise a second balance tank for spent aqueous scrubbing liquid. The second balance tank has a first inlet for receiving spent aqueous scrubbing liquid from the scrubber arrangement, a second inlet for receiving the concentrated stream comprising hydrogen carbonate (HCO 3 â ) from the concentrator, and an outlet for feeding spent aqueous scrubbing liquid to the anode chamber of electrolytic cell. Furthermore, the regeneration arrangement may comprise a fourth buffer tank for spent aqueous scrubbing liquid. The fourth buffer tank is in flow communication with the anode chamber, such that spent aqueous scrubbing liquid to be regenerated, may be withdrawn from the fourth buffer tank. Furthermore, the fourth buffer tank has inlet for receiving spent aqueous scrubbing liquid. Thus, the fourth buffer tank may be filled up in emptying a corresponding buffer tank of the scrubbing system.
The regeneration arrangement may further comprise a first compressor unit for compressing hydrogen withdrawn from the cathode chamber. Further, the regeneration arrangement may comprise a second compressor unit for compressing oxygen and carbon dioxide withdrawn from the anode chamber, and/or a first gas separator for separating oxygen and carbon dioxide withdrawn from the anode chamber from each other. Typically, the first gas separator is arranged downstream the second compressor unit to separate liquid carbon dioxide from gaseous oxygen.
Although the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims and other embodiments than the specific embodiments described above are equally possible within the scope of these appended claims.
In the claims, the term âcomprises/comprisingâ does not exclude the presence of other elements or steps. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous.
In addition, singular references do not exclude a plurality. The terms âaâ, âanâ, âfirstâ, âsecondâ etc. do not preclude a plurality.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects, features and advantages of which the invention is capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which:
FIG. 1 shows a flow path between a scrubber and an electrolytic cell;
FIG. 2 shows a process scheme of a system for scrubbing flue gas;
FIG. 3 shows a scrubber arrangement of the process scheme of FIG. 2 ;
FIG. 4 shows a regeneration arrangement of the process scheme of FIG. 2 ;
FIG. 5 shows test results of the overall generation of gas flow in the electrolytic cell and the pH-value over time;
FIG. 6 shows test results of the gas flow of CO 2 and O 2 in relation to the pH-value over time;
FIG. 7 shows test results of the gas production of CO 2 and O 2 in relation to the energy consumption over time; and
FIG. 8 shows test results of the relationship between the production of gases leaving the electrolytic cell over time.
DETAILED DESCRIPTION
With reference to FIG. 1 , a system 100 according to an embodiment is shown having a scrubber arrangement 200 and a regeneration arrangement 300 . Here, a method of scrubbing a gas, such as flue gas or an exhaustive gas, comprising carbon dioxide CO 2 , is illustrated. The gas enters the scrubber through the scrubber inlet 213 . To deplete the flue gas from carbon dioxide CO 2 , the scrubbing method can be described as follows. The gas is scrubbed in the scrubber 210 in a counter flow manner with a first alkaline, aqueous scrubbing liquid to dissolve carbon dioxide CO 2 as hydrogen carbonate HCO 3 â and/or as carbonate CO 3 2â in the first alkaline, aqueous scrubbing liquid. A first spent aqueous scrubbing liquid comprising dissolved hydrogen carbonate HCO 3 â and/or carbonate CO 3 2â results. The first spent aqueous scrubbing liquid has a pH from about 7 to about 9 when it leaves at the outlet 211 â³ for withdrawing spent aqueous scrubbing liquid of the scrubber 210 . The first spent aqueous scrubbing liquid is then fed to an anode chamber 313 of an electrolytic cell 310 via an anode inlet 313 â². The electrolytic cell 310 has apart from the anode chamber 313 also a cathode chamber 312 . The anode chamber 313 and the cathode chamber 312 are separated by a membrane 311 . This membrane 311 may be a semi-permeable membrane, being permeable to cations, but essentially impermeable to anions. Thus, the membrane cation-exchange membrane. The electrolysis increases the pH of the first spent aqueous scrubbing liquid in the cathode chamber 312 . In the anode chamber 313 , the electrolysis further depletes the first spent aqueous scrubbing liquid of hydrogen carbonate HCO 3 â and of carbonate CO 3 2â by decreasing the pH-value to release gaseous carbon dioxide. The outlet 211 â³ for spent aqueous scrubbing liquid of the scrubber 210 is in flow communication with the inlet 313 â² for the spent aqueous scrubbing liquid of the anode chamber 313 . Moreover, the outlet 312 â³ for regenerated aqueous scrubbing liquid of the cathode chamber 312 is flow communication with the inlet 212 â² for the alkaline, aqueous scrubbing liquid of the scrubber 210 .
