Patent Publication Number: US-2023151960-A1

Title: Heat generation for separate endothermic process with carbon capture

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 63/280,822 filed Nov. 18, 2021, and entitled “Oxy Fuel Heating With Carbon Capture,” the contents of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     Endothermic processes are driven by heat energy that is transferred to the process from an outside source. Such endothermic processes are commonplace in various industries, and some examples include ethylene production from naphtha and ethane cracking, hydrogen and carbon monoxide production by steam and hydrocarbon catalytic reforming, oil refinery processes, the production of styrene (e.g., via dehydrogenation or ethyl-benzene), metallurgical heat treatment processes, and steam production (e.g., in the context of electric power generation). 
     The heat source for an endothermic process may be derived from the combustion of a carbonaceous fuel, such as a hydrocarbon (e.g., diesel, gasoline, natural gas, etc.). However, such a process emits carbon dioxide (CO 2 ), which is increasingly becoming undesirable as societies world-wide attempt to move toward reduced-carbon, carbon-neutral, or carbon-negative operations. 
     BRIEF SUMMARY 
     The embodiments disclosed herein are directed to systems and methods for generating thermal energy to drive or power an endothermic process while also capturing carbon (e.g., in the form of CO 2 ) that is produced to reduce net carbon emissions during operations. In some embodiments, the systems and methods described herein may be utilized to capture carbon that is produced from the oxidation (including combustion) of a carbonaceous fuel, such as a natural gas. Thus, through use of the embodiments disclosed herein, thermal energy may be provided to an endothermic process without a corresponding increase in the output of CO 2  to the atmosphere. 
     Some embodiments disclosed herein are directed to a method of transferring thermal energy to a separate endothermic process. In an embodiment, the method includes (a) providing a CO 2  stream and a carbonaceous fuel to a heater, and (b) reacting the carbonaceous fuel with an oxidant in the heater to produce a heated stream. In addition, the method can include (c) transferring heat from the heated stream to the separate endothermic process, (d) separating the CO 2  stream from the heated stream after (c), and (e) recycling the CO 2  stream to the heater after (d). 
     As used herein, a “heater” is intended to reference any unit that is operable under conditions so that a fuel material that passed through the heater can undergo a reaction effective to at least partially oxidize the fuel material and release heat. The oxidation reaction is intended to expressly include partial or complete combustion of the fuel as well as oxidation of the fuel without combustion (e.g., reaction below the auto-ignition temperature of the fuel). The heater may be configured to achieve auto-combustion or auto-oxidation, such as may be experienced by passing the fuel material through a heater include one or more catalytic materials effective to at least partially oxidize, substantially completely oxidize, at least partially combust, or substantially completely combust the curl material. Likewise, the term “reacting” can indicate that the fuel has at least partially oxidized, substantially completely oxidized, at least partially combusted, or substantially completely combusted. 
     In some embodiments, the method includes (a) producing a CO 2  stream from a first outlet of a separator, (b) flowing the CO 2  stream to a heater, and (c) reacting a carbonaceous fuel with an oxidant in the presence of the CO 2  stream within the heater. In addition, the method includes (d) outputting a heated stream from the heater, (e) transferring heat from the heated stream to the separate endothermic process, and (f) heating the carbonaceous fuel with the heated stream, upstream of the heater after (e). Further, the method includes (g) flowing the heated stream to the separator after (f). 
     Some embodiments disclosed herein are directed to a system for transferring thermal energy to a separate endothermic process. In some embodiments, the system includes a heater including one or more inlets that are configured to receive a carbonaceous fuel and a CO 2  stream and an outlet, the heater configured react the carbonaceous fuel with an oxidantin the presence of the CO 2  stream to produce a heated stream. In addition, the system includes a heat transfer assembly fluidly coupled to the outlet, the heat transfer assembly configured to transfer heat from the heated stream to the separate endothermic process. Further, the system includes a separator fluidly coupled to and downstream of the heat transfer assembly, the separator configured to separate out the CO 2  stream from the heated stream. The separator is further coupled to and upstream of the one or more inlets of the heater such that the CO 2  stream is to flow from the separator back toward the one or more inlets of the heater. 
