Apparatus and method for processing carbon dioxide generated by an engine

Abstract

An apparatus and a method for processing carbon dioxide generated by an engine are disclosed. A first absorption unit is configured to receive an exhaust gas from the engine and receive a first lean solvent for absorbing the carbon dioxide from the exhaust gas to generate a first rich solvent. Further, a desorption unit is fluidically connected to the first absorption unit. The desorption unit receives a portion of the first rich solvent and segregates the absorbed carbon dioxide from the portion of the first rich solvent to generate a desorbed lean solvent. A second absorption unit is fluidically connected to the desorption unit. The second absorption unit receives the segregated carbon dioxide from the desorption unit and receives a second lean solvent for absorbing the segregated carbon dioxide to generate a second rich solvent.

Description

APPARATUS AND METHOD FOR PROCESSING CARBON DIOXIDE GENERATED BY AN ENGINETECHNICAL FIELD

[0001] The present disclosure relates to an apparatus for processing carbon dioxide generated by an engine, a method for processing carbon dioxide generated by an engine, and a marine vessel including the apparatus.BACKGROUND

[0002] Carbon dioxide (CO2) is a greenhouse gas commonly present in exhaust gases resulting from a variety of combustion processes burning carbon-based fuels. It is prudent to remove the carbon dioxide from the exhaust gas before discharging it into the atmosphere, as the presence of carbon dioxide in the atmosphere contributes to the greenhouse effect, climate change, and air pollution, among other issues. Traditionally, solvent-based carbon dioxide capture techniques are used to capture carbon dioxide emissions from industrial processes, such as power plants, refineries, cement production, and other industrial facilities. It involves the use of chemical solvents to selectively absorb carbon dioxide from flue gas streams (or the exhaust) before it is released into the atmosphere. However, in the traditional approach, the regeneration process requires significant energy input, primarily in the form of heat. This leads to an increase in operating costs, reduces overall efficiency, and may increase parasitic emissions.

[0003] Further, the process of carbon dioxide reliquefaction and carbon dioxide storage under pressure and low temperature is required for efficient and safe storage. The reliquefaction and carbon dioxide storage require secure design, operation, and monitoring to ensure the safety, integrity, and effectiveness of carbon dioxide storage facilities. However, reliquefaction and carbon dioxide storage under pressure and low temperature, particularly in the context of storing carbon dioxide captured from industrial processes using solvent-based systems incur several challenges. In particular, reliquefaction and carbon dioxide storage are energy-intensive processes that result in increased operating costs, reduced overall efficiency, and may increase parasitic emissions. Further, achieving and maintaining the required pressures and temperatures of carbon dioxide requires sophisticated process equipment, instrumentation, and control systems. Therefore, there is a need for a cost-effective and efficient system and method for processing carbon dioxide present in the flue gas.SUMMARY

[0004] In order to solve the foregoing problem and to provide other advantages, one aspect of the present disclosure is to provide an apparatus for processing carbon dioxide generated by an engine. The apparatus includes a first absorption unit. The first absorption unit is configured to receive an exhaust gas from the engine and receive a first lean solvent for absorbing the carbon dioxide from the exhaust gas to generate a first rich solvent including the absorbed carbon dioxide. The apparatus further includes a desorption unit. The desorption unit is fluidically connected or connectable to the first absorption unit. The desorption unit is configured to receive at least a portion of the first rich solvent. The desorption unit segregates the absorbed carbon dioxide from the portion of the first rich solvent to generate a desorbed lean solvent. Further, the apparatus includes a second absorption unit. The second absorption unit is fluidically connected or connectable to the desorption unit. The second absorption unit is configured to receive the segregated carbon dioxide from the desorption unit. Further, the second absorption unit receives a second lean solvent to absorb the segregated carbon dioxide for generating a second rich solvent.The utilization of two absorbers (i.e., the first absorption unit and the second absorption unit) reduces the size of the absorbers. Advantageously, in cases where only a portion of the first rich solvent is provided to the desorption unit, a smaller size of the desorption unit can be used. Advantageously, the use of two absorbers enables a reduction of the reaction time at the second absorption unit. Further, as the second absorption unit is provided with the segregated carbon dioxide having an increased concentration of carbon dioxide, a higher absorption rate of the carbon dioxide by the second lean solvent can be achieved, thereby providing increased carbon dioxide storage capacity per mass or volume. In other words, the second absorption unit increases the saturation level of the carbon dioxide in the second lean solvent to form the second rich solvent which allows for more efficient carbon dioxide storage. For example, the first rich solvent generated by the first absorption unit may be saturated up to 50%. Further, the second lean solvent in the second absorption unit absorbs the segregated carbon dioxide in the second absorption unit to generate the second rich solvent. For example, the saturation level of the second rich solvent is further increased to a higher value above 50%. Hence, the solvent for the storage of carbon dioxide is minimized.

[0005] In an aspect of the apparatus, the first absorption unit is further configured to receive the first lean solvent and the desorbed lean solvent for absorbing the carbon dioxide from the exhaust gas to generate the first rich solvent. Advantageously, by regenerating the solvent (or generatingthe desorbed lean solvent), the apparatus can operate continuously, efficiently, and cost- effectively. This ensures the capture of the target gases (i.e., carbon dioxide) while minimizing solvent usage.

[0006] In an aspect, the apparatus includes a valve assembly. The valve assembly is configured to distribute a first portion of the first rich solvent to the desorption unit and a second portion of the first rich solvent to the second absorption unit or a rich solvent storage. Advantageously, the valve assembly allows operators to control the flow of the solvent (e.g., the first rich solvent) between the first absorption unit, the second absorption unit, and the desorption unit. This control is essential for managing the distribution of solvent to the second absorption unit and the desorption unit for allowing the regeneration of the captured gases (i.e., carbon dioxide). Further, by controlling the flow of the first rich solvent between the first absorption unit, the second absorption unit, and the desorption unit, operators can optimize solvent utilization and reduce operating costs associated with solvent replenishment and disposal.

[0007] In an aspect, the second portion of the first rich solvent is split into a first stream and a second stream for providing the first steam to the second absorption unit and the second stream to the rich solvent storage. Advantageously, the first stream of the second portion of the first rich solvent in the second absorption unit is further enriched by absorbing the carbon dioxide circulating in the second absorption unit. It is to be noted that the partial pressure of the carbon dioxide in the second absorption unit is maintained at the predefined partial pressure (or high partial pressure) resulting in further enrichment of the stream of the second portion of the first rich solvent. This way of capturing the carbon dioxide results in optimization of solvent utilization (i.e. capture carbon dioxide with minimum solvent usage) and reduces operating costs.

[0008] In an aspect, the apparatus includes a mixing unit. The mixing unit is fluidically connected or connectable to the valve assembly and the second absorption unit. The mixing unit is configured to mix the second portion of the first rich solvent and the second lean solvent to generate a mixed solvent to be supplied to the second absorption unit. Further, the second absorption unit is configured to receive the mixed solvent for absorbing the carbon dioxide and to generate the second rich solvent. Advantageously, the mixing unit is configured to generate the mixed solvent by diluting the second portion of the first rich solvent with the second lean solvent. The mixed solvent is used for further absorption of the carbon dioxide circulating in the secondabsorption unit. It is to be noted that the diluted solvent (i.e., the mixed solvent) supplied to the second absorption unit results in maximizing the efficiency of solvent utilization in the apparatus.