One can say that the first spent aqueous scrubbing liquid is regenerated by generating gaseous hydrogen H 2 and dissolved hydroxide ions OH â in the cathode chamber 312 and a gaseous mixture of oxygen O 2 and carbon dioxide CO 2 in the anode chamber 313 by electrolysis. This is indicated by the upwards pointing arrows from the cathode outlet 312 â³ and the anode outlet 313 â³ in FIG. 1 , respectively. The gaseous hydrogen H 2 and dissolved hydroxide ions OH â is withdrawn from the cathode chamber 312 and the gaseous mixture of oxygen O 2 and carbon dioxide CO 2 is withdrawn from the anode chamber 313 . For instance, the hydrogen H 2 may be used in downstream processes (not shown) such as in fuel or methanol production. The regenerated alkaline, aqueous scrubbing liquid from the cathode chamber 312 is then recirculated via the inlet 212 â² for receiving the alkaline, aqueous scrubbing liquid to the scrubber 210 . Gas depleted of carbon dioxide CO 2 then exits the scrubber 210 via the scrubber outlet 214 .
In FIG. 2 , a detailed view of the system 100 descried in relation to FIG. 1 is shown. The system is separated into two parts; the scrubber arrangement 200 and the regeneration arrangement 300 . These two arrangements are also shown separately in FIGS. 3 and 4 , respectively. For increased understanding, the scrubber arrangement 200 and the regeneration arrangement 300 will now be described separately. The dotted arrows in FIGS. 3 and 4 indicate where the scrubber arrangement 200 and the regeneration arrangement 300 may meet in FIG. 2 to form the system 100 in its entirety. Alternatively, the scrubber arrangement 200 and the regeneration arrangement 300 , may be operated independently.
With reference to FIG. 3 , the scrubber arrangement 200 has a first buffer tank 230 and a second buffer tank 240 for alkaline, aqueous scrubbing liquid. The scrubber 210 has a first absorber 211 and a second absorber 212 for scrubbing the gas of carbon dioxide. Scrubbing liquid may be re-circulated to the first absorber 211 via the first buffer tank 230 . Further, scrubbing liquid may be re-circulated to the second absorber 212 via the second buffer tank 240 . The first absorber 211 thus has an inlet 211 â² for receiving alkaline, aqueous scrubbing liquid from the first buffer tank 230 , and an outlet 211 â³ for withdrawing spent aqueous scrubbing liquid and feeding it to the inlet 313 â² for the spent aqueous scrubbing liquid of the anode chamber 313 directly (as shown in FIG. 1 ) or via the first buffer tank 230 , as shown in FIGS. 2 and 3 . The second absorber 212 has an inlet 212 â² for receiving alkaline, aqueous scrubbing liquid from the second buffer tank
CLAIMS
Claims ( 28 )
The invention claimed is:
1. A method of scrubbing a gas comprising carbon dioxide to deplete the gas of the carbon dioxide (CO 2 ), the method comprising:
scrubbing the gas in a scrubber with a first alkaline, aqueous scrubbing liquid to dissolve carbon dioxide (CO 2 ) as hydrogen carbonate (HCO 3 â ) and/or as carbonate (CO 3 2â ) in the first alkaline, aqueous scrubbing liquid, thereby providing a first spent aqueous scrubbing liquid comprising hydrogen carbonate (HCO 3 â ) and/or carbonate (CO 3 2â ),
the first spent aqueous scrubbing liquid having a pH from about 7 to about 9;
feeding the first spent aqueous scrubbing liquid to an anode chamber of an electrolytic cell comprising the anode chamber and a cathode chamber separated by a membrane;
regenerating the first spent aqueous scrubbing liquid in the electrolytic cell by electrolysis, the electrolysis increasing the pH of the first spent aqueous scrubbing liquid in the cathode chamber, the electrolysis further depleting the first spent aqueous scrubbing liquid of hydrogen carbonate (HCO 3 â ) and of carbonate (CO 3 2â ) in the anode chamber by decreasing the pH, the regeneration further comprising generating gaseous hydrogen in the cathode chamber and a gaseous mixture of oxygen and carbon dioxide (CO 2 ) in the anode chamber by electrolysis; and
withdrawing regenerated alkaline, aqueous scrubbing liquid from the cathode chamber and re-circulating it to the scrubber;
wherein:
the scrubbing of the gas is performed in a first stage and in a second stage, the regenerated alkaline, aqueous scrubbing liquid withdrawn from the cathode chamber, being fed as a second alkaline, aqueous scrubbing liquid to the second stage of scrubbing downstream of the first stage of scrubbing, and wherein a second spent scrubbing liquid, resulting from the second stage of scrubbing, at least partly is fed as the first alkaline, aqueous scrubbing liquid to the first stage of scrubbing upstream of the second stage of scrubbing, the pH of the second alkaline, aqueous scrubbing liquid being higher than the pH of the first alkaline, aqueous scrubbing liquid,
the gaseous hydrogen is withdrawn from the cathode chamber; and
the gaseous mixture of oxygen and carbon dioxide is withdrawn from the anode chamber.