     Embodiments described herein comprise a combination of features and characteristics. The foregoing has outlined rather broadly the features and technical characteristics of at least some of the disclosed embodiments in order that the detailed description that follows may be better understood. The various characteristics and features described above, as well as others, will be readily apparent to those having ordinary skill in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that this disclosure may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the embodiments disclosed herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a detailed description of various embodiments, reference will now be made to the accompanying drawings in which: 
         FIG.  1    is a schematic diagram of a system for transferring heat to a separate endothermic process according to some embodiments; and 
         FIG.  2    is a schematic diagram of another system for transferring heat to a separate endothermic process according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure is directed to systems and methods for generating and transferring heat to a separate endothermic process while capturing produced CO 2 . As used herein, a “separate endothermic process” or “separate process” refers to an industrial process (e.g., any of the above-mentioned example industrial endothermic processes) that is separate and independent from the systems and methods for transferring heat described herein. Thus, as described herein, a “separate endothermic process” may receive heat (thermal energy) via the disclosed systems and methods but would otherwise be a separate industrial process wholly apart and independent from the disclosed systems and methods. However, in some embodiments, the “separate endothermic process” may utilize one or more other output streams (e.g., an output CO 2  stream, an output water stream, etc.) from the systems disclosed herein. 
     In some embodiments, a carbonaceous fuel may be reacted with an oxidant in the presence of a circulating stream of CO 2  to generate heat that is then transferred via suitable processes and/or components to the separate endothermic process. The carbonaceous fuel may comprise any suitable fuel such as, for instance, a hydrocarbon fuel or a non-hydrocarbon carbonaceous fuel such as carbon monoxide (CO). For example, in some embodiments, the carbonaceous fuel may comprise natural gas or one or more components thereof (e.g., ethane, methane, propane, etc.). 
     In some embodiments, oxygen (O 2 ) may be used as an oxidant when reacting the carbonaceous fuel. In some embodiments, the oxidant stream provided to the heater may comprise pure or nearly pure O 2 . For instance, the oxidant stream may comprise between about 95 vol % and about 100 vol % O 2 . In some embodiments, the oxidant may be diluted with a diluent, such as CO 2  or other material that exhibits a suitably low reactivity with the fuel under the operating conditions of the heater (e.g., via the circulating stream) to provide an oxidant stream to the heater with a reduced O 2  concentration, including in the range of about 20% to about 30% molar. Without being limited to this or any other theory, diluting the oxidant in this manner may allow for moderation of the adiabatic flame temperature in the heater. In some embodiments, the quantity of O 2  fed to the heater may be in excess of that required for complete reaction (e.g., oxidation or actual combustion), thereby leading to an oxygen concentration in the output stream from the heater of about 0.5 vol % to about 10 vol % O 2 . Without being limited to this or any other theory, providing such an excess quantity of oxygen to the heater may help to ensure complete reaction of the carbonaceous fuel. 
     The products of reaction of the carbonaceous fuel may comprise CO 2  and water (H 2 O). These products are mixed with the circulating stream of CO 2  and are then routed to transfer thermal energy (e.g., heat) to the separate endothermic process. Without being limited to this or any other theory, the circulating stream of CO 2  may operate as a working fluid that receives thermal energy from the reaction process and then transfers that thermal energy to the separate endothermic process downstream of the heater. As a result, the circulating stream of CO 2  may allow thermal energy to be more efficiently transferred from the reaction process to the separate endothermic process during operations. In addition, any CO 2  produced during the reaction process may be integrated into the circulating stream of CO 2  so that atmospheric CO 2  emissions from the reaction of the carbonaceous fuel may be significantly reduced or even eliminated. Because the circulating stream of CO 2  may be utilized as a heat transfer medium with the embodiments disclosed herein, the circulating stream of CO 2  may be referred to as a “CO 2  work stream.” 
     In some embodiments, the CO 2  work stream may be at an elevated pressure. For instance, in some embodiments, the CO 2  work stream may be at a pressure from about 30 bar (3 MPa) to about 100 bar (10 MPa). In some embodiments, the CO 2  work stream, at the elevated pressure, may deliver heat to a separate endothermic process at temperatures up to about 1000° C. (e.g., via suitable heat exchanger devices and systems) or higher, if materials allow. Thus, in some embodiments, the CO 2  work stream may comprise supercritical CO 2 . 
