Patent Publication Number: US-11639677-B1

Title: System and methods for capturing carbon dioxide from a flow of exhuast gas from a combustion process

Description:
TECHNICAL FIELD 
     The present disclosure relates to carbon dioxide capture systems and methods of making the same. More specifically, the disclosure relates to carbon dioxide capture systems and methods used to remove carbon dioxide from a flow of exhaust gas from an internal combustion engine. 
     BACKGROUND 
     One of the most challenging aspects of today&#39;s energy technologies is to effectively capture the carbon dioxide from the exhaust gas of a combustion process of, for example, an internal combustion engine. Carbon dioxide capture systems frequently route such exhaust gas through one or more tanks containing a carbon dioxide absorbent material. The carbon dioxide absorbent material then absorbs the carbon dioxide from the exhaust gas as the exhaust gas passes through the tanks. 
     However, the carbon dioxide absorbent material will become saturated over time. When that occurs, the carbon dioxide absorbent material will have to be heated to regenerate the carbon dioxide and containerize it. 
     Problematically, the heating process to regenerate carbon dioxide is energy intensive and may result in a significant decrease in the efficiency of the internal combustion engine that the carbon dioxide capture system is servicing. The efficiency drop may be between 10% to 15% of the overall efficiency of the engine. Often time, this efficiency drop makes the engine connected to the carbon dioxide capture system uncompetitive with other engines that do not utilize a carbon dioxide capture system. As a result, there is little financial incentive for a user to retrofit an engine with a carbon dioxide capture system, unless the user is regulated to do so by law. 
     Accordingly, there is a need for a carbon dioxide capture system that provides a reduced burden on the efficiency of the engine it is associated with. Additionally, there is a need for a carbon dioxide capture system that would have no detrimental effect on the efficiency of an engine it is associated with. 
     BRIEF DESCRIPTION 
     The present disclosure offers advantages and alternatives over the prior art by providing a carbon dioxide capture system that utilizes the waste heat generated from an engine that the carbon dioxide capture system is servicing to regenerate the captured carbon dioxide and containerize it. The carbon dioxide capture system may utilize the waste heat from the engine&#39;s engine coolant. Alternatively, the carbon dioxide capture system may utilize the waste heat from the engine&#39;s exhaust gas that the carbon dioxide capture system is removing carbon dioxide from. Moreover, the carbon dioxide capture system may utilize a turbine-generator system to generate electric power from the waste heat of the exhaust gas to help power the carbon dioxide capture system itself. 
     The result of such carbon dioxide systems and methods of the present disclosure is that they present little to no burden on the efficiency of the engines they service. Additionally, such carbon dioxide capture systems may be retrofit to any electric power generator system that is powered by an internal combustion engine without effecting the competitiveness of the generator system. 
     A carbon dioxide capture system in accordance with one or more aspects of the present disclosure includes a first capture tank containing carbon dioxide absorbent material which operates to absorb carbon dioxide from a flow of exhaust gas from an internal combustion engine. A heat exchange loop is in heat exchange communication with the first capture tank and further in heat exchange communication with one of the flow of exhaust gas or a flow of engine coolant from the internal combustion engine. A heat exchange fluid is operable to flow through the heat exchange loop. The heat exchange fluid operates to transfer heat from the exhaust gas or the engine coolant to the first capture tank. The heat from the exhaust gas or the engine coolant operates to release a portion of the carbon dioxide absorbed by the carbon dioxide absorbent material in the first capture tank. 
     In some examples of the carbon dioxide capture system, there is included an exhaust gas to heat exchange fluid heat exchanger. The exhaust gas to heat exchange fluid heat exchanger includes a first flow path and a second flow path, which operate to exchange heat therebetween. The first flow path operates to receive therethrough the flow of exhaust gas from the engine. The second flow path operates to receive therethrough the flow of heat exchange fluid in the heat exchange loop. The exhaust gas to heat exchange fluid heat exchanger operates to transfer heat from the exhaust gas to the heat exchange fluid. The heat exchange loop operates to flow the heat exchange fluid to the first capture tank and to transfer heat from the heat exchange fluid to the absorbent material in the first capture tank. 
     In some examples of the carbon dioxide capture system, the flow of exhaust gas passes through the first capture tank prior to the flow of exhaust gas passing through the first flow path of the exhaust gas to heat exchange fluid heat exchanger. 
     In some examples of the carbon dioxide capture system, the flow of exhaust gas passes through the first flow path of the exhaust gas to heat exchange fluid heat exchanger prior to the flow of exhaust gas passing the first capture tank. 
     In some examples of the carbon dioxide capture system, there is included a turbine-generator system. The turbine generator system includes a turbo-expander and turbo-compressor disposed on a turbo-crankshaft. The turbo-expander operates to rotate the turbo-crankshaft as the flow of exhaust gas passes through the turbo-expander. The turbo-compressor operates to compress the flow of exhaust gas after the exhaust gas passes through the turbo-expander. The flow of exhaust gas is routed through the turbo-expander, then through the first flow path of the exhaust gas to heat exchange fluid heat exchanger, then through the turbo-compressor, then through the first capture tank. 
     In some examples of the carbon dioxide capture system, the heat exchange loop is configured to receive the exhaust gas from the engine such that the exhaust gas is the heat exchange fluid that is operable to flow through the heat exchange loop. 
     In some examples of the carbon dioxide capture system, the flow of exhaust gas passes through the first capture tank prior to the exhaust gas passing through the heat exchange loop. 
     In some examples of the carbon dioxide capture system, the flow of exhaust gas passes through the heat exchange loop prior to the exhaust gas passing through the first capture tank. 
     In some examples of the carbon dioxide capture system, there is included an engine coolant to heat exchange fluid heat exchanger. The engine coolant to heat exchange fluid heat exchanger includes a first flow path and a second flow path, which operate to exchange heat therebetween. The first flow path operates to receive therethrough the flow of engine coolant from the engine. The second flow path operates to receive therethrough the flow of heat exchange fluid in the heat exchange loop. The engine coolant to heat exchange fluid heat exchanger operates to transfer heat from the engine coolant to the heat exchange fluid. The heat exchange loop operates to flow the heat exchange fluid to the first capture tank and to transfer heat from the heat exchange fluid to the absorbent material in the first capture tank. 
     In some examples of the carbon dioxide capture system, the heat exchange loop is configured to receive the engine coolant from the engine such that the engine coolant is the heat exchange fluid that is operable to flow through the heat exchange loop. 
     In some examples of the carbon dioxide capture system, there is included a turbine-generator system. The turbine-generator system includes a turbo-expander and turbo-compressor disposed on a turbo-crankshaft. The turbo-expander operates to rotate the turbo-crankshaft as the flow of exhaust gas passes through the turbo-expander. The turbo-compressor operates to compress the flow of exhaust gas after the exhaust gas passes through the turbo-expander. 
     In some examples of the carbon dioxide capture system, the turbine-generator system includes a bottoming cycle generator disposed on the turbo-crankshaft. The bottoming cycle generator is connected to the carbon dioxide capture system. The bottoming cycle generator operates to provide at least a portion of electric power required to operate the carbon dioxide capture system. 
     In some examples of the carbon dioxide capture system, the flow of exhaust gas passes through the turbo-expander and the turbo-compressor prior to the flow of exhaust gas passing through the first capture tank. 
     In some examples of the carbon dioxide capture system, the flow of exhaust gas passes through the first capture tank prior to the flow of exhaust gas passing through turbo-expander and the turbo-compressor. 
     In some examples of the carbon dioxide capture system, an exhaust gas processing system receives and cools the flow of exhaust gas after the exhaust gas has passed through turbo-expander and prior to the exhaust gas being compressed by the turbo-compressor. The exhaust gas processing system may include at least one of a cooling tower, a cooling tower heat exchanger, an absorption chiller, an absorption chiller heat exchanger, a dehumidifier system and a vapor-compression refrigeration system. 
     In some examples of the carbon dioxide capture system, there is included an exhaust gas to exhaust gas heat exchanger. The exhaust gas to exhaust gas heat exchanger includes a first flow path and a second flow path which operate to exchange heat therebetween. The first flow path operates to receive the flow of exhaust gas from the turbo-expander prior to the exhaust gas being compressed by the turbo-compressor. The second flow path operates to receive the flow of exhaust gas from the turbo-compressor after the exhaust gas has been compressed by the turbo-compressor. 
     In some examples of the carbon dioxide capture system, the first capture tank includes an exhaust gas inlet port connected to the flow of exhaust gas prior to the exhaust gas passing through the carbon dioxide absorbent material. An exhaust gas outlet port is connected to the flow of exhaust gas after the flow of exhaust gas has passed through carbon dioxide absorbent material. A second capture tank, contains carbon dioxide absorbent material which operates to absorb carbon dioxide from the exhaust gas. The second capture tank includes an exhaust gas inlet port connected to the flow of exhaust gas prior to the exhaust gas passing through the carbon dioxide absorbent material. An exhaust gas outlet port is connected to the flow of exhaust gas after the flow of exhaust gas has passed through carbon dioxide absorbent material. The heat exchange loop is in heat exchange communication with either the first capture tank or the second capture tank. The heat exchange fluid operates to transfer heat from the exhaust gas or the engine coolant to either the first capture tank or the second capture tank. The heat from the exhaust gas or the engine coolant operates to release a portion of the carbon dioxide absorbed by the carbon dioxide absorbent material in either the first capture tank or the second capture tank. 
