Latent Heat and Condensation Exchanger

Abstract

A system and method are disclosed for the separation of a component from a mixed gas stream by a combination of direct contact heat and mass exchange in an indirect contact heat exchanger. A contact liquid stream wets the inner surfaces of the process channels of the indirect contact heat exchanger, and the mixed gas stream flows through the process channels and contacts the contact liquid stream for heat and mass exchange. A refrigerant in the refrigerant channels of the indirect contact heat exchanger is used for heat exchange with the contact liquid.

Description

[Technical Field]

[0001] Priority claims

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 481,916, filed January 27, 2023, the contents of which are incorporated herein by reference.

[0002]

[0002] The methods and processes described herein relate generally to heat and mass exchange. More particularly, the methods and processes described herein relate to gas separation. [Background technology]

[0003] Flue gas, syngas, and other gases frequently require the removal of carbon dioxide, other acid gases, and pollutants, and various methods, such as scrubbers, absorbers, catalytic conversion, condensation, and similar gas separation processes, meet these needs. These methods can have limitations, including high energy requirements, inefficiencies, and costs. Vapor removal from gas streams is important, and improved devices, methods, and systems can be beneficial. Summary of the Invention [Means for solving the problem]

[0004] In a first aspect, the disclosure provides a method for removing a first component from a mixed gas stream. A refrigerant stream flows through a first channel of an indirect-contact heat exchanger. A contact liquid stream flows through a second channel of the indirect-contact heat exchanger, whereby the contact liquid stream wets the inner walls of the second channel. The mixed gas stream also flows through the center of the second channel, either cocurrently or countercurrently to the liquid stream, whereby the mixed gas stream and the contact liquid stream exchange heat, mass, or heat and mass. The system may include sensible heat exchange between the two phases, whereby the contact liquid stream exchanges heat with the mixed gas stream and transfers a first portion of the heat through the inner wall of the second channel to the inner wall of the refrigerant stream in the first channel, maintaining the balance of the heat streams. The system preferably operates with minimal sensible heat exchange, and in all cases involving mass transfer between the two streams, a first component is condensed or absorbed from the mixed gas stream into the contact liquid stream, resulting in a depleted gas stream and an enriched contact liquid stream, generating a certain amount of heat associated with the condensation or absorption from the contact liquid that is at least partially conducted through the wall separating the two streams into the second stream.

[0005] In a second aspect, the disclosure provides a method for removing a first component from a mixed gas stream. A refrigerant stream flows through a first channel of an indirect contact heat exchanger. A contact liquid stream flows through a second channel, whereby the contact liquid stream wets the inner walls of the second channel. The mixed gas stream also flows through the center of the second channel, whereby the mixed gas stream and the contact liquid stream exchange heat, mass, or heat and mass. The contact liquid stream receives heat from the mixed gas stream and transfers heat to the refrigerant stream, and the contact liquid stream and the mixed gas stream remain substantially isothermal throughout the second channel, whereby the refrigerant evaporates. In a preferred embodiment, the refrigerant stream may remain essentially isothermal. The first component condenses from the mixed gas stream into the contact liquid stream, resulting in a depleted gas stream and an enriched contact liquid stream.

[0006] In a third aspect, the disclosure provides a system for removing a first component from a mixed gas stream. The indirect contact heat exchanger includes a process channel and one or more refrigerant channels, the process channel sharing a wall with the one or more refrigerant channels. The process channel is configured to receive a contact liquid stream through the process channel inlet while leaving a gas space within the process channel and to wet the inner surface of the process channel with the contact liquid stream. The process channel is further configured to receive a mixed gas stream through the process channel inlet and flow the mixed gas stream through the gas space. The one or more refrigerant channels are each configured to receive one refrigerant stream from a group of refrigerant streams from one or more refrigerant controllers. One or more devices are located at least at the inlet of the process channel, the outlet of the process channel, or both. The one or more devices are configured to measure one or more process variables of the process channel and send the one or more process variables to a main controller. The main controller is programmed to receive the one or more process variables and send signals to each of the one or more refrigerant controllers. The one or more refrigerant controllers are configured to control the flow rate of one of the group of refrigerant streams to each of the one or more refrigerant channels to maintain one or more process variables in the contact liquid stream at a set point. The mixed gas stream condenses a first component into the contact liquid stream. The mixed gas stream passes a heat stream to the contact liquid stream. The contact liquid stream transfers a first portion of the heat stream to the one of the group of refrigerant streams. The contact liquid stream maintains the balance of the heat stream.

