Cryogenic carbon capture system and method integrated with a liquefied natural gas vaporizer

Abstract

The sublimation heat exchanger receives a cooled process gas stream from the precooling heat exchanger and includes a clean gas outlet, a contact liquid inlet, and a slurry outlet. The contact liquid heat exchanger is connected to the contact liquid inlet of the sublimation heat exchanger and heats the liquefied natural gas stream to provide cooling within the contact liquid heat exchanger. The sublimation heat exchanger contacts the cooled process gas stream with the cooled contact liquid, causing carbon dioxide to be absorbed into the contact liquid, thereby forming a carbon dioxide-laden slurry stream and a carbon dioxide-depleted clean process gas stream. The clean process gas stream flows through the clean gas outlet to the precooling heat exchanger, and the slurry stream flows through the slurry outlet. The precooling heat exchanger heats the clean process gas stream to provide cooling for the process gas stream. A solids separator is connected to the contact inlet of the sublimation heat exchanger and separates the carbon dioxide-laden slurry stream from the sublimation heat exchanger into a condensed carbon dioxide stream and a contact liquid stream.

Description

[0001] Priority Statement

[0002] This application claims priority to U.S. Provisional Application No. 63 / 553,399, filed February 14, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to systems and methods for purifying gases, and more specifically, to systems and methods for integrating cryogenic carbon capture with liquefied natural gas vaporization. Background Technology

[0004] Gas purification, including carrier gas or feed gas, has been an important process in industry for many years. One example is the treatment of combustion flue gas. Combustion flue gas consists of exhaust gases from fireplaces, ovens, furnaces, boilers, steam generators, or other burners. Fuel sources include coal, natural gas, liquid hydrocarbons, black liquor, and biomass. The composition of combustion flue gas varies considerably depending on the combustion method and fuel source. Combustion using air results in flue gas that is predominantly nitrogen. The non-nitrogenous components of the flue gas consist primarily of carbon dioxide (or CO2), water, and unconsumed oxygen. Depending on the source, trace amounts of carbon monoxide, nitrogen oxides, sulfur dioxide, and hundreds of other chemicals are also present. Most combustion flue gas streams also contain entrained dust and particulate matter.

[0005] Separating carbon dioxide from light gases such as nitrogen is known as carbon capture, which is crucial for reducing CO2 emissions and their associated environmental impacts. CO2 is generally considered a significant contributor to the greenhouse effect and global warming. Therefore, there is a clear need for methods to efficiently capture CO2 from flue gas to produce concentrated CO2 streams that can be easily transported to safe storage sites or used for further applications.

[0006] Natural gas is often liquefied for storage and transportation because liquefaction reduces the fluid volume and lowers the cost of storage and processing equipment. However, once the resulting liquefied natural gas (LNG) reaches its intended use location, it must typically be regasified to be used as natural gas.

[0007] Existing technology has recognized that the heat required for LNG gasification can be provided by a cryogenic carbon capture system. More specifically, see [reference needed]. Figure 1LNG from storage tank 10 can be supplied directly or via pump 12 to cryogenic carbon capture system 14. Cryogenic carbon capture system 14 receives flue gas 16 from the combustion source, which contains CO2 and light gases such as nitrogen. Cryogenic carbon capture system 14 uses the cooling provided by LNG to separate flue gas 16 into a CO2 stream 18 and a light gas stream 20. The resulting gasified natural gas exits cryogenic carbon capture system 14 as stream 22. If stream 22 is not completely gasified, additional heating can be provided by heat exchanger 24. Alternatively, the natural gas fluid stream can be expanded by expansion device 26 to reduce the pressure of the stream. U.S. Patent No. 9,410,736, jointly owned by Baxter, discloses a system integrating cryogenic carbon capture and LNG gasification, the contents of which are incorporated herein by reference.