     In some examples of the carbon dioxide capture system, when the exhaust gas inlet port of the first capture tank is connected to receive the flow of exhaust gas prior to the exhaust gas passing through the carbon dioxide absorbent material in the first capture tank, then the exhaust gas outlet port of the first capture tank is connected to output the flow of exhaust gas after the exhaust gas has passed through the carbon dioxide absorbent material in the first capture tank and the heat exchange loop is in heat exchange communication with the second capture tank. The heat exchange fluid operates to transfer heat from the exhaust gas or the engine coolant to the second capture tank. The heat from the exhaust gas or the engine coolant operates to release a portion of the carbon dioxide absorbed by the carbon dioxide absorbent material in the second capture tank. When the exhaust gas inlet port of the second capture tank is connected to receive the flow of exhaust gas prior to the exhaust gas passing through the carbon dioxide absorbent material in the second capture tank, then the exhaust gas outlet port of the second capture tank is connected to output the flow of exhaust gas after the exhaust gas has passed through the carbon dioxide absorbent material in the second capture tank and the heat exchange loop is in heat exchange communication with the first capture tank. The heat exchange fluid operates to transfer heat from the exhaust gas or the engine coolant to the first capture tank. The heat from the exhaust gas or the engine coolant operates to release a portion of the carbon dioxide absorbed by the carbon dioxide absorbent material in the first capture tank. 
     A method of removing carbon dioxide from a flow of exhaust gas from an internal combustion engine in accordance with one or more aspects of the present disclosure incudes routing the flow of exhaust gas into a first capture tank of a carbon dioxide capture system. Carbon dioxide in the first capture tank is absorbed from the exhaust gas with carbon dioxide absorbent material disposed in the first capture tank. The flow of exhaust gas is routed out of the first capture tank. A heat exchange loop is connected in heat exchange communication with the first capture tank and further in heat exchange communication with one of the flow of exhaust gas or a flow of engine coolant from the internal combustion engine. A heat exchange fluid is circulated through the heat exchange loop. Heat from the exhaust gas or the engine coolant is transferred to the first capture tank via the heat exchange fluid. A portion of the carbon dioxide absorbed by the carbon dioxide absorbent material in the first capture tank is released, as a result of the heat transferred from the exhaust gas or the engine coolant. 
     In some examples of the method, the flow of exhaust gas is routed through a first flow path of an exhaust gas to heat exchange fluid heat exchanger. The heat exchange fluid is routed through a second flow path of the exhaust gas to heat exchange fluid heat exchanger. Heat is transferred from the exhaust gas to the heat exchange fluid via the exhaust gas to heat exchange fluid heat exchanger. The heat exchange fluid flows to the first capture tank. Heat is transferred from the heat exchange fluid to the absorbent material in the first capture tank. 
     In some examples of the method, the exhaust gas from the engine is received into the heat exchange loop, such that the exhaust gas is the heat exchange fluid that flows through the heat exchange loop. 
     In some examples of the method, the flow of engine coolant is routed through a first flow path of an engine coolant to heat exchange fluid heat exchanger. The heat exchange fluid is routed through a second flow path of the engine coolant to heat exchange fluid heat exchanger. Heat is transferred from the engine coolant to the heat exchange fluid via the engine coolant to heat exchange fluid heat exchanger. The heat exchange fluid flows to the first capture tank. Heat is transferred from the heat exchange fluid to the absorbent material in the first capture tank. 
     In some examples of the method, the engine coolant from the engine is received into the heat exchange loop, such that the exhaust gas is the heat exchange fluid that flows through the heat exchange loop. 
     In some examples of the method, the flow of exhaust gas is routed through a turbo-expander disposed on a turbo-crankshaft of a turbine-generator system. The flow of exhaust gas is compressed via a turbo-compressor disposed on the turbo-crankshaft of the turbine-generator system after the exhaust gas passes through the turbo-expander. Electric power is generated via a bottoming cycle generator disposed on the turbo-crankshaft of the turbine-generator system. At least a portion of electric power required to operate the carbon dioxide capture system is provided from the electric power generated by the bottoming cycle generator. 
     In some examples of the method, the flow of exhaust gas is routed into a second capture tank of the carbon dioxide capture system. Carbon dioxide in the second capture tank is absorbed from the exhaust gas with carbon dioxide absorbent material disposed in the second capture tank. The flow of exhaust gas is routed out of the second capture tank. The heat exchange loop is connected in heat exchange communication with either the first capture tank or the second capture tank and further in heat exchange communication with one of the flow of exhaust gas or a flow of engine coolant from the internal combustion engine. The heat exchange fluid is circulated through the heat exchange loop. Heat from the exhaust gas or the engine coolant is transferred to either the first capture tank or the second capture tank via the heat exchange fluid. A portion of the carbon dioxide absorbed by the carbon dioxide absorbent material in either the first capture tank or the second capture tank is released, as a result of the heat transferred from the exhaust gas or the engine coolant. 
     In some examples of the method, the heat exchange loop is connected in heat exchange communication with the second capture tank and further in heat exchange communication with one of the flow of exhaust gas or a flow of engine coolant when the flow of exhaust gas is routed into the first capture tank. The heat exchange loop is connected in heat exchange communication with the first capture tank and further in heat exchange communication with one of the flow of exhaust gas or a flow of engine coolant when the flow of exhaust gas is routed into the second capture tank. 
     In some examples of the method, the flow of exhaust gas is routed through a turbo-expander of a turbine-generator system, then through the first flow path of the exhaust gas to heat exchange fluid heat exchanger, then through a turbo-compressor of the turbine-generator system, then through the first capture tank. 
     It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein and may be used to achieve the benefits and advantages described herein. 
    
    
     
       DRAWINGS 
       The disclosure will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG.  1    depicts an example of a schematic view of at least a portion of a carbon dioxide capture system having a first capture tank with carbon dioxide absorbent material disposed therein, wherein the carbon dioxide capture system is removing carbon dioxide from a flow of exhaust gas from an internal combustion engine that is passing through the first capture tank and further utilizing heat from the exhaust gas to regenerate the carbon dioxide according to aspects described herein; 
         FIG.  2    depicts an example of a schematic view of the carbon dioxide capture system of  FIG.  1    having a first and a second capture tank, wherein the carbon dioxide capture system utilizes an exhaust gas to heat exchange fluid heat exchanger to transfer heat from the exhaust gas to a heat exchange fluid in a heat exchange loop that is in heat exchange communication with the first and second capture tanks, according to aspects described herein; 
         FIG.  3    depicts another example of a schematic view of the carbon dioxide capture system of  FIG.  1    having a first and a second capture tank, wherein the carbon dioxide capture system utilizes an exhaust gas to heat exchange fluid heat exchanger to transfer heat from the exhaust gas to a heat exchange fluid in a heat exchange loop that is in heat exchange communication with the first and second capture tanks, according to aspects described herein; 
         FIG.  4    depicts an example of a schematic view of the carbon dioxide capture system of  FIG.  1    having a first and a second capture tank, wherein the exhaust gas is the heat exchange fluid that is circulated in the heat exchange loop, according to aspects described herein; 
         FIG.  5    depicts another example of a schematic view of the carbon dioxide capture system of  FIG.  1    having a first and a second capture tank, wherein the exhaust gas is the heat exchange fluid that is circulated in the heat exchange loop, according to aspects described herein; 
         FIG.  6    depicts an example of a schematic view of at least a portion of a carbon dioxide capture system having a first capture tank with carbon dioxide absorbent material disposed therein, wherein the carbon dioxide capture system is removing carbon dioxide from a flow of exhaust gas from an internal combustion engine that is passing through the first capture tank and further utilizing heat from engine coolant from the internal combustion engine to regenerate the carbon dioxide according to aspects described herein; 
         FIG.  7    depicts an example of a schematic view of the carbon dioxide capture system of  FIG.  6    having a first and a second capture tank, wherein the carbon dioxide capture system utilizes an engine coolant to heat exchange fluid heat exchanger to transfer heat from the engine coolant to a heat exchange fluid in a heat exchange loop that is in heat exchange communication with the first and second capture tanks, according to aspects described herein; 
         FIG.  8    depicts an example of a schematic view of the carbon dioxide capture system of  FIG.  6    having a first and a second capture tank, wherein the engine coolant is the heat exchange fluid that is circulated in the heat exchange loop, according to aspects described herein; 
         FIG.  9    depicts an example of a schematic view of the carbon dioxide capture system of  FIG.  1   , which includes a turbine-generator system, which is utilized to supply power to the carbon dioxide capture system, in accordance with aspects described herein; 
         FIG.  10    depicts an example of a schematic view of the carbon dioxide capture system of  FIG.  6   , which includes a turbine-generator system, which is utilized to supply power to the carbon dioxide capture system, in accordance with aspects described herein; 
         FIG.  11    depicts another example of a schematic view of the carbon dioxide capture system of  FIG.  1   , which includes a turbine-generator system, which may be utilized to supply power to the carbon dioxide capture system, in accordance with aspects described herein. 
         FIG.  12    depicts an example of a flow diagram of a method of capturing carbon dioxide from a flow of exhaust gas from an internal combustion engine, in accordance with aspects described herein; 
         FIG.  13    depicts an example of a continuation of the flow diagram of the method of  FIG.  12   , in accordance with aspects described herein; 
         FIG.  14    depicts an example of a continuation of the flow diagram of the method of  FIG.  12   , in accordance with aspects described herein; 
         FIG.  15    depicts an example of a continuation of the flow diagram of the method of  FIG.  12   , in accordance with aspects described herein; 
         FIG.  16    depicts an example of a continuation of the flow diagram of the method of  FIG.  12   , in accordance with aspects described herein; 
         FIG.  17    depicts an example of a continuation of the flow diagram of the method of  FIG.  12   , in accordance with aspects described herein; 
         FIG.  18    depicts an example of a continuation of the flow diagram of the method of  FIG.  12   , in accordance with aspects described herein; 
         FIG.  19    depicts an example of a continuation of the flow diagram of the method of  FIG.  18   , in accordance with aspects described herein; and 
         FIG.  20    depicts an example of a continuation of the flow diagram of the method of  FIG.  13   , in accordance with aspects described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Certain examples will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the methods, systems, and devices disclosed herein. One or more examples are illustrated in the accompanying drawings. Those skilled in the art will understand that the methods, systems, and devices specifically described herein and illustrated in the accompanying drawings are non-limiting examples and that the scope of the present disclosure is defined solely by the claims. The features illustrated or described in connection with one example maybe combined with the features of other examples. Such modifications and variations are intended to be included within the scope of the present disclosure. 