[0009] In an aspect, the apparatus includes a cooler. The cooler is fluidically connected or connectable to the valve assembly, a lean solvent storage, and the second absorption unit. The cooler is configured to adjust temperature of the second portion of the first rich solvent received from the valve assembly based on a threshold temperature for supplying the second portion of the first rich solvent to the second absorption unit. Advantageously, the cooler reduces the temperature of the second portion of the first rich solvent which increases the absorption efficiency of the second portion of the first rich solvent. This enables further enrichment of the second portion of the first rich solvent by absorbing the segregated carbon dioxide in the second absorption unit.

[0010] In an aspect, the apparatus includes a compressor device. The compressor device is fluidically connected or connectable to the desorption unit and the second absorption unit. The compressor device is configured to adjust pressure of the segregated carbon dioxide received from the desorption unit based at least on a predefined partial pressure. The segregated carbon dioxide maintained at the predefined partial pressure is supplied to the second absorption unit. Advantageously, the carbon dioxide is absorbed by the second lean solvent based on the predefined partial pressure. In particular, the predefined partial pressure (or the high partial pressure) of the segregated carbon dioxide in the second absorption unit enhances the absorption efficiency, thereby enabling the second lean solvent to absorb the carbon dioxide. To that effect, the size of the second absorption unit is reduced thus reducing the capital costs. Further, the increase in the partial pressure leads to efficient use of the solvent’s (i.e., the second lean solvent) capacity and possibly reduces the operational costs.

[0011] In an aspect of the apparatus, the desorption unit comprises at least one thermal system to provide thermal energy for segregating the absorbed carbon dioxide from the first rich solvent. The at least one thermal system heats the first rich solvent to create a high concentration of the carbon dioxide stream that allows for the higher partial pressure in the second absorption unit. Further, the reduction of the reaction time increases the efficiency of the apparatus.

[0012] In an aspect of the apparatus, the second lean solvent includes Monoethanolamine (MEA) or Methyldiethanolamine (MDEA) of a predefined weight percentage.

[0013] Another aspect of the present disclosure is to provide a method for processing the carbon dioxide generated by an engine. The method includes receiving, by a first absorption unit, an exhaust gas from the engine. The method further includes receiving, by the first absorption unit, a first lean solvent for absorbing the carbon dioxide from the exhaust gas to generate a first rich solvent. Further, the method includes receiving, by a desorption unit, at least a portion of the first rich solvent. The method further includes segregating, by desorption unit, the absorbed carbon dioxide from the portion of the first rich solvent to obtain a desorbed lean solvent. The method further includes receiving, by a second absorption unit, the segregated carbon dioxide from the desorption unit, and a second lean solvent. The second lean solvent absorbs the segregated carbon dioxide to generate a second rich solvent. Advantageously, this enables efficient stripping off the carbon dioxide from the exhaust gas without additional energy demand or energy demand that matches the availability of heat for a heat source. The utilization of two absorbers (i.e. , the first absorption unit and the second absorption unit) reduces the size of the absorbers. In addition, the utilization of the first absorption unit and the second absorption unit reduces the size of the desorption unit as only a part of the first rich solvent is supplied to the desorption unit. Finally, the second absorption unit ensures perfect / optimal conditions to obtain the maximum enrichment / saturation level of the solvent. In other words, the second absorption unit increases the saturation level of the carbon dioxide in the second lean solvent to form the second rich solvent which allows for more efficient carbon dioxide storage. For example, the first rich solvent generated by the first absorption unit may be saturated up to 50%. Further, the second lean solvent in the second absorption unit absorbs the segregated carbon dioxide in the second absorption unit to generate the second rich solvent. Typically, the second rich solvent is fully saturated / enriched (up to 100%). Hence, the solvent for the storage of carbon dioxide is minimized.

[0014] In an aspect, the method includes receiving, by the first absorption unit, the first lean solvent and the desorbed lean solvent for absorbing the carbon dioxide from the exhaust gas to generate the first rich solvent. Advantageously, by regenerating the solvent (or generating the desorbed lean solvent), the apparatus can operate continuously, efficiently, and cost-effectively. This ensures the capture of the target gases (i.e., carbon dioxide) while optimizing solvent usage by high enrichment / saturation level.

[0015] In an aspect, the method includes distributing, by a valve assembly, a first portion of the first rich solvent to the desorption unit and a second portion of the first rich solvent to the secondabsorption unit or a rich solvent storage unit. Advantageously, the valve assembly allows operators to control the flow of the solvent (e.g., the first rich solvent) between the first absorption unit, the second absorption unit, and the desorption unit. This control is essential for managing the distribution of solvent to the second absorption unit and the desorption unit for allowing the regeneration of the captured gases (i.e., carbon dioxide). Further, by controlling the flow of the first rich solvent between the first absorption unit, the second absorption unit, and the desorption unit, operators can optimize solvent utilization and reduce operating costs associated with solvent replenishment and disposal.

[0016] In an aspect, the method includes splitting the second portion of the first rich solvent into a first stream and a second stream for providing the first stream to the second absorption unit and the second stream to the rich solvent storage. Advantageously, the first stream of the second portion of the first rich solvent in the second absorption unit is further enriched by absorbing the carbon dioxide circulating in the second absorption unit. It is to be noted that the partial pressure of the carbon dioxide in the second absorption unit is maintained at the predefined partial pressure (or high partial pressure) resulting in further enrichment of the stream of the second portion of the first rich solvent. This way of capturing the carbon dioxide results in optimization of solvent utilization (i.e. capture carbon dioxide with minimum solvent usage) and reduces operating costs.

[0017] In an aspect, the method includes mixing, by a mixing unit, the second portion of the first rich solvent and the second lean solvent to generate a mixed solvent to be supplied to the second absorption unit. Further, the method includes receiving, by the second absorption unit, the mixed solvent for absorbing the carbon dioxide and generating the second rich solvent. Advantageously, the mixing unit is configured to generate the mixed solvent by diluting the second portion of the first rich solvent with the second lean solvent. The mixed solvent is used for further absorption of the carbon dioxide circulating in the second absorption unit. It is to be noted that the diluted solvent (i.e., the mixed solvent) supplied to the second absorption unit results in maximizing the efficiency of solvent utilization in the apparatus.

[0018] In an aspect, the method includes receiving, by a cooler, the second portion of the first rich solvent from the valve assembly and the second lean solvent from the lean solvent storage. Further, the method includes adjusting, by the cooler, temperature of the second portion of the first rich solvent to a threshold temperature for supplying the second portion of the first rich solvent to the second absorption unit. Advantageously, the cooler reduces the temperature of the secondportion of the first rich solvent which increases the absorption efficiency of the second portion of the first rich solvent. This enables further enrichment of the second portion of the first rich solvent by absorbing the segregated carbon dioxide in the second absorption unit.

[0019] In an aspect, the method includes receiving, by a compressor device, the segregated carbon dioxide from the desorption unit. Further, the method includes adjusting, by the compressor device, pressure of the segregated carbon dioxide from the desorption unit based at least on a predefined partial pressure. The segregated carbon dioxide maintained at the predefined partial pressure is supplied to the second absorption unit. Advantageously, the carbon dioxide is absorbed by the second lean solvent based on the predefined partial pressure. In particular, the predefined partial pressure (or the high partial pressure) of the segregated carbon dioxide in the second absorption unit enhances the absorption efficiency, thereby enabling the second lean solvent to absorb the carbon dioxide. To that effect, the size of the second absorption unit is reduced which can lower the capital costs. Further, the increase in the partial pressure leads to efficient use of the solvent’s (i.e., the second lean solvent) capacity and possibly reduces the operational costs.