[0008] The goal is to develop new technologies that integrate cryogenic carbon capture with LNG gasification to provide efficiency and / or cost advantages. Summary of the Invention

[0009] This subject matter has several aspects, which may be embodied individually or collectively in the methods, apparatus, and systems described and claimed below. These aspects may be used alone or in combination with other aspects of the subject matter described herein, and the collective description of these aspects is not intended to exclude their individual use, nor is it intended to exclude the claiming of these aspects individually or in different combinations as described in the appended claims.

[0010] In one aspect, a system for separating carbon dioxide from process gas includes a precooling heat exchanger configured to receive and cool a process gas stream, thereby forming a cooled process gas stream. A sublimation heat exchanger includes a process gas inlet, a clean gas outlet, a contact liquid inlet, and a slurry outlet, wherein the process gas inlet is configured to receive the cooled process gas stream from the precooling heat exchanger. A contact liquid heat exchanger is in fluid communication with the contact liquid inlet of the sublimation heat exchanger and is configured to receive and heat a liquefied natural gas stream to provide cooling within the contact liquid heat exchanger. The sublimation heat exchanger is configured to contact the cooled process gas stream received from the precooling heat exchanger with a contact liquid cooled by the contact liquid heat exchanger, such that carbon dioxide is absorbed into the contact liquid, thereby forming a carbon dioxide-laden slurry stream and a carbon dioxide-depleted clean process gas stream. The clean process gas stream is directed to the precooling heat exchanger via the clean gas outlet, and the slurry stream is directed via the slurry outlet. The precooling heat exchanger is configured to heat the clean process gas stream to provide cooling for the process gas stream. The solid separation device is in fluid communication with the contact liquid inlet of the sublimation heat exchanger and is configured to receive a slurry stream carrying carbon dioxide from the slurry outlet of the sublimation heat exchanger and separate the slurry stream into a condensed carbon dioxide stream and a contact liquid stream.

[0011] On the other hand, a system for separating carbon dioxide from process gas includes a precooling heat exchanger configured to receive and cool the process gas stream, thereby forming a cooled process gas stream. A sublimation heat exchanger includes a process gas inlet, a clean gas outlet, a contact liquid inlet, and a slurry outlet, wherein the process gas inlet is configured to receive the cooled process gas stream from the precooling heat exchanger. A solids separation unit is configured to guide the contact liquid to the contact liquid inlet of the sublimation heat exchanger. The sublimation heat exchanger is configured to contact the cooled process gas stream received from the precooling heat exchanger with the contact liquid from the solids separation unit, such that carbon dioxide is absorbed into the contact liquid, thereby forming a carbon dioxide-laden slurry stream and a carbon dioxide-depleted clean process gas stream. The clean process gas stream is guided to the precooling heat exchanger via the clean gas outlet, and the slurry stream is guided to the contact liquid heat exchanger via the slurry outlet. The precooling heat exchanger is configured to heat the clean process gas stream to provide cooling for the process gas stream. The contact liquid heat exchanger is configured to receive and heat the liquefied natural gas stream to cool the slurry stream. The contact liquid heat exchanger is also configured to direct the cooled slurry stream to a solids separation unit. The solids separation unit is configured to separate the carbon dioxide-carrying slurry stream into a condensed carbon dioxide stream and a contact liquid stream.

[0012] On the other hand, a method for separating carbon dioxide from process gas includes the following steps: precooling a process gas stream by heating a clean process gas stream to form a cooled process gas stream; cooling a contact liquid by heating a liquefied natural gas stream to form a cooled contact liquid stream; contacting the cooled process gas stream with the cooled contact liquid stream so that carbon dioxide is absorbed into the contact liquid, thereby forming a carbon dioxide-laden slurry stream and a carbon dioxide-depleted clean process gas stream, wherein the clean process gas stream is heated to cool the process gas stream; and separating the slurry stream into a condensed carbon dioxide stream and a contact liquid stream. Attached Figure Description

[0013] Figure 1 This is a simplified process flow diagram showing the main components of a prior art cryogenic carbon capture system integrated with a liquefied natural gas gasification system.

[0014] Figure 2 This is a simplified process flow diagram illustrating the main components of an embodiment of the system disclosed herein.

[0015] Figure 3 yes Figure 2 A simplified process flow diagram of the system, in which a heater is added for the LNG stream.