     In some embodiments, following heat transfer to the separate endothermic process, additional thermal energy may be transferred from the CO 2  work stream (which now includes the products of reaction of the carbonaceous fuel as previously described) to preheat other streams (e.g., the CO 2  work stream upstream of the heater, the oxidant, the carbonaceous fuel, etc.) before they enter the heater. In some embodiments, a single heat exchanger or multiple heat exchangers may be used to transfer the additional heat from the CO 2  work stream to the other stream(s) as described. For instance, in some embodiments, a first heat exchanger may be used to transfer heat from the CO 2  work stream to the carbonaceous fuel, while a second heat exchanger may be used to transfer heat from the CO 2  work stream to the oxidant. Without being limited to this or any other theory, by preheating the oxidant and carbonaceous fuel in separate heat exchangers (e.g., the first heat exchanger and the second heat exchanger), one may avoid heating these components in a single heat exchanger, which may pose a risk of unintentional reaction. In some embodiments, the heat exchanger(s) used to preheat one or more streams via the CO 2  work stream, following heat transfer to the separate endothermic process, may comprise one or more heat exchangers of any physical configuration (embodiments of which include plate-and-fin heat exchangers, and other heat exchangers suitable for high temperature operation with possibly corrosive materials—e.g., a high nickel allow). 
     In some embodiments, after transferring heat to the separate endothermic process, the CO 2  work stream (including the products of reaction from the heater) may be cooled (e.g., to or near to ambient temperature) so that the H 2 O produced in the heater may be separated from the CO 2  work stream. Excess or net CO 2  may be removed from the process and provided to a separate process or unit. The excess or net CO 2  may be removed under pressure control at (or near) ambient temperature. For instance, the net CO 2  removed from the CO 2  work stream may be at a pressure from about 30 bar (3 MPa) to about 100 bar (10 MPa). In some embodiments, the net CO 2  removed from the CO 2  work stream may comprise the excess O 2  from the heater and additional impurities (e.g., argon, nitrogen, etc.) that may be present in the oxidant stream. 
     The remaining, CO 2  work stream (e.g., following removal of H 2 O and the net CO 2 ) may then be recirculated back to the heater to complete the fluid circuit and reinitiate the process described above. In some embodiments, the CO 2  work stream may be pressurized to initiate the flow thereof back toward the heater (or the one or more heat exchangers for preheating as previously described). For instance, in some embodiments, the CO 2  work stream may be pressurized to a level sufficient to maintain a desired pressure thereof during the processes described above (e.g., from about 30 bar to about 100 bar as previously described). In some embodiments, the CO 2  work stream may be enriched with O 2  diffused through a semi-permeable barrier (which may or may not be electrostatically charged) from a feed work stream consisting of a reduced mixture of O 2  and other gases (including the gases in air and including CO 2 ), at a reduced concentration of O 2 , including in the range of about 20% to about 30% molar, where the differentials of temperatures and pressures of the feed work stream and of the CO 2  work stream drive the enrichment of the CO 2  work stream with O 2 , in a single pass or in multiple passes, all as may or may not be aided by a charge on the semi-permeable barrier. 
     In some embodiments, the CO 2  work stream may be routed to and through a heater in which O 2  is diffused through a semi-permeable barrier (one embodiment of which is an oxygen ion transport membrane (ITM)). For instance, in some embodiments, the CO 2  work stream may have a pre-heated hydrocarbon vapor added upstream of the ITM heater. An air stream at near atmospheric pressure may be preheated in a heat exchanger (e.g., a recuperator heat exchanger) and then passed through the ITM heater on a first side of the ITM membrane. A fraction of the O 2  in the air may then diffuse through the membrane to a second, opposite side of the membrane whereby it reacts with the carbonaceous fuel in the circulating CO 2  stream. Within the heater, the CO 2  work stream may be heated to a temperature of about 400° C. to about 1000° C. or higher, if materials allow. The depleted air stream emitted from the heater (e.g., on the first side of the membrane) may be cooled (e.g., in the same heat exchanger that is used to preheat the incoming air stream as previously described) and then vented to the atmosphere. The operation of the ITM unit may call for an air inlet temperature above about 800° C. in order for the ITM membrane to be able to rapidly diffuse O 2  from the air steam to the carbonaceous fuel laden recycle CO 2  stream. With the CO 2  outlet from the ITM at about 1000° C., it may be desirable to have about 60 vol % of the O 2  in the air stream diffused through the ITM membrane during operations. In addition, the heat exchanger that may be used to both preheat the incoming air stream and cool the outgoing airstream may operate with a cold end temperature difference of about 5° C. to about 15° C. In addition, the heat exchanger may operate with an air inlet temperature above about 800° C. when the air outlet temperature from the ITM above about 925° C. 