[0020] Another aspect of the present disclosure is to provide a marine vessel. The marine vessel includes an engine and an apparatus for processing carbon dioxide generated by the engine. The apparatus includes a first absorption unit. The first absorption unit is configured to receive an exhaust gas from the engine and receive a first lean solvent for absorbing the carbon dioxide from the exhaust gas to generate a first rich solvent including the absorbed carbon dioxide. The apparatus further includes a desorption unit. The desorption unit is fluidically connected or connectable to the first absorption unit. The desorption unit is configured to receive at least a portion of the first rich solvent. The desorption unit segregates the absorbed carbon dioxide from the portion of the first rich solvent to generate a desorbed lean solvent. Further, the apparatus includes a second absorption unit. The second absorption unit is fluidically connected or connectable to the desorption unit. The second absorption unit is configured to receive the segregated carbon dioxide from the desorption unit. Further, the second absorption unit receives a second lean solvent to absorb the segregated carbon dioxide for generating a second rich solvent.The utilization of two absorbers (i.e., the first absorption unit and the second absorption unit) reduces the size of the absorbers and ensures optimized space utilization in the marine vessel. Advantageously, in cases where only a portion of the first rich solvent is provided to the desorption unit, a smaller size of the desorption unit can be used. Advantageously, the use of twoabsorbers enables a reduction of the reaction time at the second absorption unit. Further, as the second absorption unit is provided with the segregated carbon dioxide having an increased concentration of carbon dioxide, a higher absorption rate of the carbon dioxide by the second lean solvent can be achieved, thereby providing increased carbon dioxide storage capacity per mass or volume. In other words, the second absorption unit increases the saturation level of the carbon dioxide in the second lean solvent to form the second rich solvent which allows for more efficient carbon dioxide storage. For example, the first rich solvent generated by the first absorption unit may be saturated up to 50%. Further, the second lean solvent in the second absorption unit absorbs the segregated carbon dioxide in the second absorption unit to generate the second rich solvent. For example, the saturation level of the second rich solvent is further increased to a higher value above 50%. Hence, the solvent for the storage of carbon dioxide is minimized.BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other features and advantages of the present disclosure will become readily apparent to those skilled in the art by the following detailed description of exemplary embodiments thereof with reference to the attached drawings, in which:

[0022] FIG. 1A illustrates a schematic representation of an environment related to various embodiments of the present disclosure;

[0023] FIG. 1 B illustrates a schematic representation of the environment of FIG. 1 A depicting the coupling of a compressor device between a second absorption unit and a desorption unit, in accordance with an embodiment of the present disclosure;

[0024] FIG. 1C illustrates a schematic representation of an apparatus of FIG. 1A equipped in a marine vessel for absorbing carbon dioxide emissions of the marine vessel, in accordance with an embodiment of the present disclosure;

[0025] FIG. 2A illustrates a schematic representation of the environment of FIG. 1A depicting a fluidic coupling between a heat exchanger and a first absorption unit via a valve assembly and routing a second portion of a first rich solvent to a rich solvent storage, in accordance with an embodiment of the present disclosure;

[0026] FIG. 2B illustrates a schematic representation of the environment of FIG. 2A depicting routing the second portion of the first rich solvent to the second absorption unit, in accordance with an embodiment of the present disclosure;

[0027] FIG. 2C illustrates a schematic representation of the environment of FIG. 2A depicting the second portion of the first rich solvent supplied to the rich solvent storage and the second absorption unit, in accordance with an embodiment of the present disclosure;

[0028] FIG. 3 illustrates a schematic representation of the environment of FIG. 2A depicting a fluidic coupling of a mixing unit to a lean solvent storage, the valve assembly, and the second absorption unit, in accordance with an embodiment of the present disclosure;

[0029] FIG. 4 illustrates a schematic representation of the environment of FIG. 2A depicting a fluidic coupling of a cooler to the valve assembly and the second absorption unit, in accordance with an embodiment of the present disclosure; and

[0030] FIG. 5 illustrates a flow diagram of an example representation of a method for processing carbon dioxide (CO2) generated by the engine, in accordance with an embodiment of the present disclosure.DETAILED DESCRIPTION

[0031] As used herein, the term “solvent” refers to a fluid that absorbs carbon dioxide (CO2) present in an exhaust gas. The absorbed carbon dioxide may remain bound with the solvent until further processing (e.g., heating) of the solvent. Solvents useful in the present disclosure include solvents having a high carbon dioxide absorption capacity (e.g., greater than 2 moles CO2 / kilogram). Examples of the high carbon dioxide absorption capacity solvents include but are not limited to, aminomethyl propanol (2-Amino-2-methylpropan-1-ol), methyldiethanolamine (2,2’- (Methylazanediyl)di(ethan-l-ol)), monoethanolamine (MEA), Methyldiethanolamine (MDEA), piperazine (1 ,4-Diazacyclohexane), and so forth.

[0032] As used herein, the term “lean solvent” refers to a solvent with a relatively low concentration of the carbon dioxide. Lean solvents may be used to absorb the carbon dioxide present in the exhaust gas.

[0033] As used herein, the term “rich solvent” refers to a solvent with a relatively high concentration of the carbon dioxide. Rich solvents can be generated by reacting lean solvents with the exhaust gas containing the carbon dioxide and the carbon dioxide being absorbed by the solvent. The carbon dioxide contained in the rich solvent may be extracted by processing the rich solvent. When the carbon dioxide is extracted from the rich solvent, the rich solvent may return to a “lean solvent” state. In other words, the rich solvent may convert back to the lean solvent after extraction of the carbon dioxide therefrom. Consequently, after extraction of the carbon dioxide from the rich solvent, it may be reused for absorbing the carbon dioxide from the gas.

[0034] As used herein, the term “fluidically connected” refers to two components between which a connection is formed which allows a fluid (e.g., lean solvent, rich solvent, exhaust gas, etc.) to flow directly or indirectly between the two components. The two components are connected by one or more conduits, pipes, tubes, and the like to allow the fluid to flow therebetween. Optionally, a pump, a valve, a regulator, or the like may be arranged between the two components to control the flow of the fluid between the two components.

[0035] As used herein, the term “fluidically connectable” refers to two components between which a detachable connection can be formed which allows a fluid (e.g., lean solvent, rich solvent, exhaust gas, etc.) to flow directly or indirectly between the two components. The two components may be connected by one or more conduits, pipes, tubes, and the like to allow the fluid to flow therebetween. Optionally, a pump, a valve, a regulator, or the like may be arranged between the two components to control the flow of the fluid between the two components.

[0036] As used herein, the term “thermal system” or “at least one thermal system” may refer to a plurality of thermal systems. The at least one thermal system supplies heat to the heating devices through at least one mode of heat transfer for example, a sensible heat transfer (f.e., heat transfer through a temperature difference) and a latent heat transfer, without limiting the scope of the invention.

[0037] Various exemplary embodiments and details are described hereinafter, with reference to the Figures when relevant. It should be noted that the Figures may or may not be drawn to scale and that elements of similar structures or functions are represented by reference numerals throughout the Figures. It should also be noted that the Figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of thedisclosure or as a limitation on the scope of the disclosure. In addition, an illustrated embodiment does not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated, or if not so explicitly described.

