Dual use energy plant with fuel cell system

Abstract

A system for generating power with reduced or negative carbon emissions includes a power plant portion having a power generation unit including a solid oxide fuel cell (SOFC) system. The SOFC system includes a SOFC fuel cell reactor and a combustor having an energy exchange pathway. The combustor is coupled to the fuel cell reactor to combust unutilized fuel. The system also includes a direct air capture (DAC) portion having a carbon dioxide (CO2) adsorption device having a CO2 adsorption material and a ventilator electrically coupled to the generator for flowing ambient air through the CO2 adsorption device in a carbon capture mode. The CO2 adsorption device is coupled to and in energy communication with the energy exchange pathway for releasing adsorbed CO2 in a carbon release mode.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Application No. 18 / 503271, filed November 7, 2023, the entire contents of which are incorporated herein by reference. Background Technology

[0002] This disclosure relates in general to a dual-purpose energy plant, and more specifically to an energy plant that generates electricity with reduced or even negative carbon emissions.

[0003] Electricity in power grids is typically supplied by several power plants that burn fossil fuels to generate energy to power generators connected to the grid. As is generally known, the combustion process emits carbon as a byproduct. Unfortunately, these emissions contribute to atmospheric “greenhouse gases,” which in turn contribute to what is known as climate change. Climate change can be potentially dangerous, causing natural disasters or economic problems, which could be due to factors such as rising sea levels or agricultural issues. Therefore, the power industry would welcome technological improvements that generate electricity with reduced or even negative carbon emissions compared to conventional power plants, where the power generation process as a whole removes more carbon from the atmosphere than could possibly be added through combustion. Summary of the Invention

[0004] A system for generating electricity with reduced or negative carbon emissions is disclosed. The system includes: a power plant section comprising a solid oxide fuel cell (SOFC) system and a direct air capture (DAC) section. The SOFC system includes: an SOFC fuel cell reactor having a fuel inlet for receiving hydrogen fuel and an air inlet for receiving compressed air, the fuel cell reactor being configured to react hydrogen with compressed air to generate electricity; a combustor coupled to an outlet of the SOFC fuel cell reactor that discharges unused fuel, the combustor being configured to burn the unused fuel to provide an energy exchange path; a reformer coupled to a hydrocarbon fuel supply source and coupled to a heat outlet and a steam outlet of the fuel cell reactor, the reformer being configured to use heat and steam from the fuel cell reactor to reform the hydrocarbon fuel to supply hydrogen fuel to the SOFC reactor; and a high-pressure compressor having a high-pressure output coupled to the air inlet of the SOFC fuel cell for compressing the air supplied to the SOFC reactor. The direct air capture (DAC) component includes: a carbon dioxide (CO2) adsorption device having a CO2 adsorption material; and a fan electrically coupled to the SOFC fuel cell reactor, the fan being configured to allow air to flow through the CO2 adsorption device in carbon capture mode; wherein the CO2 adsorption device is coupled to and in energy communication with an energy exchange path for releasing the adsorbed CO2 in carbon release mode.

[0005] A method for generating electricity with reduced or negative carbon emissions is also disclosed. The method includes: generating electricity in a power plant section comprising a solid oxide fuel cell (SOFC) system; in a carbon capture mode, in a direct air capture (DAC) section, collecting carbon dioxide (CO2) from the air by adsorption using a CO2 adsorption device having CO2 adsorption material; in a carbon capture mode, using a fan receiving power from the SOFC system to circulate air through the CO2 adsorption device; and in a carbon release mode, releasing CO2 from the CO2 adsorption device by providing energy to the CO2 adsorption material from an energy exchange path. The SOFC system: receives hydrogen fuel and air; reacts hydrogen with air to generate electricity; burns unused fuel to provide an energy exchange path; reforms hydrocarbon fuel from a hydrocarbon fuel supply source using heat and steam from the fuel cell reactor to supply hydrogen fuel to the SOFC reactor; and compresses air to supply compressed air to the SOFC reactor. Attached Figure Description

[0006] The following description should not be considered as limiting in any way. Referring to the accompanying drawings, similar element numbers are similar:

[0007] Figure 1 The description covers various aspects of the power plant section coupled to the direct air capture (DAC) section in carbon capture mode;

[0008] Figure 2 Aspects of the carbon dioxide adsorption device in the DAC section are described;

[0009] Figure 3 It describes the various aspects of the power plant section coupled to the DAC section in carbon emission mode;

[0010] Figure 4 The power plant section is depicted in various aspects coupled to the DAC section in carbon release mode, wherein the power plant section has an energy exchanger;

[0011] Figure 5 The various aspects of the power plant section with supercritical CO2 power cycle coupled to the DAC section in carbon capture mode are described.

[0012] Figure 6 The various aspects of the power plant section with a supercritical CO2 power cycle coupled to the DAC section in carbon release mode are described.

[0013] Figure 7 The power plant section with gas turbines and heat recovery components is depicted in various aspects coupled to the DAC section in carbon capture mode;

[0014] Figure 8 The various aspects of the power plant section with gas turbines and heat recovery components coupled to the DAC section in carbon release mode are described;

[0015] Figure 9 The paper describes various aspects of a power plant section with a gas turbine but no heat recovery components coupled to the DAC section in carbon capture mode.

[0016] Figure 10 The various aspects of a power plant section with a gas turbine but no heat recovery components coupled to the DAC section in carbon release mode are described.

[0017] Figure 11 It is a flowchart representation of a method for generating electricity with reduced or negative carbon emissions; and

[0018] Figure 12 Aspects of a solid oxide fuel cell (SOFC) system are described.

[0019] Figure 13 The various aspects of the SOFC system with enhanced configuration in carbon capture mode are described;

[0020] Figure 14The various aspects of an SOFC system with an enhanced configuration under carbon emission mode are described; and

[0021] Figure 15 It is a flowchart representation of a method for generating electricity with reduced or negative carbon emissions using a fuel cell system. Detailed Implementation

[0022] Detailed descriptions of one or more embodiments of the apparatus and methods disclosed herein are presented by way of example rather than limitation with reference to the accompanying drawings, in which like elements are indicated by like reference numerals.