[0016] Figure 4 yes Figure 3 A simplified process flow diagram of the system, in which the contact liquid is guided through an additional heat exchanger.

[0017] Figure 5 This is a process flow diagram and schematic diagram of an embodiment of the system disclosed herein.

[0018] Figure 6 This is a process flow diagram and schematic diagram of an alternative embodiment of the system disclosed herein. Detailed Implementation

[0019] It should be noted that pipelines, conduits, pipes, channels and similar structures, as well as the corresponding flows, shown in the accompanying drawings are sometimes referred to by the same reference numerals.

[0020] Furthermore, as used herein and as is known in the art, a heat exchanger is a device or region within a device in which indirect heat exchange occurs between two or more flows at different temperatures, or between a flow and the environment. Additionally, all heat exchangers mentioned herein may be combined in one or more heat exchanger units, or each heat exchanger may be a separate heat exchanger unit. As used herein, unless otherwise stated, the terms “connected,” “communicating,” etc., generally refer to fluid communication. Furthermore, although two fluids in communication with each other may exchange heat upon mixing, this exchange is not considered the same as heat exchange within a heat exchanger, although such exchange can occur within a heat exchanger.

[0021] As used herein, the terms “high,” “intermediate,” “warm,” “cold,” etc., are all relative to comparable flows, which is consistent with the conventions of the field.

[0022] Any column or tower mentioned in the following description is by way of non-limiting example only and may be a spray tower, a packed tower, and / or a plate tower.

[0023] To provide context for other features, reference numerals introduced in connection with a particular drawing in the specification may be reused in one or more subsequent drawings for the same element or component without further description in the specification.

[0024] In the claims, letters are used to identify the claimed steps (e.g., a., b., and c.). These letters are used to help indicate the method steps and are not intended to indicate the order in which the claimed steps are performed, unless and only to the extent that such order is specifically recited in the claims.

[0025] Embodiments of the processes and methods disclosed herein separate a CO2-containing process gas stream into a liquid CO2 stream of arbitrary purity (including beverage-grade CO2) and a CO2-lean stream containing other light gases. In the case of processing flue gas streams, the light gases may include N2, O2, and Ar; in the case of processing producer gas or syngas streams, the light gases may include H2, CO, and possibly CH4; and in the case of processing hydrogen production streams, the light gases may include H2.

[0026] exist Figure 2 In one embodiment of the system and method of this disclosure, the LNG stream from storage tank 40 may be supplied directly or via pump 42 to cryogenic carbon capture system 44. Although a storage tank for LNG is illustrated, cryogenic carbon capture system 44 may receive LNG from another source or another type of storage facility.

[0027] The cryogenic carbon capture system 44 receives flue gas 46 from a combustion source, which contains CO2 and light gases such as nitrogen. As described in more detail below, the cryogenic carbon capture system 44 uses the cooling capacity (refrigeration) provided by LNG to separate the flue gas 46 into a CO2 stream 48 and a light gas stream 50. The resulting gasified natural gas exits the cryogenic carbon capture system 44 as a stream 52. If stream 52 is not completely gasified, additional heating can be provided by a heat exchanger 54. Alternatively, the natural gas fluid stream can be expanded by an expansion device 56 to reduce the pressure of the stream. By way of example only, the expansion device 56 may be a turbine.

[0028] exist Figure 2 In the cryogenic carbon capture system 44, the flue gas stream 46, after initial treatment including cooling, proceeds to a direct contact sublimation heat exchanger, which may use LNG. In this direct contact sublimation heat exchanger, CO2 is captured by further cooling to the temperature required to capture the designed amount of CO2 as a condensed phase in the contact liquid using a cryogenic contact liquid stream 62. The required temperature depends on the amount of CO2 in the process gas, the desired capture rate, and the type and initial CO2 load of the contact liquid. As an example only, for a process gas stream containing 16% CO2 and a typical hydrocarbon contact liquid, this temperature can be approximately -106°C to achieve 90% capture. The gaseous CO2 in the flue gas stream 46 condenses in the contact liquid stream 62 as absorbed gas, sublimated solids, or a combination of both, forming a slurry stream.