     Referring now to  FIG.  1   , which shows a non-limiting example of a system  50  for transferring heat to a separate endothermic process  2  according to some embodiments. As previously described, the system  50  may circulate a CO 2  working stream  16  to transfer heat to the separate endothermic process  2  via a heat transfer assembly  37 . 
     The system  50  may include a heater  1  that receives an oxidant stream  15 , the CO 2  work stream  14 , and a carbonaceous fuel stream  20 . The oxidant stream  15  may be derived from an O 2  feed stream  10 , which may have a high purity of O 2  (e.g., between 95% and 100% molar, such as about 99.5% molar in some embodiments). The O 2  feed stream  10  may be supplied from a cryogenic air separation unit or other suitable source. The O 2  feed stream  10  may be mixed with a portion of the CO 2  work stream (e.g., via  25 ), upstream of the heater  1  to form oxidant stream  15  such that the oxidant stream  15  may comprise a reduced concentration of O 2  as compared to the O 2  feed stream  10 . For instance, the oxidant stream  15  may comprise approximately 25 vol. % O 2  with a balance (e.g., approximately 75 vol. %) being CO 2  from the circulating CO 2  stream (including other potential impurities). 
     The carbonaceous fuel stream  20  may comprise any suitable fuel. For instance, in some embodiments, the carbonaceous fuel stream  20  may comprise a hydrocarbon fuel, such as natural gas or one or more components thereof (e.g., ethane, methane, propane, etc.), or a non-hydrocarbon fuel, such as carbon monoxide (CO). In some embodiments, the carbonaceous fuel stream  20  may comprise methane (CH 4 ). 
     Within the heater  1 , the carbonaceous fuel stream  20  is mixed with the oxidant stream  15  and is reacted in the presence of the CO 2  work stream  14  so that the products of the reaction (e.g., CO 2  and H 2 O as previously described) mix with the CO 2  work stream  14  and exit the heater  1  as a total heated stream  16 . The total heated stream  16  comprises the CO 2  work stream  14  and the products of the reaction of the carbonaceous fuel stream  20  and any remnants of oxidant stream  15 . The total heated stream  16  may be at an elevated temperature, such as, for instance about 950° C. in some embodiments. In some embodiments, the pressure of the total heated stream  16  may be at an elevated pressure, such as, for instance approximately 50 bar (5 MPa). The total heated stream  16  is then routed to the heat transfer assembly  37  such that the heat (thermal energy) within total heated stream  16  is transferred to the separate endothermic process  2  as previously described. 
     The heat transfer assembly  37  may comprise any suitable heat transfer component or device, or a collection of such components or devices. In some embodiments, the heat transfer assembly  37  may comprise a heat exchanger or a plurality of heat exchangers. In addition, in some embodiments, the heat transfer assembly  37  may be partially or wholly incorporated within the separate endothermic process  2 . 
     Downstream of the heat transfer assembly  37 , the total heated stream  16  is split into a first heated stream  18  and a second heated stream  19 . Due to the heat transfer to the separate endothermic process  2  via the heat transfer assembly  37 , the temperature of the first heated stream  18  and second heated stream  19  may be less than that of the total heated stream  16  upon its initial exit from the heater  1 . However, additional heat may still be recovered from the first heated stream  18  and the second heated stream  19  for use within the system  50 . For instance, in some embodiments, the total heated stream  16  (and thus also the first heated stream  18  and the second heated stream  19 ) may be at a temperature of about 450° C. downstream of the heat transfer assembly  37 . 