[0023] The accompanying figures illustrate various embodiments for generating electricity with reduced or negative carbon emissions. These figures include arrows illustrating the direction of fluid flow from a first component to a second component coupled to the first. These arrows indicate conduits, pipes, tubes, ducts, or other types of flow paths used to contain and guide the fluid flow. These arrows may also indicate valves or dampers within the flow path used to control the fluid flow according to the operating mode. These valves may be remotely controlled by a controller that can provide automatic or manual operation. These arrows may also indicate any pumps required to stimulate fluid flow, depending on the design configuration of the disclosed components. Arrows identifying electrical communications indicate electrical conductors, transformers, switchgear, or other components required to power the device. The location where arrows leave or enter a component may indicate an output or input port for fluid flow or a connection of electrical components, respectively. As can be seen from the figures, the arrows also indicate how a component is coupled directly or indirectly (using intermediate components) to another component.

[0024] This article discloses an implementation plan for a power plant system that generates electricity with reduced or negative carbon emissions. Therefore, the power plant system serves a dual purpose—generating electricity and reducing or even completely removing carbon from ambient air.

[0025] Figure 1A simplified diagram of a power plant system 10 is illustrated, having a power plant section 11 coupled to a direct air capture (DAC) section 12 operating in carbon capture mode. The power plant section 12 includes a power generation unit 9 for converting fossil fuels or hydrocarbon fuels into electricity or electrical energy. Non-limiting embodiments of the power generation unit 9 include a supercritical carbon dioxide power cycle, a gas turbine, a reciprocating engine (e.g., a gasoline or diesel engine), or a fuel cell system (e.g., a solid oxide fuel cell system) that produces a carbon dioxide stream and an energy emission stream. Each embodiment of the power generation unit 9 includes an energy exchange path (e.g., a thermal emission path), which in some embodiments may also be referred to as engine exhaust. In one or more embodiments, the power generation unit 9 includes a prime mover or engine 13 that burns hydrocarbon fuel to provide mechanical energy to drive a generator 14 mechanically connected (e.g., via an illustrated shaft) or hydraulically connected to the engine 13. The generator 14 generates electricity, and a first portion of the generated electricity is supplied to the power grid via a grid connection. In an embodiment using a fuel cell system, an inverter (not shown) connected to the electrodes of the fuel cell system can be used to supply a first portion of the alternating current (AC) electricity generated by the fuel cell system to the power grid. A second portion of the generated electricity is provided to the DAC section 12 for the operation of the DAC section components. A hot gas recirculation line 15 receives hot gas from the engine 13 and provides the hot gas to an energy exchanger 16. The energy exchanger 16, in a first option, provides the thermal energy from the hot gas to the engine 13, or in a second option, provides thermal energy to the surrounding environment. Cooler gas from the energy exchanger 16 passes through a first water intake or water separator 17 to remove water from the gas. Optionally, a first compressor 18 compresses the drier gas from the water separator 17 and provides the compressed gas back to the engine 13.

[0026] The DAC section 12 includes a fan 19 that supplies or directs ambient air to a carbon dioxide (CO2) adsorption unit 20. The CO2 adsorption unit 20 removes CO2 from the ambient air, and thus removes the associated carbon. Air with less CO2 is then discharged from the CO2 adsorption unit 20. The fan 19 is electrically coupled to and receives power from the power generation unit 9. Any discussion below of the power supplied by the generator 14 inherently includes the power supplied when the fuel cell system is used as the power generation unit 9.

[0027] Controller 25 may be located in power plant section 11 and / or DAC section 12 for controlling the operation of power plant system 10 in relation to the operating equipment disclosed herein to achieve power production with reduced or negative carbon emissions, depending on the different operating modes discussed herein. For example, controller 25 may be configured to control valves or dampers to control the flow of fluids such as working fluids, heat transfer fluids, CO2 for storage or export or for recycling, or air. Furthermore, controller 25 may be configured to control electrical switching equipment to control power to fan 19 and / or CO2 compressor. Controller 25 may be configured to accept manual input and / or provide automatic control. Automatic control may be implemented by an analog or digital processor that implements algorithms. Algorithms may include model-based learning, machine learning, and / or artificial intelligence. In one or more embodiments, the algorithm may implement a neural network. Controller 25 may also include conventional control systems such as proportional, integral, and / or derivative (PID) control. Additionally, controller 25 may receive input from sensors such as temperature, pressure, and / or flow sensors distributed throughout power plant system 10. Furthermore, controller 25 can be configured to communicate with other processing devices, whether through local communication (such as wireless communication) or remote communication (such as via the Internet). Therefore, controller 25 can be used to optimize the reduction of carbon emissions.

[0028] Figure 2 Various aspects of the CO2 adsorption device 20 are described. Figure 2 In one embodiment, the CO2 adsorption device 20 includes a housing 22 that supports the CO2 adsorption material 21 and directs airflow from the fan 19 to the adsorption material 21. In a carbon release mode, heating the CO2 adsorption material 21 causes it to release CO2 for further processing and storage. In a non-limiting embodiment, the CO2 adsorption material 21 is a metal-organic framework (MOF) known in the art.

[0029] Figure 3A simplified diagram of a power plant system 10 is illustrated, which has a power plant section 11 coupled to a DAC section 12 operating in carbon release mode. In carbon release mode, heat from the energy exchanger 16 is used to heat the CO2 adsorption material 21 to release adsorbed CO2. Heat can be provided indirectly, where the energy exchanger 16 acts as a heat exchanger; or it can be provided directly, i.e., high-temperature exhaust gas or emissions from the power generation unit 9 are directly directed to the CO2 adsorption device 20 in the form of a mass flow. In the case where the energy exchanger 16 is a heat exchanger, heat from the high-temperature exhaust fluid on the primary side heats the heat transfer fluid on the secondary side, which is then used to heat the CO2 adsorption material 21. In the case where the energy exchanger 16 directly provides heat to the CO2 adsorption material 21, the energy exchanger 16 includes components such as pipes and valves to allow the high-temperature exhaust fluid to flow directly to the CO2 adsorption device 20 in a mode referred to as a “mass flow.”