[0029] By way of example only, contact fluids 62 and 64 can be any fluid whose freezing point is below the frost point or dew point of the condensable vapor and which is non-volatile or has low volatility. Low volatility minimizes the amount of contact fluid escaping from the direct contact sublimation heat exchanger, thereby minimizing environmental impact and cost. Examples of suitable contact fluids include, but are not limited to, methylcyclopentane, methylcyclohexane, various fluorinated or chlorinated hydrocarbons, or any compound or solution, including mixtures of these compounds, that has a low vapor pressure at system operating temperatures, has controllable viscosity, and does not present material incompatibility or uncontrollable health and safety issues.

[0030] exist Figure 2In the low-temperature carbon capture system 44, a light gas stream is separated from the slurry stream and exits the sublimation heat exchanger and the low-temperature carbon capture system 44 as a light gas stream 50. CO2 is separated from the slurry stream in the separation unit, melted (while in the solid phase), and exits the low-temperature carbon capture system 44 as a condensed CO2 stream 48. After CO2 removal, the heated contact liquid stream exits the separation unit of the low-temperature carbon capture system 44 as a stream 64.

[0031] Figure 2 Further details of an example of a cryogenic carbon capture system 44 are disclosed in U.S. Patent No. 8,764,885, jointly assigned to Baxter et al., the contents of which are incorporated herein by reference. Furthermore, regarding... Figure 2 Further details of the cryogenic carbon capture system 44 are provided in U.S. Patent No. 10,724,793, jointly owned by Baxter, the contents of which are incorporated herein by reference.

[0032] According to the technology disclosed herein, the heated contact liquid flow 64 is directed to an indirect contact heat exchanger 66, which is cooled by an LNG flow from the storage tank 40 until the temperature required to capture the designed amount of CO2 is reached.

[0033] exist Figure 3 In the system, Figure 2 An LNG heater 72 is added to the system. The LNG heater may be needed to heat the LNG from tank 40 to prevent the contact liquid in heat exchanger 66 from freezing. For example, the LNG leaving tank 40 may be at -160°C, while the freezing point of the contact liquid flow 64 may be -120°C. The LNG heater 72 can heat the LNG to a temperature slightly above the freezing point of the contact liquid flow 64. The flow rate of the contact liquid in heat exchanger 66 should also be maintained at a sufficient level to prevent freezing within heat exchanger 66.

[0034] By way of example only, the LNG heater 72 can use ambient air to heat the LNG stream, or it can be an electric heater.

[0035] exist Figure 4 In the system, Figure 2 and Figure 3 The function of heat exchanger 66 can be distributed between the first heat exchanger 74 and the second heat exchanger 76. More specifically, the heated contact liquid flow 64 is directed to indirect contact heat exchangers 74 and 76, where it is cooled by the LNG flow from tank 40 until it reaches the temperature required for the design amount of CO2 capture. To prevent the contact liquid 64 from freezing in the cooler heat exchanger 74, a ceramic sleeve can be provided to insulate the contact liquid passage from the LNG. Alternatively, ceramic insulation can be provided for the LNG passage of heat exchanger 74 to reduce heat transfer from the contact liquid flow.

[0036] exist Figure 4 In an alternative embodiment of the system, the intermediate fluid may pass through a first heat exchanger 74 and a second heat exchanger 76, and the resulting cooled intermediate fluid may be used to cool the contact liquid used in the cryogenic carbon capture process 44 via an indirect contact heat exchanger.

[0037] Reference Figure 5 The illustration shows in more detail one embodiment of the system and method of this disclosure, in which pretreated flue gas, as process gas 100, is directed to a precooling heat exchanger, such as a cooling tower 102; by way of example only, the cooling tower 102 may be a direct-contact cooling tower that uses a chilled water flow 104 to provide cooling. The precooling tower 102 cools the process gas flow 100 to slightly above 0°C (by way of example only). The resulting cooled flow is directed to a blower 106, such as a compressor. After leaving the blower 106, the pressurized process gas flow passes through a second heat exchanger, such as a second cooling tower 108, which is cooled by a water flow 112.