[0038] The Figures are schematic and simplified for clarity, and they merely show details that aid in understanding the disclosure, while other details have been left out. Throughout, the same reference numerals are used for identical or corresponding parts.

[0039] Various embodiments of the present disclosure relate to an apparatus for processing the carbon dioxide generated by an engine and a method thereof. The apparatus includes a first absorption unit configured to receive an exhaust gas from the engine and receive a first lean solvent from a lean solvent storage. The first lean solvent present in the first absorption unit absorbs the carbon dioxide from the exhaust gas to generate a first rich solvent. Further, the apparatus includes a desorption unit fluidically connected or connectable to the first absorption unit. The desorption unit is configured to receive at least a portion of the first rich solvent and segregate the absorbed carbon dioxide from the portion of the first rich solvent to generate a desorbed lean solvent. The desorbed lean solvent is recirculated to the first absorption unit. The apparatus further includes a second absorption unit fluidically connected or connectable to the desorption unit. The second absorption unit is configured to receive the segregated carbon dioxide from the desorption unit and receive a second lean solvent from the lean solvent storage. The second lean solvent present in the second absorption unit absorbs the segregated carbon dioxide to generate a second rich solvent. The second rich solvent is stored at low pressure in a rich solvent storage. It should be noted that the use of two absorbers (the first absorption unit and the second absorption unit) provides the advantage of reducing the size of the absorbers. Also, the size of the desorption unit is reduced as only a portion of the first rich solvent is supplied to the desorption unit. Further, the utilization of two absorbers replaces the need for carbon dioxide reliquification and the carbon dioxide storage under pressure and low temperature, hence, the overall operating cost of stripping off the carbon dioxide is reduced.

[0040] Various example embodiments of the present disclosure are described hereinafter with reference to FIGS. 1A-1C to FIG. 5.

[0041] FIG. 1A illustrates a schematic representation of an environment 100 related to various embodiments of the present disclosure. Although the environment 100 is presented in one arrangement, other arrangements are also possible where the parts of the environment 100 (or other parts) are arranged or interconnected differently. The environment 100 includes an apparatus 102 fluidically connected or connectable to an engine 104. The engine 104 can take the form of any combustion engine that works on the principle of converting chemical energy of fuel 156 into mechanical energy and that discharges an exhaust gas containing carbon dioxide. For the explanation purposes of embodiments of the present invention, the engine 104 is explained by taking an example of a diesel engine, however, teachings of the present invention can be applicable to any type of combustion engine. The diesel engine may be equipped in marine vehicles (e.g., vessels, ships, barges, boats, etc.), automobiles, locomotives, generators, diesel engine power plants, and the like. For example, the diesel engine may be a two-stroke diesel engine, a four-stroke engine, a single-cylinder diesel engine, a multi-cylinder diesel engine, and the like.

[0042] Typically, the engine 104 includes a cylinder, a piston, a cylinder head mounted on the cylinder, a cooling jacket thermally connected to the cylinder and the cylinder head, a fuel injection system, an inlet manifold, an outlet manifold, and the like. During a suction stroke of the piston, engine air enters the cylinder through the inlet manifold. Subsequently, during a compression stroke, the piston compresses the engine air, and at the end of this stroke, the fuel injection system injects the fuel 156. Consequently, the fuel 156 ignites due to the compression of the engine air, and an expansion stroke (i.e., power stroke) of the piston occurs. As a result, an exhaust gas 106 is liberated during an exhaust stroke and is discharged to the apparatus 102. The geometrical configuration and operating aspects of these components are well-known in the art and are not extensively discussed herein for the sake of brevity.

[0043] The apparatus 102 is designed to process the exhaust gas 106 of the engine 104 to segregate carbon dioxide (CO2) 108 in the exhaust gas 106. As shown, the apparatus 102 includes a first absorption unit 110, a desorption unit 112, and a second absorption unit 114.

[0044] The first absorption unit 110 is configured to receive the exhaust gas 106 from the engine 104. The first absorption unit 110 may be connected or connectable to the engine 104 via a scrubber 116. In other words, the scrubber 116 is provided between the engine 104 and the first absorption unit 110. The scrubber 116 is configured to purify or clean the exhaust gas 106 in aninitial stage. In particular, the scrubber 116 removes harmful pollutants, such as sulfur oxides (SOx) and particulate matter, from the exhaust gas 106 before the exhaust gas 106 enters the first absorption unit 110 for further processing or treatment.

[0045] Further, the first absorption unit 110 includes a first inlet 118. The first inlet 118 is configured to receive the exhaust gas 106 from the engine 104 via the scrubber 116. The first absorption unit 110 is circulated with a first lean solvent 122 continuously (e.g., multiple cycles per hour). The first lean solvent 122 may be the solvent for minimum energy use in the desorption unit 112. In other words, the concentration of the first lean solvent 122 in the first absorption unit 110 results in energy optimizations.

[0046] The first lean solvent 122 in the first absorption unit 110 absorbs the carbon dioxide 108 from the exhaust gas 106 to generate a first rich solvent 124 including the absorbed carbon dioxide 108. Hence, the carbon dioxide 108 molecules in the exhaust gas 106 are captured in the liquid phase. The absorption process is often facilitated by chemical reactions between the target gas (i.e., the carbon dioxide 108 in the exhaust gas 106) and the first lean solvent 122, depending on the specific properties of the first lean solvent 122 and the target gas (the carbon dioxide 108). It is to be noted that the absorption process continues in the first absorption unit 110 until the first lean solvent 122 is substantially saturated with the target gas (i.e., the carbon dioxide 108) to generate the first rich solvent 124. In other words, the absorption process continues in the first absorption unit 110 until equilibrium is reached between the gas phase and the liquid phase of the carbon dioxide 108. The first rich solvent 124 may be partially enriched or saturated. Upon removal of the harmful pollutants from the exhaust gas 106, the exhaust gas 106 is expelled into the atmosphere through a first outlet 128 of the first absorption unit 110.

[0047] The desorption unit 112 is fluidically connected or connectable to the first absorption unit 110. The desorption unit 112 is configured with a first inlet 134 to receive at least a portion of the first rich solvent 124 routed through a second outlet 136 of the first absorption unit 110. According to one example, a heat exchanger 126 (e.g., rich-lean solvent heat exchanger) is disposed between the first absorption unit 110 and the desorption unit 112. In other words, the heat exchanger 126 fluidically connects the first absorption unit 110 with the desorption unit 112. The desorption unit 112 segregates the absorbed carbon dioxide 108 from the portion of the first rich solvent 124 to generate a desorbed lean solvent 130. In the desorption unit 112, the first rich solvent 124 may be subjected to conditions such as temperature, pressure, or chemical treatmentthat cause the absorbed carbon dioxide 108 to desorb or release from the first rich solvent 124 to obtain the desorbed lean solvent 130.