[0007] In a fourth aspect, the device includes first and second channels as described above arranged in a stack, preferably with alternating first and second channels. The channel cross-sectional area controls the fluid velocity within each channel, while the channel length controls the contact time between streams. The number of channels controls the total flow rate the device can manage.

[0008]

[0008] Further aspects and embodiments are provided in the following drawings, detailed description, and claims.

[0009] The following drawings are provided to illustrate certain embodiments described herein. The drawings are illustrative only and are not intended to limit the scope of the claimed invention, nor are they intended to show every possible feature or embodiment of the claimed invention. The drawings are not necessarily drawn to scale, and in some instances, certain elements of the drawings may be enlarged relative to other elements of the drawings for illustrative purposes. [Brief explanation of the drawings]

[0009] [Figure 1]

[0010] 1 is a process diagram illustrating a method for separating a component from a gas stream. [Figure 2]

[0011] 1 is a process diagram illustrating a method for separating a component from a gas stream. [Figure 3]

[0012] FIG. 2 is a cutaway elevation view showing a heat exchange system for separating certain components from a gas stream. [Figure 4]

[0013] FIG. 1 is an isometric view of a section of a pipe-in-pipe for separating a component from a gas stream. [Figure 5]

[0014] 1 is a block flow diagram illustrating a method for separating a component from a gas stream. [Figure 6]

[0015] 1 is a process flow diagram showing an extraction exchanger. [Figure 7]

[0016] 7 is a process flow diagram showing a close-up of the exchanger of FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0017] The following description lists various aspects and embodiments of the invention disclosed herein. No particular embodiment is intended to define the scope of the invention. Rather, the embodiments provide non-limiting examples of various compositions and methods that fall within the scope of the claimed invention. The description is read from the perspective of one of ordinary skill in the art. Therefore, information that is familiar to one of ordinary skill in the art is not necessarily included. definition

[0018] The following terms and phrases have the meanings indicated below unless otherwise provided herein. This disclosure may use other terms and phrases not expressly defined herein. Such other terms and phrases shall have the meaning they would have to one of ordinary skill in the art within the context of this disclosure. In some cases, a term or phrase may be defined in the singular or in the plural. In such cases, it is understood that any term in the singular may include its plural counterpart, and vice versa, unless expressly indicated to the contrary.

[0011]

[0019] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a substituent" includes a single substituent as well as two or more substituents, and the like.

[0012]

[0020] As used herein, "for example," "for instance," "such as," or "including" means introducing an example that further clarifies a more general subject matter. Unless expressly indicated otherwise, such examples are provided only as an aid in understanding the embodiments set forth in this disclosure and are not meant to be limiting in any way. These phrases do not imply any kind of preference for the disclosed embodiments.

[0013]

[0021] As used herein, "condensing" is meant to refer to the process by which vapor cools to a liquid.

[0022] As used herein, "desublimating" is meant to refer to the process by which vapor is cooled to a solid. As used herein, "cryogenic" is intended to refer to temperatures below about -50°C (-58°F).

[0014]

[0023] Combustion flue gas consists of exhaust gases from fireplaces, ovens, furnaces, boilers, steam generators, or other combustors. Combustion fuel sources include coal, hydrocarbons, and biomass. Combustion fuel gases vary significantly in composition depending on the combustion method and fuel source. Combustion in pure oxygen produces little to no nitrogen in the flue gas. Combustion using air leads to a large amount of flue gas consisting of nitrogen. Non-nitrogen flue gas consists mostly of carbon dioxide, water, and occasionally unconsumed oxygen. Small amounts of carbon monoxide, nitrogen oxides, sulfur oxides, hydrogen sulfide, and trace amounts of hundreds of other chemicals are present, depending on the source. Entrained dust and soot will also be present in all combustion flue gas streams. The disclosed method applies to any combustion flue gas. Dried combustion flue gas has water removed.