[0038] The cooled and pressurized process stream 114, exiting the second cooling tower 108, proceeds to a desiccant dryer 116, where moisture is recovered from the process gas. The resulting dried process gas stream exits the dryer as stream 118. A CO2-depleted "clean" light gas stream is also formed and exits the dryer as clean light gas stream 122.

[0039] Suitable desiccant dryers are well known in the art. By way of example only, desiccant dryer 116 may employ the technology disclosed in U.S. Patent Application Publication No. 2019 / 0128604 (U.S. Patent Application No. 15 / 795,953) granted to Baxter et al., the contents of which are incorporated herein by reference.

[0040] Cooling water for cooling towers 102 and 108 enters the system as stream 124 and is cooled in a heat exchanger, for example, cooling tower 126. Cooling within cooling tower 126 is provided by a cooled light gas stream 128, the manner of which will be described below. The heated clean light gas stream exits cooling tower 126 as stream 132 and merges with the clean light gas stream 122 exiting desiccant dryer 116; the resulting combined stream exits the system.

[0041] The drying process gas stream 118 leaving the desiccant dryer 116 is directed to a multi-stream precooling heat exchanger 134, where it is further cooled, preferably to near its frost point (typically -95 to -105°C).

[0042] The resulting pre-cooled process stream 136 is directed to a direct-contact sublimation heat exchanger, such as a cooling tower 140, where the process gas stream is further cooled to the temperature required to capture the designed amount of CO2 as a condensate phase in the contact liquid using a cryogenic contact liquid stream 142, thereby capturing CO2. The required temperature depends on the amount of CO2 in the process gas, the desired capture rate, and the type of contact liquid and initial CO2 load, and by way of example only, for a process gas stream containing 16% CO2 and a typical hydrocarbon contact liquid, this temperature is typically around -106°C to achieve 90% capture. The gaseous CO2 in the further cooled process gas stream condenses in the contact liquid stream 142 as absorbed gas, sublimated solids, or a combination of both, forming a slurry stream 144. At this stage, all other components below their dew point / frost point may also condense, which typically includes most components that are less volatile than CO2, including most contaminants and other impurities (NO2, SO2, SO3, Hg, VOCs, PCHs).

[0043] As previously stated, and by way of example only, the direct contact condensation heat exchanger 140 may employ the technology disclosed in U.S. Patent No. 8,764,885, which was jointly assigned to Baxter et al., the contents of which are incorporated herein by reference.

[0044] CO2-deficient process gas stream 146 (i.e., “clean” flue gas) exits from the top of sublimation heat exchanger 140 and splits into streams 148a and 148b, both of which pass through precooling heat exchanger 134 and are heated therein to provide cooling. The heated clean light gas stream 148a exits precooling heat exchanger 134 as clean light gas stream 128 and is directed to cooling water cooling tower 126 to provide cooling (refrigeration) therein as previously described. Stream 148b, after being heated in heat exchanger 134, is directed through regenerated gas heater 149, where it is further heated, and then directed to desiccant dryer 116 to remove moisture.

[0045] The CO2-carrying slurry stream 144 is pumped by a cryogenic pump 145 to contact liquid cooling heat exchangers 150 and 152, where it is cooled, and then exits the second heat exchanger 152 as a cooled slurry stream 154.

[0046] The cooled slurry stream 154 is pumped by slurry pump 156 to screw press 158 or other solids separation device, where solid CO2 is separated from the contact liquid, thereby forming a solid CO2 stream 160 and a purified contact liquid stream 162. The purified contact liquid stream 162 may be combined with a portion of the cooled slurry stream 154 and guided as contact liquid stream 142 to direct contact sublimation heat exchanger 140.

[0047] Alternative solid separation devices can be used to replace the screw press 158, including but not limited to filters or cyclones.

