System and method for controlling a biochar system in a power plant

Abstract

To provide a system and method for controlling a biochar system in a power plant.SOLUTION: The system includes a controller having a processor, a memory, and instructions stored in the memory and executable by the processor to control the biochar pyrolysis reactor to heat the biomass feedstock using heat from the power plant to cause a pyrolysis reaction of the biomass feedstock to produce biochar and syngas, and to control the biochar adsorbent system to adsorb undesired gases from an exhaust gas of the power plant onto the biochar to produce enriched biochar and a treated gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] TECHNICAL FIELD This application relates generally to systems and methods for heat integration of biochar systems in power plants.

[0002] Industrial plants, such as combustion-driven power plants, can produce a variety of gases, such as exhaust gases from combustion systems. The combustion systems may include gas turbine engines, reciprocating piston-cylinder engines, furnaces, boilers, or other industrial equipment. These exhaust gases may include one or more undesirable gases, such as acid gases and / or greenhouse gases. For example, undesirable gases include carbon oxides (CO), such as carbon dioxide (CO) and carbon monoxide (CO). X ), nitrogen oxides such as nitrogen dioxide (NO2) X ), and / or sulfur oxides (SO ), such as sulfur dioxide (SO ). X ) may be included. Specifically, NO X are considered acid gases, and they can react with water in the atmosphere to form acids such as nitric acid (HNO3) and nitrous acid (HNO2). These acids can contribute to acid rain, which can have harmful effects on ecosystems, and NO X makes it a serious environmental issue. X Although not typically considered a greenhouse gas, NO can indirectly contribute to the greenhouse effect. For example, through various atmospheric reactions, NO X can lead to the production of nitrous oxide (NO), a potent greenhouse gas with a much greater global warming potential than CO over a 100-year period. X can contribute to the formation of ground-level ozone, which is a harmful air pollutant and a significant component of smog. Due to various regulations and environmental concerns regarding public welfare and global warming, there are restrictions on the emission of undesirable gases (e.g., NO) into the atmosphere, particularly for hydrocarbon fuel-consuming equipment, e.g., combustion systems. X It would be desirable to reduce emissions of Summary of the Invention

[0003] Certain embodiments commensurate in scope with the originally claimed subject matter are summarized below. These embodiments are not intended to limit the scope of the claimed embodiments; rather, these embodiments are intended only to provide a brief outline of possible forms of the present subject matter. Indeed, the embodiments claimed herein may encompass a variety of forms that may be similar to or different from the embodiments set forth below.

[0004] In certain embodiments, the system includes a controller having a processor, a memory, and instructions stored in the memory and executable by the processor, the controller controlling a biochar pyrolysis reactor to heat the biomass feedstock using heat from the power plant to cause a pyrolysis reaction of the biomass feedstock to produce biochar and syngas, and controlling a biochar sorbent system to adsorb undesirable gases from the power plant exhaust gas onto the biochar to produce enriched biochar and treated gas.

[0005] In certain embodiments, the method includes controlling a biochar pyrolysis reactor to heat the biomass feedstock using heat from the power plant to cause a pyrolysis reaction of the biomass feedstock to produce biochar and syngas.

[0006] In certain embodiments, the method includes controlling a biochar sorbent system to adsorb undesirable gases from an exhaust gas of a power plant onto the biochar to produce enriched biochar and a treated gas.

[0007] These and other features, aspects, and advantages of the techniques disclosed herein will be better understood when the following detailed description is read in conjunction with the accompanying drawings, in which like reference numerals represent like parts throughout. [Brief explanation of the drawings]