2. The method according to claim 1 , wherein the method further comprises separating the gaseous mixture of oxygen and carbon dioxide into:
a first stream rich in oxygen and/or depleted of carbon dioxide; and
a second stream rich in carbon dioxide and/or depleted of oxygen.
3. The method according to claim 1 , wherein:
the regenerated alkaline, aqueous scrubbing liquid withdrawn from the cathode chamber is mixed with a part of the second spent scrubbing liquid to provide the second alkaline, aqueous scrubbing liquid, whereby the pH of the second alkaline, aqueous scrubbing liquid is lower than the pH of the regenerated alkaline, aqueous scrubbing liquid withdrawn from the cathode chamber; and/or
part of the second spent scrubbing liquid is mixed with a part of a first spent scrubbing liquid, resulting from the first stage of scrubbing, to provide the first alkaline, aqueous scrubbing liquid, whereby the pH of the first alkaline, aqueous scrubbing liquid being higher than the pH the first spent scrubbing liquid.
4. The method according to claim 1 , wherein carbon dioxide (CO 2 ) and/or oxygen (O 2 ) withdrawn from the anode chamber is compressed into liquid carbon dioxide and/or compressed oxygen (O 2 ).
5. The method according to claim 1 , wherein the gas is flue gas or exhaust gas.
6. The method according to claim 1 , wherein the carbon dioxide (CO 2 ) is dissolved as the hydrogen carbonate (HCO 3 â ) and the carbonate (CO 3 2â ) in the first alkaline, aqueous scrubbing liquid, thereby providing a first spent aqueous scrubbing liquid comprising the hydrogen carbonate (HCO 3 â ) and the carbonate (CO 3 2â ).
7. The method according to claim 1 , wherein the pH of the second alkaline, aqueous scrubbing liquid is 12 to 14 and the pH of the first alkaline, aqueous scrubbing liquid is 8 to 10.
8. The method according to claim 1 , wherein hydrogen withdrawn from the cathode chamber is used as a fuel to provide electricity.
9. The method according to claim 8 wherein the fuel is provided in a fuel cell.
10. The method according to claim 1 , wherein the method further comprises:
withdrawing an aqueous stream still comprising some hydrogen carbonate (HCO 3 â ) from the anode chamber;
concentrating the withdrawn aqueous stream comprising some hydrogen carbonate (HCO 3 â ) to provide a concentrated stream comprising hydrogen carbonate (HCO 3 â ); and
re-circulating the concentrated stream comprising hydrogen carbonate (HCO 3 â ) to the electrolytic cell.
11. The method according to claim 10 , wherein the concentrating is achieved by reversed osmosis.
12. The method according to claim 1 , wherein the first alkaline, aqueous scrubbing liquid comprises a dissolved metal hydroxide.
13. The method according to claim 12 , wherein the dissolved metal hydroxide comprises one or more of dissolved potassium hydroxide (KOH), dissolved sodium hydroxide (NaOH), and dissolved lithium hydroxide (LiOH).
14. The method according to claim 12 , wherein the first alkaline, aqueous scrubbing liquid comprises potassium hydroxide (KOH).
15. The method according to claim 1 , wherein part of the regenerated alkaline, aqueous scrubbing liquid is re-circulated to the cathode chamber.