[0048] Solid CO2 stream 160 is directed to a melter, such as an indirect contact heat exchanger 164, and the resulting liquid CO2 stream is pumped by a melter pump 166 to a multi-stream product heat exchanger 170, where it is cooled. The resulting cooled liquid CO2 stream 172 is directed to a CO2 refining tower 174.

[0049] The contact liquid is further removed from the CO2 in stream 172, and this contact liquid exits the CO2 purification column 174 as contact liquid stream 176. Contact liquid stream 176 is cooled in product heat exchanger 170, and the resulting stream is expanded via expansion device 182. By way of example only, expansion device 182 may be a Joule-Thomson (JT) valve. The expanded stream exits expansion device 182 and flows into contact liquid purification column 184.

[0050] Carbon dioxide vapor stream 186 exits from the top of contact liquid purification column 184 and is compressed in compressor 194 after passing through heat exchanger 192. The compressed CO2 stream exiting compressor 194 is cooled in heat exchanger 192 (by stream 186), and the resulting cooled stream 196 is directed to CO2 stream 198, which is then directed into CO2 purification column 174.

[0051] Contact liquid flow 202 flows out from the bottom of contact liquid refining tower 184 and is cooled in product heat exchanger 170 to form cooled contact liquid flow 204. Cooled contact liquid flow 204 merges with slurry flow exiting slurry pump 146, and the merged flow is guided to first heat exchanger 150 and second heat exchanger 152 for cooling.

[0052] CO2 vapor stream 206 exits from the top of CO2 refining column 174 and proceeds to melter 164 to provide the heat required to melt CO2 solid stream 160 from screw press 158. The resulting cooled CO2 stream is further cooled in LNG vaporizer heat exchanger 212 and then directed to flash tank 214. The resulting CO2 vapor stream 216 exits from the top of flash tank 214 and is directed to sublimation heat exchanger 140. CO2 liquid stream 218 exits from the bottom of flash tank 214 and is directed back to CO2 refining column 174.

[0053] CO2 liquid product stream 222 exits CO2 purification tower 174 and is guided by pump 224 through product heat exchanger 170 for cooling. This forms cooled CO2 liquid product stream 226, which is then directed out of the system.

[0054] The following will describe an embodiment of the present disclosure. Figure 5The system is cooled by a liquefied natural gas (LNG) stream 232, which can be pumped by pump 234 or otherwise supplied by a storage tank or other source. The LNG stream 232 passes through heat exchangers 150 and 152 for cooling, forming a heated LNG stream 236. The resulting vaporized (or partially vaporized) natural gas stream 236 exits heat exchanger 170.

[0055] After leaving heat exchanger 152, LNG stream 236 is split into LNG streams 238, 240 and 242.

[0056] LNG stream 238 passes through product heat exchanger 170 for cooling. The resulting vaporized (or partially vaporized) natural gas stream 250 exits heat exchanger 170.

[0057] LNG stream 240 splits into streams 244 and 246, both flowing towards precooling heat exchanger 134. Stream 246 is heated in precooling heat exchanger 134, and the resulting heated LNG stream 248 leaves the heat exchanger and merges with the LNG stream leaving heat exchanger 150. LNG stream 244 is also heated in precooling heat exchanger 134, and the resulting heated LNG stream 252 leaves the heat exchanger.

[0058] LNG stream 242 passes through heat exchanger 212 and is cooled therein, resulting in a heated stream 254 that merges with streams 250 and 252 to form a combined stream 256. If the combined stream 256 still contains liquid, or if a higher temperature natural gas stream is desired, the combined stream 256 can be heated by heater 260. Natural gas stream 258 can then flow directly out of the system, or it can be expanded first via expansion device 262; by way of example only, expansion device 262 could be a turbine.

[0059] exist Figure 6 In an alternative embodiment of the system and method of this disclosure, the system precooling heat exchanger 302 (which replaces...) Figure 5 No LNG cooling is provided in the precooling heat exchanger 134. Instead, the drying process gas stream 118 exiting the desiccant dryer 116 is cooled only by the clean, light gas stream 304 from the sublimation heat exchanger 140 in the precooling heat exchanger 302. More specifically, in Figure 6 In this embodiment, a clean, light gas stream 146 exits from the top of the heat exchanger 140 and is heated in the heater 306. The resulting stream 304 is then directed to a pre-cooling heat exchanger 302 where it is cooled, and then exits as a further heated stream 308.