     The terms “significantly”, “substantially”, “approximately”, “about”, “relatively,” or other such similar terms that may be used throughout this disclosure, including the claims, are used to describe and account for small fluctuations, such as due to variations in processing from a reference or parameter. Such small fluctuations include a zero fluctuation from the reference or parameter as well. For example, they can refer to less than or equal to ±10%, such as less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. 
     Referring to  FIG.  1   , an example is depicted of a schematic view of at least a portion of carbon dioxide capture system  100  according to aspects described herein. The carbon dioxide capture system  100  has at least a first capture tank  108  with carbon dioxide absorbent material  106  disposed therein. The carbon dioxide capture system  100  operates to remove carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104  that is passing through the first capture tank  108 . 
     The flow of exhaust gas  102  to the first capture tank  108  is controlled by a flow valve  136 A. When the flow valve  136 A is open, the exhaust gas  102  enters the first capture tank  108  through an exhaust gas inlet port  134 A of the first capture tank  108 . Carbon dioxide  142  is then removed from the exhaust gas  102  upon contact with the carbon dioxide absorbent material  106  disposed within the first capture tank  108 . The flow of exhaust gas then exits the first capture tank  108  through an exhaust gas outlet port  138 A of the first capture tank  108 . 
     The flow of exhaust gas  102  exiting the exhaust gas outlet port  138 A is controlled by a flow valve  140 A. When the flow valve  140 A is open, the flow of exhaust gas  102  exiting the outlet port  138 A is routed to a first flow path  130  of an “exhaust gas to heat exchange fluid heat exchanger”  126 . The flow of exhaust gas  102  exiting the first flow path  130  is then routed up a stack  103  associated with the engine  104 . 
     The engine  104  may be part of a primary power system  110  which includes a primary electric generator  112  that is operatively connected to the crankshaft  114  of the engine  104 . The primary electric generator  112  may supply a primary electrical output  116  that may be used to supply electric power to, for example, a factory, an electrical grid system or a residence. 
     The internal combustion engine  104  may include a turbine engine, a piston engine or similar. The engine  104  utilizes fuel in a combustion process as the motive force that rotates the engine crankshaft  114  and the primary electric generator  112  to generate a primary electrical output  116 . Additionally, the combustion process produces the flow of exhaust gas  102 , which may be routed to the carbon dioxide capture system  100 . The flow of exhaust gas  102  from the combustion process of the internal combustion engine  104  may be at, or near, atmospheric pressure and may have a temperature in the range of 850 to 950 degrees Fahrenheit (F). The engine  104  is cooled by an engine coolant  164  (see  FIG.  6   ), such as glycol, water or the like, to keep the engine&#39;s operating temperature within a predetermined acceptable temperature range. After removing heat from the engine  104 , the engine coolant  164  may have a temperature in the range of 230 degrees F. or less. 
     The carbon dioxide capture system  100  may utilize heat from the exhaust gas  102  to regenerate the carbon dioxide  142 . Additionally, the carbon dioxide capture system  100  may also utilize heat from the engine coolant  164  (see  FIG.  6   ) of the internal combustion engine  104  to regenerate the carbon dioxide  142 . The regenerated carbon dioxide may exit the first capture tank  108  through carbon dioxide outlet port  150 A. Advantageously, by utilizing waste heat from either the engine&#39;s exhaust gas  102  or engine coolant  164 , the detrimental effect on the efficiency of the engine  104  by the heating process required to regenerate the carbon dioxide  142  is greatly reduced. 
     The carbon dioxide absorbent material  106  may be composed of such materials as zeolite, metal organic frameworks material, calcium hydroxide or the like. As used herein, carbon dioxide absorbent material  106  may include any material that has a physical or chemical affinity for carbon dioxide  142 . The carbon dioxide absorbent material  106  may remove carbon dioxide  142  from the flow of exhaust gas  102  by several different processes. For example, the carbon dioxide absorbent material  106  may remove the carbon dioxide  142  from the exhaust gas  102  by the process of absorption, wherein the carbon dioxide is dissolved by a liquid or solid absorbent. An example of such an absorbent material may be calcium hydroxide. Also, by way of example, the carbon dioxide absorbent material  106  may remove the carbon dioxide  142  from the exhaust gas  102  by the process of adsorption, wherein the carbon dioxide molecules adhere to the surface of the adsorbent. An example of such an adsorbent material may be zeolite. 
     The carbon dioxide absorbent materials  106  that remove carbon dioxide utilizing the adsorption process, may later regenerate (or release) the carbon dioxide at fairly low temperature ranges. For example, such adsorbent materials may release the carbon dioxide when heated to temperature ranges of 220 degrees Fahrenheit (F) or lower. This may be advantageous when utilizing heat from the engine coolant  164  (see  FIG.  6   ) of the internal combustion engine  104  to regenerate the carbon dioxide  142 , since the engine coolant  164  may have an operating temperature that is about 230 degrees F. or lower. 
     The carbon dioxide capture system  100  also includes a heat exchange loop  118  that is in heat exchange communication with the first capture tank  108 . The heat exchange loop  118  is also in heat exchange communication with either the flow of exhaust gas  102  (as shown in  FIG.  1   ) or a flow of engine coolant  164  (as shown in  FIG.  6   ) from the internal combustion engine  104 . A heat exchange fluid  120  is operable to flow through the heat exchange loop  118  via heat exchange fluid pump  122 . 
     The heat exchange fluid  120  may be glycol, water or other similar fluid. As will be described in greater detail herein, the heat exchange fluid  120  may also be the exhaust gas  102  itself, or the engine coolant  164  itself, from the engine  104 . 
     The heat exchange fluid  120  operates to transfer heat from the exhaust gas  102  or the engine coolant  164  to the first capture tank  108 . The heat from the exhaust gas  102  or the engine coolant  164  operates to release a portion of the carbon dioxide  142  absorbed by the carbon dioxide absorbent material  106  in the first capture tank  108 . 
     In heat exchange communication, as used herein, includes any structure, device or method that transfers heat energy from one structure or substance to another. In the example illustrated in  FIG.  1   , the heat exchange loop  118  is in heat exchange communication with the first capture tank through a first capture tank heating jacket  124 , which partially, or entirely, surrounds the first capture tank  108  and through which the heat exchange fluid  120  flows. Additionally, as illustrated in the example of  FIG.  1   , the heat exchange loop  118  is in heat exchange communication with the exhaust gas  102  through the “exhaust gas to heat exchange fluid heat exchanger”  126 , which transfers heat energy from the exhaust gas  102  to the heat exchange fluid  120 . 
     More specifically, the flow of heat exchange fluid  120  is controlled by flow valves  144 A and  146 A. When flow valves  144 A and  146 A are open, the heat exchange fluid pump  122  is operable to circulate the heat exchange fluid  120  through the heat exchange loop  118  from the heating jacket  124  of the first capture tank  108  to a second flow path  132  of the exhaust gas to heat exchange fluid heat exchanger  126 . The exhaust gas  102  entering the first flow path  130  will transfer its heat energy to the heat exchange fluid  120  entering the second flow path  132 . The heat exchange fluid  120  will then flow from the second flow path  132  and through the heating jacket  124  of the first capture tank. The heat exchange fluid  120  will then transfer the heat energy picked up from the exhaust gas  102  in the exhaust gas to heat exchange fluid heat exchanger  126  to the carbon dioxide absorption material  106  in the first capture tank. 
     Referring to  FIG.  2   , an example is depicted of a more detailed schematic view of the carbon dioxide capture system  100  of  FIG.  1   , according to aspects described herein. The carbon dioxide capture system  100  of  FIG.  2    has a first capture tank  108  and a second capture tank  128 , both of which have carbon dioxide absorption material  106  disposed therein. As illustrated in  FIG.  2   , the carbon dioxide capture system  100  utilizes an exhaust gas to heat exchange fluid heat exchanger  126  to transfer heat from the exhaust gas  102  to the heat exchange fluid  120  in the heat exchange loop  118 , which is in heat exchange communication with the first and second capture tanks  108 ,  128 . 
     The exhaust gas to heat exchange fluid heat exchanger  126  includes a first flow path  130  and a second flow path  132  which operate to exchange heat therebetween. The first flow path  130  operates to receive therethrough the flow of exhaust gas  102  from the engine  104  and/or primary power system  110 . In the example illustrated in  FIG.  2   , the exhaust gas  102  is then routed to the stack  103  (or chimney stack system) associated with the engine  104 , after the exhaust gas  102  exits the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 . 
     The stack  103 , as used herein, will refer to the extended exhaust piping system (or chimney stack system) designed to route exhaust gas  102  away from the source of the combustion process (in this example, the source of the combustion process is the internal combustion engine  104 ). In the example illustrated in  FIG.  2   , the stack  103  of the internal combustion engine is designed to route the flow of exhaust gas  102  away from the primary power system  110  after the exhaust gas exits the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 . 