     In some embodiments, the first heated stream  18  is routed through a first heat exchanger  4  to pre-heat the carbonaceous fuel stream  20  and the CO 2  work stream  14 , upstream of the heater  1 . In addition, in some embodiments, the second heated stream  19  is routed through a second heat exchanger  3  to pre-heat the oxidant stream  15  upstream of the heater  1 . In some embodiments, the carbonaceous fuel stream  20  and the circulating CO 2  stream  14  may be heated to about 440° C. at a pressure of about 50 bar (5 MPa) within the first heat exchanger  4 , and the oxidant stream  15  may be heated to about 440° C. within the second heat exchanger  3 . Because the first heat exchanger  4  and the second heat exchanger  3  recover or recuperate excess heat from the total heated stream  16  following heat transfer to the separate endothermic process  2 , the heat exchangers  4 , 3  may be referred to herein as “recuperator” heat exchangers. In some embodiments, the oxidant stream  15  may enter the second heat exchanger  3  at a temperature of about 25° C., the carbonaceous fuel stream  20  may enter the first heat exchanger  4  at temperature of about 15° C., and the CO 2  work stream  14  may enter the first exchanger  4  at a temperature of about 40° C. 
     In some embodiments, the first heat exchanger  4  and the second heat exchanger  3  may be combined into a single heat exchanger. However, in some embodiments, the first heat exchanger  4  and the second heat exchanger  3  may be separate from one another to avoid heating the carbonaceous fuel stream  20  and the oxidant stream  15  in the same heat exchanger, upstream of the heater  1 . Without being limited to this or any other theory, separating the first heat exchanger  4  from the second heat exchanger  3  may reduce the likelihood of an unintentional (and possibly uncontrolled) reaction of the carbonaceous fuel stream  20  and the oxidant stream  15 . 
     After flowing through the heat exchangers  4 ,  3 , the first heated stream  18  and second heated stream  19  may be recombined as a recombined heated stream  22  and routed to a separator or cooler  5  wherein H 2 O is separated from CO 2  and other constituents in the recombined heated stream  22 , thereby producing a supply of water  29 . The supply of water  29  (or a portion thereof) may be emitted from the process via a water product stream  13 . Alternatively (or additionally) the supply of water  29  (or a portion thereof) may be recycled back into the cooler  5  via a pump  7 . The recycled supply of water  29  may first be routed through a heat exchanger  8  such that the recycled supply of water  29  may be cooled via a cooling water stream  33  therein. Thereafter, the cooled, recycled supply of water  29  is emitted back into the cooler  5  wherein the recycled supply of water  29  irrigates a packing  6  positioned within the cooler  5 . The incoming recombined heated stream  22  contacts the irrigated packing  6  thereby cooling the recombined heated stream  22  to near ambient temperature. As a result, H 2 O is separated out of the recombined heated stream  22  and settles at the bottom of cooler  5  where it is emitted as the supply of water  29  as previously described. Because the recombined heated stream  22  directly contacts the water within the packing  6 , the cooler  5  may be referred to herein as a direct contact water cooler. 
     The remaining CO 2  and other constituents are then emitted from cooler  5  as the CO 2  work stream  14 . In some embodiments the CO 2  work stream  14  that is emitted from the cooler  5  may be at a temperature of about 20° C. In addition, in some embodiments, the CO 2  work stream  14  that is emitted from cooler  5  may be at a pressure of about 49 bar (4.9 MPa). 
     Downstream of cooler  5 , the CO 2  work stream may be pressurized via a blower  9  that is driven by a driver  35  (e.g., electric motor, hydraulic motor, internal combustion engine, turbine, etc.). In some embodiments, the CO 2  work stream may be pressurized by the blower  9  to a pressure of about 52 bar (MPa). 
     Net CO 2  produced within the system  50  may be removed from the CO 2  work stream  14  via a product stream  12 . The product stream  12  may be at a pressure of approximately 52 bar (5.2 MPa) in some embodiments and may be further compressed for delivery to a pipeline or other destination. For instance, in some embodiments, the product stream  12  may be further compressed as a gas to a pressure of about 150 bar (15 MPa) to about 250 bar (25 MPa) or pressurized as a liquid at a pressure of about 6 bar (0.6 MPa). Following removal of the product stream  12 , the remaining CO 2  work stream  14  is then routed back toward the heater  1  to transfer heat to the separate endothermic process  2  as previously described above. 
     Thus, operation of the system  50  as described above allows heat to be transferred to a separate endothermic process  2  while capturing all (or substantially all) of the CO 2  produced via the reaction within the heater  1 . In some embodiments, the system  50  may deliver heat efficiently to the separate endothermic process  2  over a temperature range of about 300° C. to about 1000° C. or higher, if materials allow. 