[0008] [Figure 1]FIG. 1 is a block diagram of an embodiment of a power plant in a combined cycle configuration having a gas turbine system, a steam generator, a steam turbine system, an exhaust gas recirculation (EGR) system, and a biochar system having a biochar pyrolysis reactor and a biochar sorbent system. [Figure 2] FIG. 2 is a block diagram of one embodiment of the power plant of FIG. 1, showing a simple cycle configuration with a biochar system that uses both exhaust gas and steam as heat sources for the biochar pyrolysis reactor. [Figure 3] FIG. 2 is a block diagram of one embodiment of the power plant of FIG. 1, showing a simple cycle configuration with a biochar system that uses exhaust gas as the heat source for the biochar pyrolysis reactor. [Figure 4] FIG. 2 is a block diagram of one embodiment of the power plant of FIG. 1, showing a simple cycle configuration with a biochar system that uses steam as the heat source for the biochar pyrolysis reactor. [Figure 5] FIG. 2 is a block diagram of one embodiment of the power plant of FIG. 1 , showing a stoichiometric exhaust gas recirculation (SEGR) configuration with a biochar system, in which the heat source for the biochar pyrolysis reactor is exhaust gas and there is a duct burner downstream of the biochar pyrolysis reactor. [Figure 6] FIG. 2 is a block diagram of one embodiment of the power plant of FIG. 1 , showing a stoichiometric exhaust gas recirculation (SEGR) configuration with a biochar system, in which the heat source for the biochar pyrolysis reactor is exhaust gas and there is a nitrogen-selective membrane downstream of the biochar pyrolysis reactor. [Figure 7] FIG. 7 is a schematic diagram of one embodiment of a biochar pyrolysis reactor of the biochar system of FIGS. 1-6, further illustrating an indirect heat transfer configuration. [Figure 8] FIG. 7 is a schematic diagram of one embodiment of a biochar pyrolysis reactor of the biochar system of FIGS. 1-6, further illustrating a direct heat transfer configuration. [Figure 9] FIG. 7 is a flow chart of one embodiment of a process for operating a biochar system in the power plant of FIGS. 1-6. [Figure 10]FIG. 7 is a flow chart of one embodiment of a process for controlling the operation of the power plant and biochar system of FIGS. 1-6. DETAILED DESCRIPTION OF THE INVENTION

[0009] One or more specific embodiments of the systems and methods disclosed herein are described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described herein. It should be understood that the development of such an actual implementation, like any engineering or design project, will require numerous implementation-specific decisions to achieve the developer's particular goals, including, for example, compliance with system-related and business-related constraints, which may vary from implementation to implementation. Moreover, it should be understood that such a development effort may be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill in the art having the benefit of this disclosure.

[0010] When introducing elements of various embodiments of the presently disclosed embodiments, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0011] Embodiments of the present disclosure include systems and methods for heat integration with industrial plants, such as combustion-driven power plants, that use available heat for biochar production and biochar for exhaust gas treatment. In certain embodiments, embodiments of the present disclosure provide a biochar system having a biochar pyrolysis reactor and / or a biochar sorbent system. The biochar pyrolysis reactor is configured to receive a biomass feedstock and use one or more available heat sources (e.g., exhaust gases and / or steam) within the power plant to drive a pyrolysis reaction of the biomass feedstock, thereby producing both syngas as a fuel source for the power plant and biochar for various on-site and / or off-site uses. For example, the biochar can be used off-site for various soil applications and / or on-site as a sorbent material in a biochar sorbent system. In certain embodiments, the biochar sorbent system uses biochar (e.g., produced on-site or off-site by a biochar pyrolysis reactor and / or other biochar source) as a sorbent material to remove undesirable gases (e.g., NO) from the exhaust gas. X ), thereby producing a treated gas that is low in undesirable gases (e.g., NO X The power plant produces lean exhaust gases and nitrogen-rich biochar for use in various soil applications. In certain embodiments, the power plant can use only a biochar pyrolysis reactor, only a biochar sorbent system, or a combination thereof as the biochar system. Additionally, in certain embodiments, the power plant can include a gas turbine system operating in a simple cycle or a combined cycle with a steam generator and steam turbine system. Additionally, in certain embodiments, the power plant can include or exclude exhaust gas recirculation. Finally, the power plant can utilize NO X benefit from (e.g., adsorption on biochar) and NO in exhaust gases X Various fuel-lean, fuel-rich, or stoichiometric operating modes, as well as different NO emissions, can be achieved in combination with biochar systems to help reduce X Mode (e.g., low NO X , Intermediate NO X, or high NO X ) can be configured to operate at NO X The present invention includes various control schemes to enable more flexible power plant operation while using a biochar system for carbon dioxide reduction and nitrogen-rich biochar production. While the following description presents various aspects of the biochar system in the context of a power plant, the biochar system is intended for use in any plant or application that has available heat and exhaust / flue gases that require treatment.