     The second flow path  132  operates to receive therethrough the flow of heat exchange fluid  120  in the heat exchange loop  118 . The exhaust gas to heat exchange fluid heat exchanger  126  operates to transfer heat from the exhaust gas  102  to the heat exchange fluid  120 . The heat exchange loop  118  operates to flow the heat exchange fluid  120  selectively to the first capture tank  108  and the second capture tank  128  via the heat exchange fluid pump  122  and flow valves  144 A,  144 B,  146 A and  146 B. The flow valves  144 A and  146 A control flow of the heat exchange fluid  120  in the heat exchange loop  118  through the heating jacket  124  of the first capture tank  108 . The flow valves  144 B and  146 B control flow of the heat exchange fluid  120  through a similar heating jacket  148  of the second capture tank  128 . The heat exchange loop  118  also operates to selectively transfer heat from the heat exchange fluid  120  to the carbon dioxide absorbent material  106  in either the first capture tank  108  or the second capture tank  128  via the heating jackets  124  and  148 . 
     For purposes herein, a heating jacket (such as jackets  124  and  148 ) may refer to an outer casing or system of tubing, which holds fluid and through which the fluid circulates to heat a vessel or device. For example, the first and second capture tank heating jackets  124  and  148  may be casings or systems of tubing, which are operable to transfer heat from the exhaust gas  102  or engine coolant  164  to the selected first or second capture tanks  108 ,  128  and to heat the carbon dioxide  142  captured within the selected tank  108 ,  128 . 
     The heating jackets  124  and  148  are operable to selectively contain and circulate the heat exchange fluid  120  (which is heated with the heat from the exhaust gas  102  or engine coolant  164  from engine  104 ) around the outer surfaces of the first or second capture tanks  108 ,  128  respectively to heat the selected capture tank  108 ,  128 . The heat exchange fluid  120  will add the heat from the exhaust gas  102  or engine coolant  164  to the selected capture tank  108 ,  128 . The heat from either the exhaust gas  102  or engine coolant  164  from the engine  104  will then advantageously be used to regenerate (or desorb) a portion, or substantially all, of the carbon dioxide  142  from the carbon dioxide absorbent material  106  disposed in capture tanks  108 ,  128 , so that the carbon dioxide  142  may be pumped by a compressor  152  into a holding tank  156  for later use, storage and/or disposal. 
     In the example illustrated in  FIG.  2   , the carbon dioxide capture system  100  may be configured such that the flow of exhaust gas  102  passes through the first capture tank  108  prior to the flow of exhaust gas  102  passing through the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 . However, as will be seen in  FIG.  3   , the carbon dioxide capture system  100  may also be configured such that the flow of exhaust gas  102  passes through the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126  prior to the flow of exhaust gas  102  passing the first capture tank  108 . 
     The first capture tank  108  includes an exhaust gas inlet port  134 A that is selectively connected to the flow of exhaust gas  102  from the engine  104  via the flow valve  136 A. The exhaust gas  102  passes through the exhaust gas inlet port  134 A prior to the exhaust gas  102  passing through the carbon dioxide absorbent material  106  in the first capture tank  108 . The first capture tank  108  also includes an exhaust gas outlet port  138 A that is connected to the flow of exhaust gas  102  after the flow of exhaust gas  102  has passed through carbon dioxide absorbent material  106  in the first capture tank  108 . The exhaust gas  102  leaving the outlet port  138 A may be connected to the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126  via flow valve  140 A. 
     The second capture tank  128  includes an exhaust gas inlet port  134 B that is selectively connected to the flow of exhaust gas  102  from the engine via flow valve  136 B. The exhaust gas  102  passes through the exhaust gas inlet port  134 B prior to the exhaust gas  102  passing through the carbon dioxide absorbent material  106  in the second capture tank  128 . The second capture tank  128  also includes an exhaust gas outlet port  138 B that is connected to the flow of exhaust gas  102  after the flow of exhaust gas  102  has passed through carbon dioxide absorbent material  106  in the second capture tank  128 . The exhaust gas  102  leaving the outlet port  138 B may be connected to the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126  via flow valve  140 B. 
     As will be explained in greater detail herein, the heat exchange loop  118  may be selectively in heat exchange communication with either the first capture tank  108  or the second capture tank  128  via the series of flow valves  144 A,  144 B,  146 A and  146 B. Additionally, the heat exchange fluid  120  may operate to transfer heat from the exhaust gas  102  or the engine coolant  164  (see  FIG.  7   ) to either the first capture tank  108  or the second capture tank  128 . Further, the heat from the exhaust gas  102  or the engine coolant  164  may operate to release a portion of the carbon dioxide  142  absorbed by the carbon dioxide absorbent material  106  in either the first capture tank  108  or the second capture tank  128 . 
     When the flow valve  136 B is closed and flow valve  136 A is open, the exhaust gas inlet port  134 A of the first capture tank  108  is selectively connected to the flow of exhaust gas  102  from the engine  104 . When the first capture tank  108  is receiving exhaust gas  102  from the engine  104 , then the flow valve  140 A is open and flow valve  140 B is closed to selectively connect the exhaust gas outlet port  138 A of the first capture tank  108  to the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 . Additionally, the flow valves  144 B and  146 B are opened and flow valves  144 A and  146 A are closed to enable flow of the heat exchange fluid  120  through the heating jacket  148  of the second capture tank  128 . Accordingly, in this configuration, the heat exchange loop  118  is connected in heat exchange communication with the second capture tank  128  such that the heat exchange fluid  120  operates to transfer heat from the exhaust gas  102  or the engine coolant  164  to the second capture tank  128 . The heat from the exhaust gas  102  or the engine coolant  164  operates to release a portion of the carbon dioxide  142  absorbed by the carbon dioxide absorbent material  106  in the second capture tank  128 . 
     Alternatively when the flow valve  136 A is closed and flow valve  136 B is open, the exhaust gas inlet port  134 B of the second capture tank  128  is selectively connected to the flow of exhaust gas  102  from the engine  104 . When the second capture tank  128  is receiving exhaust gas  102  from the engine  104 , then the flow valve  140 B is open and flow valve  140 A is closed to selectively connect the exhaust gas outlet port  138 B of the second capture tank  128  to the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 . Additionally, flow valves  144 A and  146 A are opened and flow valves  144 B and  146 B are closed to enable flow of the heat exchange fluid  120  through the heating jacket  124  of the first capture tank  108 . Accordingly, in this configuration, the heat exchange loop  118  is connected in heat exchange communication with the first capture tank  108  such that the heat exchange fluid  120  operates to transfer heat from the exhaust gas  102  or the engine coolant  164  to the first capture tank  108 . The heat from the exhaust gas  102  or the engine coolant  164  operates to release a portion of the carbon dioxide  142  absorbed by the carbon dioxide absorbent material  106  in the first capture tank  108 . 
     The first and second capture tanks  108 ,  128  also include a carbon dioxide outlet port  150 A and  150 B, which are selectively connectable to a carbon dioxide compressor  152 . More specifically, flow valve  154 A controls flow of regenerated carbon dioxide  142  out of the carbon dioxide outlet port  150 A of the first capture tank  108  and into the carbon dioxide compressor  152 . Additionally, flow valve  154 B controls flow of regenerated carbon dioxide  142  out of the carbon dioxide outlet port  150 B of the second capture tank  128  and into the carbon dioxide compressor  152 . The carbon dioxide compressor  152  is operable to pump carbon dioxide  142  out of the carbon dioxide outlet ports  150 A,  150 B that the carbon dioxide compressor  152  is connected to and into the holding tank  156  for later use, storage and/or disposal. The carbon dioxide compressor  152  may be a rotary screw type compressor, a piston compressor or the like. 
     A carbon dioxide heat exchanger  158  may be disposed between the holding tank  156  and the carbon dioxide compressor  152  to cool the carbon dioxide  142  prior to entering the holding tank  156 . The carbon dioxide heat exchanger  158  may be cooled by a cooling tower  160  that circulates coolant fluid between the cooling tower  160  and the carbon dioxide heat exchanger  158  via carbon dioxide heat exchanger coolant loop  162 . 
     During operation, the various flow valves  136 A,  136 B,  140 A,  140 B,  144 A,  144 B,  146 A,  146 B,  154 A and  154 B may be configured such that the exhaust gas inlet port  134 A of the first capture tank  108  is connected (i.e., in fluid communication) to the flow of exhaust gas  102  from the engine  104 . In other words, the exhaust gas inlet port  134 A is connected to the flow of exhaust gas  102  prior to the exhaust gas  102  passing through the carbon dioxide absorbent material  106  in the first capture tank  108 . Additionally, the first capture tank&#39;s exhaust gas outlet port  138 A is connected (i.e., in fluid communication) to the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 . In other words, the exhaust gas outlet port  138 A is connected to the flow of exhaust gas  102  after the exhaust gas has passed through the carbon dioxide absorbent material  106  in the first capture tank  108 . Additionally, the carbon dioxide compressor  152  may be connected to the carbon dioxide outlet port  150 B of the second capture tank  128 . The heat exchange loop  118  may be connected between the exhaust gas to heat exchange fluid heat exchanger  126  and the second capture tank  128 . In this configuration, exhaust gas  102  will flow into the first capture tank  108  to remove the carbon dioxide  142  from the exhaust gas  102  flow prior to entering the exhaust gas to heat exchange fluid heat exchanger  126 . The exhaust gas to heat exchange fluid heat exchanger  126  will transfer heat from the exhaust gas  102  into the heat exchange fluid  120 , which will be pumped via pump  122  through the heat exchange loop  118  to the heating jacket  148  of the second capture tank  128 . Accordingly, the heat from the exhaust gas  102  will advantageously be used to heat the second capture tank  128  to regenerate the carbon dioxide from the second capture tank  128  and to pump the carbon dioxide  142  into the holding tank  156 . By using the heat from the exhaust gas  102  to regenerate the carbon dioxide in the second capture tank  128 , the energy needed from external sources (such as electric heaters or the like) to regenerate the carbon dioxide  142  is advantageously reduced. 