[0015]

[0024] Syngas consists of hydrogen, carbon monoxide, and carbon dioxide.

[0025] Producer gas consists of flue gas produced from materials such as coal, wood, or syngas. Producer gas consists mostly of carbon monoxide, with tars and carbon dioxide also present.

[0016]

[0026] Steam reforming is a process that produces hydrogen, carbon monoxide, and other compounds from hydrocarbon fuels, including natural gas. The steam reformate gas referred to herein consists primarily of carbon monoxide and hydrogen, with varying amounts of carbon dioxide and water.

[0017]

[0027] Light gases include gases that have a higher volatility than water, including hydrogen, helium, carbon dioxide, nitrogen, and oxygen. This list is exemplary only and should not be implied to place limitations on the viability of other gases in the process. One skilled in the art will be able to evaluate any gas as to whether it has a higher volatility than water.

[0018]

[0028] Refinery off-gas includes gases produced by refining precious metals such as gold and silver. These off-gases tend to contain significant amounts of mercury and other metals.

[0019]

[0029] Mixed gas streams, such as flue gas, syngas, producer gas, and refinery off-gas, tend to contain moisture in varying amounts. With the recent push for carbon dioxide sequestration, moisture removal is generally crucial before carbon dioxide removal can be attempted. Without water removal, the cryogenic temperatures typical of carbon dioxide sequestration can result in ice blocking unit operation. Methods for water removal can vary greatly and include distillation, ice making, and even drying. All of these methods are extremely energy intensive, require batch operations, or are prohibitively expensive. Embodiments of the present disclosure overcome at least some of these and other problems that will become apparent to those skilled in the art.

[0020]

[0030] A combination of indirect contact heat exchange and direct contact heat and mass exchange is utilized to remove vapor components, such as water, from a mixed gas stream, such as flue gas. While a water / flue gas example will be used to summarize the method, those skilled in the art may use the method for removing various vapor components from a variety of mixed gas streams. The indirect contact heat exchanger has refrigerant channels carrying a refrigerant stream, which extracts heat from a contact liquid stream carried in a process channel of the same indirect contact heat exchanger. The process channel carries an amount of contact liquid that wets the inner surface of the process channel. The flue gas stream flows through the balance of the process channel volume. In a preferred embodiment, the contact liquid stream wets the inner surface of the process channel, resulting in the flue gas stream rarely contacting the inner surface. In a more preferred embodiment, the contact liquid stream completely prevents the flue gas stream from contacting the inner surface. The flue gas stream flows through the process channel with water as one component. As the flue gas flows over the contact liquid, moisture leaves the flue gas and condenses into the contact liquid.

[0021]

[0031] In embodiments of the present disclosure, the amount of contact liquid required is minimized—only enough to coat the surfaces of the process channels. This is because there will always be some amount of carbon dioxide that exits the flue gas and dissolves in the contact liquid. By minimizing this volume, the amount of carbon dioxide becomes insignificant when regenerating the contact liquid. Water removal steps in which large volumes of contact liquid are processed can produce large amounts of carbon dioxide that condense, clogging exchangers and vessels. Embodiments of the present disclosure provide liquid that condenses water from the flue gas but not enough to remove a significant amount of carbon dioxide. Furthermore, by minimizing the contact liquid, the amount of carbon dioxide that can condense into the contact liquid at the flue gas inlet and evaporate from the contact liquid at the contact liquid outlet is minimized, limiting disturbances to the temperature profile of the contact liquid.

[0022]

[0032] In one embodiment, the contacting liquid stream enters at a lower temperature and leaves at a higher temperature. In a preferred embodiment, the contacting liquid stream is isothermal throughout the channel.