[0030] CO2 and water emitted from CO2 adsorption unit 20 enter a second water absorber or water separator 30, where water is separated from the incoming CO2-water mixture. The dried CO2 from the second water separator 30 enters a first compressor 18. A first portion of the compressed CO2 from the first compressor 18 is recycled back to engine 13, while a second portion of the compressed CO2 is exported for storage. Optionally, a carbon export heat exchanger (HX) 31 may be coupled to the output of the first compressor 18 (e.g., in a line supplying the second portion of the compressed CO2 for export) to extract energy from the second portion of the compressed CO2 for heating the CO2 adsorbent material 21 in carbon release mode. The second portion of the compressed CO2 flows through the primary side of the carbon export heat exchanger 31 to heat the heat transfer fluid in the secondary side of the carbon export heat exchanger 31. This heat transfer fluid delivers energy to the CO2 adsorbent material 21 in carbon release mode to aid in the release of adsorbed CO2.

[0031] Figure 4 A simplified diagram of a power plant system 10 is illustrated, which has a power plant section 11 coupled to a DAC section 12 operating in carbon release mode (also known as regeneration). Here, heat is supplied to a CO2 adsorber 20 via a heat exchanger 40 disposed in the DAC section 12 to release adsorbed CO2. The primary side of the heat exchanger 40 is coupled to and receives thermal energy from an energy exchanger 16. The secondary side of the heat exchanger 40 is coupled to and supplies heat to the CO2 adsorption unit 20. CO2 from a second water absorber or water separator 30 is compressed by a second compressor 41 disposed in the DAC section 12 for external discharge and storage. The second compressor 41 is electrically coupled to and powered by a generator 14.

[0032] Figure 5A simplified diagram of a power plant system 10 is illustrated, which has a power plant section 11 coupled to a DAC section 12 operating in carbon capture mode, wherein the engine 13 is a supercritical CO2 power cycle. Figure 5 In one embodiment, the supercritical CO2 power cycle includes a combustor 50 configured to burn hydrocarbon fuel to produce supercritical CO2 and water. In one or more embodiments, the combustor 50 includes a combustion chamber (not shown) in which fuel and oxidant are combined and combusted. Supercritical CO2 and water are supplied to a turbine expander 51. The outlet of the turbine expander 51 is coupled to an energy exchanger 16, which provides a heat sink to cause the supercritical CO2 and water to expand within the turbine expander 51, thereby rotating an output shaft directly or indirectly coupled to a generator 14. Generally, the turbine expander 51 includes a turbine with blades (not shown) and a turbine shaft coupled to the generator 14, the expanding fluid impinging on the blades to rotate the turbine. An air separation unit (ASU) 52 is disposed in the power plant section 11, its output coupled to the combustor 50. The ASU 52 is configured to separate oxygen (O2) from ambient air to supply the separated oxygen to the combustor 50 to aid the combustion process.

[0033] Figure 6 A simplified diagram of a power plant system 10 is illustrated, which has a power plant section 11 coupled to a DAC section 12 operating in carbon emission mode, wherein the engine 13 is a supercritical CO2 power cycle. In carbon emission mode, heat is supplied to the CO2 adsorption unit 20 via a heat transfer fluid in a line or pipe to an energy exchanger 16. Heat can be supplied directly via mass flow or indirectly via the energy exchanger 16, which is a heat exchanger where heat is supplied on the secondary side. Figure 6 In one implementation, the second compressor 41 supplies compressed CO2 to the output line of the energy exchanger 16 or a separate input to the water separator 17.

[0034] Figure 7 A more detailed embodiment of power plant system 10 is illustrated, which has a power plant section 11 coupled to a DAC section 12 operating in carbon capture mode, wherein the engine 13 is a gas turbine 90 (or may be a reciprocating engine, a fuel cell inherently having power generation electrodes, or any engine having a heat and CO2 exhaust flow). Components not shown in power plant section 11 or DAC section 12 may be considered to be located adjacent to power plant section 11, or alternatively located within power plant section 11. Figure 9In one embodiment, a heat recovery power cycle (HRPC) is arranged in the exhaust path of the gas turbine 90, located between the exhaust heat exchanger 95 and the gas turbine 90. The HRPC uses the waste energy from the gas turbine exhaust to generate more electricity, thereby improving power generation efficiency. The heat recovery power cycle includes a heat recovery steam generator (HRSG) 91, a steam turbine 92, an HRPC heat exchanger 93, and an HRPC pump 94. The HRSG 91 uses heat from the exhaust path of the gas turbine 90 to generate steam. The generated steam is received by the steam turbine 92 to convert the steam's energy into mechanical energy to rotate a shaft coupled to generator 14 or alternatively coupled to another generator also connected to the power grid. The HRPC heat exchanger 93 provides a heat sink for the exhaust of the steam turbine 92 by condensing the steam to provide the necessary pressure drop across the steam turbine 92. The HRPC pump 94 pumps the condensate from the HRPC heat exchanger 93 back to the HRSG 91 to complete the heat recovery power cycle.

[0035] Downstream of the HRPC, an exhaust heat exchanger 95 further cools the exhaust gas from the gas turbine 90. The exhaust gas is cooled by air or another cooling source on the secondary side of the exhaust heat exchanger 95. A first portion of the exhaust gas flows from the exhaust heat exchanger 95 to a CO2 trapping device 97, which traps CO2 from the exhaust gas. In one or more embodiments, the CO2 trapping device 97 implements a cold ammonia process (CAP) or a rotating bed compact carbon capture (3C), all of which are known in the art. The trapped CO2 is then compressed by a first trapped CO2 compressor 98 and dried by a trapped CO2 water separator 99. The dried trapped CO2 is then further compressed by a second trapped CO2 compressor 89 and provided for export and storage. A second portion of the exhaust gas discharged from the exhaust heat exchanger 95 is used for exhaust gas recirculation (EGR) and flows to a water separator 96 to separate water from the second portion of the exhaust gas to provide dried EGR exhaust gas. The dried EGR exhaust gas is then combined with air entering the gas turbine 90 for combustion.

[0036] Figure 8 A more detailed embodiment of power plant system 10 is illustrated, having a power plant section 11 coupled to a DAC section 12 operating in carbon release mode, wherein engine 13 is a gas turbine 90. In carbon release mode, both exhaust heat exchanger 95 and HRPC heat exchanger 93 supply heat to CO2 adsorption unit 20 to release CO2 (also known as regeneration) and supply the released CO2 to a first CO2 capture compressor 98. Thus, in carbon release mode, the first CO2 capture compressor 98 compresses the CO2 supplied by CO2 capture unit 97 and CO2 adsorption unit 20. Generally, in carbon release mode, controller 25 shuts off fan 19 and opens flow control to supply energy (e.g., heat) to CO2 adsorption unit 20.