     Also during operation, the various flow valves  136 A,  136 B,  140 A,  140 B,  144 A,  144 B,  146 A,  146 B,  154 A and  154 B may be configured such that the exhaust gas inlet port  134 B of the second capture tank  128  is connected (i.e., in fluid communication) to the flow of exhaust gas  102  from the engine  104 . In other words, the exhaust gas inlet port  134 B is connected to the flow of exhaust gas  102  prior to the exhaust gas  102  passing through the carbon dioxide absorbent material  106  in the second capture tank  128 . Additionally, the second capture tank&#39;s exhaust gas outlet port  138 B is connected (i.e., in fluid communication) to the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 . In other words, the exhaust gas outlet port  138 B is connected to the flow of exhaust gas  102  after the exhaust gas has passed through the carbon dioxide absorbent material  106  in the second capture tank  128 . Additionally, the carbon dioxide compressor  152  may be connected to the carbon dioxide outlet port  150 A of the first capture tank  108 . The heat exchange loop  118  may be connected between the exhaust gas to heat exchange fluid heat exchanger  126  and the first capture tank  128 . In this configuration, exhaust gas  102  will flow into the second capture tank  128  to remove the carbon dioxide  142  from the exhaust gas  102  flow prior to entering the exhaust gas to heat exchange fluid heat exchanger  126 . The exhaust gas to heat exchange fluid heat exchanger  126  will transfer heat from the exhaust gas  102  into the heat exchange fluid  120 , which will be pumped via pump  122  through the heat exchange loop  118  to the heating jacket  124  of the first capture tank  108 . Accordingly, the heat from the exhaust gas  102  will advantageously be used to heat the first capture tank  108  to regenerate the carbon dioxide from the first capture tank  108  and to pump the carbon dioxide  142  into the holding tank  156 . By using the heat from the exhaust gas  102  to regenerate the carbon dioxide in the first capture tank  108 , the energy needed from external sources (such as electric heaters or the like) to regenerate the carbon dioxide  142  is advantageously reduced. 
     Referring to  FIG.  3   , another example is depicted of a schematic view of the carbon dioxide capture system  100  of  FIG.  1    according to aspects described herein. The carbon dioxide capture system  100  of  FIG.  3    has a first capture tank  108  and a second capture tank  128 . The carbon dioxide capture system  100  utilizes an exhaust gas to heat exchange fluid heat exchanger  126  to transfer heat from the exhaust gas  102  to a heat exchange fluid  120  in a heat exchange loop  118  that is in heat exchange communication with the first and second capture tanks  108  and  128 . 
     The carbon dioxide capture system  100  of  FIG.  3    functions similarly to that of the carbon dioxide capture system  100  of  FIG.  2   . However, the flow of exhaust gas  102  in  FIG.  3    passes through the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126  prior to the flow of exhaust gas  102  passing through the first capture tank  108 . This is different from the example of the carbon dioxide capture system  100  illustrated in  FIG.  2   , wherein the flow of exhaust gas passes through the first capture tank  108  prior to the flow of exhaust gas passing through the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 . 
     More specifically in  FIG.  3   , the flow of exhaust gas  102  from engine  104  flows directly into the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 , wherein heat from the exhaust gas  102  is exchanged with the heat exchange fluid  120  of the heat exchange loop  118 . Also, when the exhaust gas  102  exits the first flow path  130 , it does not then get routed to the stack  103 . Rather, the exhaust gas  102  gets routed to the exhaust gas inlet ports  134 A and  134 B, wherein it enters the first or second capture tanks  108  and  128 . The carbon dioxide  142  is then removed by the carbon dioxide absorbent material  106  disposed in the first and second capture tanks  108 ,  128 . The exhaust gas  102  then exits the first and second capture tanks  108 ,  128  via the exhaust gas outlet ports  138 A and  138 B, wherein the exhaust gas  102  is then routed to the stack  103 . 
     Advantageously, by routing the flow of exhaust gas first into the first flow path  130  of the heat exchanger  126 , there may be more heat energy within the exhaust gas  102  to be transferred to the heat exchange fluid  120  relative to the carbon dioxide capture system  100  of  FIG.  2   . Accordingly, there may be more heat energy that can be transferred from the heat exchange fluid  120  to the carbon dioxide absorption material  106 . 
     Referring to  FIG.  4   , an example is depicted of a schematic view of the carbon dioxide capture system  100  of  FIG.  1    having a first capture tank  108  and a second capture tank  128 , and wherein the exhaust gas  102  is the heat exchange fluid  120  that is circulated in the heat exchange loop  118 , according to aspects described herein. 
     The carbon dioxide capture system  100  illustrated in  FIG.  4    operates similarly to the carbon dioxide capture system of  FIG.  2   . However, in the carbon dioxide capture system  100  of  FIG.  4   , the exhaust gas to heat exchange fluid heat exchanger  126  is removed. Accordingly, the heat exchange communication between the flow of exhaust gas  102  and the first and second capture tanks  108 ,  128  occurs directly, rather than indirectly through the exhaust gas to heat exchange fluid heat exchanger  126 . Accordingly, the heat exchange loop  118  is configured to receive the exhaust gas  102  from the engine  104  such that the exhaust gas  102  is the heat exchange fluid  120  that is operable to flow through the heat exchange loop  118 . 
     More specifically, when flow valves  136 A,  140 A,  144 B and  146 B are open, and flow valves  136 B,  140 B,  144 A and  146 A are closed, the exhaust gas  102  is routed from the engine  104 , through inlet port  134 A and into the first capture tank  108  to remove the carbon dioxide  142  from the exhaust gas  102 . The exhaust gas  102  is then routed from the outlet port  138 A directly into the heat exchange loop  118 , wherein it functions as the heat exchange fluid  120 . That is, the exhaust gas  102  is routed, via the heat exchange loop  118 , through the heating jacket  148  of the second capture tank  128  to heat and regenerate the carbon dioxide  142  trapped in the carbon dioxide absorbent material  106  of the second capture tank  128 . The exhaust gas  102  is then routed out of the heat exchange loop  118  and up the stack  103 . 
     Additionally, when flow valves  136 B,  140 B,  144 A and  146 A are open, and flow valves  136 A,  140 A,  144 B and  146 B are closed, the exhaust gas  102  is routed from the engine  104 , through inlet port  134 B and into the second capture tank  128  to remove the carbon dioxide  142  from the exhaust gas  102 . The exhaust gas  102  is then routed from the outlet port  138 B directly into the heat exchange loop  118 , wherein it functions as the heat exchange fluid  120 . That is, the exhaust gas  102  is routed, via the heat exchange loop  118 , through the heating jacket  124  of the first capture tank  128  to heat and regenerate the carbon dioxide  142  trapped in the carbon dioxide absorbent material  106  of the first capture tank  128 . The exhaust gas  102  is then routed out of the heat exchange loop  118  and up the stack  103 . 
     In the example of the carbon dioxide capture system  100  illustrated in  FIG.  4   , the flow of exhaust gas  102  passes through the first capture tank  108  prior to the exhaust gas  102  passing through the heat exchange loop  118 . 
     Referring to  FIG.  5   , another example is depicted of a schematic view of the carbon dioxide capture system  100  of  FIG.  1    having a first and a second capture tank  108 ,  128 , wherein the exhaust gas  102  is the heat exchange fluid  120  that is circulated in the heat exchange loop  118 , according to aspects described herein. In this example of the carbon dioxide capture system  100 , the flow of exhaust gas  102  passes through the heat exchange loop  118  prior to the exhaust gas  102  passing through the first capture tank  108 . 
     More specifically, when flow valves  136 A,  140 A,  144 B and  146 B are open, and flow valves  136 B,  140 B,  144 A and  146 A are closed, the exhaust gas  102  is routed from the engine  104 , directly into the heat exchange loop  118 , wherein it functions as the heat exchange fluid  120 . That is, the exhaust gas  102  is routed, via the heat exchange loop  118 , through the heating jacket  148  of the second capture tank  128  to heat and regenerate the carbon dioxide  142  trapped in the carbon dioxide absorbent material  106  of the second capture tank  128 . The exhaust gas  102  is then routed out of the heat exchange loop  118  and through inlet port  134 A and into the first capture tank  108  to remove the carbon dioxide  142  from the exhaust gas  102 . The exhaust gas  102  is then routed from the outlet port  138 A of the first capture tank  108  and up the stack  103 . 
     Additionally, when flow valves  136 B,  140 B,  144 A and  146 A are open, and flow valves  136 A,  140 A,  144 B and  146 B are closed, the exhaust gas  102  is routed from the engine  104 , directly into the heat exchange loop  118 , wherein it functions as the heat exchange fluid  120 . That is, the exhaust gas  102  is routed, via the heat exchange loop  118 , through the heating jacket  124  of the first capture tank  108  to heat and regenerate the carbon dioxide  142  trapped in the carbon dioxide absorbent material  106  of the first capture tank  108 . The exhaust gas  102  is then routed out of the heat exchange loop  118  and through inlet port  134 B and into the second capture tank  128  to remove the carbon dioxide  142  from the exhaust gas  102 . The exhaust gas  102  is then routed from the outlet port  138 B of the second capture tank  128  and up the stack  103 . 