[0023]

[0033] Examples of systems that the present invention can treat include CO removal from flue gas, syngas, natural gas, biogas, and process gases; HO removal from most moisture-bearing gases; and SO removal from pollutant streams and other sulfur-containing gases. X This includes, but is not limited to, removal, and absorption / condensation of any gaseous components by a contacting liquid capable of absorbing some portion of the component.

[0024]

[0034] Referring now to FIG. 1, a process diagram illustrating a method for separating a component from a mixed gas stream containing a first component may be used in one embodiment of the present invention. This is referred to as an extractive exchange process. Process channel 101 and refrigerant channel 102 constitute an indirect contact heat exchanger 100. Refrigerant stream 112 enters refrigerant channel 102 and flows upward. Contact liquid stream 114 enters process channel 101 and flows downward. The refrigerant and contact liquid can be countercurrent, cocurrent, or crosscurrent as shown. The contact liquid stream 114 has a volumetric flow rate sufficient to wet the surface of process channel 101, but not sufficient to fill all or even a significant portion of process channel 101. As a result, the contact liquid stream has a hollow concentric linear or annular flow profile. Contact liquid stream 114 preferably wets the surface of process channel 101 but does not penetrate or adhere to it. The liquid preferably flows in a sheet that covers the surface to avoid water droplets. By way of example only, the surface may have a similar polarity to the liquid, may include an oxide or polishing layer as needed to promote wetting, may have increased surface roughness, anodization, coating, or etching to promote surface coating, and / or the contacting liquid or channel surface may include a surfactant. This also applies to the process channels in the following embodiments. The mixed gas stream 116 flows through the balance of the volume of the process channel 101. Mass and possibly heat exchange occurs between the mixed gas stream 116 and the contacting liquid stream 114. Preferably, the mixed gas stream 116 and the contacting liquid stream 114 flow countercurrently to maximize the amount of the first component in the gas that is absorbed or condensed in the liquid. In the case of mass exchange, the first component from the mixed gas stream 116 aggregates, is absorbed, or condenses into the contacting liquid stream 114.In the case of heat exchange, in the most preferred embodiment, no heat is transferred from the mixed gas stream 116 into the contact liquid stream 114, but the amount of heat generated by absorption / condensation / freezing of the gas components is transferred from the contact liquid stream 114 into the refrigerant stream 112, typically resulting in minimal temperature gradients within the lean contact liquid stream 114. In this mode of operation, there are no substantial temperature gradients within any of the streams in the streamwise direction, only sufficient temperature gradients within the streams in the transverse direction to provide heat transfer. Heat and mass exchange results in a depleted gas stream 117, an enriched contact liquid stream 115, and a partially evaporated or warmed refrigerant stream 113. As an alternative to this embodiment, both sensible heat exchange and heat exchange associated with absorption / condensation / freezing occur, and the streams experience streamwise temperature gradients in addition to transverse temperature gradients.

[0025]

[0035] Absorption occurs when a gas component is above its dew point temperature, or equivalently, below its dew point concentration or vapor pressure at the temperature of the liquid. That is, a gas that would not condense on an inert surface may still be absorbed into the liquid. Condensation occurs when a gas is at or below its dew point temperature, or equivalently, at or above its dew point concentration or vapor pressure of the liquid / surface. Condensation is the same as (liquid) condensation, except that conditions are such that the gas goes from vapor directly to solid and does not form a liquid.

[0026]

[0036] In another embodiment, the first component condenses out of the mixed gas stream 116, heat is extracted from the mixed gas stream 116 by the contact liquid stream 114, and the refrigerant stream 112 extracts heat from the contact liquid stream 114. In this embodiment, the contact liquid stream 114 may be isothermal or non-isothermal.