[0048] In the illustrated embodiment, the desorption unit 112 includes at least one thermal system 132 to provide thermal energy for segregating the absorbed carbon dioxide (CO2) 108 from the first rich solvent 124. The at least one thermal system 132 associated with the desorption unit 112 depends on factors such as the target gas (i.e., carbon dioxide 108), the properties of the solvent (i.e., the first rich solvent 124), efficiency, and temperature control. Specifically, the first rich solvent 124 is heated by the at least one thermal system 132 in the desorption unit 112 to temperatures sufficient to thermally desorb the absorbed carbon dioxide 108. The heat energy in the desorption unit 112 enables the generation of a high concentration of the carbon dioxide 108 stream that allows the carbon dioxide 108 to be maintained at an increased partial pressure (high partial pressure) in the second absorption unit 114. For example, the increased partial pressure may be predefined partial pressure. According to an embodiment, the temperature is controlled and optimized based on the characteristics of the first rich solvent 124 and the absorbed gases (i.e., carbon dioxide 108). As the first rich solvent 124 is heated, the absorbed carbon dioxide 108 molecules begin to desorb from the first rich solvent 124 and vaporize. In one example scenario, the desorbed lean solvent 130 may include a low concentration of the target gas (i.e., the carbon dioxide 108).

[0049] Further, the desorbed lean solvent 130 is recirculated to the first absorption unit 110 via the heat exchanger 126, thus completing the regeneration cycle. This enables the regeneration of the first lean solvent 122 which provides the advantage of reduced storage required for the first lean solvent 122. In particular, the desorption unit 112 is configured with a first outlet 138 for supplying the desorbed lean solvent 130 to the heat exchanger 126 from which the desorbed lean solvent 130 is circulated to the first absorption unit 110 through a third inlet 140 of the first absorption unit 110. For example, the heat exchanger 126 may be a pre-heater heat exchanger. The heat exchanger 126 facilitates the transfer of thermal energy of the desorbed lean solvent 130 being received from the desorption unit 112 to the first rich solvent 124 being received from the first absorption unit 110. More specifically, the heat exchanger 126 pre-heats the first rich solvent 124 to be supplied to the desorption unit 112 using the thermal energy of the desorbed lean solvent 130. Hence, the first absorption unit 110 receives the first lean solvent 122 and the desorbed lean solvent 130 for absorbing the carbon dioxide 108 from the exhaust gas 106 to generate the first rich solvent 124.

[0050] Further, according to the illustrated embodiment, the second absorption unit 114 is fluidically connected or connectable to the desorption unit 112. The second absorption unit 114 includes a first inlet 142 for receiving a gas feed (i.e., the segregated carbon dioxide 108) from the desorption unit 112. According to an embodiment, the second absorption unit 114 is fluidically connected or connectable to the lean solvent storage 150 and a rich solvent storage 152. The second absorption unit 114 includes a second inlet 146 for receiving a second lean solvent 144 from the lean solvent storage 150. The second lean solvent 144 may be the solvent capable of capturing maximum carbon dioxide per mass / volume. In one example, the second lean solvent 144 may be Monoethanolamine (MEA) of a predefined weight percentage. The predefined weight percentage of EA may be about 70% by weight, which has a large holding capacity.

[0051] In an embodiment, the first lean solvent 122 and the second lean solvent 144 may be of the same composition. In the illustrated embodiment, the first lean solvent 122 and the second lean solvent 144 are supplied from the lean solvent storage 150 as per the requirements. In an embodiment, the second lean solvent 144 may be a solvent different than the first lean solvent 122. The lean solvent storage 150 may include a separate compartment or storage unit for storing the first lean solvent 122 and the second lean solvent 144 in the lean solvent storage 150. In one embodiment, the second lean solvent 144 may be a mixture of different lean solvents stored in the lean solvent storage 150.

[0052] The second lean solvent 144 circulating in the second absorption unit 114 absorbs the segregated carbon dioxide 108 for generating a second rich solvent 148. Similar to the absorption process in the first absorption unit 110, the contact between the carbon dioxide 108 and the second lean solvent 144 allows for the transfer of the carbon dioxide 108 molecules from the gas phase into the liquid phase of the second lean solvent 144. Thereafter, the second rich solvent 148 is transmitted to the rich solvent storage 152 via an outlet 154 of the second absorption unit 114. It is to be noted that the utilization of two absorbers of different types (i.e., the first absorption unit 110 and the second absorption unit 114) results in a reduction in the size of the absorbers and the reaction time for capturing the carbon dioxide 108. In other words, the use of two absorbers (i.e., the first absorption unit 110 and the second absorption unit 114) enables in a reduction of the reacting time at the second absorption unit 114. Further, as the second absorption unit 114 is provided with the segregated carbon dioxide 108 having an increased concentration of carbon dioxide, a higher absorption rate of the carbon dioxide by the second lean solvent 144 can be achieved. This provides increased carbon dioxide storage capacity per mass or volume.

[0053] According to an embodiment, in the shown example of FIG. 1 B, the second absorption unit 114 and the desorption unit 112 are fluidically connected or connectable to each other via a compressor device 158. In other words, the compressor device 158 is fluidically connected or connectable to the second absorption unit 114 and the desorption unit 112. The compressor device 158 is configured to adjust / increase pressure of the carbon dioxide 108 received from the desorption unit 112 based on a predefined partial pressure. In this scenario, the second absorption unit 114 acts as a pressure vessel which is further explained in detail. For example, the predefined partial pressure may be about 1-3 bar. The second absorption unit 114 includes the first inlet 142 for receiving the gas feed ( / .e., the segregated carbon dioxide 108) from the compressor device 158 at the predefined partial pressure (as shown in FIG. 1 B). The pressure of the carbon dioxide 108 maintained at the predefined partial pressure increases the absorption ability and thereby achieves an increased saturation level of the carbon dioxide 108 in the solvent (i.e. the second lean solvent 144).

[0054] The second lean solvent 144 circulating in the second absorption unit 114 absorbs the segregated carbon dioxide 108 maintained at the predefined partial pressure for generating the second rich solvent 148. Similar to the absorption process in the first absorption unit 110, the contact between the carbon dioxide 108 that is maintained at the predefined partial pressure and the second lean solvent 144 allows for the transfer of the carbon dioxide 108 molecules from the gas phase into the liquid phase of the second lean solvent 144. It is to be noted that the carbon dioxide 108 circulating in the second absorption unit 114 is absorbed by the second lean solvent 144 based on the predefined partial pressure of the carbon dioxide 108. In other words, the second lean solvent 144 absorbs the carbon dioxide 108 with the predefined partial pressure to generate the second rich solvent 148 with an increased saturation level. For example, the second rich solvent 148 may be fully saturated / enriched (ideally 100%). This ensures the storage of the carbon dioxide 108 using minimal solvent (i.e., the second lean solvent 144). Thereafter, the second rich solvent 148 is transmitted to the rich solvent storage 152 via the outlet 154 of the second absorption unit 114. The second rich solvent 148 may be replenished once at each discharge cycle, for example, a few days or weeks. It is to be noted that the utilization of two absorbers of different types (i.e., the first absorption unit 110 and the second absorption unit 114) reduces the absorbers' size and prolongs the reaction time for capturing the carbon dioxide 108 within minimal solvent. In other words, the use of two absorbers (i.e., the first absorption unit 110 and the second absorption unit 114) enables a reduction of the reaction time at the second absorption unit 114. Further, as the second absorption unit 114 is provided with the segregatedcarbon dioxide 108 having an increased concentration of carbon dioxide, a higher absorption rate of the carbon dioxide by the second lean solvent 144 can be achieved. This provides increased carbon dioxide storage capacity per mass or volume.