     Referring to  FIG.  6   , an example is depicted of a schematic view of at least a portion of carbon dioxide capture system  100  having a first capture tank  108  with carbon dioxide absorbent material  106  disposed therein, according to aspects described herein. The carbon dioxide capture system  100  is removing carbon dioxide  142  from the flow of exhaust gas  102  that is passing through the first capture tank  108  and further utilizing heat from engine coolant  164  from the engine  104  to regenerate the carbon dioxide  142 . 
     The carbon dioxide capture system  100  as illustrated in  FIG.  6    functions similarly to the carbon dioxide capture system  100  as illustrated in  FIG.  1   . However, rather than using the exhaust gas  102  as a heat source to regenerate the carbon dioxide  142  trapped in the carbon dioxide absorbent material  106 , the system  100  of  FIG.  6    utilizes a flow of engine coolant  164  from the engine  104  as the heat source. 
     The carbon dioxide capture system  100  of  FIG.  6    includes a first capture tank  108  containing carbon dioxide absorbent material  106  which operates to absorb carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 . A heat exchange loop  118  is in heat exchange communication with the first capture tank  108  and further in heat exchange communication with a flow of engine coolant  164  from the internal combustion engine  104 . A heat exchange fluid  120 , such as glycol, water of the like, is operable to flow through the heat exchange loop  118 . The heat exchange fluid  120  operates to transfer heat from the engine coolant  164  to the first capture tank  108 . The heat from the engine coolant  164  operates to release a portion of the carbon dioxide  142  absorbed by the carbon dioxide absorbent material  106  in the first capture tank  108 . 
     The system  100  also includes an “engine coolant to heat exchange fluid heat exchanger”  168 . The engine coolant to heat exchange fluid heat exchanger  168  includes a first flow path  170  and a second flow path  172  which operate to exchange heat therebetween. The first flow path  170  operates to receive therethrough the flow of engine coolant  164  from the engine  104 . The second flow path  172  operates to receive therethrough the flow of heat exchange fluid  120  in the heat exchange loop  118 . The engine coolant to heat exchange fluid heat exchanger  168  operates to transfer heat from the engine coolant  164  to the heat exchange fluid  120 . The heat exchange loop  118  operates to flow the heat exchange fluid  120  to the first capture tank  108  and to transfer heat from the heat exchange fluid  120  to the carbon dioxide absorbent material  106  in the first capture tank  108 . 
     More specifically, the flow of exhaust gas  102  to the first capture tank  108  is controlled by a flow valve  136 A. When the flow valve  136 A is open, the exhaust gas  102  enters the first capture tank  108  through an exhaust gas inlet port  134 A of the first capture tank  108 . Carbon dioxide  142  is then removed from the exhaust gas  102  upon contact with the carbon dioxide absorbent material  106  disposed within the first capture tank  108 . The flow of exhaust gas then exits the first capture tank  108  through an exhaust gas outlet port  138 A of the first capture tank  108  and routed up the stack  103  of the engine  104 . 
     The flow of engine coolant  164  is routed from the engine  104  to the first flow path  170  of the engine coolant to heat exchange fluid heat exchanger  168  via engine coolant pump  166 . The engine coolant  164  then flows through the first flow path  170  and back to the engine  104 . 
     The flow of heat exchange fluid  120  in the heat exchange loop  118  is controlled by flow valves  144 A and  146 A and by heat exchange fluid pump  122 . When the flow valves  144 A,  146 A are open, the heat exchange fluid pump  122  routes the flow of heat exchange fluid  120  from the second flow path  172  of heat exchanger  168  and through the heating jacket  124  of the first capture tank  108 . The heat exchange fluid  120  in the heating jacket  124  then transfers heat picked up from the engine coolant  164  into the carbon dioxide absorbent material  106 . The heated absorbent material  106  then releases (or regenerates) the carbon dioxide  142  trapped within. The carbon dioxide  142  may be routed out of the carbon dioxide outlet port  150 A of the first capture tank  108 . 
     The carbon dioxide absorbent materials  106  may be composed of carbon dioxide adsorbent materials such as zeolite or similar. As such, the adsorbent materials may release their adsorbed carbon dioxide at fairly low temperatures, such as 220 degrees F. or less. This may be advantageous when utilizing heat from the engine coolant  164  of the internal combustion engine  104  to regenerate the carbon dioxide  142 , since the engine coolant  164  may have an operating temperature that is about 230 degrees F. or lower. 
     Referring to  FIG.  7   , an example is depicted of a schematic view of the carbon dioxide capture system  100  of  FIG.  6    having a first capture tank  108  and a second capture tank  128  according to aspects described herein. The carbon dioxide capture system  100  illustrated in  FIG.  7    functions similarly to the carbon dioxide capture system of  FIG.  2   . However, instead of utilizing an exhaust gas to heat exchange fluid heat exchanger  126  to transfer heat from the exhaust gas  102  to the heat exchange fluid  120  in the heat exchange loop  118 , the system illustrated in  FIG.  7    utilizes an engine coolant to heat exchange fluid heat exchanger  168  to transfer heat from the engine coolant  164  to the heat exchange fluid  120 . 
     During operation, the various flow valves  136 A,  136 B,  140 A,  140 B,  144 A,  144 B,  146 A,  146 B,  154 A and  154 B may be configured such that the exhaust gas inlet port  134 A of the first capture tank  108  is connected (i.e., in fluid communication) to the flow of exhaust gas  102  from the engine  104 . Additionally, the first capture tank&#39;s exhaust gas outlet port  138 A is connected (i.e., in fluid communication) to the stack  103  of the engine  104 . Additionally, the carbon dioxide compressor  152  may be connected to the carbon dioxide outlet port  150 B of the second capture tank  128 . The heat exchange loop  118  may be connected between the engine coolant to heat exchange fluid heat exchanger  168  and the second capture tank  128 . In this configuration, exhaust gas  102  will flow into the first capture tank  108  to remove the carbon dioxide  142  from the exhaust gas  102  flow. The exhaust gas  102  will then be routed out of the outlet port  138 A of the first capture tank  108  and up the stack  103 . The engine coolant will be pumped via engine coolant pump  166  to engine coolant to heat exchange fluid heat exchanger  168 . The heat exchanger  168  will transfer heat from the engine coolant  164  into the heat exchange fluid  120 , which will be pumped via pump  122  through the heat exchange loop  118  to the heating jacket  148  of the second capture tank  128 . Accordingly, the heat from the engine coolant  164  will advantageously be used to heat the second capture tank  128  to regenerate the carbon dioxide from the second capture tank  128  and to pump the carbon dioxide  142  into the holding tank  156 . By using the heat from the engine coolant  164  to regenerate the carbon dioxide in the second capture tank  128 , the energy needed from external sources (such as electric heaters or the like) to regenerate the carbon dioxide  142  is advantageously reduced. 
     Also during operation, the various flow valves  136 A,  136 B,  140 A,  140 B,  144 A,  144 B,  146 A,  146 B,  154 A and  154 B may be configured such that the exhaust gas inlet port  134 B of the second capture tank  128  is connected (i.e., in fluid communication) to the flow of exhaust gas  102  from the engine  104 . Additionally, the second capture tank&#39;s exhaust gas outlet port  138 B is connected (i.e., in fluid communication) to the stack  103  of the engine  104 . Additionally, the carbon dioxide compressor  152  may be connected to the carbon dioxide outlet port  150 A of the first capture tank  108 . The heat exchange loop  118  may be connected between the engine coolant to heat exchange fluid heat exchanger  168  and the first capture tank  108 . In this configuration, exhaust gas  102  will flow into the second capture tank  128  to remove the carbon dioxide  142  from the exhaust gas  102  flow. The exhaust gas  102  will then be routed out of the outlet port  138 B of the first capture tank  108  and up the stack  103 . The engine coolant will be pumped via engine coolant pump  166  to the engine coolant to heat exchange fluid heat exchanger  168 . The heat exchanger  168  will transfer heat from the engine coolant  164  into the heat exchange fluid  120 , which will be pumped via pump  122  through the heat exchange loop  118  to the heating jacket  124  of the first capture tank  108 . Accordingly, the heat from the engine coolant  164  will advantageously be used to heat the first capture tank  108  to regenerate the carbon dioxide from the first capture tank  108  and to pump the carbon dioxide  142  into the holding tank  156 . By using the heat from the engine coolant  164  to regenerate the carbon dioxide in the first capture tank  108 , the energy needed from external sources (such as electric heaters or the like) to regenerate the carbon dioxide  142  is advantageously reduced. 
     Referring to  FIG.  8   , another example is depicted of a schematic view of the carbon dioxide capture system  100  of  FIG.  6    having a first and a second capture tank  108 ,  128 , wherein the engine coolant  164  is the heat exchange fluid  120  that is circulated in the heat exchange loop  118 , according to aspects described herein. 
     The carbon dioxide capture system  100  illustrated in  FIG.  8    operates similarly to the carbon dioxide capture system of  FIG.  7   . However, in the carbon dioxide capture system  100  of  FIG.  8   , the engine coolant to heat exchange fluid heat exchanger  168  is removed. Accordingly, the heat exchange communication between the flow of engine coolant  164  and the first and second capture tanks  108 ,  128  occurs directly, rather than indirectly through the engine coolant to heat exchange fluid heat exchanger  168 . Accordingly, the heat exchange loop  118  is configured to receive the engine coolant  164  from the engine  104  such that the engine coolant  164  is the heat exchange fluid  120  that is operable to flow through the heat exchange loop  118 . 