[0012] 1 is a block diagram of an embodiment of a power plant 10 in a combined cycle configuration having a gas turbine system 12, a steam generator 14 (e.g., a heat recovery steam generator (HRSG)), a steam turbine system 16, an exhaust gas recirculation (EGR) system 18, a biochar system 20 having one or more biochar pyrolysis reactors 22 and one or more biochar sorbent systems 24, and a controller 26 coupled to each of systems 12, 14, 16, 18, 20, 22, and 24. As described below, the one or more biochar pyrolysis reactors 22 of biochar system 20 are configured to produce biochar 28 by applying heat to a biomass feedstock 30 using one or more heat transfer fluids or heat sources 32 (e.g., exhaust gas 34 and / or steam 36) from the power plant 10. Biomass feedstock 30 may include, for example, industrial waste and by-products, food waste, agricultural residues (e.g., wheat straw), plants (e.g., corn, switchgrass, miscanthus, and bamboo), energy crops, wood, wood residues, or any combination thereof in various forms (e.g., pellets). Additionally, as described below, biochar sorbent system 24 uses biochar 28 as a sorbent material to remove nitrogen oxides (NO ) from exhaust gas 34. X), thereby reducing the emission of undesirable gases in exhaust gas 34, while simultaneously enriching biochar 28 with nitrogen to produce nitrogen-rich biochar 38 for various soil applications 40 (e.g., agriculture, forestry, farming, etc.). Various embodiments of biochar system 20 and power plant 10 configurations are described in further detail below.

[0013] The gas turbine system 12 includes an air intake 50, a compressor 52 having one or more compressor stages, one or more combustors 54, a turbine 56 having one or more turbine stages, and a load 58 (e.g., a generator) driven by the turbine 56. In certain embodiments, the gas turbine system 12 further includes an exhaust gas recirculation (EGR) system 18 configured to recirculate the exhaust gas 34 to the air intake 50. The recirculated exhaust gas 34 is purified from certain emissions associated with combustion in the combustor 54, such as nitrogen oxides (NO X ))。 During operation, the compressor 52 receives air from the air intake 50 (and also the exhaust gases 34 if the EGR system 18 is activated) and compresses the air and / or exhaust gases 34 in one or more compressor stages (e.g., stages of rotating compressor blades). In certain embodiments, such as those having the EGR system 18, the gas turbine system 12 includes an air compressor 60 configured to compress air 62 and supply the compressed air 64 to a combustor 54 that is separate from the compressor 52. The air compressor 60 may be driven by a shaft of the gas turbine system 12 or may be independently driven by another power source, such as an electric motor or combustion engine. The combustor 54 then combusts fuel from a fuel supply system 66 with the compressed air and / or exhaust gases to generate hot combustion gases. The hot combustion gases expand and drive one or more turbine stages (e.g., stages of rotating turbine blades) in the turbine 56, thereby driving the rotation of the compressor 52 and a load 58 via the shaft. Turbine 56 then exhausts the hot combustion gases as exhaust gases 34 .

[0014] The steam generator 14 recovers heat from the exhaust gas 34 and generates steam 68 for driving the steam turbine system 16. The steam generator 14 may include one or more different steam pressure sections, such as one or more of a high-pressure (HP) steam section, an intermediate-pressure (IP) steam section, and a low-pressure (LP) steam section, configured to generate HP steam, IP steam, and LP steam. However, the steam generator 14 is not limited to a specific number or configuration of different steam pressure sections. The steam turbine system 16 may include one or more different steam turbine sections, such as one or more of a HP steam turbine driven by HP steam, a IP steam turbine driven by IP steam, and a LP steam turbine driven by LP steam. However, the steam turbine system 16 is not limited to a specific number or configuration of different steam turbine sections. In addition to the steam 68 provided by the steam generator 14, the steam turbine system 16 may return any remaining steam / water to the steam generator 14 as a return flow 70. During operation, the steam turbine system 16 drives a load 72 (e.g., an electrical generator) via a shaft. In certain embodiments, the steam turbine system 16 and / or the steam generator 14 may supply heated water and / or steam 36 (e.g., HP steam, IP steam, and / or LP steam) to the biochar pyrolysis reactor 22 of the biochar system 20 to assist in the pyrolysis of the biomass feedstock to produce biochar.