16. The method according to claim 15 , wherein the regenerated alkaline, aqueous scrubbing liquid is diluted by an aqueous stream before re-circulating it to the cathode chamber.
17. The method according to claim 15 , wherein said aqueous stream is provided by withdrawing an aqueous stream still comprising some hydrogen carbonate (HCO 3 â ) from the anode chamber and concentrating it to provide an aqueous stream depleted of hydrogen carbonate (HCO 3 â ) and a concentrated stream comprising hydrogen carbonate (HCO 3 â ).
18. The method according to claim 17 , where the concentrating is achieved by reversed osmosis.
19. A system for scrubbing a gas comprising carbon dioxide to deplete the gas of the carbon dioxide (CO 2 ), the system comprising:
a scrubber configured to scrub the gas with a first alkaline, aqueous scrubbing liquid to dissolve carbon dioxide (CO 2 ) as hydrogen carbonate (HCO 3 â ) and/or as carbonate (CO 3 2â ) in the first alkaline, aqueous scrubbing liquid, thereby providing a first spent aqueous scrubbing liquid comprising hydrogen carbonate (HCO 3 â ) and/or carbonate (CO 3 2â ),
the first spent aqueous scrubbing liquid having a pH from about 7 to about 9;
an electrolytic cell comprising an anode chamber and a cathode chamber separated by a membrane, the anode chamber being configured to receive the first spent aqueous scrubbing liquid;
a regeneration arrangement configured to regenerate the first spent aqueous scrubbing liquid in the electrolytic cell by electrolysis, the electrolysis increasing the pH of the first spent aqueous scrubbing liquid in the cathode chamber, the electrolysis further depleting the first spent aqueous scrubbing liquid of hydrogen carbonate (HCO 3 â ) and of carbonate (CO 3 2â ) in the anode chamber by decreasing the pH, the regeneration further comprising generating gaseous hydrogen in the cathode chamber and a gaseous mixture of oxygen and carbon dioxide (CO 2 ) in the anode chamber by electrolysis; wherein, in use:
the scrubber is configured to perform scrubbing at least in a first stage and in a second stage, the regenerated alkaline, aqueous scrubbing liquid withdrawn from the cathode chamber, being fed as a second alkaline, aqueous scrubbing liquid to the second stage of scrubbing downstream of the first stage of scrubbing, and wherein a second spent scrubbing liquid, resulting from the second stage of scrubbing, at least partly is fed as the first alkaline, aqueous scrubbing liquid to the first stage of scrubbing upstream of the second stage of scrubbing, the pH of the second alkaline, aqueous scrubbing liquid being higher than the pH of the first alkaline, aqueous scrubbing liquid,
the regenerated alkaline, aqueous scrubbing liquid is withdrawn from the cathode chamber and re-circulated to the scrubber;
the gaseous hydrogen is withdrawn from the cathode chamber; and
the gaseous mixture of oxygen and carbon dioxide is withdrawn from the anode chamber.
20. The system according to claim 19 , further comprising a separator to separate the gaseous mixture of oxygen and carbon dioxide into:
a first stream rich in oxygen and/or depleted of carbon dioxide; and
a second stream rich in carbon dioxide and/or depleted of oxygen.
21. The system according to claim 19 , wherein the system further comprises:
an aqueous stream still comprising some hydrogen carbonate (HCO 3 â ) is withdrawn from the anode chamber; wherein:
the withdrawn aqueous stream comprising some hydrogen carbonate (HCO 3 â ) is concentrated to provide a concentrated stream comprising hydrogen carbonate (HCO 3 â ); and
the concentrated stream comprising hydrogen carbonate (HCO 3 â ) is re-circulated to the electrolytic cell.
22. The system according to claim 19 , wherein the pH of the second alkaline, aqueous scrubbing liquid is 12 to 14 and the pH of the first alkaline, aqueous scrubbing liquid is 8 to 10.
23. The system according to claim 19 , wherein the first alkaline, aqueous scrubbing liquid comprises a dissolved metal hydroxide.
24. The system according to claim 23 , wherein the dissolved metal hydroxide comprises one or more of dissolved potassium hydroxide (KOH), dissolved sodium hydroxide (NaOH), and dissolved lithium hydroxide (LiOH).
25. The system according to claim 23 , wherein the first alkaline, aqueous scrubbing liquid comprises potassium hydroxide (KOH).