[0037] Figure 9 Another more detailed embodiment of the power plant system 10 is illustrated, which has a power plant section 11 coupled to a DAC section 12 operating in carbon capture mode, wherein the engine 13 is a gas turbine 90. Figure 9 The implementation plan is similar to Figure 7 The implementation scheme does not include a heat recovery power cycle downstream of the gas turbine exhaust. Here, the gas turbine exhaust directly enters the exhaust heat exchanger 95, where it undergoes primary cooling, and then sequentially enters the CO2 capture device 97, the first CO2 capture compressor 98, the CO2 capture water separator 99, and the second CO2 capture compressor 89.

[0038] Figure 10 Another, more detailed embodiment of the power plant system 10 is illustrated, which has a power plant section 11 coupled to a DAC section 12 operating in carbon release mode, wherein the engine 13 is a gas turbine 90. Here, in carbon release mode, the heat for releasing CO2 from the adsorption unit 20 is provided solely or primarily by a heat transfer fluid flowing through the secondary side of the exhaust heat exchanger 95. The heat transfer fluid is heated by thermal energy in the exhaust gas from the gas turbine.

[0039] Figure 11 This is a flowchart of method 130 for generating electricity with reduced or negative carbon emissions. Box 131 requires the use of a power generation unit in the power plant section of a power plant system, the power generation unit being coupled to a hydrocarbon fuel supply source and having an electrical output and an energy exchange path. In one or more embodiments, the energy exchange path operates as an energy emission path. In non-limiting embodiments, the power generation unit operates in a supercritical CO2 power cycle, as a gas turbine, as a reciprocating engine, or as a fuel cell system with both an energy emission stream and a CO2 emission stream.

[0040] Box 132 requires that, in the carbon capture mode, in the direct air capture (DAC) section of a power plant system, a CO2 adsorption device with CO2 adsorption material be used to collect carbon dioxide (CO2) from the air by adsorption.

[0041] Box 133 requires that, in carbon capture mode, a fan that receives power from the power generation unit is used to circulate air through the CO2 adsorption device.

[0042] Box 134 requires that, in carbon release mode, CO2 be released from the CO2 adsorption device by providing energy to the CO2 adsorption material with energy from the energy exchange pathway.

[0043] In an embodiment where the power generation unit operates in a supercritical CO2 power cycle, method 130 may further include: (1) burning hydrocarbon fuel using a burner disposed in the supercritical CO2 power cycle; (2) converting the energy released from combustion into mechanical output energy using an expander disposed in the supercritical CO2 power cycle and coupled to the output of the burner; (3) supplying oxidant to the burner using an air separation unit (ASU) coupled to the input of the burner; and (4) extracting water from the working fluid flow after expansion in the expander using a water separation unit coupled to the output of the expander; wherein the generator is coupled to the mechanical output of the expander; and wherein the energy exchange path is the working fluid discharge path of the expander.

[0044] Method 130 may also include using an energy exchanger coupled to the working fluid discharge path of the expander for supplying energy to the CO2 adsorption device indirectly in the form of heat or directly in the form of CO2 mass flow in carbon release mode to release CO2 from the CO2 adsorption material, wherein the CO2 adsorption material includes a metal-organic framework (MOF).

[0045] Method 130 may further include: introducing a CO2 stream from the DAC section into the burner in carbon release mode by using a first CO2 compressor disposed in the DAC section; and the first CO2 compressor receiving power from a generator to compress the CO2 released from the CO2 adsorbent material in carbon release mode.

[0046] Method 130 may further include using a second CO2 compressor disposed in a power plant section to compress CO2 emitted from an energy exchanger and from the output of a first CO2 compressor, the second CO2 compressor receiving power from a generator and coupled to the output of a water separator and the output of the first CO2 compressor, wherein a first portion of the emissions from the second CO2 compressor is discharged for storage and a second portion of the emissions from the second CO2 compressor is recycled to a burner.

[0047] In embodiments where the power generation unit includes a gas turbine, reciprocating engine, or fuel cell system, each with its own energy exhaust, method 130 may include: (1) capturing CO2 from the energy exhaust using a CO2 capture unit coupled to the energy exhaust path; and (2) compressing the CO2 captured by the CO2 capture unit into the compressed CO2 for export using a CO2 compressor coupled to the outlet of the CO2 capture unit, the CO2 compressor receiving electricity from the power generation unit. The CO2 capture unit may implement cold ammonia capture (CAP) or rotating bed compact carbon capture (3C). The CO2 adsorbent material may include a metal-organic framework (MOF). Method 130 may further include: (3) recovering heat from the energy exhaust path used to generate steam using a heat recovery steam generator (HRSG), the heat recovery steam generator (HRSG) being disposed in the power plant section, located in the energy exhaust path between the engine and the CO2 capture unit; and (4) generating electricity using a steam turbine coupled to the generator, the steam turbine receiving steam from the HRSG. The method 130 may further include: (5) compressing CO2 captured by the CO2 capture unit using a first CO2 compressor coupled to the outlet of the CO2 capture unit, the first CO2 compressor receiving power from the power generation unit; extracting water from the compressed CO2 from the first CO2 compressor using a water separator coupled to the output of the first CO2 compressor to provide dried compressed CO2; and (6) compressing the dried compressed CO2 using a second CO2 compressor coupled to the output of the water separator, the second CO2 compressor receiving power from the power generation unit.

[0048] As disclosed herein, the term "fuel cell" relates to a type of fuel cell or fuel cell system that produces a stream of carbon dioxide and a stream of energy emissions. An example of this type of fuel cell is a solid oxide fuel cell (SOFC) system, which is referred to as... Figure 12 The SOFC 140 is illustrated in the diagram. The SOFC 140 includes a fuel cell reactor 141 that generates electrical output to power the grid and the DAC section 12. The fluid output of the fuel cell reactor 141 is coupled to a burner 142 and a reformer 143. Figure 12 The diagram also illustrates the chemical reactions in the fuel cell reactor 141 and the reformer 143. The burner 142 burns unused hydrocarbon fuel from the fuel cell reactor 141. The output from the burner 142 provides an energy emission stream or energy exchange path. The reformer 143 uses heat and steam from the fuel cell reactor 141 to perform a steam reforming reaction to reform the hydrocarbon fuel, thereby supplying hydrogen to the fuel cell reactor 141, where the hydrogen is oxidized at the electrodes to generate electricity.