[0027]

[0037] Figure 2 is a process diagram illustrating a method for separating water vapor from a flue gas stream that may be used in one embodiment of the present invention. This is referred to as an extractive exchange process. Process channel 201 and a series of refrigerant channels 202, 203, 204, and 205 comprise an indirect contact heat exchanger 200. A first refrigerant stream 212 enters refrigerant channel 202 and flows upward. A second refrigerant stream 220 enters refrigerant channel 203 and flows upward. A third refrigerant stream 222 enters refrigerant channel 204 and flows upward. A fourth refrigerant stream 224 enters refrigerant channel 205 and flows upward. A methanol liquid stream 214, acting as a contact liquid, enters process channel 201 and flows downward. The methanol liquid stream 214 flows at a volumetric rate sufficient to wet the surface of process channel 201 but not enough to fill the entire process channel 201. A flue gas stream 216 flows upward, filling the balance of the process channel 201 volume. Heat and mass exchange occurs between flue gas stream 216 and methanol liquid stream 214. In the case of mass exchange, essentially all of the water vapor from flue gas stream 216 condenses into contact liquid stream 214. In the case of heat exchange, in the most preferred embodiment, an amount of heat is transferred from flue gas stream 216 into methanol liquid stream 214, and an equal amount of heat is transferred from methanol liquid stream 214 into refrigerant streams 212, 220, 222, and 224, causing methanol liquid stream 214 to remain isothermal throughout process channel 201. Heat and mass exchange results in dry flue-depleted gas stream 217, enriched contact liquid stream 215, and warmed refrigerant streams 213, 221, 223, and 225. A benefit of having multiple refrigerant streams is that the temperature of methanol liquid stream 214 is controlled by charging each section of refrigerant at a temperature and flow rate to keep methanol liquid stream 214 isothermal. With this design, control can be increased in granularity by having more coolant channels with their own temperature and flow rate.Although four coolant channels are shown, alternative numbers may be used in other embodiments.

[0028]

[0038] In a preferred version of this embodiment, the flue gas stream 216 is cooled to a temperature below the dew point of the water vapor, causing essentially all of the water vapor to condense out of the flue gas stream 216. In a preferred embodiment, essentially all of the water vapor is 99% of the water vapor in the flue gas stream 216. In a more preferred embodiment, essentially all of the water vapor is 99.9% of the water vapor in the flue gas stream 216. In a most preferred embodiment, essentially all of the water vapor is 99.99% of the water vapor in the flue gas stream 216.

[0029]

[0039] In one embodiment, the methanol liquid stream 214 consists entirely of methanol. In a preferred embodiment, the methanol liquid stream 214 consists of a mixture of methanol and ethanol. In some embodiments, the methanol liquid stream 214 contains some water at the inlet to the process channels 201. In one embodiment, the methanol liquid stream enters the process channels 201 saturated with carbon dioxide, whereby isothermal operation means that carbon dioxide does not dissolve into the methanol liquid stream 214 from the flue gas stream 216.

[0030]

[0040] In another embodiment, contact liquid stream 214 consists entirely of ethanol.

[0041] Figure 3 is a cutaway elevation view illustrating a shell-and-tube style extractive exchanger utilizing a system for separating a first component from a gas stream, which may be used in one embodiment of the present invention. The extractive exchanger 300 consists of a process channel 301, comprised of a bundle of tubes 302, through which a mixed gas stream 316 and a contact liquid stream 314 flow. The extractive exchanger 300 also consists of a series of refrigerant channels 303, 304, and 305. A first refrigerant stream 312 enters refrigerant channel 303 and flows upward. A second refrigerant stream 320 enters refrigerant channel 304 and flows upward. A third refrigerant stream 322 enters refrigerant channel 305 and flows upward. A contact liquid stream 314 enters the bundle of tubes 302 and flows downward. The contact liquid stream 314 has a volumetric flow rate sufficient to wet the surfaces of the bundle of tubes 302, but not sufficient to fill the entire process channel 301, resulting in the contact liquid stream having an annular flow profile. The mixed gas stream 316 flows upward through the center of the annular flow profile. Heat and mass exchange occurs between the flue gas stream 316 and the contact liquid stream 314. In the mass exchange, a first component from the flue gas stream 316 condenses into the contact liquid stream 314. A certain amount of heat is transferred from the flue gas stream 316 into the contact liquid stream 314. In one embodiment, the amount of heat is divided into two parts. A first part of the amount of heat is transferred from the contact liquid stream 314 into the refrigerant streams 312, 320, and 322. A second part of the amount of heat is retained in the contact liquid stream 314, raising the temperature of the resulting enriched contact liquid stream 315. The heat and mass exchange results in a dry flue gas stream 317, an enriched contact liquid stream 315, and warmed refrigerant streams 313, 321, and 323. In a more preferred embodiment, all of the heat is transferred from contact liquid stream 314 into coolant streams 312, 320, and 322, causing contact liquid stream 314 to remain isothermal throughout process channel 301. The number of coolant channels may vary from the number shown.