26. The system according to claim 19 , wherein part of the regenerated alkaline, aqueous scrubbing liquid is re-circulated to the cathode chamber.
27. The system according to claim 26 , wherein the regenerated alkaline, aqueous scrubbing liquid is diluted by an aqueous stream before re-circulating it to the cathode chamber.
28. The system according to claim 26 , wherein said aqueous stream is provided by withdrawing an aqueous stream still comprising some hydrogen carbonate (HCO 3 â ) from the anode chamber and concentrating it to provide an aqueous stream depleted of hydrogen carbonate (HCO 3 â ) and a concentrated stream comprising hydrogen carbonate (HCO 3 â ).
US17/331,040
2020-11-06
2021-05-26
CO2 capture process with electrolytic regeneration
Active
US11219860B1
( en )
Applications Claiming Priority (2)
Application Number
Priority Date
Filing Date
Title
EP20206242.8A
EP3995204B1
( en )
2020-11-06
2020-11-06
Co2 capture process with electrolytic regeneration
EP20206242
2020-11-06
Publications (1)
Publication Number
Publication Date
US11219860B1
true
US11219860B1 ( en )
2022-01-11
Family
ID=73172584
Family Applications (2)
Application Number
Title
Priority Date
Filing Date
US17/331,040
Active
US11219860B1
( en )
2020-11-06
2021-05-26
CO2 capture process with electrolytic regeneration
US18/250,088
Pending
US20230390702A1
( en )
2020-11-06
2021-11-05
Co2 capture process with electrolytic regeneration
Family Applications After (1)
Application Number
Title
Priority Date
Filing Date
US18/250,088
Pending
US20230390702A1
( en )
2020-11-06
2021-11-05
Co2 capture process with electrolytic regeneration
Country Status (9)
Country
Link
US
( 2 )
US11219860B1
( en )
EP
( 3 )
EP3995204B1
( en )
JP
( 1 )
JP2023550023A
( en )
KR
( 1 )
KR20230104635A
( en )
AU
( 1 )
AU2021373306B2
( en )
CA
( 1 )
CA3198968A1
( en )
DK
( 1 )
DK3995204T3
( en )
ES
( 1 )
ES2927597T3
( en )
WO
( 1 )
WO2022096644A1
( en )
Cited By (14)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US20210268434A1
( en )
*
2018-02-09
2021-09-02
Nano Silver Manufacturing Sdn Bhd
An apparatus for cleaning exhaust smoke
US11471829B2
( en )
*
2019-01-14
2022-10-18
Skyre, Inc.
Electrochemical carbon dioxide recovery system
EP4238630A1
( en )
2022-03-04
2023-09-06
Estech A/S
Electrolytic regeneration of co2 rich alkaline absorbent for co2 recovery
DE102022105042A1
( en )
2022-03-03
2023-09-07
Greenlyte Carbon Technologies Gmbh
Process for separating carbon dioxide from an air stream
EP4252888A1
( en )
2022-03-31
2023-10-04
Estech A/S
Electrolytic regeneration of amine based co2 absorbent
WO2023226172A1
( en )
*
2022-05-25
2023-11-30
å¿å éåï¼å京ï¼ç§ææéå ¬å¸
Carbon dioxide capture and purification method and system
US11850566B2
( en )
2020-11-24
2023-12-26
Aircela Inc.
Synthetic fuel production system and related techniques
CN117883974A
( en )
*
2024-03-15
2024-04-16
ä¸å大å¦
Modular membrane isolation carbon desorption device, carbon capture system, method and application
US12151206B1
( en )
*
2023-10-31
2024-11-26
Carbon Utility LLC
Direct air capture of carbon dioxide
CN119186200A
( en )
*
2024-09-18
2024-12-27
ä¸å½åè½éå¢æ¸ æ´è½æºææ¯ç 究é¢æéå ¬å¸
Electrochemical carbon dioxide trapping system and method for preparing coupled high-purity hydrogen
US12383858B2
( en )
*
2022-01-21
2025-08-12
Zhejiang University
Energy-saving system and method for direct air capture with precise ion control
EP4483990A4
( en )
*
2022-03-28
2026-01-07
Xeca Turbo Tech Beijing Co Ltd
CARBON DIOXIDE SEPARATION PROCESS AND SYSTEM FOR THE SIMULTANEOUS PRODUCTION OF CARBON MONOXIDE AND HYDROGEN
DE102024209472A1
( en )
2024-09-30
2026-04-02
Robert Bosch Gesellschaft mit beschränkter Haftung
Carbon dioxide climate system and method for operating a carbon dioxide climate system
US12611629B2
( en )
2021-05-03
2026-04-28
Carbon Engineering Ulc
Systems and methods for capturing carbon dioxide and regenerating a capture solution
Families Citing this family (6)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
EP4186998A1
( en )
*
2021-11-25
2023-05-31
Vito NV
System and method for integrated co2 capture and hydrogen production
EP4494744A4
( en )
*
2022-07-18
2025-05-07
Xeca Turbo Technologies (beijing) Co., Ltd.