[0049] Figure 13A simplified diagram of a power plant system 10 is illustrated, which has a power plant section 11 coupled to a DAC section 12 operating in carbon capture mode, wherein a power generation unit 9 is an SOFC 140 integrated with an enhanced configuration including an expander. In this embodiment, the power generation unit 9 includes an SOFC system 140, an electric motor (EM) 150, a low-pressure (LP) air compressor 151, a high-pressure (HP) compressor 152, an expander 153, and a multi-flow heat exchanger (HX) 154. The EM 150 is coupled to the LP compressor 151 to drive the LP compressor 151 and receives power from the SOFC system 140. During startup, a local battery can be used to temporarily power the EM 150 until the fuel cell reactor begins generating electricity. Compressed air from the LP compressor 151 is supplied to the input of the HP compressor 152. The terms LP and HP can be considered relative terms, such that the pressure output of the HP compressor 152 is higher than the pressure output of the LP compressor 151. Expander 153 is coupled to HP compressor 152 to drive HP compressor 152. Multi-flow heat exchanger (HX) 154 has a primary side and at least two secondary sides heated by the primary side. The primary side inlet is coupled to the high-pressure and high-temperature exhaust flow of SOFC system 140, while the primary side outlet is coupled to the inlet of expander 153. Therefore, the high-pressure and high-temperature exhaust flow of SOFC system 140 drives expander 153, thereby driving HP compressor 152. One secondary side of HX 154 is coupled to the hydrocarbon fuel inlet of SOFC system 140 to heat the hydrocarbon fuel in SOFC 140. The other secondary side of HX 154 is coupled to the HP outlet of HP compressor 152 to heat the oxidant supply to SOFC system 140.

[0050] The SOFC system 140, integrated with the aforementioned components, is configured to generate electricity to supply the power grid, EM 150, and DAC components. The SOFC system 140 generates electricity when fuel and oxidant undergo an electrochemical reaction within the SOFC system 140 under certain defined conditions. An expander generates mechanical power by converting the work done on the high-temperature, high-pressure exhaust gas from the SOFC system 140, which is expanded to a low-temperature, low-pressure state. LP compressor 151 and HP compressor 152 are configured to deliver high-pressure oxidant (e.g., air) to the SOFC system 140. The SOFC system 140 is configured to receive compatible hydrocarbon fuels, such as natural gas. The heat exchanger 154 is located outside the SOFC system 140 and is configured to allow heat exchange between the following three flows: (1) the fuel flow from the SOFC fuel feed line upstream of SOFC 140; (2) the exhaust gas from SOFC 140 downstream of SOFC 140; and (3) the oxidant flow from the high-pressure oxidant feed line upstream of SOFC 140.

[0051] Electricity is generated by performing an electrochemical reaction between a preheated fuel stream and an oxidant stream from a multi-stream heat exchanger 154 in a pressurized fuel cell reactor 141. The combustion chamber of burner 142, an integral part of the SOFC 140, generates high-temperature exhaust gas by using an oxidant to aid in the combustion of unused fuel from the pressurized fuel cell reactor 141. The hot exhaust gas from the fuel cell reactor 141 exchanges heat with the fuel stream and oxidant stream in the multi-stream heat exchanger 154. An expander 153 is arranged downstream of the heat exchanger 154 and is driven by the hot exhaust gas from the SOFC system 140. In one or more embodiments, the expander 153 and the HP compressor 152 are connected to each other via a common shaft. Power generated by the expander 153 is used to drive the HP compressor 152, and excess power can be extracted by a generator (not shown) connected to the other side of the shaft of the expander 153.

[0052] The solid oxide fuel cell system 140, integrated with expander 153 as a power generation unit, operates as follows: Air destined for the SOFC system 140 is compressed via a two-stage compression system. A low-pressure compressor 151, driven by a small electric motor 150, draws air from the atmosphere and compresses it to a first pressure stage. The air from the first compression stage is supplied to a high-pressure compressor 152, driven by gas expander 153, where it is further compressed to a high pressure. The compressed air stream from the high-pressure compressor 152 passes through a heat exchanger 154 before being introduced into the SOFC system 140. The heat exchanger 154 also heats a fuel stream (power source) from an external source. The heated air stream and heated fuel stream from the heat exchanger are injected into the SOFC system 140. Inside the fuel cell reactor 141, the heated air and heated fuel undergo an electrochemical reaction at the electrodes of the fuel cell reactor 141 to generate electricity. Exhaust gas, unused fuel, and air are mixed in the integral combustor 142 of the SOFC 140 and burned in the combustion chamber. This combustion energy further increases the temperature of the exhaust stream from burner 142. The high-temperature exhaust stream is then supplied to heat exchanger 154 to exchange heat with the incoming fuel and air stream. The high-pressure and high-temperature exhaust stream is supplied from heat exchanger 154 to expander 153. The high-pressure and high-temperature exhaust stream undergoes expansion in expander 153, thereby converting its energy into work and, optionally, electricity. Expander 153 transmits a portion of the power to HP compressor 152 and, optionally, transmits the remaining power to generator via a connected common shaft.

[0053] Figure 14A simplified diagram of a power plant system 10 is illustrated, which has a power plant section 11 coupled to a DAC section 12 operating in carbon release mode, wherein the power generation unit 9 is an SOFC system 140 integrated with an expander 153. In carbon release mode, energy (i.e., heat) is directed from a heat exchanger 95 to a CO2 adsorption unit 20 to heat the CO2 adsorption unit 20. CO2 released from the CO2 adsorption unit 20 is directed to a first CO2 capture compressor 98 for further processing before being exported for storage.

[0054] Figure 15 This is a flowchart of method 170 for generating electricity using a fuel cell system to reduce or reduce carbon emissions. Box 171 requires the use of a solid oxide fuel cell (SOFC) system to generate electricity in a power plant section. The SOFC system: receives hydrogen fuel and air; reacts the hydrogen with the air to generate electricity; burns unused fuel to provide an energy exchange path; reforms hydrocarbon fuel from a hydrocarbon fuel supply source using heat and steam from the fuel cell reactor to supply hydrogen fuel to the SOFC reactor; and compresses air to supply compressed air to the SOFC reactor. In one or more embodiments, the energy exchange path operates as an energy emission path.