[0055] FIG. 1C illustrates a schematic representation of an apparatus (such as the apparatus 102) equipped in a marine vessel 160 for absorbing the carbon dioxide 108, in accordance with an embodiment of the present disclosure. More specifically, the apparatus 102 including the first absorption unit 110, the desorption unit 112, and the second absorption unit 114 are equipped in the marine vessel 160 for absorbing the carbon dioxide 108 liberated by an engine (such as the engine 104) of the marine vessel 160. For the sake of brevity, the structural configuration of the apparatus 102 is not explained herein in detail.

[0056] As explained above, the exhaust gas 106 from the engine 104 associated with the marine vessel 160 is transmitted to the first absorption unit 110. The first absorption unit 110 including the first lean solvent 122 absorbs the carbon dioxide 108 from the exhaust gas 106 to generate the first rich solvent 124. The first rich solvent 124 may be partially enriched or substantially saturated with the target gas (i.e. the carbon dioxide 108). Thereafter, the desorption unit 112 receives the portion of the first rich solvent 124 from the first absorption unit 110. The desorption unit 112 segregates the absorbed carbon dioxide 108 from the portion of the first rich solvent 124 to generate the desorbed lean solvent 130. The composition of the desorbed lean solvent 130 obtained upon segregating the carbon dioxide 108 from the first rich solvent 124 is analogous to the first lean solvent 122. In other words, the first lean solvent is regenerated by stripping off (or segregating) the carbon dioxide 108 from the first rich solvent 124. Further, the desorbed lean solvent 130 is recirculated to the first absorption unit 110, thus completing the regeneration cycle. The regeneration of the first lean solvent 122 (i.e. the desorbed lean solvent 130) provides the advantage of reduced storage required for the first lean solvent 122 in the marine vessel 160.

[0057] Furthermore, the segregated carbon dioxide 108 is transmitted to the second absorption unit 114. In this scenario, the second lean solvent 144 circulating in the second absorption unit 114 absorbs the segregated carbon dioxide 108 to generate the second rich solvent 148. The second lean solvent 144 may absorb the carbon dioxide 108 with the predefined partial pressure to generate the second rich solvent 148 with the increased saturation level as explained with reference to FIG. 1 B. The second rich solvent 148 is stored in the rich solvent storage 152 as explained above.

[0058] Additionally, a portion of the first rich solvent 124 may be further enriched. In particular, the portion of the first rich solvent 124 may be transmitted to the second absorption unit 114 for further enrichment of the first rich solvent 124 by absorbing the segregated carbon dioxide 108 circulating in the second absorption unit 114. The portion of the first rich solvent 124, further enriched by absorbing the carbon dioxide 108 in the second absorption unit 114, forms the second rich solvent 148 which is transmitted to the rich solvent storage 152 for storage. It is to be noted that further enrichment of the first rich solvent 124 in the second absorption unit 114 provides the advantage of reduced storage required for the rich solvent in the marine vessel 160. The description related to further enrichment of the portion of the first rich solvent 124 is provided in detail with references to FIGS. 2B and 2C.

[0059] FIG. 2A illustrates a schematic representation of the environment 100 depicting a fluidic coupling between the heat exchanger 126 and the first absorption unit 110 via a valve assembly 202, in accordance with an embodiment of the present disclosure. As shown, the valve assembly 202 is fluidically connected to the heat exchanger 126 and the first absorption unit 110. The valve assembly 202 is configured to distribute a first portion 204 of the first rich solvent 124 to the desorption unit 112. In this scenario, the desorption unit 112 is configured to segregate the absorbed carbon dioxide 108 from the first portion 204 of the first rich solvent 124 and generate the desorbed lean solvent 130. Similarly, the desorbed lean solvent 130 is recirculated to the first absorption unit 110 via the heat exchanger 126. In this scenario, the first absorption unit 110 receives the first lean solvent 122 from the lean solvent storage 150 through a second inlet 120 of the first absorption unit 110. It is to be noted that the heat energy of the desorbed lean solvent 130 is reduced with a fraction proportional to the quantity of the first lean solvent 122 received from the lean solvent storage 150. The combination of the desorbed lean solvent 130 and the first lean solvent 122 from the lean solvent storage 150 in the first absorption unit 110 absorbs the carbon dioxide 108 from the exhaust gas 106 fed to the first absorption unit 110 and generates the first rich solvent 124.

[0060] Further, the segregated carbon dioxide 108 is transmitted from the desorption unit 112 to the second absorption unit 114. According to an embodiment, the segregated carbon dioxide 108 is transmitted from the desorption unit 112 to the second absorption unit 114 at the predefined partial pressure. As explained above, the second lean solvent 144 in the second absorption unit 114 absorbs the segregated carbon dioxide 108 to generate the second rich solvent 148 which is then supplied to the rich solvent storage 152 for storage. According to an embodiment, as shownin the example of FIG. 2A, a second portion 206 of the first rich solvent 124 from the valve assembly 202 is also supplied to the rich solvent storage 152 for storage. It should be understood that the second lean solvent 144 may be completely saturated (ideally 100%) by absorbing the segregated carbon dioxide 108 in the second absorption unit 114 to generate the second rich solvent 148 (as shown in FIG. 2A). Splitting of the first rich solvent 124 into the first portion 204 and the second portion 204 provides the advantage of reduction in the size of the desorption unit 112 as only a fraction of the first rich solvent 124 is provided to the desorption unit 112.

[0061] Referring now to FIG. 2B, according to an embodiment, the valve assembly 202 is configured to distribute the first portion 204 of the first rich solvent 124 to the desorption unit 112 and the second portion 206 of the first rich solvent 124 to the second absorption unit 114. In the shown embodiment of FIG. 2B, the second portion 206 of the first rich solvent 124 is the second lean solvent 144. The second portion 206 of the first rich solvent 124 provided as the second lean solvent 144 is further enriched with the segregated carbon dioxide 108 in the second absorption unit 114. The second portion 206 of the first rich solvent 124 further enriched by absorbing the carbon dioxide 108 in the second absorption unit 114 forms the second rich solvent 148 which is transmitted to the rich solvent storage 152 from the second absorption unit 114 for storage. As explained above, the partial pressure of the carbon dioxide 108 maintained at the predefined partial pressure may enable further enrichment of the second portion 206 of the first rich solvent 124. The further enrichment of the second lean solvent 144 (i.e., the second portion 206 of the first rich solvent 124) achieves higher absorption of the carbon dioxide 108 for the same quantity of solvent. For example, in certain implementations, saturation of the second lean solvent 144 (the second portion 206 of the first rich solvent 124) may be achieved by absorbing the segregated carbon dioxide 108. Additionally, splitting the first rich solvent 124 into the first portion 204 and the second portion 204 provides the advantage of reduction in the size of the desorption unit 112 as only a fraction of the first rich solvent 124 is provided to the desorption unit 112.