[0015] After the steam generator 14, the exhaust gases 34 may flow to the EGR system 18 and / or an exhaust stack 74. In embodiments including the EGR system 18, at least a portion of the exhaust gases 34 may flow through a heat exchanger 76 (e.g., an EGR cooler) configured to cool the exhaust gases 34 before recirculating through the gas turbine system 12 via the intake 50. For example, the heat exchanger 76 may indirectly transfer heat from the exhaust gases 34 to a thermal fluid (e.g., water) circulating through the heat exchanger 76 from a fluid input 78 to a fluid output 80, where the thermal fluid discharged from the fluid output 78 may be used for heating elsewhere in the power plant 10, for district heating applications, for combined heat and power (CHP) applications, or any combination thereof. In embodiments with or without EGR system 18, at least a portion or all of exhaust gas 34 may flow along exhaust flow path 82 having exhaust stack 74, and biochar sorbent system 24 is configured to treat exhaust gas 34 along exhaust flow path 82 (e.g., within exhaust stack 74) before discharging treated gas 84 to the atmosphere. As described in further detail below, biochar sorbent system 24 receives biochar 28 from biochar pyrolysis reactor 22 using heat source 36 from power plant 10, and biochar sorbent system 24 then uses biochar 28 to sorb nitrogen oxides (NO ) from exhaust gas 34. X ), and discharges treated gas 84 from exhaust stack 74 and nitrogen-rich biochar 38 for use in various soil applications 40. Details of biochar sorbent system 24 are further described below after describing biochar pyrolysis reactor 22.

[0016] In the illustrated embodiment, biochar system 20 includes one or more biochar pyrolysis reactors 22 for producing biochar 28 and syngas 86 using biomass feedstock 30 and one or more heat sources 32 (e.g., exhaust gas 34 and / or steam 36) that are supplied together during operation of power plant 10. In certain embodiments, biochar system 20 can include a single biochar pyrolysis reactor 22 that uses only one or more of the heat sources 32, such as exhaust gas 34 only, steam 36 only, or a combination of both exhaust gas 34 and steam 36. In certain embodiments, biochar system 20 can include multiple biochar pyrolysis reactors 22 operating in a series configuration, a parallel configuration, or a combination thereof, and each of the biochar pyrolysis reactors 22 can operate with the same or a different heat source 32. In certain embodiments, biochar pyrolysis reactor 22 can include a reactor vessel having a metal casing, an insulated internal lining (e.g., a ceramic lining), a feedstock inlet 88, an exhaust gas inlet 90, a steam inlet 92, an exhaust gas outlet 94, a steam outlet 96, a syngas outlet 98, a biochar outlet 100, and an internal flow path 102 along a conveyor 104 through biochar pyrolysis reactor 22. Generally, biochar pyrolysis reactor 22 is configured to transfer heat from a heated fluid (e.g., exhaust gas 34 and / or steam 36) from heat source 32 to biomass feedstock 30 (e.g., directly and / or indirectly) at a sufficient residence time and temperature within biochar pyrolysis reactor 22 to cause a pyrolysis reaction of biomass feedstock 30, thereby producing biochar 28 and syngas 86. Various aspects of biochar system 20 can be controlled by controller 26 to control the pyrolysis reaction and the properties of biochar 28 and syngas 86.

[0017] The biochar pyrolysis reactor 22 is configured to receive the biomass feedstock 30 from a feedstock supply system 106 via a feedstock inlet 88 and move the biomass feedstock 30 along an internal flow path 102 through the biochar pyrolysis reactor 22 via a conveyor 104 to a biochar outlet 100. The feedstock supply system 106 can include an electric motor-driven external conveyor, such as a belt conveyor, a screw conveyor or auger conveyor, a hopper, or any combination thereof. Similarly, the conveyor 104 can include an electric motor-driven internal conveyor, such as a belt conveyor, a screw conveyor or auger conveyor, an inclined gravity-driven conveyor, or any combination thereof. The controller 26 is configured to control the speed (e.g., increasing or decreasing the speed) of the feedstock supply system 106 and the conveyor 104 to control the residence time of the pyrolysis reaction inside the biochar pyrolysis reactor 22, thereby controlling the properties of the biochar 28 and the syngas 86.