CARBON DIOXIDE CAPTURE PROCESS AND GAS ABSORPTION SYSTEM
WO2025031777A1
( en )
*
2023-08-04
2025-02-13
Triple Helix Electricon International Bv
System and method for a gaseous compound capture from off gases and air such as co2
EP4635605A1
( en )
2024-04-17
2025-10-22
Estech A/S
Co2 capture process with regeneration of scrubber liquid
WO2026015475A1
( en )
*
2024-07-07
2026-01-15
The Board Of Trustees Of The Leland Stanford Junior University
Electrochemical co2 capture through ph-independent redox chemistry
WO2026071182A1
( en )
*
2024-09-30
2026-04-02
æ ªå¼ä¼ç¤¾ï¼§ï½ã¦ã¢ãµ
Carbon dioxide concentration device and information processing method
Citations (8)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US3519488A
( en )
1969-03-21
1970-07-07
United Aircraft Corp
Carbon dioxide absorber means and fuel cell to regenerate absorbent
US4197421A
( en )
1978-08-17
1980-04-08
The United States Of America As Represented By The United States Department Of Energy
Synthetic carbonaceous fuels and feedstocks
JP2008100211A
( en )
2006-09-21
2008-05-01
Yukio Yanagisawa
Mixed gas separation method and system
EP2737937A1
( en )
2012-11-30
2014-06-04
Alstom Technology Ltd
Electrolytic reduction of carbon capture solutions
US20150246314A1
( en )
*
2014-03-03
2015-09-03
Blue Planet, Ltd.
Alkali enrichment mediated co2 sequestration methods, and systems for practicing the same
US20170107478A1
( en )
*
2015-06-10
2017-04-20
Kevin C. Harmon
System and method for biomass growth and processing
CN206799327U
( en )
2017-03-28
2017-12-26
ä¸å½ç§å¦é¢åå¸ç¯å¢ç 究æ
A kind of ship tail gas and ballast water integrated treatment unit
US20190240621A1
( en )
*
2018-02-08
2019-08-08
Palo Alto Research Center Incorporated
Energy efficient removal of co2 from air by integrating with h2 generation
Family Cites Families (5)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
JPH03245811A
( en )
*
1990-02-21
1991-11-01
Sumitomo Heavy Ind Ltd
Method for removing, concentrating and fixing carbon dioxide in atmosphere
WO2009048685A1
( en )
*
2007-10-11
2009-04-16
Los Alamos National Security Llc
Method of producing synthetic fuels and organic chemicals from atmospheric carbon dioxide
US8535502B2
( en )
*
2008-09-08
2013-09-17
Palo Alto Research Center Incorporated
System and method for recovery of CO2 by aqueous carbonate flue gas capture and high efficiency bipolar membrane electrodialysis
US20120244053A1
( en )
*
2011-03-25
2012-09-27
Kyle Self
Staged absorber system and method
EP3673972A1
( en )
*
2018-12-28
2020-07-01
Vito NV
Alkali-mediated carbon dioxide capture and utilization
2020
2020-11-06
DK
DK20206242.8T
patent/DK3995204T3/en
active
2020-11-06
ES
ES20206242T
patent/ES2927597T3/en
active
Active
2020-11-06
EP
EP20206242.8A
patent/EP3995204B1/en
active
Active
2021
2021-05-26
US
US17/331,040
patent/US11219860B1/en
active
Active
2021-11-05
EP
EP21802745.6A
patent/EP4240517A1/en
active
Pending
2021-11-05
CA
CA3198968A
patent/CA3198968A1/en
active
Pending
2021-11-05
WO
PCT/EP2021/080763
patent/WO2022096644A1/en
not_active
Ceased
2021-11-05
AU
AU2021373306A
patent/AU2021373306B2/en
active
Active
2021-11-05
KR
KR1020237016701A
patent/KR20230104635A/en
active
Pending
2021-11-05
JP
JP2023526612A
patent/JP2023550023A/en
active
Pending
2021-11-05
EP
EP25179495.4A
patent/EP4606463A3/en
active
Pending
2021-11-05
US
US18/250,088
patent/US20230390702A1/en
active
Pending
Patent Citations (9)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US3519488A
( en )
1969-03-21
1970-07-07
United Aircraft Corp
Carbon dioxide absorber means and fuel cell to regenerate absorbent
US4197421A
( en )
1978-08-17
1980-04-08
The United States Of America As Represented By The United States Department Of Energy
Synthetic carbonaceous fuels and feedstocks
JP2008100211A
( en )
2006-09-21
2008-05-01
Yukio Yanagisawa
Mixed gas separation method and system
EP2737937A1
( en )
2012-11-30
2014-06-04
Alstom Technology Ltd
Electrolytic reduction of carbon capture solutions
US20150246314A1
( en )
*
2014-03-03
2015-09-03
Blue Planet, Ltd.