[0055] Box 172 requires that, in the carbon capture mode, in the direct air capture (DAC) section, a CO2 adsorption device with CO2 adsorption material be used to collect carbon dioxide (CO2) from the air by adsorption.

[0056] Box 173 requires that, in carbon capture mode, a fan powered by the SOFC system be used to circulate air through the CO2 adsorption unit.

[0057] Box 174 requires that, in carbon release mode, CO2 be released from the CO2 adsorption device by providing energy to the CO2 adsorbent material from an energy exchange path. Release may include at least one of the following: heating the CO2 adsorbent material using a mass flow of fluid in the energy exchange path; or heating the CO2 adsorbent material using a heat transfer fluid heated by a heat exchanger on the secondary side, the primary side of which is heated by energy from the energy exchange path.

[0058] Method 170 may also include using a CO2 capture device that receives exhaust gas from the burner to capture CO2.

[0059] Method 170 may further include: compressing CO2 released by the CO2 adsorbent and CO2 capture device to provide compressed CO2; separating water from the compressed CO2 to provide dry compressed CO2; compressing the dry compressed CO2 to provide further compressed dry CO2; and exporting the further compressed dry CO2.

[0060] Method 170 may further include: using an expander to drive a high-pressure compressor for supplying compressed air to the SOFC reactor, the expander being coupled to the high-pressure compressor and driven by exhaust gas from the burner; and using energy from the SOFC reactor to reform the hydrocarbon fuel.

[0061] Method 170 may further include: supplying low-pressure compressed air to the high-pressure compressor using a low-pressure compressor; and driving the low-pressure compressor using an electric motor coupled to the low-pressure compressor.

[0062] The method 170 may further include: drying the exhaust gas from the expander to provide dried exhaust gas; and recirculating the dried exhaust gas into the low-pressure compressor.

[0063] To support the teachings herein, various analytical components, including digital and / or analog systems, may be used. For example, controller 25 may include digital and / or analog systems. These systems may have components such as processors, storage media, memories, inputs, outputs, communication links (wired, wireless, optical, or others), user interfaces (e.g., displays or printers), software programs, signal processors (digital or analog), and other such components (e.g., resistors, capacitors, inductors, etc.) for providing operation and analysis of the devices and methods disclosed herein in any of several manners well known in the art. It is conceivable that these teachings may be implemented, but not necessarily, in conjunction with a set of computer-executable instructions stored on a non-transitory computer-readable medium, including memory (ROM, RAM), optical media (CD-ROM), or magnetic media (e.g., disks, hard disk drives), which, when executed, cause a computer to implement the methods of the invention. In addition to the functions described herein, these instructions may also provide equipment operation, control, data collection and analysis, and other functions that a system designer, owner, user, or other such person deems relevant.

[0064] Batteries used to supply power for starting or stopping purposes can be located at various locations throughout the power plant system 10. The batteries can be charged using electricity generated within the power plant section 11.

[0065] The following are some of the aforementioned publicly disclosed implementation schemes:

[0066] Implementation Scheme 1. A system for generating electricity with reduced or negative carbon emissions, the system comprising: a power plant portion including a solid oxide fuel cell (SOFC) system, the SOFC system comprising: an SOFC fuel cell reactor having a fuel inlet for receiving hydrogen fuel and an air inlet for receiving compressed air, the fuel cell reactor being configured to react hydrogen with the compressed air to generate electricity; a combustor coupled to an outlet of the SOFC fuel cell reactor that discharges unused fuel, the combustor being configured to burn the unused fuel to provide an energy exchange path; and a reformer coupled to a hydrocarbon fuel supply source and coupled to a heat outlet and a steam outlet of the fuel cell reactor, the reformer being configured to use hydrogen fuel to generate electricity. The hydrocarbon fuel is reformed from the heat and steam of the fuel cell reactor to supply the hydrogen fuel to the SOFC reactor; a high-pressure compressor having a high-pressure output coupled to the air input of the SOFC fuel cell for compressing the air supplied to the SOFC reactor; a direct air capture (DAC) section including: a CO2 adsorption device having carbon dioxide (CO2) adsorption material; and a fan electrically coupled to the SOFC fuel cell reactor, the fan being configured to allow air to flow through the CO2 adsorption device in carbon capture mode; wherein the CO2 adsorption device is coupled to and in energy communication with the energy exchange path for releasing the adsorbed CO2 in carbon release mode.

[0067] Implementation Scheme 2. The system according to any of the foregoing embodiments further includes an expander having: an output shaft coupled to the high-pressure compressor for driving the high-pressure compressor; and a fluid input coupled to the energy discharge path.

[0068] Implementation Scheme 3. The system according to any of the foregoing embodiments further includes a low-pressure compressor having a fluid output terminal coupled to a fluid input terminal of the high-pressure compressor.

[0069] Implementation Scheme 4. The system according to any of the foregoing embodiments further includes an electric motor coupled to the low-pressure compressor for driving the low-pressure compressor.

[0070] Implementation Scheme 5. According to any of the foregoing embodiments, the system further includes a multi-flow heat exchanger comprising: a primary-side input coupled to the energy exchange path of the SOFC burner; a primary-side output coupled to the input of the expander; a first-stage-side input coupled to the input of the high-pressure compressor; a first-stage-side output coupled to the air input of the SOFC reactor to supply heated air to the SOFC reactor; a second-stage-side input coupled to the hydrocarbon fuel supply source; and a second-stage-side output coupled to the fuel input of the reformer; wherein heat from the primary side is transferred to the first-stage side and the second-stage side.

[0071] Implementation Scheme 6. The system according to any of the foregoing embodiments further includes: a CO2 compressor coupled to a CO2 release port of the CO2 adsorption device for compressing a portion of the adsorbed CO2 in a carbon release mode and providing the portion for external discharge; and a carbon discharge heat exchanger having a primary side coupled to an output end of the CO2 compressor and a secondary side coupled to the CO2 adsorption device for heating the CO2 adsorption material in the carbon release mode.