[0018] The biochar pyrolysis reactor 22 is configured to receive one or more heated fluids from a heat source 32 (e.g., exhaust gas 34 and / or steam 36) via an exhaust gas inlet 90 and / or a steam inlet 92, and to direct the heated fluids to transfer heat (e.g., direct and / or indirect heat transfer) to the biomass feedstock 30 moving along the conveyor 104, for example, in a flow direction parallel to and along the conveying direction of the conveyor 104, a flow direction parallel to and opposite the conveying direction of the conveyor 104, and / or a flow direction intersecting the conveying direction of the conveyor 104. For example, for direct heat transfer, the biomass feedstock 30 may be directly exposed to the heated fluid (e.g., exhaust gas 34 and / or steam 36), or for indirect heat transfer to the biomass feedstock 30, the heated fluid (e.g., exhaust gas 34 and / or steam 36) may flow through one or more conduits, hollow walls, or heat exchangers coupled to and / or within the biochar pyrolysis reactor 22. The heated fluid (e.g., exhaust gas 34 and / or steam 36) flows through the biochar pyrolysis reactor 22, transfers heat to the biomass feedstock 30 on the conveyor 104, and then is discharged through the exhaust gas outlet 94 and the steam outlet 96. Within the biochar pyrolysis reactor 22, the heat transferred from the heated fluid (e.g., exhaust gas 34 and / or steam 36) to the biomass feedstock 30 causes a pyrolysis reaction in the biomass feedstock 30, thereby producing both biochar 28 and syngas 86. The fluid properties (e.g., temperature, pressure, flow rate, etc.) of the heated fluid (e.g., exhaust gas 34 and / or steam 36) can alter the pyrolysis reactions of the biomass feedstock 30. Accordingly, the controller 26 is configured to control the fluid properties (e.g., temperature, pressure, flow rate, etc.) of the heated fluid (e.g., exhaust gas 34 and / or steam 36) to control the pyrolysis reactions within the biochar pyrolysis reactor 22, thereby controlling the properties of the biochar 28 and syngas 86.

[0019] In certain embodiments, the controller 26 is configured to control the speed of the feedstock supply system 106 and the conveyor 104, the fluid properties (e.g., temperature, pressure, flow rate, etc.) of the heated fluid (e.g., the exhaust gas 34 and / or the steam 36), or a combination thereof, based on sensor feedback and the operating mode of the power plant 10. For example, the sensor feedback may include feedback from one or more sensors internal to the biochar pyrolysis reactor 22, such as a temperature sensor, a flow sensor, a pressure sensor, a gas composition sensor, an optical sensor, or any combination thereof, that provide sensor feedback regarding the pyrolysis reaction. In a further example, the sensor feedback may include feedback from one or more sensors coupled to the gas turbine system 12 and / or along the exhaust gas flow path of the exhaust gas 34, such as a temperature sensor, a pressure sensor, a flow sensor, a gas composition sensor, or any combination thereof, that provide sensor feedback regarding the exhaust gas 34. In a further example, the sensor feedback may include feedback from one or more sensors coupled to the steam generator 14, the steam turbine system 16, and / or along the steam flow path of the steam 36, such as a temperature sensor, a pressure sensor, a flow sensor, or any combination thereof, that provide sensor feedback regarding the steam 36. The aforementioned sensor feedback regarding the pyrolysis reaction, the exhaust gas 34, and the steam 36 may be used to control the velocity, volume, and residence time of the biomass feedstock 30 moving through the biochar pyrolysis reactor 22, as well as the flow rate, temperature, and pressure of the heated fluid used to drive the pyrolysis reaction, thereby further controlling the properties of the biochar 28 and the syngas 86.

[0020] Additionally, as described in further detail below, controller 26 is configured to control biochar system 20 based on the operating mode of power plant 10, such as startup mode, steady-state mode, shutdown mode, full load mode, or part load mode. For example, power plant 10 may operate in full load mode to generate more power when power demand is high, while power plant 10 may operate in part load mode to generate less power when power demand is low. When power plant 10 changes between full load mode and part load mode (or between any of the operating modes), the fluid properties (e.g., temperature, pressure, flow rate, etc.) of the heated fluid (e.g., exhaust gas 34 and / or steam 36) and the demand for syngas 86 generally change; therefore, controller 26 may modify the use of heated fluid in biochar pyrolysis reactor 22 when power plant 10 changes between full load mode and part load mode or when power plant 10 changes between any of the operating modes.