     Referring now to  FIG.  2   , which shows a non-limiting example of another system  100  for transferring heat to a separate endothermic process  2  according to some embodiments. As previously described, the system  100  may circulate a CO 2  work stream  133  to transfer thermal energy to the separate endothermic process  2  via a heat transfer assembly  37 . 
     The system  100  includes a first heater  101  and a second heater  140  operating in series. In some embodiments, the first heater  101  and the second heater  140  may each comprise oxygen ITM heaters that include membranes  102  and  142 , respectively, that are configured to diffuse O 2  therethrough. The first heater  101  and second heater  140  may receive inputs derived from the CO 2  work stream  133 , a carbonaceous fuel stream  121 , and an oxidant stream  115  as described in more detail below. 
     The oxidant stream  115  may comprise air that is compressed via a compressor  111  that is driven by a driver  112  (e.g., electric motor, hydraulic motor, internal combustion engine, turbine, etc.). In some embodiments, the compressor  111  may compress the oxidant stream  115  to about 1.3 bar (0.13 MPa). After being output by the compressor  111 , the oxidant stream  115  is split such that a first portion  116  of the oxidant stream  115  is routed to the first heater  101  and a second portion  117  of the oxidant stream  115  is routed to the second heater  140 . The amount or flow of air to the first heater  101  and second heater  140  via the first portion  116  and second portion  117 , respectively, of the oxidant stream  115  may be controlled via a pair of control valves  147  and  148 , respectively, positioned downstream of the first heater  101  and the second heater  140 . 
     The carbonaceous fuel stream  121  may comprise any suitable fuel. For instance, in some embodiments, the carbonaceous fuel stream  121  may comprise a hydrocarbon fuel, such as natural gas or one or more components thereof (e.g., ethane, methane, propane, etc.), or a non-hydrocarbon fuel such as carbon monoxide (CO). In some embodiments, the carbonaceous fuel stream  121  may comprise methane (CH 4 ). The carbonaceous fuel stream  121  is split into a first portion  122  and a second portion  143 . The first portion  122  of the carbonaceous fuel stream  121  is routed toward the first heater  101 , and the second portion  143  of the carbonaceous fuel stream  121  is routed toward the second heater  140 . Further details of how the first portion  122  and the second portion  143  of the carbonaceous fuel stream  121  are flowed into the first heater  101  and the second heater  140 , respectively, are provided below. 
     The CO 2  work stream  133  is initially flowed into the first heater  101 . Specifically, the first portion  122  of the carbonaceous fuel stream  121  is mixed with the CO 2  work stream and the mixture is then routed into the first heater  101 . Within the first heater  101 , the mixture of the circulating CO 2  stream  133  and the first portion  122  of the carbonaceous fuel stream  121  are passed along a first side  102   a  of the membrane  102  and the first portion  116  of the oxidant stream  115  is passed along a second side  102   b  of the membrane  102 . As shown in  FIG.  2   , the first side  102   a  is opposite the second side  102   b . The O 2  (or at least some of the O 2 ) within the first portion of the oxidant stream  115  is diffused across the membrane  102  from the second side  102   b  to the first side  102   a  such that the O 2  mixes with the carbonaceous fuel and is reacted in the presence of the CO 2  work stream to thereby form a first heated stream  134  that is output from the first heater  101 . In some embodiments, 60 vol % of the O 2  in the first portion  116  of the oxidant stream  115  diffuses across the membrane within the first heater  101 . The first heated stream  134  includes the CO 2  work stream and the products of reaction from the first heater  101  (which may comprise CO 2  and H 2 O as previously described). In some embodiments, the first heated stream  134  may be at a temperature of about 1020° C. 
     The heated stream  134  is then passed through a heat exchanger  141  so that heat may be transferred to the CO 2  work stream  133  prior to the mixing of the CO 2  work stream  133  and the first portion  122  of the carbonaceous fuel stream  121  upstream of the first heater  101 . In some embodiments, the mixing point of the first portion  122  of the carbonaceous fuel stream  121  and the CO 2  work stream  133  may be relatively close to the outlet heat exchanger  141  so as to avoid significant CH 4  cracking or CH 4  plus CO 2  reforming upstream of the first heater  101 . In some embodiments, the first heated stream  134  may exit the heat exchanger  141  at a temperature of about 800° C. 