Alkali enrichment mediated co2 sequestration methods, and systems for practicing the same
US20170107478A1
( en )
*
2015-06-10
2017-04-20
Kevin C. Harmon
System and method for biomass growth and processing
CN206799327U
( en )
2017-03-28
2017-12-26
ä¸å½ç§å¦é¢åå¸ç¯å¢ç 究æ
A kind of ship tail gas and ballast water integrated treatment unit
US20190240621A1
( en )
*
2018-02-08
2019-08-08
Palo Alto Research Center Incorporated
Energy efficient removal of co2 from air by integrating with h2 generation
EP3524337A1
( en )
2018-02-08
2019-08-14
Palo Alto Research Center Incorporated
Electrolyzer and electrolytical process for the recovery of co2 from air and hydrogen generation
Non-Patent Citations (1)
* Cited by examiner, â Cited by third party
Title
Extended Search Report EP20206242.8, dated May 25, 2021, 10 pages.
Cited By (20)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US20210268434A1
( en )
*
2018-02-09
2021-09-02
Nano Silver Manufacturing Sdn Bhd
An apparatus for cleaning exhaust smoke
US11471829B2
( en )
*
2019-01-14
2022-10-18
Skyre, Inc.
Electrochemical carbon dioxide recovery system
US12263461B2
( en )
2020-11-24
2025-04-01
Aircela Inc.
Synthetic fuel production system and related techniques
US11850566B2
( en )
2020-11-24
2023-12-26
Aircela Inc.
Synthetic fuel production system and related techniques
US12611629B2
( en )
2021-05-03
2026-04-28
Carbon Engineering Ulc
Systems and methods for capturing carbon dioxide and regenerating a capture solution
US12383858B2
( en )
*
2022-01-21
2025-08-12
Zhejiang University
Energy-saving system and method for direct air capture with precise ion control
DE102022105042A1
( en )
2022-03-03
2023-09-07
Greenlyte Carbon Technologies Gmbh
Process for separating carbon dioxide from an air stream
US12528045B2
( en )
2022-03-03
2026-01-20
Greenlyte Carbon Technologies Gmbh
Process for separating carbon dioxide from an air flow
EP4238630A1
( en )
2022-03-04
2023-09-06
Estech A/S
Electrolytic regeneration of co2 rich alkaline absorbent for co2 recovery
WO2023166166A1
( en )
2022-03-04
2023-09-07
Estech A/S
Electrolytic regeneration of co2 rich alkaline absorbent for co2 recovery
EP4483990A4
( en )
*
2022-03-28
2026-01-07
Xeca Turbo Tech Beijing Co Ltd
CARBON DIOXIDE SEPARATION PROCESS AND SYSTEM FOR THE SIMULTANEOUS PRODUCTION OF CARBON MONOXIDE AND HYDROGEN
EP4252888A1
( en )
2022-03-31
2023-10-04
Estech A/S
Electrolytic regeneration of amine based co2 absorbent
WO2023187143A1
( en )
2022-03-31
2023-10-05
Estech A/S
Method for increased carbon capture in an electrolytic process
JP2025517497A
( en )
*
2022-05-25
2025-06-05
å¢å éåï¼å京ï¼ç§ææéå ¬å¸
Carbon dioxide capture and purification method and system
WO2023226172A1
( en )
*
2022-05-25
2023-11-30
å¿å éåï¼å京ï¼ç§ææéå ¬å¸
Carbon dioxide capture and purification method and system
JP7838855B2
( en )
2022-05-25
2026-04-01
å¢å éåï¼å京ï¼ç§ææéå ¬å¸
Methods and systems for carbon dioxide capture and purification.