[0021] The controller 26 is configured to control the speed of the feedstock supply system 106 and the conveyor 104 in various manners depending on the sensor feedback and the operating mode of the power plant 10. For example, the controller 26 may be configured to increase the speed of the feedstock supply system 106 and the conveyor 104 to shorten the residence time of the biomass feedstock 30 in the biochar pyrolysis reactor 22, or to decrease the speed of the feedstock supply system 106 and the conveyor 104 to increase the residence time of the biomass feedstock 30 in the biochar pyrolysis reactor 22. In a further example, controller 26 may be configured to increase the speed of feedstock supply system 106 for a particular speed of conveyor 104 to increase the volume of biomass feedstock 30 per area on conveyor 104 in biochar pyrolysis reactor 22, or to decrease the speed of feedstock supply system 106 for a particular speed of conveyor 104 to decrease the volume of biomass feedstock 30 per area on conveyor 104 in biochar pyrolysis reactor 22. In a further example, controller 26 may be configured to vary the speed of feedstock supply system 106 and / or conveyor 104 depending on the availability of heat from heat source 32 (e.g., exhaust gas 34 and / or steam 36).

[0022] The controller 26 is configured to control the heated fluid (e.g., exhaust gas 34 and / or steam 36) supplied to the biochar pyrolysis reactor 22 in various ways depending on the sensor feedback and the operating mode of the power plant 10. For example, the controller 26 may be configured to increase the flow rate of the heated fluid (e.g., exhaust gas 34 and / or steam 36) to increase heat transfer from the heated fluid to the biomass feedstock 30 in the biochar pyrolysis reactor 22, or to decrease the flow rate of the heated fluid (e.g., exhaust gas 34 and / or steam 36) to decrease heat transfer from the heated fluid to the biomass feedstock 30 in the biochar pyrolysis reactor 22. In a further example, the controller 26 may be configured to change between different extraction points or sources of the heated fluid (e.g., the exhaust gas 34 and / or steam 36) to change the temperature and / or pressure of the heated fluid used to facilitate the pyrolysis reaction of the biomass feedstock 30 in the biochar pyrolysis reactor 22, for example, by changing between different extraction points where the exhaust gas 34 and / or steam 36 have different temperatures and / or pressures. Accordingly, the controller 26 may be configured to control valves coupled to each supply line of the heated fluid (e.g., the exhaust gas 34 and / or steam 36). In certain embodiments, the extraction points of the heated fluid (e.g., the exhaust gas 34 and / or steam 36) may include low-property extraction points (e.g., low pressure and / or low temperature), intermediate-property extraction points (e.g., intermediate pressure and / or intermediate temperature), and high-property extraction points (e.g., high pressure and / or high temperature). The selection of the extraction points may vary depending on the operating mode of the power plant 10, the demand for syngas 86, the demand for biochar 28, and / or fluctuations in pressure and temperature at each extraction point.

[0023] In the illustrated embodiment, the biochar pyrolysis reactor 22 can receive exhaust gas 34 via exhaust supply line 108, steam 36 via steam supply line 110 coupled to the steam generator 14, steam 36 via steam supply line 112 coupled to the steam turbine system 16, or a combination thereof. Accordingly, the controller 26 can be configured to control valves coupled to each of the supply lines 108, 110, 112. In some embodiments, each of the supply lines 108, 110, 112 can include a single supply line or multiple supply lines coupled to different extraction points having different characteristics (e.g., pressure, temperature, etc.) of the exhaust gas 34 and steam 36. In certain embodiments, all or a portion of the exhaust gas 34 can bypass the biochar pyrolysis reactor 22 via exhaust bypass line 114, which extends to the steam generator 14 to generate steam using heat from the exhaust gas 34. Again, the controller 26 may be configured to control a valve coupled to the exhaust bypass line 114 to control the amount of exhaust bypass flow along the exhaust bypass line 114 .