     More specifically, when flow valves  136 A,  140 A,  144 B and  146 B are open, and flow valves  136 B,  140 B,  144 A and  146 A are closed, the exhaust gas  102  is routed from the engine  104 , through inlet port  134 A and into the first capture tank  108  to remove the carbon dioxide  142  from the exhaust gas  102 . The exhaust gas  102  is then routed from the outlet port  138 A to the stack  103 . The engine coolant is routed via pump  166  directly into the heat exchange loop  118 , wherein it functions as the heat exchange fluid  120 . That is, the engine coolant  164  is routed, via the heat exchange loop  118 , through the heating jacket  148  of the second capture tank  128  to heat and regenerate the carbon dioxide  142  trapped in the carbon dioxide absorbent material  106  of the second capture tank  128 . 
     Additionally, when flow valves  136 B,  140 B,  144 A and  146 A are open, and flow valves  136 A,  140 A,  144 B and  146 B are closed, the exhaust gas  102  is routed from the engine  104 , through inlet port  134 B and into the second capture tank  128  to remove the carbon dioxide  142  from the exhaust gas  102 . The exhaust gas  102  is then routed from the outlet port  138 B to the stack  103 . The engine coolant  164  is routed via pump  166  directly into the heat exchange loop  118 , wherein it functions as the heat exchange fluid  120 . That is, the engine coolant  164  is routed, via the heat exchange loop  118 , through the heating jacket  124  of the first capture tank  108  to heat and regenerate the carbon dioxide  142  trapped in the carbon dioxide absorbent material  106  of the first capture tank  108 . 
     Referring to  FIG.  9   , an example is depicted of a schematic view of the carbon dioxide capture system  100  of  FIG.  1   , which includes a turbine-generator system  174 , which may be utilized to supply power to the carbon dioxide capture system  100 , in accordance with aspects described herein. The turbine-generator system  174  is a form of bottoming cycle power system, that can be used to supply a portion of, or all, electrical power requirements of the carbon dioxide capture system  100 . Such bottoming system power systems are described in patent application Ser. No. 17/448,943, filed on Sep. 27, 2021, titled: SYSTEMS AND METHODS ASSOCIATED WITH BOTTOMING CYCLE POWER SYSTEMS FOR GENERATING POWER AND CAPTURING CARBON DIOXIDE, and in issued U.S. Pat. No. 11,346,256, filed on Sep. 27, 2021, titled: SYSTEMS AND METHODS ASSOCIATED WITH BOTTOMING CYCLE POWER SYSTEMS FOR GENERATING POWER, CAPTURING CARBON DIOXIDE AND PRODUCING PRODUCTS, both of which are incorporated herein by reference in their entirety. 
     The turbine-generator system  174  includes a turbo-expander and turbo-compressor  178  disposed on a turbo-crankshaft  180 . The turbo-expander  176  operates to rotate the turbo-crankshaft  180  as the flow of exhaust gas  102  from the engine  104  passes through the turbo-expander  176 . The turbo-compressor  178  operates to compress the flow of exhaust gas  102  after the exhaust gas  102  passes through the turbo-expander  176 . A bottoming cycle generator  182  may be disposed on the turbo-crankshaft  180 . The bottoming cycle generator  182  may be connected to the carbon dioxide capture system  100 . The bottoming cycle generator  182  may operate to provide at least a portion of electric power required to operate the carbon dioxide capture system  100 . 
     As illustrated in  FIG.  9   , the flow of exhaust gas  102  may pass through the turbo-expander  176  and the turbo-compressor  178  prior to the flow of exhaust gas  102  passing through the first capture tank  108 . Alternatively however, the flow of exhaust gas  102  may pass through the first capture tank  108  prior to the flow of exhaust gas  102  passing through turbo-expander  176  and the turbo-compressor  178 . 
     Advantageously, by supplying some or all of the electric power requirements of the carbon dioxide capture system  100  with the turbine-generator system  174 , the detrimental effects on the efficiency of the primary power system  110  are significantly reduced. 
     Referring to  FIG.  10   , an example is depicted of a schematic view of the carbon dioxide capture system  100  of  FIG.  6   , which includes a turbine-generator system  174 , which is utilized to supply power to the carbon dioxide capture system  100 , in accordance with aspects described herein. 
     The turbine-generator system  174  includes a turbo-expander and turbo-compressor  178  disposed on a turbo-crankshaft  180 . The turbo-expander  176  operates to rotate the turbo-crankshaft  180  as the flow of exhaust gas  102  from the engine  104  passes through the turbo-expander  176 . The turbo-compressor  178  operates to compress the flow of exhaust gas  102  after the exhaust gas  102  passes through the turbo-expander  176 . A bottoming cycle generator  182  may be disposed on the turbo-crankshaft  180 . The bottoming cycle generator  182  may be connected to the carbon dioxide capture system  100 . The bottoming cycle generator  182  may operate to advantageously provide at least a portion of electric power required to operate the carbon dioxide capture system  100 . However, the turbine-generator system  174  of  FIG.  10    may also include an exhaust gas to exhaust gas heat exchanger  184  and an exhaust gas processing system  190  to help enhance the output of the bottoming cycle generator  182 . 
     The exhaust gas to exhaust gas heat exchanger  184  includes a first flow path  186  and a second flow path  188  which operate to exchange heat therebetween. The first flow path  186  operates to receive the flow of exhaust gas  102  from the turbo-expander  176  prior to the exhaust gas  102  being compressed by the turbo-compressor  178 . At this stage, the flow of exhaust gas  102  is hot (e.g., 850 to 950 degrees F.). The second flow path  188  operates to receive the flow of exhaust gas  102  from the turbo-compressor  178  after the exhaust gas  102  has been compressed by the turbo-compressor  178 . More specifically, the second flow path  188  would receive the flow of exhaust gas  102  after it has passed through the turbo-compressor  178 , then entered the carbon dioxide capture system  100  to have its carbon dioxide  142  removed, and then has exited output port  138 A to be routed into the second flow path  188  of the heat exchanger  184 . At this stage, the exhaust gas has cooled substantially (e.g., 200-100 degrees F.). Accordingly, the much cooler exhaust gas in the second flow path  188  will help to cool the hotter exhaust gas  102  in the first flow path  186 . By cooling the exhaust gas  102  prior to entering the turbo-compressor  178 , the exhaust gas is made denser and the work needed to compress the denser exhaust gas  102  is reduced. Accordingly, the efficiency of the turbine-generator system  174  is increased and more power can be produced by the bottoming cycle generator  182 . 
     The exhaust gas processing system  190  may also be used to further cool and/or remove water from the exhaust gas  102  prior to the exhaust gas  102  entering the turbo-compressor  178 . This will also tend to reduce the work needed by the turbo-compressor  178  to compress the exhaust gas  102  and, therefore, further increase the efficiency of the turbine-generator system  174 . 
     The exhaust gas processing system  190  may be configured to receive and cool and/or dry the flow of exhaust gas  102  after the exhaust gas  102  has passed through turbo-expander  176  and prior to the exhaust gas  102  being compressed by the turbo-compressor  178 . In the example illustrated in  FIG.  10   , the exhaust gas processing system  190  receives the flow of exhaust gas  102  after it has passed through the turbo-expander  176  and the exhaust gas to exhaust gas heat exchanger  184 . The exhaust gas processing system  190  may include, for example, at least one of a cooling tower, a cooling tower heat exchanger, an absorption chiller, an absorption chiller heat exchanger, a dehumidifier system, a vapor-compression refrigeration system or the like. 
     Referring to  FIG.  11   , another example is depicted of a schematic view of the carbon dioxide capture system  100  of  FIG.  1   , which includes a turbine-generator system  174 , which may be utilized to supply power to the carbon dioxide capture system  100 , in accordance with aspects described herein. The system  100  illustrate in  FIG.  11    functions similarly to the system  100  illustrated in  FIG.  9   . However, in  FIG.  11   , the exhaust gas  102  is routed from the turbo-expander  176  to the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126  prior to entering the turbo-compressor  178 . Upon exiting the turbo-compressor, the exhaust gas is the routed into the first capture tank  108  to have its carbon dioxide  142  removed. 
     In the configuration of  FIG.  11   , the carbon dioxide capture system  100  functions as a type of exhaust gas processing system (such as the exhaust gas processing system  190  of  FIG.  10   ). More specifically, the carbon dioxide capture system  100  in  FIG.  11    is used to cool the exhaust gas  102  prior to entering the turbo-compressor, which increases the density of the exhaust gas and reduces the amount of work required by the turbo-compressor  178  to compress the exhaust gas  102 . Accordingly, the efficiency of the turbine-generator system  174  is increased and the power output of the bottoming cycle generator  182  is also increased. 
     Referring to  FIG.  12   , an example is depicted of a flow diagram of a method  200  of capturing carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 , in accordance with aspects described herein. The method may utilize one or more of the examples of the carbon dioxide capture systems  100  describe herein. 
     The method  200  ( FIG.  12   ), as well each following method  220  ( FIG.  13   ), method  240  ( FIG.  14   ), method  250  ( FIG.  15   ), method  260  ( FIG.  16   ), method  280  ( FIG.  17   ), method  300  ( FIG.  18   ), method  320  ( FIG.  19   ) and method  330  ( FIG.  20   ) depicts non-limiting examples of various steps of carrying out the methods. However, the order in which the steps of each method are executed may not coincide with the order in which the steps are illustrated in each of  FIGS.  12  through  20   . Additionally, certain other unillustrated steps may be added to the illustrated methods. 
     At  202 , the method includes routing a flow of exhaust gas  102  from an internal combustion engine  104  into a first capture tank  108  of a carbon dioxide capture system;  100 . 
     At  204 , carbon dioxide  142  is absorbed from the exhaust gas  102  in the first capture tank  108  with carbon dioxide absorbent material  106  that is disposed (or positioned) in the first capture tank  108 . 