[0060] The clean, light gas stream 308 is split to form streams 310 and 312. Figure 5Similar to the system described above, stream 310 is heated in heater 149 and then directed to desiccant dryer 116. Stream 312 is directed to cooling water cooling tower 126 to provide cooling therein.

[0061] Figure 6 The system and Figure 5 The system also differs in that a single contact liquid cooling heat exchanger 150, which receives LNG stream 232 to provide cooling, is included in a cooling loop that receives slurry from slurry pump 145 and cooling contact liquid stream 204 from product heat exchanger 170. Figure 5 The contact liquid cooling heat exchanger 152 is omitted.

[0062] Except as otherwise provided above, Figure 6 The system and Figure 5 The system is the same.

[0063] Although preferred embodiments of the present disclosure have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made thereto without departing from the spirit of the present disclosure, the scope of which is defined by the appended claims.

Claims

1. A system for separating carbon dioxide from process gas, comprising: a. A precooling heat exchanger configured to receive and cool a process gas stream, thereby forming a cooled process gas stream; b. A sublimation heat exchanger, the sublimation heat exchanger including a process gas inlet configured to receive the cooled process gas flow from the precooling heat exchanger, the sublimation heat exchanger further including a clean gas outlet, a contact liquid inlet and a slurry outlet; c. A contact liquid heat exchanger, which is in fluid communication with the contact liquid inlet of the sublimation heat exchanger and is configured to receive and heat a stream of liquefied natural gas to provide cooling within the contact liquid heat exchanger; d. The sublimation heat exchanger is configured to contact the cooled process gas stream received from the precooling heat exchanger with a contact liquid cooled by the contact liquid heat exchanger, such that carbon dioxide is absorbed in the contact liquid, thereby forming a carbon dioxide-laden slurry stream and a carbon dioxide-depleted clean process gas stream, wherein the clean process gas stream is directed to the precooling heat exchanger via the clean gas outlet, and the slurry stream is directed via the slurry outlet. e. The precooling heat exchanger is configured to heat the clean process gas stream in order to provide cooling for the process gas stream; f. A solids separation device, which is in fluid communication with the contact inlet of the sublimation heat exchanger and is configured to receive the carbon dioxide-laden slurry stream from the slurry outlet of the sublimation heat exchanger and separate the slurry stream into a condensed carbon dioxide stream and a contact liquid stream.

2. The system according to claim 1, wherein, The solids separation device is configured to direct the contact liquid flow to the contact liquid heat exchanger, and the contact liquid heat exchanger is configured to cool the contact liquid flow by heating the liquefied natural gas flow.

3. The system according to claim 1, wherein, The contact liquid heat exchanger is configured to receive the slurry stream from the slurry outlet of the sublimation heat exchanger, cool the slurry stream by heating the liquefied natural gas stream, and guide the cooled slurry stream to the solids separation unit.

4. The system of claim 1 further includes a liquefied natural gas heater, the liquefied natural gas heater being configured to receive a natural gas stream or a partially vaporized liquefied natural gas stream from the contact liquid heat exchanger.

5. The system of claim 4 further includes a liquefied natural gas (LNG) expansion device configured to receive heated fluid from the LNG heater.

6. The system of claim 1 further includes a liquefied natural gas (LNG) expansion device configured to receive a natural gas stream or a partially vaporized LNG stream from the contact liquid heat exchanger.

7. The system according to claim 1 further includes a liquefied natural gas source in fluid communication with the contact liquid heat exchanger.

8. The system of claim 7 further includes a liquefied natural gas pump configured to direct liquefied natural gas from the liquefied natural gas source to the contact liquid heat exchanger.

9. The system of claim 7 further includes an upstream liquefied natural gas heater, the upstream liquefied natural gas heater being configured to heat the liquefied natural gas as it is transported from the liquefied natural gas source to the contact heat exchanger.