[0062] Referring now to FIG. 2C, according to an embodiment, the second portion 206 of the first rich solvent 124 may be split into a first stream 206A and a second stream 206B. In this scenario, the first stream 206A of the second portion 206 of the first rich solvent 124 is provided to the second absorption unit 114, and the second stream 206B of the second portion 206 of the first rich solvent 124 is provided to the rich solvent storage 152 (as shown in FIG. 2C). The first stream 206A of the second portion 206 of the first rich solvent 124 supplied to the second absorption unit 114 is the second lean solvent 144 for absorbing the carbon dioxide 108 in the second absorptionunit 114. Specifically, the first stream 206A of the second portion 206 of the first rich solvent 124 may be further enriched by absorbing the segregated carbon dioxide 108 in the second absorption unit 114 as explained with reference to FIG. 2B. The first stream 206A of the second portion 206 of the first rich solvent 124 further enriched by absorbing the carbon dioxide 108 in the second absorption unit 114 forms the second rich solvent 148 which is transmitted to the rich solvent storage 152 from the second absorption unit 114 (as shown in FIG. 2C). As explained above, the partial pressure of the carbon dioxide 108 maintained at the predefined partial pressure may enable further enrichment of the first stream 206A of the second portion 206 of the first rich solvent 124. The further enrichment of the first stream 206A of the second portion 206 of the first rich solvent 124 achieves higher absorption of the carbon dioxide 108 for the same quantity of solvent. It is to be noted that further enrichment of the first rich solvent (the first stream 206A or second portion 206 of the first rich solvent 124) in the second absorption unit 114 provides the advantage of reduced storage required for the rich solvent in the marine vessel 160.

[0063] FIG. 3 illustrates a schematic representation of the environment 100 depicting a fluidic coupling of a mixing unit 302 to the lean solvent storage 150, the valve assembly 202, and the second absorption unit 114, in accordance with an embodiment of the present disclosure. As shown, the mixing unit 302 is fluidically coupled to the lean solvent storage 150, the valve assembly 202, and the second absorption unit 114. The second portion 206 of the first rich solvent 124 is transmitted from the valve assembly 202 to the mixing unit 302. Further, the mixing unit 302 receives the second lean solvent 144 from the lean solvent storage 150. The mixing unit 302 is configured to mix the second portion 206 of the first rich solvent 124 and the second lean solvent 144 to generate a mixed solvent 304. The mixed solvent 304 generated by mixing the second portion 206 of the first rich solvent 124 with the second lean solvent 144 is diluted. The dilution reduces the concentration of the captured gases (i.e., the carbon dioxide 108) in the mixed solvent 304, thus enabling the mixed solvent 304 to be used for further absorption process. The second portion 206 of the first rich solvent 124 with the second lean solvent 144 may be mixed with a predefined ratio for generating the mixed solvent 304. The predefined ratio may be defined based on the concentration of the carbon dioxide 108 to be captured.

[0064] The mixed solvent 304 is further supplied to the second absorption unit 114. The mixed solvent 304 circulating the second absorption unit 114 absorbs the carbon dioxide 108 to generate the second rich solvent 148. The carbon dioxide 108 may be maintained at the predefined partial pressure as per the requirements. It is to be noted that the diluted solvent (i.e., the mixed solvent304) supplied to the second absorption unit 114 results in maximizing the efficiency of solvent utilization in the apparatus 102.

[0065] FIG. 4 illustrates a schematic representation of the environment 100 depicting a fluidic coupling of a cooler 402 to the valve assembly 202, the lean solvent storage 150, and the second absorption unit 114, in accordance with an embodiment of the present disclosure. The cooler 402 is configured to adjust temperature (i.e., cool) of the second portion 206 of the first rich solvent 124 received by the valve assembly 202 based on a threshold temperature. The threshold temperature may be lower temperatures (e.g., 104°F to 122T). Typically, in the first absorption unit 110, the exhaust gas 106 reacts with a cold, lean solution (i.e., the first lean solvent 122). The reaction between the exhaust gas 106 and the first lean solvent 122 is generally exothermic, indicating that heat is released during the process. Thus, the cooler 402 (e.g., an Absorber-lnter- Cooler (AIC)) may be used to cool the first rich solvent 124 (or the second portion 206 of the first rich solvent 124) during the reaction in the first absorption unit 110. Thereafter, the second portion 206 of the first rich solvent 124 and the second lean solvent 144 are supplied to the second absorption unit 114 via the cooler 402. In the second absorption unit 114, the second portion 206 of the first rich solvent 124 may be further enriched by the segregated carbon dioxide 108 circulating in the second absorption unit 114. It is to be noted that the temperature of the second portion 206 of the first rich solvent 124 adjusted to the threshold temperature (or lower temperatures) increases the absorption efficiency of the second portion 206 of the first rich solvent 124. As a result, the second portion 206 of the first rich solvent 206 is further enriched by absorbing the segregated carbon dioxide 108 in the second absorption unit 114.

[0066] FIG. 5 illustrates a method 500 for processing carbon dioxide 108 generated by the engine 104, in accordance with an embodiment of the present disclosure. The method 400 is performed by the apparatus 102. The method 500 starts at step 502.

[0067] At 502, the method 500 includes receiving, by the first absorption unit 110, the exhaust gas 106 from the engine 104. The exhaust gas 106 has high carbon dioxide 108 content and needs to be removed before discharging into the atmosphere. Hence the apparatus 102 of the present invention strips off the carbon dioxide 108 from the exhaust gas 106.

[0068] At 504, the method 500 includes receiving, by the first absorption unit 110, the first lean solvent 122 for absorbing the carbon dioxide 108 from the exhaust gas 106 to generate the firstrich solvent 124. Specifically, the first absorption unit 110 receives the first lean solvent 122 from the lean solvent storage 150. The first lean solvent 122 in the first absorption unit 110 absorbs the carbon dioxide 108 in the exhaust gas 106, and the exhaust gas 106 is expelled to the atmosphere i.e., the exhaust gas 106 containing a negligible amount of the carbon dioxide 108 to the atmosphere). It is to be noted that the chemical composition of the first lean solvent 122 is such that, as soon as the exhaust gas 106 enters the first absorption unit 110, the first lean solvent 122 absorbs the carbon dioxide 108, thereby generating the first rich solvent 124 having high carbon dioxide content.

[0069] At 506, the method 500 includes receiving, by the desorption unit 112, at least a portion of the first rich solvent 124. In one scenario, the first rich solvent 124 is transmitted to the desorption unit 112 via the heat exchanger 126 (as shown in FIG. 1A). In another scenario, the first portion 204 of the first rich solvent 124 is transmitted to the heat exchanger 126 via the valve assembly 202 (as shown in Figures 2 and 3). Thereafter, the first portion 204 of the first rich solvent 124 is transmitted to the desorption unit 112 via the heat exchanger 126 (as shown in FIGS. 2A and 3).

[0070] At 508, the method 500 includes segregating, by desorption unit 112, the absorbed carbon dioxide 108 from the portion of the first rich solvent 124 to obtain the desorbed lean solvent 130. Specifically, the desorption unit 112 includes the at least one thermal system 132 to provide thermal energy for segregating the absorbed carbon dioxide (CO2) 108 from the first rich solvent 124. The at least one thermal system 132 associated with the desorption unit 112 depends on factors such as the target gas (i.e., carbon dioxide 108), the properties of the solvent (i.e., the first rich solvent 124), efficiency, and temperature control. The first rich solvent 124 is heated by the at least one thermal system 132 in the desorption unit 112 to temperatures sufficient to thermally desorb the absorbed carbon dioxide (CO2) 108 in the first rich solvent 124, thus generating the desorbed lean solvent 130. Thereafter, the desorbed lean solvent 130 is recirculated to the first absorption unit 110. Hence, the first lean solvent 122 and the desorbed lean solvent 130 in the first absorption unit 110 absorb the carbon dioxide 108 from the exhaust gas 106.