     At  206 , the flow of exhaust gas is routed out of the first capture tank. 
     At  208 , a heat exchange loop  118  is connected in heat exchange communication with the first capture tank  108 . Additionally, the heat exchange loop  118  is connected in heat exchange communication with one of the flow of exhaust gas  102  or a flow of engine coolant  164  from the internal combustion engine  104 . 
     At  210 , a heat exchange fluid  120  is circulated through the heat exchange loop  118 . 
     At  212 , heat is transferred from the exhaust gas  102  or the engine coolant  164  to the first capture tank  108  via the heat exchange fluid  120 . 
     At  214 , a portion of the carbon dioxide  142  absorbed by the carbon dioxide absorbent material  106  in the first capture tank  108  is released, as a result of the heat transferred from the exhaust gas  102  or the engine coolant  164 . 
     Referring to  FIG.  13   , another example is depicted of a flow diagram of a method  220  of capturing carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 , in accordance with aspects described herein. The flow diagram of the method  220  is a continuation of the flow diagram of the method  200  of  FIG.  12   . 
     At  222 , the method includes routing the flow of exhaust gas  102  through a first flow path  130  of an exhaust gas to heat exchange fluid heat exchanger  126 . 
     At  224 , The heat exchange fluid  120  is routed through a second flow path  132  of the exhaust gas to heat exchange fluid heat exchanger  126 . 
     At  226 , Heat is transferred from the exhaust gas  102  to the heat exchange fluid  120  via the exhaust gas to heat exchange fluid heat exchanger  126 . 
     At  228 , The heat exchange fluid  120  is flowed to the first capture tank  108 . 
     At  230 , Heat is transferred from the heat exchange fluid  120  to the carbon dioxide absorbent material  106  in the first capture tank  108 . 
     Referring to  FIG.  14   , another example is depicted of a flow diagram of a method  240  of capturing carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 , in accordance with aspects described herein. The flow diagram of the method  240  is a continuation of the flow diagram of the method  200  of  FIG.  12   . 
     At  242 , the method incudes receiving the exhaust gas  102  from the engine  104  into the heat exchange loop  118 , such that the exhaust gas  102  is the heat exchange fluid  120  that flows through the heat exchange loop  118 . In other words, in this method  240 , the exhaust gas to heat exchange fluid heat exchanger  126  is not utilized. Therefore, the exhaust gas  102  flows into the heat exchange loop  118  to heat the first capture tank  108  directly, rather than heating the first capture tank  108  indirectly through an exhaust gas to heat exchange fluid heat exchanger  126 . 
     Referring to  FIG.  15   , another example is depicted of a flow diagram of a method  250  of capturing carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 , in accordance with aspects described herein. The flow diagram of the method  250  is a continuation of the flow diagram of the method  200  of  FIG.  12   . 
     At  252 , the method incudes receiving the engine coolant  164  from the engine  104  into the heat exchange loop  118 , such that the engine coolant  164  is the heat exchange fluid  120  that flows through the heat exchange loop  118 . In other words, in this method  250 , the engine coolant to heat exchange fluid heat exchanger  168  is not utilized. Therefore, the engine coolant  164  flows into the heat exchange loop  118  to heat the first capture tank  108  directly, rather than heating the first capture tank  108  indirectly through an engine coolant to heat exchange fluid heat exchanger  168 . 
     Referring to  FIG.  16   , another example is depicted of a flow diagram of a method  260  of capturing carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 , in accordance with aspects described herein. The flow diagram of the method  260  is a continuation of the flow diagram of the method  200  of  FIG.  12   . 
     At  262 , the method includes routing the flow of engine coolant  164  through a first flow path  170  of an engine coolant to heat exchange fluid heat exchanger  168 . 
     At  264 , the heat exchange fluid  120  is routed through a second flow path  172  of the engine coolant to heat exchange fluid heat exchanger  168 . 
     At  266 , heat is transferred from the engine coolant  164  to the heat exchange fluid  120  via the engine coolant to heat exchange fluid heat exchanger  168 . 
     At  268 , the heat exchange fluid  120  is flowed to the first capture tank  108 . 
     At  270 , heat is transferred from the heat exchange fluid  120  to the absorbent material  106  in the first capture tank  108 . Referring to  FIG.  17   , another example is depicted of a flow diagram of a method  280  of capturing carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 , in accordance with aspects described herein. The flow diagram of the method  280  is a continuation of the flow diagram of the method  200  of  FIG.  12   . 
     At  282 , the method includes routing the flow of exhaust gas  102  through a turbo-expander  176  disposed on a turbo-crankshaft  180  of a turbine-generator system  174 . 
     At  284 , the flow of exhaust gas  102  is compressed via a turbo-compressor  178  disposed on the turbo-crankshaft  180  of the turbine-generator system  174  after the exhaust gas  102  passes through the turbo-expander  176 . 
     At  286 , electric power is generated via a bottoming cycle generator  182  disposed on the turbo-crankshaft  180  of the turbine-generator system  174 . 
     At  288 , at least a portion of electric power required to operate the carbon dioxide capture system  100  is provided from the electric power generated by the bottoming cycle generator  182 . 
     Referring to  FIG.  18   , another example is depicted of a flow diagram of a method  300  of capturing carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 , in accordance with aspects described herein. The flow diagram of the method  300  is a continuation of the flow diagram of the method  200  of  FIG.  12   . 
     At  302 , the method includes routing the flow of exhaust gas  102  into a second capture tank  128  of the carbon dioxide capture system  100 . 
     At  304 , carbon dioxide  142  is absorbed in the second capture tank  128  from the exhaust gas  102  with carbon dioxide absorbent material  106  disposed in the second capture tank  128 . 
     At  306 , the flow of exhaust gas  102  is routed out of the second capture tank  128 . 
     At  308 , the heat exchange loop  118  is connected in heat exchange communication with either the first capture tank  108  or the second capture tank  128 . Additionally the heat exchange loop  118  is connected in heat exchange communication with one of the flow of exhaust gas  102  or a flow of engine coolant  164  from the internal combustion engine  104 . 
     At  310 , the heat exchange fluid is circulated through the heat exchange loop  118 . 
     At  312 , heat is transferred from the exhaust gas  102  or the engine coolant  164  to either the first capture tank  108  or the second capture tank  128  via the heat exchange fluid  120 . 
     At  314 , a portion of the carbon dioxide  142  absorbed by the carbon dioxide absorbent material  106  in either the first capture tank  108  or the second capture tank  128  is released, as a result of the heat transferred from the exhaust gas  102  or the engine coolant  164 . 
     Referring to  FIG.  19   , another example is depicted of a flow diagram of a method  320  of capturing carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 , in accordance with aspects described herein. The flow diagram of the method  320  is a continuation of the flow diagram of the method  300  of  FIG.  18   . 
     At  322 , the method includes connecting the heat exchange loop  118  in heat exchange communication with the second capture tank  128  and further connecting the heat exchange loop  118  in heat exchange communication with one of the flow of exhaust gas  102  or a flow of engine coolant  164  when the flow of exhaust gas  102  is routed into the first capture tank  108 . In this configuration, the exhaust gas  102  or engine coolant  164  will heat the second capture tank  128  to regenerate the carbon dioxide  142  trapped within, while the carbon dioxide  142  from the exhaust gas  102  will be absorbed in the first capture tank  108 . 
     At  324 , the heat exchange loop  118  is connected in heat exchange communication with the first capture tank  108  and the heat exchange loop  118  is further connected in heat exchange communication with one of the flow of exhaust gas  102  or a flow of engine coolant  164  when the flow of exhaust gas  102  is routed into the second capture tank  128 . In this configuration, the exhaust gas  102  or engine coolant  164  will heat the first capture tank  108  to regenerate the carbon dioxide  142  trapped within, while the carbon dioxide  142  from the exhaust gas  102  will be absorbed in the second capture tank  128 . 
     Referring to  FIG.  20   , another example is depicted of a flow diagram of a method  330  of capturing carbon dioxide  142  from a flow of exhaust gas  102  from an internal combustion engine  104 , in accordance with aspects described herein. The flow diagram of the method  330  is a continuation of the flow diagram of the method  220  of  FIG.  13   . 
     At  332 , the method includes routing the flow of exhaust gas  102  through a turbo-expander  176  of a turbine-generator system  174 , then through the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126 , then through a turbo-compressor  178  of the turbine-generator system  174 , then through the first capture tank  108 . 
     This method is associated with the carbon dioxide capture system  100  of  FIG.  11   . In the system  100  of  FIG.  11   , the exhaust gas  102  is routed from the turbo-expander  176  to the first flow path  130  of the exhaust gas to heat exchange fluid heat exchanger  126  prior to entering the turbo-compressor  178 . Upon exiting the turbo-compressor, the exhaust gas is the routed into the first capture tank  108  to have its carbon dioxide  142  removed. 
     In the configuration of  FIG.  11   , the carbon dioxide capture system  100  functions as a type of exhaust gas processing system (such as the exhaust gas processing system  190  of  FIG.  10   ). More specifically, the carbon dioxide capture system  100  in  FIG.  11    is used to cool the exhaust gas  102  prior to entering the turbo-compressor, which increases the density of the exhaust gas and reduces the amount of work required by the turbo-compressor  178  to compress the exhaust gas  102 . Accordingly, the efficiency of the turbine-generator system  174  is increased and the power output of the bottoming cycle generator  182  is also increased. 
     It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail herein (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matter disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein. 
     Although the invention has been described by reference to specific examples, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the disclosure not be limited to the described examples, but that it have the full scope defined by the language of the following claims.