     After being output from the heat exchanger  141 , the heated stream  134  is mixed with the second portion  143  of the carbonaceous fuel stream  121 , and the mixture is then routed into the second heater  140 . Within the second heater  140 , the mixture of the first heated stream  134  and the second portion  143  of the carbonaceous fuel stream  121  are passed along a first side  142   a  of the membrane  142  and the second portion  117  of the oxidant stream  115  is passed along a second side  142   b  of the membrane  142 . The first side  142   a  is opposite the second side  142   b . The O 2  (or at least some of the O 2 ) within the second portion  117  of the oxidant stream  115  is diffused across the membrane  142  from the second side  142   b  to the first side  142   a  such that the O 2  mixes with the carbonaceous fuel and is reacted in the presence of the CO 2  within the first heated stream  134  to thereby form a second heated stream  136  that is output from the second heater  140 . In some embodiments, 60 vol % of the O 2  in the second portion  117  of the oxidant stream  115  diffuses across the membrane within the second heater  140 . The second heated stream  136  includes the CO 2  work stream  133  and the products of reaction from both the first heater  101  and the second heater  140  (which may comprise CO 2  and H 2 O as previously described). 
     The second heated stream  136  may be at an elevated temperature, such as, for instance about 1000° C. in some embodiments. In some embodiments, the pressure of the second heated stream  136  may be approximately 50 bar (5 MPa) (e.g., 51.5 bar or 5.15 MPa). The second heated stream  136  is then routed to the heat transfer assembly  37  such that heat within second heated stream  136  is transferred to the separate endothermic process  2  as previously described. 
     Due to the heat transfer to the separate endothermic process  2  via the heat transfer assembly  37 , the temperature of the second heated stream  136  may be reduced as it flows through the one or more heat transfer components  37 . However, additional heat may still be recovered from the second heated stream  136  for use within the system  100 . For instance, in some embodiments, the second heated stream  136  may be at a temperature of about 450° C. after being output from the heat transfer assembly  37 . In addition, in some embodiments, the second heated stream  136  may be at a pressure of about 49.5 bar (4.95 MPa) after being output from the heat transfer assembly  37 . 
     In some embodiments, the second heated stream  136  is routed through a first heat exchanger  104  to pre-heat the carbonaceous fuel stream  121  and the CO 2  work stream  133 , upstream of the heater  1 . In some embodiments, the carbonaceous fuel stream  121  and the CO 2  work stream  133  may be heated to a temperature of about 440° C. at a pressure of about 52 bar (5.2 MPa) within the first heat exchanger  104 . Because the first heat exchanger  104  recovers or recuperates excess heat from the second heated stream  136  following thermal heat transfer to the separate endothermic process  2 , the heat exchanger  104  may be referred to herein as a “recuperator” heat exchanger. In some embodiments, the carbonaceous fuel stream  121  may enter the first heat exchanger  104  at temperature of about 15° C., and the CO 2  work stream  133  may enter the first exchanger  104  at a temperature of about 40° C. Upon exiting the first heat exchanger  104 , the CO 2  work stream  133  is then routed through the heat exchanger  141  as previously described, such that the CO 2  work stream  133  is further heated to a temperature of about 800° C. 
     In addition, the first portion  116  and the second portion  117  of the oxidant stream  115  are heated within the first heater  101  and the second heater  140 , respectively. Thus, after the first portion  116  and the second portion  117  are emitted from the first heater  101  and the second heater  140 , respectively, they are routed through a second heat exchanger  103  to preheat the oxidant stream  115  upstream of the first heater  101  and the second heater  140 . Because the second heat exchanger  103  recovers or recuperates excess heat from the first portion  116  and second portion  117  of the oxidant stream  115 , the heat exchanger  103  may be referred to herein as a “recuperator” heat exchanger. In some embodiments, the oxidant stream  115  may enter the second heat exchanger  103  at a temperature of about 40° C., and may exit the second heat exchanger  103  at a temperature of about 850° C. (e.g., 848° C.). 