[0031]

[0042] FIG. 4 is an isometric view of a section of a pipe-in-pipe style extractive exchanger for separating a first component from a mixed gas stream, which may be used in one embodiment of the present invention. The inner pipe 402 passes through the center of the vertical outer pipe 401, creating an outer annular space between the outer pipe 401 and the inner pipe 402 and a cylindrical space inside the inner pipe 402. The refrigerant stream 412 flows through the outer annular space. The contact liquid stream 414 flows downward through the cylindrical space, thereby wetting the inner wall of the inner pipe 402 with an annular film and leaving the inner space through which the mixed gas stream 416 can flow. In FIG. 4, the mixed gas stream 416 flows downward through the inner space. In other embodiments, the mixed gas stream 416 flows upward through the inner space. Flowing the mixed gas stream 416 and the contact liquid stream 414 against each other allows them to participate in heat and mass exchange. The contact liquid stream 414 receives heat from the mixed gas stream 416, and a first component from the mixed gas stream 416 condenses into the contact liquid stream 414. The contact liquid stream 414 transfers a first portion of the heat through the inner pipe 402 and into the refrigerant stream 412. The contact liquid stream 414 retains a second portion of the heat as it leaves the inner pipe 402 as an enriched contact liquid stream. The flue gas stream 416 leaves as a depleted flue gas stream. In one embodiment, the second portion of the heat is zero, meaning that the first portion of the heat is all of the heat, causing the contact liquid stream 414 to remain isothermal from the inlet to the outlet of the inner pipe 402. In another embodiment, the second portion of the heat is non-zero, causing the contact liquid stream 414 to increase or decrease in temperature from the inlet to the outlet of the inner pipe 402.

[0032]

[0043] Figure 5 is a block flow diagram illustrating a system for separating a component from a gas stream that may be used in one embodiment of the present invention. This is referred to as an extractive exchange process. The indirect contact heat exchanger 500 consists of a process channel 501 and four refrigerant channels 502, 504, 506, and 508. The process channel is constructed of a tube bundle, with the tube walls in contact with the refrigerant channels. Refrigerant channels 502, 504, 506, and 508 have refrigerants 520, 522, 524, and 526, respectively, flowing therethrough. The refrigerants vary in chemical composition, temperature, and flow rate. The refrigerant chemical composition, temperature, and flow rate are selected to provide heat exchange across the tube walls at a rate that produces a desired temperature profile within the process channel 501. The number of refrigerant channels may vary from the number shown.

[0033]

[0044] The process channel 501 is configured to receive a contact liquid stream 514 through an inlet of the process channel 501 and wet the inner surface of the process channel 501 with the contact liquid stream 514 while leaving a gas space in the central volume of each of the tubes of the process channel 501, similar to Figure 4. The process channel 501 is further configured to receive a mixed gas stream 516 through an inlet of the process channel 501 and flow the mixed gas stream 516 through the gas space in the central volume of the tubes of the process channel 501.

[0034]

[0045] Refrigerant channels 502, 504, 506, and 508 are configured to receive refrigerant streams 520, 522, 524, and 526, respectively, controlled by refrigerant control valves 520, 522, 524, and 526, respectively. In other embodiments, other control elements, such as pumps, may be used. These valves are controlled by a main controller 550. The main controller 550 receives temperature data from temperature elements 540, 542, 544, 546, and 548, which measure the temperature of contact liquid 514 at points through the tubing of process channel 501. In a preferred embodiment, the main controller 550 sends signals to vary the valves to provide refrigerant 520, 522, 524, and 526 at a rate that maintains an isothermal temperature profile. In other embodiments, the temperature profile is maintained such that the temperature of contact liquid 514 increases or decreases as it flows through exchanger 500.