10. The system according to claim 1, wherein, The contact liquid heat exchanger includes a first contact liquid heat exchanger and a second contact liquid heat exchanger.

11. The system according to claim 10, wherein, The first contact liquid heat exchanger is located upstream of the second contact liquid heat exchanger, and the first contact liquid heat exchanger includes a ceramic insulation element configured to insulate the contact liquid from the liquefied natural gas.

12. The system according to claim 1, wherein, The precooling heat exchanger is also configured to receive and heat the liquefied natural gas stream to provide cooling for the process gas stream.

13. The system according to claim 12, wherein, The contact liquid heat exchanger and the precooling heat exchanger receive a stream of liquefied natural gas from a common source.

14. A system for separating carbon dioxide from process gas, comprising: a. A precooling heat exchanger configured to receive and cool a process gas stream, thereby forming a cooled process gas stream; b. A sublimation heat exchanger, the sublimation heat exchanger including a process gas inlet configured to receive the cooled process gas flow from the precooling heat exchanger, the sublimation heat exchanger further including a clean gas outlet, a contact liquid inlet and a slurry outlet; c. Contact liquid heat exchanger; d. A solids separation device configured to direct the contact liquid to the contact liquid inlet of the sublimation heat exchanger; e. The sublimation heat exchanger is configured to contact the cooled process gas stream received from the precooling heat exchanger with a contact liquid from the solids separation unit, such that carbon dioxide is absorbed in the contact liquid, thereby forming a carbon dioxide-laden slurry stream and a carbon dioxide-depleted clean process gas stream, wherein the clean process gas stream is directed to the precooling heat exchanger via the clean gas outlet, and the slurry stream is directed to the contact liquid heat exchanger via the slurry outlet. f. The precooling heat exchanger is configured to heat the clean process gas stream in order to provide cooling for the process gas stream; g. The contact liquid heat exchanger is configured to receive and heat the liquefied natural gas stream to cool the slurry stream, and the contact liquid heat exchanger is also configured to guide the cooled slurry stream to the solids separation device; h. The solid separation device is configured to separate the carbon dioxide-carrying slurry stream into a condensed carbon dioxide stream and a contact liquid stream.

15. The system according to claim 14, wherein, The precooling heat exchanger is also configured to receive and heat the liquefied natural gas stream to provide cooling for the process gas stream.

16. The system according to claim 15, wherein, The contact liquid heat exchanger and the precooling heat exchanger receive a stream of liquefied natural gas from a common source.

17. The system according to claim 14, wherein, The separation device is a screw press.

18. The system of claim 14, further comprising a product heat exchanger in fluid communication with the solids separation device and configured to receive a carbon dioxide stream, the product heat exchanger being further configured to receive and heat a liquefied natural gas stream to cool the received carbon dioxide stream.

19. The system of claim 18 further includes a melter configured to receive and melt a stream of solid carbon dioxide from the solid separation device and direct the resulting liquid carbon dioxide stream to the product heat exchanger.

20. A method for separating carbon dioxide from a process gas, comprising: a. Pre-cooling the process gas stream by heating the clean process gas stream, thereby forming a cooled process gas stream; b. A cooled contact liquid flow is formed by heating the liquefied natural gas stream to cool the contact liquid; c. Contact the cooled process gas stream with the cooled contact liquid stream, so that carbon dioxide is absorbed into the contact liquid, thereby forming a carbon dioxide-carrying slurry stream and a carbon dioxide-depleted clean process gas stream, wherein the clean process gas stream is heated in step a. d. Separate the slurry flow into a condensed carbon dioxide flow and a contact liquid flow.

21. The method according to claim 20, wherein, The contact fluid flow in step d is cooled in step b.

22. The method according to claim 20, wherein, Step a. includes heating the liquefied natural gas stream.

23. The method according to claim 22, wherein, The liquefied natural gas streams described in steps a. and b. originate from a common source.

24. The method of claim 20, wherein, Step b. includes cooling the slurry flow of step c.

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