US12151206B1
( en )
*
2023-10-31
2024-11-26
Carbon Utility LLC
Direct air capture of carbon dioxide
CN117883974A
( en )
*
2024-03-15
2024-04-16
ä¸å大å¦
Modular membrane isolation carbon desorption device, carbon capture system, method and application
CN119186200A
( en )
*
2024-09-18
2024-12-27
ä¸å½åè½éå¢æ¸ æ´è½æºææ¯ç 究é¢æéå ¬å¸
Electrochemical carbon dioxide trapping system and method for preparing coupled high-purity hydrogen
DE102024209472A1
( en )
2024-09-30
2026-04-02
Robert Bosch Gesellschaft mit beschränkter Haftung
Carbon dioxide climate system and method for operating a carbon dioxide climate system
Also Published As
Publication number
Publication date
JP2023550023A
( en )
2023-11-30
EP4606463A3
( en )
2026-01-07
EP4240517A1
( en )
2023-09-13
EP3995204A1
( en )
2022-05-11
EP4606463A2
( en )
2025-08-27
AU2021373306A1
( en )
2023-06-22
ES2927597T3
( en )
2022-11-08
EP3995204B1
( en )
2022-07-13
US20230390702A1
( en )
2023-12-07
AU2021373306B2
( en )
2024-12-05
DK3995204T3
( en )
2022-10-17
KR20230104635A
( en )
2023-07-10
WO2022096644A1
( en )
2022-05-12
CA3198968A1
( en )
2022-05-12
Similar Documents
Publication
Publication Date
Title
EP3995204B1
( en )
2022-07-13
Co2 capture process with electrolytic regeneration
US20250128204A1
( en )
2025-04-24
Reduced reagent regeneration energy for carbon dioxide capture with bipolar membrane electrodialysis, systems and related methods
US20250205644A1
( en )
2025-06-26
Method for increased carbon capture in an electrolytic process
US20140151240A1
( en )
2014-06-05
Electroylytic reduction of carbon capture solutions
US20250170518A1
( en )
2025-05-29
Method of producing carbon dioxide from a gas scrubbing process
CN108970334A
( en )
2018-12-11
Regenerative system and application thereof for rich carbon amine liquid
US9557113B2
( en )
2017-01-31
Direct reduced iron manufacturing system
JP2008100211A
( en )
2008-05-01
Mixed gas separation method and system
US20250018341A1
( en )
2025-01-16
Method and system for capturing and utilizing carbon dioxide
WO2024016114A1
( en )
2024-01-25
Method and device for carbon capture coupled hydrogen production
CN118854320A
( en )
2024-10-29
A carbon dioxide coupled desulfurization wastewater co-electrolysis device and method
EP4437165B1
( en )
2025-07-30
System and method for integrated co2 capture and hydrogen production
Lippert et al.
2025
Neutral water electrolysis unifies green hydrogen and renewable natural gas production from biogas
CN209405989U
( en )
2019-09-20
The device of ionic liquid absorption carbon dioxide in flue gas
Prajapati et al.
0
Supporting Information Assessment of Artificial Photosynthetic Systems for Integrated Carbon Capture and Conversion
Legal Events
Date
Code
Title
Description
2021-05-26
FEPP
Fee payment procedure
Free format text : ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY
2021-06-03
FEPP
Fee payment procedure
Free format text : ENTITY STATUS SET TO SMALL (ORIGINAL EVENT CODE: SMAL); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY
2021-12-21
STCF
Information on status: patent grant
Free format text : PATENTED CASE
2025-07-03
MAFP
Maintenance fee payment
Free format text : PAYMENT OF MAINTENANCE FEE, 4TH YR, SMALL ENTITY (ORIGINAL EVENT CODE: M2551); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY
Year of fee payment : 4