[0035]

[0046] The mixed gas stream 516 condenses a first component into the contact liquid stream 514. The mixed gas stream 516 transfers a heat stream to the contact liquid stream 514. The contact liquid stream 514 transfers a first portion of the heat stream to the refrigerant streams 520, 522, 524, and 526. The contact liquid stream 514 maintains the balance of the heat stream. In a preferred embodiment, the first portion of the heat stream is the entire heat stream, and the contact liquid stream 514 remains isothermal.

[0036]

[0047] The results of the heat and mass exchange in FIG. 5 are enriched contact liquid stream 515, depleted mixed gas stream 517, and spent refrigerant streams 521, 523, 525, and 527.

[0037]

[0048] In some embodiments, as few as two temperature elements are used, one temperature element at the inlet and one temperature element at the outlet.

[0049] In some embodiments, the mixed gas is selected from the group consisting of flue gas, natural gas, liquefied petroleum gas, and syngas.

[0038]

[0050] In some embodiments, the gas mixture also includes a second component, in particular an acid gas, selected from the group consisting of carbon dioxide, sulfur oxides, nitrogen oxides, mercury, mercury oxides, carbon monoxide, other pollutants, and combinations thereof.

[0039]

[0051] In some embodiments, the contact liquid stream is selected from the group consisting of water, isopentane, methanol, ethanol, and combinations thereof.

[0052] In one embodiment, the refrigerant stream is co-current to the contacting liquid stream. In a most preferred embodiment, the refrigerant stream is counter-current to the contacting liquid stream.

[0040]

[0053] In some embodiments, the mixed gas stream is countercurrent to the contacting liquid stream.

[0054] Figure 6 is a process flow diagram illustrating an extractive exchanger that may be used in Figures 1, 2, and 3. Figure 7 is a process flow diagram showing a close-up of the exchanger of Figure 6. The extractive exchanger 620 is configured to flow the partially depleted dry gas stream 617 countercurrently upwardly directly against the second contact liquid stream 615, forcing it against a second refrigerant stream 613 to indirectly cool the second contact liquid stream 615, and condense carbon dioxide from the partially depleted dry gas stream 617 into the second contact liquid stream 615, resulting in a partially enriched second contact liquid stream 619 and a depleted dry gas stream 607. The refrigerant 613 flows through a second channel 622 to indirectly cool the first channel 624.

[0041]

[0055] While the invention has been described with reference to various specific and preferred embodiments and techniques, it will be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention.

Claims

1. 1. A method for removing a first component from a mixed gas stream, comprising: flowing a refrigerant stream through a first channel of an indirect contact heat exchanger; flowing a contact liquid stream through a second channel of the indirect contact heat exchanger, whereby the contact liquid stream wets an inner wall of the second channel; flowing a mixed gas stream through a center of the second channel, whereby the mixed gas stream and the contact liquid stream exchange heat, mass, or heat and mass; The contact liquid stream comprises: receiving the heat from the mixed gas stream; transferring a first portion of the heat through the interior wall of the second channel into the refrigerant stream; leaving the second channel while maintaining the heat balance; The method wherein the first component condenses from the mixed gas stream into the contact liquid stream, resulting in a depleted gas stream and an enriched contact liquid stream.

2. 10. The method of claim 1, The method wherein the first portion of the heat stream is all of the heat stream and causes the contacting liquid stream to be isothermal throughout the second channel.

3. 10. The method of claim 1, The method wherein the mixed gas stream is cooled to a temperature below the dew point of the first component.

4. 10. The method of claim 1, The method wherein the heat stream balance is positive and the temperature of the contacting liquid stream increases from the inlet of the second channel to the outlet of the second channel.

5. 10. The method of claim 1, The method wherein the heat stream balance is negative and the temperature of the contacting liquid stream decreases from the inlet of the second channel to the outlet of the second channel.