[0072] Implementation Scheme 7. The system according to any of the foregoing embodiments further includes a water separation unit having an input coupled to the output of the expander and an output coupled to the input of the low-pressure compressor for recirculating the dried exhaust gas.

[0073] Implementation Scheme 8. The system according to any of the foregoing embodiments further includes a heat exchanger comprising: a primary side coupled to the exhaust outlet of the expander; and a secondary side coupled to and in energy communication with the carbon dioxide (CO2) adsorption device in the carbon release mode.

[0074] Implementation Scheme 9. The system according to any of the foregoing embodiments further includes a CO2 capture unit coupled to the primary side output of the heat exchanger for removing CO2 from the exhaust gas of the expander.

[0075] Implementation Scheme 10. The system according to any of the foregoing embodiments further includes a first CO2 compressor having an input terminal coupled to a CO2 output terminal of the CO2 capture unit and coupled to an output terminal of the CO2 adsorption device in the carbon release mode.

[0076] Implementation Scheme 11. The system according to any of the foregoing embodiments, the system further comprising: a water separation unit having an input terminal coupled to the output terminal of the first CO2 compressor; and a second CO2 compressor having an input terminal coupled to the output terminal of the water separation unit and an output terminal coupled to a CO2 output path.

[0077] Implementation Scheme 12. The system according to any of the foregoing embodiments, wherein the CO2 adsorption material comprises a metal-organic framework (MOF), and the CO2 capture unit comprises a cold ammonia process (CAP) or a rotating bed compact carbon capture (3C).

[0078] Implementation Scheme 13. A method for generating electricity with reduced or negative carbon emissions, the method comprising: generating electricity in a power plant section, the power plant section including a solid oxide fuel cell (SOFC) system, the SOFC system: receiving hydrogen fuel and air; reacting the hydrogen with the air to generate the electricity; burning unused fuel to provide an energy exchange path; reforming hydrocarbon fuel from a hydrocarbon fuel supply source using heat and steam from a fuel cell reactor to supply the hydrogen fuel to the SOFC reactor; compressing air to supply the compressed air to the SOFC reactor; in a carbon capture mode, in a direct air capture (DAC) section, collecting carbon dioxide (CO2) from the air by adsorption using a CO2 adsorption device having CO2 adsorption material; in the carbon capture mode, using a fan receiving power from the SOFC system to circulate the air through the CO2 adsorption device; and in a carbon release mode, releasing CO2 from the CO2 adsorption device by providing energy to the CO2 adsorption material from the energy exchange path.

[0079] Implementation Scheme 14. The method according to any of the preceding embodiments, wherein the release includes at least one of: heating the CO2 adsorbent material using a mass flow of fluid in the energy exchange path; or heating the CO2 adsorbent material using a heat transfer fluid heated by a heat exchanger on the secondary side, the primary side of the heat exchanger being heated by energy from the energy exchange path.

[0080] Implementation Scheme 15. The method according to any of the preceding embodiments, the method further comprising capturing CO using a CO2 capture device that receives exhaust gas from the burner.2。

[0081] Implementation Scheme 16. The method according to any of the preceding embodiments, the method further comprising compressing CO2 released by the CO2 adsorbent material and the CO2 capture device to provide compressed CO2; separating water from the compressed CO2 to provide dry compressed CO2; compressing the dry compressed CO2 to provide further compressed dry CO2; and exporting the further compressed dry CO2.

[0082] Implementation Scheme 17. The method according to any of the preceding embodiments, the method further comprising: using an expander to drive a high-pressure compressor for supplying the compressed air to the SOFC reactor, the expander being coupled to the high-pressure compressor and driven by exhaust gas from the burner; and using energy from the SOFC reactor to reform the hydrocarbon fuel.

[0083] Implementation Scheme 18. The method according to any of the foregoing embodiments, the method further comprising: supplying low-pressure compressed air to the high-pressure compressor using a low-pressure compressor; and driving the low-pressure compressor using an electric motor coupled to the low-pressure compressor.

[0084] Implementation Scheme 19. The method according to any of the foregoing embodiments, the method further comprising: drying the exhaust gas from the expander to provide dried exhaust gas; and recirculating the dried exhaust gas into the low-pressure compressor.

[0085] The elements of the implementation scheme are introduced by the articles “a” or “an”. The articles are intended to indicate the presence of one or more of these elements. The terms “comprising” and “having” are intended to be inclusive and indicate that there may be additional elements besides those already listed. The conjunction “or”, when used with a list of at least two terms, is intended to mean any term or combination of terms. The term “configuration” relates to one or more structural limitations of the apparatus that require those one or more structural limitations to perform the function or operation of which the apparatus is configured. The term “coupled” relates to direct coupling or indirect coupling using intermediate means. The terms “first,” “second,” etc., are used to distinguish terms, not to indicate a specific order.

[0086] The flowcharts depicted herein are merely examples. Many variations may be made to the diagram or the steps (or operations) described therein without departing from the scope of the invention. For example, operations may be performed in a different order, or other operations may be performed at certain points without altering the specific disclosed sequence of operations relative to each other. All such variations are considered part of the claimed invention.

[0087] The disclosures made in this illustrative document may be implemented in the absence of any elements not specifically disclosed herein.

[0088] While one or more embodiments have been shown and described herein, modifications and substitutions may be made therein without departing from the scope of the invention. Therefore, it should be understood that the invention has been described by way of illustration rather than limitation.

[0089] It should be recognized that various components or technologies may provide certain necessary or beneficial functions or features. Therefore, these functions and features that may be required to support the appended claims and their variations are considered to be inherently included as part of the teachings herein and the disclosed invention.

[0090] Although the invention has been described with reference to one or more exemplary embodiments, those skilled in the art will understand that various changes can be made and equivalents can be substituted for elements therein without departing from the scope of the invention. Furthermore, many modifications can be made to adapt particular situations or materials to the teachings of the invention without departing from the basic scope of the invention. Therefore, it is contemplated that the invention is not limited to the specific embodiments disclosed as the best mode contemplated for carrying out the invention, but rather that the invention will encompass all embodiments falling within the scope of the claims. Additionally, exemplary embodiments of the invention have been disclosed in the drawings and detailed descriptions, and although specific terminology has been used, it is used in a general and descriptive sense only, and not for limiting purposes, unless otherwise specified; therefore, the scope of the invention is not limited thereto.