     In some embodiments, the first heat exchanger  104  and the second heat exchanger  103  may be combined into a single heat exchanger. However, in some embodiments, the first heat exchanger  104  and the second heat exchanger  103  may be separate from one another to avoid heating the carbonaceous fuel stream  121  and the oxidant stream  115  (or the first portion  116  or second portion  117  thereof) in the same heat exchanger, upstream of the first heater  101  and second heater  140 . Thus, separating the first heat exchanger  104  from the second heat exchanger  103  may reduce the likelihood of an unintentional (and possibly uncontrolled) reaction of the carbonaceous fuel stream  121  and the oxidant stream  115 . 
     In some embodiments, within the first heat exchanger  104 , the first heated stream  136  may be cooled to a temperature of about 50° C. After flowing through the first heat exchanger  104 , the first heated stream  136  is routed to a separator or cooler  105  wherein H 2 O is separated from CO 2  and other constituents in the second heated stream  136 , thereby producing a supply of water  129 . The supply of water  129  (or a portion thereof) may be emitted from the process via a water product stream  128 . Alternatively (or additionally) the supply of water  129  (or a portion thereof) may be recycled back into the cooler  105  via a pump  107 . The recycled supply of water  129  may first be routed through a heat exchanger  108  such that the recycled supply of water  129  may be cooled via a cooling water stream  131  therein. In some embodiments, the cooling water  131  may enter the heat exchanger  108  at a temperature of about 20° C., and may exit the heat exchanger  108  at a temperature of about 30° C. Thereafter, the cooled, recycled supply of water  129  is emitted back into the cooler  105  wherein the recycled supply of water  129  irrigates a packing  106  positioned within the cooler  105 . In some embodiments, the supply of water  129  may be cooled to a temperature of about 25° C. within the heat exchanger  108  before recycling back into the cooler  105 . The incoming second heated stream  136  contacts the irrigated packing  106  thereby cooling the second heated stream  136  to near ambient temperature. As a result, water is separated out of the second heated stream  136  and settles at the bottom of cooler  105  where it is emitted as the supply of water  129  as previously described. Because the heated stream  136  directly contacts the water within the packing  106 , the cooler  105  may be referred to herein as a direct contact water cooler. 
     The remaining CO 2  and other constituents are then emitted from cooler  105  as the CO 2  work stream  133 . In some embodiments the CO 2  work stream  133  that is emitted from the cooler  105  may be at a temperature of about 20° C. In addition, in some embodiments, the CO 2  work stream  133  that is emitted from cooler  105  may be at a pressure of about 49 bar (4.9 MPa). 
     Downstream of cooler  105 , the CO 2  work stream  133  may be pressurized via a blower  109  that is driven by a driver  110  (e.g., electric motor, hydraulic motor, internal combustion engine, turbine, etc.). In some embodiments, the CO 2  work stream  133  may be pressurized by the blower  109  to a pressure of about 52 bar (MPa). Net CO 2  produced within the system  100  may be removed from the CO 2  work stream  14  via a product stream  150  in a similar manner described above for product stream  12  ( FIG.  1   ). Following pressurization via the blower  109  and removal of the net CO 2  as previously described, the CO 2  work stream  133  is then routed back toward the heaters  101 , 140  to transfer heat to the separate endothermic process  2  as previously described above. 
     Thus, operation of the system  100  as described above allows heat (thermal energy) to be transferred to a separate endothermic process  2  while capturing all (or substantially all) of the CO 2  produced via the reaction within the heaters  101 ,  140 . In some embodiments, the system  100  may deliver heat efficiently to the separate endothermic process over a temperature range of about 300° C. to about 1000° C. 
     As described above, the embodiments disclosed herein are directed to systems and methods for generating thermal energy to drive or power an endothermic process while also capturing carbon (e.g., in the form of CO 2 ) that is produced to reduce net carbon emissions during operations. In some embodiments, the systems and methods described herein may be utilized to capture carbon that is produced from the reaction of a carbonaceous fuel, such as a hydrocarbon or carbon monoxide. Thus, through use of the embodiments disclosed herein, thermal energy may be provided to an endothermic process without a corresponding increase in the output of CO 2  to the atmosphere 
     The preceding discussion is directed to various exemplary embodiments. However, one of ordinary skill in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment. 
     The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness. 
     In the discussion herein and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections. In addition, when used herein (including in the claims), the words “about,” “generally,” “substantially,” “approximately,” and the like, when used in reference to a stated value mean within a range of plus or minus 10% of the stated value. 
     While exemplary embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.