6. 10. The method of claim 1, The method wherein the mixed gas stream is selected from the group consisting of flue gas, natural gas, liquefied petroleum gas, and synthesis gas.

7. 10. The method of claim 1, The method, wherein the first component comprises water.

8. 8. The method of claim 7, The method of claim 1, wherein the mixed gas stream further comprises a second component comprising an acid gas selected from the group consisting of carbon dioxide, sulfur oxides, nitrogen oxides, mercury, mercury oxides, carbon monoxide, other pollutants, and combinations thereof.

9. 10. The method of claim 1, The method wherein the contact liquid stream is selected from the group consisting of water, isopentane, methanol, ethanol, and combinations thereof.

10. 10. The method of claim 1, The method wherein the refrigerant stream is countercurrent to the contact liquid stream.

11. 11. The method of claim 10, The method wherein the mixed gas stream is countercurrent to the contacting liquid stream.

12. 1. A method for removing a first component from a mixed gas stream, comprising: flowing a refrigerant stream through a first channel of an indirect contact heat exchanger; flowing a contacting liquid stream through a second channel, whereby the contacting liquid stream wets an interior wall of the second channel; flowing a mixed gas stream through a center of the second channel, whereby the mixed gas stream and the contact liquid stream exchange heat, mass, or heat and mass; the contact liquid stream receives heat from the mixed gas stream and transfers the heat to the refrigerant stream, the contact liquid stream remaining isothermal throughout the second channel; The method wherein the first component condenses from the mixed gas stream into the contact liquid stream, resulting in a depleted gas stream and an enriched contact liquid stream.

13. 13. The method of claim 12, The method, wherein the first component is water vapor and the mixed gas stream further comprises carbon dioxide.

14. 13. The method of claim 12, The method wherein the contact liquid stream comprises methanol, ethanol, or a combination thereof.

15. 1. A system for removing a first component from a mixed gas stream, comprising: an indirect contact heat exchanger comprising a process channel and one or more refrigerant channels, the process channel sharing a wall with the one or more refrigerant channels; the process channel is configured to receive a contact liquid stream through the process channel inlet while leaving a gas space within the process channel and to wet an inner surface of the process channel with the contact liquid stream; the process channel is further configured to receive the mixed gas stream through the inlet of the process channel and flow the mixed gas stream through the gas space; the one or more refrigerant channels are configured to each receive one of a group of refrigerant streams from one or more refrigerant controllers; one or more devices are located at least at an inlet of the process channel, an outlet of the process channel, or both; the one or more devices are configured to measure one or more process variables of the process channel and transmit the one or more process variables to a main controller; the master controller is programmed to receive the one or more process variables and send a signal to each of the one or more refrigerant controllers; the one or more refrigerant controllers are configured to control a flow rate of one refrigerant stream of the group of refrigerant streams to each of the one or more refrigerant channels to maintain the one or more process variables in the contact liquid stream at a set point; the mixed gas stream condenses the first component into the contact liquid stream; the mixed gas stream transferring heat to the contact liquid stream; the contact liquid stream transfers a first portion of the heat stream to the one refrigerant stream of the group of refrigerant streams; The contacting liquid stream maintains the balance of the heat stream.

16. 16. The system of claim 15, The system wherein the first portion of the heat stream is all of the heat stream, causing the contact liquid stream to be isothermal throughout the process channel.

17. 16. The system of claim 15, The system wherein the mixed gas stream is selected from the group consisting of flue gas, natural gas, liquefied petroleum gas, and syngas.

18. 16. The system of claim 15, The system, wherein the first component comprises water.

19. 20. The system of claim 18, The system wherein the mixed gas stream further comprises a second component comprising an acid gas selected from the group consisting of carbon dioxide, sulfur oxides, nitrogen oxides, mercury, mercury oxides, carbon monoxide, other pollutants, and combinations thereof.

20. 16. The system of claim 15, The system wherein the contact liquid stream is selected from the group consisting of water, isopentane, methanol, ethanol, and combinations thereof.

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