Claims

1. A system (10) for generating electricity with reduced or negative carbon emissions, said system (10) being characterized in that: The power plant section (11) includes a solid oxide fuel cell (SOFC) system (140), the SOFC system (140) being characterized in that: SOFC fuel cell reactor (141), the SOFC fuel cell reactor having a fuel input for receiving hydrogen fuel and an air input for receiving compressed air, the fuel cell reactor being configured to react hydrogen with the compressed air to generate electricity; A burner (142) coupled to the output of the SOFC fuel cell reactor (141) for discharging unused fuel, the burner (142) being configured to burn the unused fuel to provide an energy exchange path; A reformer (143) coupled to a hydrocarbon fuel supply source and to the heat output and steam output of the fuel cell reactor, the reformer (143) being configured to use heat and steam from the fuel cell reactor (141) to reform the hydrocarbon fuel to supply the hydrogen fuel to the SOFC reactor (141); A high-pressure compressor (152) having a high-pressure output coupled to the air input of the SOFC fuel cell for compressing air supplied to the SOFC reactor (141); The Direct Air Capture (DAC) section is characterized by: A carbon dioxide (CO2) adsorption device (20) having a CO2 adsorption material (21); as well as A ventilator (19) electrically coupled to the SOFC fuel cell reactor (141) is configured to allow air to flow through the CO2 adsorption device (20) in carbon capture mode. The CO2 adsorption device (20) is coupled to and connected to the energy exchange path for energy communication with the energy exchange path to release the adsorbed CO2 in carbon release mode.

2. The system (10) according to claim 1, further characterized in that the system has an expander (153) having: an output shaft coupled to the high-pressure compressor (152) for driving the high-pressure compressor (152); and a fluid input end coupled to an energy discharge path.

3. The system (10) according to claim 2, further characterized in that the system has a low-pressure compressor (151) having a fluid output end coupled to the fluid input end of the high-pressure compressor (152).

4. The system (10) according to claim 3, further characterized in that the system comprises an electric motor (150) coupled to the low-pressure compressor (151) for driving the low-pressure compressor (151).

5. The system (10) according to claim 4, further characterized by a multi-flow heat exchanger (154), wherein the multi-flow heat exchanger (154) is characterized by: Primary side input terminal, the primary side input terminal being coupled to the energy exchange path of the SOFC burner (142); Primary side output terminal, the primary side output terminal being coupled to the input terminal of the expander (153); The first stage side input terminal is coupled to the input terminal of the high-pressure compressor (152); The first stage side output terminal is coupled to the air input terminal of the SOFC reactor (141) to supply heated air to the SOFC reactor (141); A second-stage side input terminal, which is coupled to the supply source of the hydrocarbon fuel; as well as The second stage output terminal is coupled to the fuel input terminal of the reformer (143); Heat from the primary side is transferred to the first stage side and the second stage side.

6. The system (10) according to claim 1, further characterized in that: A CO2 compressor (98), coupled to the CO2 release port of the CO2 adsorption device (20), is used to compress a portion of the adsorbed CO2 in carbon release mode and provide the portion for external discharge; and A carbon external heat exchanger (31) having a primary side coupled to the output of the CO2 compressor (98) and a secondary side coupled to the CO2 adsorption device (20) for heating the CO2 adsorption material (21) in the carbon release mode.

7. The system (10) according to claim 5, further characterized in that the system has a water separation unit (96) having an input end coupled to the output end of the expander (153) and an output end coupled to the input end of the low-pressure compressor (151) for recirculating the dried exhaust gas.

8. The system (10) according to claim 5, further comprising a heat exchanger (95), the heat exchanger being characterized in that: The primary side is coupled to the exhaust outlet of the expander (153); and On the secondary side, the secondary side is coupled to the carbon dioxide (CO2) adsorption device (20) in the carbon release mode and is in energy communication with the carbon dioxide (CO2) adsorption device.

9. The system (10) according to claim 8, further comprising a CO2 capture unit (97) coupled to the primary side output of the heat exchanger (95) for removing CO2 from the exhaust gas of the expander (153).

10. The system (10) according to claim 9, further characterized in that the system has a first CO2 compressor (98) having an input end coupled to the CO2 output end of the CO2 capture unit and coupled to the output end of the CO2 adsorption device in the carbon release mode.

11. The system (10) according to claim 10, further characterized in that: A water separation unit (99) having an input terminal coupled to the output terminal of the first CO2 compressor (98); as well as A second CO2 compressor (89) has an input terminal coupled to the output terminal of the water separation unit (99) and an output terminal coupled to the CO2 output path.

12. The system (10) according to claim 9, wherein the CO2 adsorbent material (21) is characterized by a metal-organic framework (MOF), and the CO2 capture unit (97) comprises cold ammonia capture (CAP) or rotating bed compact carbon capture (3C).

13. A method for generating electricity with reduced or negative carbon emissions, the method being characterized in that: Electricity is generated in a power plant section (11), which includes a solid oxide fuel cell (SOFC) system (140), the SOFC system (140) being: Receives hydrogen fuel and air; To generate electricity by reacting hydrogen with air; Combustion of unused fuels to provide an energy exchange pathway; The hydrocarbon fuel from the hydrocarbon fuel supply source is reformed using heat and steam from the fuel cell reactor to supply hydrogen fuel to the SOFC reactor. Compressed air is supplied to the SOFC reactor; In the carbon capture mode, in the direct air capture (DAC) section, a CO2 adsorption device (20) with CO2 adsorption material (21) is used to collect carbon dioxide (CO2) from the air by adsorption. In the carbon capture mode, a fan (19) receiving power from the SOFC system (10) is used to circulate air through the CO2 adsorption device (20); and In carbon release mode, CO2 is released from the CO2 adsorption device (20) by providing energy to the CO2 adsorption material (21) from the energy exchange path.

14. The method of claim 13, wherein the release comprises at least one of the following: The CO2 adsorbent material (21) is heated using the mass flow of the fluid in the energy exchange path; or The CO2 adsorbent material (21) is heated by a heat transfer fluid heated by a heat exchanger (31) on the secondary side, the primary side of which is heated by energy from the energy exchange path.

15. The method according to claim 14, further characterized in that CO2 is captured using a CO2 capture device (20) that receives exhaust gas from the burner (142).

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