[0071] At 510, the method 500 includes receiving, by the second absorption unit 114, the segregated carbon dioxide 108 from the desorption unit 112, and the second lean solvent 144. The second lean solvent 144 absorbs the segregated carbon dioxide 108 to generate the secondrich solvent 148. Thus, the carbon dioxide 108 captured in the second rich solvent 148 is stored at low pressure in the rich solvent storage 152.

[0072] In one embodiment, the second absorption unit 114 receives the mixed solvent 304 generated by the mixing unit 302 by mixing the second portion 206 of the first rich solvent 124 and the second lean solvent 144. The mixed solvent 304 in the second absorption unit 114 absorbs the carbon dioxide 108 and generates the second rich solvent 148.

[0073] Thus, the present invention uses two absorbers (i.e. , the first absorption unit 110 and the second absorption unit 114) of different types. The use of two absorbers provides the advantage of reducing the size of the absorbers. Also, the size of the desorption unit 112 is reduced as only a portion of the first rich solvent 124 is routed to the desorption unit 112. In addition, the reaction time for capturing the carbon dioxide 108 is also reduced. Further, the utilization of two absorbers replaces the need for the carbon dioxide 108 reliquification and the storage of the carbon dioxide 108 under pressure and low temperature, hence, the overall operating cost of stripping off the carbon dioxide 108 can be reduced.

[0074] Although features have been shown and described, it will be understood that they are not intended to limit the claimed disclosure, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the scope of the claimed disclosure. The specification and drawings are, accordingly to be regarded in an illustrative rather than restrictive sense. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.

Claims

CLAIMS1 . An apparatus for processing carbon dioxide generated by an engine, comprising: a first absorption unit configured to receive an exhaust gas from the engine and receive a first lean solvent for absorbing the carbon dioxide from the exhaust gas to generate a first rich solvent comprising the absorbed carbon dioxide; a desorption unit fluidically connected or connectable to the first absorption unit, the desorption unit configured, at least in part, to receive at least a portion of the first rich solvent, and segregate the absorbed carbon dioxide from the portion of the first rich solvent to generate a desorbed lean solvent; and a second absorption unit fluidically connected or connectable to the desorption unit, the second absorption unit configured, at least in part, to receive the segregated carbon dioxide from the desorption unit, and receive a second lean solvent to absorb the segregated carbon dioxide for generating a second rich solvent.

2. The apparatus as claimed in claim 1 , wherein the first absorption unit is further configured to receive the first lean solvent and the desorbed lean solvent for absorbing the carbon dioxide from the exhaust gas to generate the first rich solvent.

3. The apparatus as claimed in any one of claims 1 and 2, further comprising a valve assembly configured to distribute a first portion of the first rich solvent to the desorption unit and a second portion of the first rich solvent to the second absorption unit or a rich solvent storage.

4. The apparatus as claimed in claim 3, wherein the second portion of the first rich solvent is split into a first stream and a second stream for providing the first stream to the second absorption unit and the second stream to the rich solvent storage.

5. The apparatus as claimed in claim 3, further comprising a mixing unit fluidically connected or connectable to the valve assembly and the second absorption unit, the mixing unit configured to mix the second portion of the first rich solvent and a second lean solvent to generate a mixed solvent to be supplied to the second absorption unit.

6. The apparatus as claimed in claim 5, wherein the second absorption unit is further configured to receive the mixed solvent for absorbing the carbon dioxide and generate the second rich solvent.

7. The apparatus as claimed in any one of claims 4 to 6, further comprising a cooler fluidically connected or connectable to the valve assembly, a lean solvent storage, and the second absorption unit, the cooler configured to adjust temperature of the second portion of the first rich solvent received from the valve assembly based on a threshold temperature for supplying the second portion of the first rich solvent to the second absorption unit.

8. The apparatus as claimed in any one of claims 1 to 7, further comprising a compressor device fluidically connected or connectable to the desorption unit and the second absorption unit, wherein the compressor device is configured to adjust pressure of the segregated carbon dioxide received from the desorption unit based at least on a predefined partial pressure, wherein the segregated carbon dioxide maintained at the predefined partial pressure is supplied to the second absorption unit.

9. The apparatus as claimed in any one of the preceding claims, wherein the desorption unit comprises at least one thermal system to provide thermal energy for segregating the absorbed carbon dioxide from the first rich solvent.

10. The apparatus as claimed in any one of the preceding claims, wherein the second lean solvent comprises Monoethanolamine (MEA) of a predefined weight percentage.11 . A method for processing carbon dioxide generated by an engine, the method comprising: receiving, by a first absorption unit, an exhaust gas from the engine; receiving, by the first absorption unit, a first lean solvent for absorbing the carbon dioxide from the exhaust gas to generate a first rich solvent; receiving, by a desorption unit, at least a portion of the first rich solvent; segregating, by desorption unit, the absorbed carbon dioxide from the portion of the first rich solvent to obtain a desorbed lean solvent; and receiving, by a second absorption unit, the segregated carbon dioxide from the desorption unit, and a second lean solvent, wherein the second lean solvent absorbs the segregated carbon dioxide to generate a second rich solvent.

12. The method as claimed in claim 11 , further comprising receiving, by the first absorption unit, the first lean solvent and the desorbed lean solvent for absorbing the carbon dioxide from the exhaust gas to generate the first rich solvent.

13. The method as claimed in any one of claims 11 and 12, further comprising: distributing, by a valve assembly, a first portion of the first rich solvent to the desorption unit and a second portion of the first rich solvent to the second absorption unit or a rich solvent storage.

14. The method as claimed in claim 13, further comprising splitting the second portion of the first rich solvent into a first stream and a second stream for providing the first stream to the second absorption unit and the second stream to the rich solvent storage.

15. The method as claimed in claim 13, further comprising: mixing, by a mixing unit, the second portion of the first rich solvent and the second lean solvent to generate a mixed solvent to be supplied to the second absorption unit.

16. The method as claimed in claim 15, further comprising receiving, by the second absorption unit, the mixed solvent for absorbing the carbon dioxide and generating the second rich solvent.

17. The method as claimed in any one of claims 13 to 16, further comprising: receiving, by a cooler, the second portion of the first rich solvent from the valve assembly and the second lean solvent from the lean solvent storage; and adjusting, by the cooler, temperature of the second portion of the first rich solvent to a threshold temperature for supplying the second portion of the first rich solvent to the second absorption unit.

18. The method as claimed in any one of claims 11 to 17, further comprising: receiving, by a compressor device, the segregated carbon dioxide from the desorption unit; and adjusting, by the compressor device, pressure of the segregated carbon dioxide from the desorption unit based at least on a predefined partial pressure, wherein the segregatedcarbon dioxide maintained at the predefined partial pressure is supplied to the second absorption unit.

19. A marine vessel, comprising: an engine; and an apparatus for processing carbon dioxide generated by the engine, the apparatus comprising: a first absorption unit configured to receive an exhaust gas from the engine and receive a first lean solvent for absorbing the carbon dioxide from the exhaust gas to generate a first rich solvent comprising the absorbed carbon dioxide; a desorption unit fluidically connected or connectable to the first absorption unit, the desorption unit configured, at least in part, to receive at least a portion of the first rich solvent, and segregate the absorbed carbon dioxide from the portion of the first rich solvent to generate a desorbed lean solvent; and a second absorption unit fluidically connected or connectable to the desorption unit, the second absorption unit configured, at least in part, to receive the segregated carbon dioxide from the desorption unit, and receive a second lean solvent to absorb the segregated carbon dioxide for generating a second rich solvent.

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