[0024] In embodiments that utilize at least a portion of the exhaust gas 34 in the biochar pyrolysis reactor 22, the exhaust gas 34 discharged from the biochar pyrolysis reactor 22 can flow through an exhaust line 116 having a nitrogen-selective membrane 118, a duct burner 120, or a combination thereof. For example, the nitrogen-selective membrane 118 and / or the duct burner 120 may be included in embodiments with direct heat transfer between the exhaust gas 34 and the biomass feedstock 30, thereby combining the exhaust gas 34 and syngas discharged from the biochar pyrolysis reactor 22 along the exhaust line 116. In certain embodiments, the nitrogen-selective membrane 118 and / or the duct burner 120 can be used in an exhaust gas recirculation (EGR) configuration, such as a stoichiometric exhaust gas recirculation (SEGR) configuration of the power plant 10. In such embodiments, the nitrogen-selective membrane 118 can be used to remove nitrogen oxides (NO ) from the discharged syngas and exhaust gas 34 mixture. X), thereby producing nitrogen 122 and syngas 86 (e.g., colorific syngas) along syngas line 124. Nitrogen-selective membrane 118 may be used with or without duct burner 120. Duct burner 120 may be configured to combust the syngas in the mixture of exhausted syngas and exhaust gas 34, thereby adding heat to exhaust gas 34 upstream of steam generator 14. As a result, the heat added by duct burner 120 can increase steam production in steam generator 14, which may also help increase power output by steam turbine system 16. However, in some embodiments, such as those involving indirect heat transfer between exhaust gas 34 and biomass feedstock 30, the syngas does not mix with exhaust gas 34, and therefore nitrogen-selective membrane 118 and / or duct burner 120 may be omitted from exhaust line 116. Alternatively, in embodiments involving indirect heat transfer between the exhaust gas 34 and the biomass feedstock 30, the biochar pyrolysis reactor 22 is configured to separately discharge the exhaust gas 34 through an exhaust gas outlet 94 and the syngas 86 through a syngas outlet 98. The use of the syngas 86 is described in further detail below.

[0025] In embodiments using at least a portion of the steam 36 in the biochar pyrolysis reactor 22, the steam 36 can be used to heat the biomass feedstock 30 via direct or indirect heat transfer to promote pyrolysis. The biochar pyrolysis reactor 22 can discharge the steam 36 (or a steam / water mixture) along a steam line 126 back to the steam generator 14. In embodiments using direct heat transfer between the steam 36 and the biomass feedstock 30, one or more post-treatment systems for separating the steam / water from the syngas may be included along the steam line 126, such as a condenser for condensing any steam into water, a separator for separating the water from the syngas, or any combination thereof. In embodiments using indirect heat transfer between the steam 36 and the biomass feedstock 30, the biochar pyrolysis reactor 22 is configured to separately discharge the steam 36 through the steam outlet 96 and the syngas 86 through the syngas outlet 98.

[0026] In certain embodiments, biochar pyrolysis reactor 22 is configured with only exhaust gas 34 as the heat source 32, only steam 36 as the heat source 32, or a combination of both heat sources 32. In embodiments using only exhaust gas 34 as the heat source 32, steam supply lines 110 and 112 may be excluded as heat sources 32. Furthermore, in certain embodiments, steam generator 14, steam turbine system 16, nitrogen-selective membrane 118, duct burner 120, or combinations thereof may be included or excluded depending on whether steam 36 is used as the heat source 32, whether steam generator 14 is downstream from biochar pyrolysis reactor 22, and whether EGR system 18 is present. In embodiments using only steam 36 as the heat source 32, exhaust supply line 108 may not be connected to biochar pyrolysis reactor 22, and exhaust line 116 with nitrogen-selective membrane 118 and duct burner 120 may be omitted from biochar system 20.

[0027] In the illustrated embodiment, the biochar pyrolysis reactor 22 produces a syngas 86, and / or the nitrogen-selective membrane 118 separates the syngas 86 from the exhaust gas 34 along the exhaust line 116, thereby functioning as part of the fuel supply system 66 of the gas turbine system 12. The syngas 86 can at least partially or completely meet the fuel needs of the gas turbine system 12. The fuel supply system 66 includes a heat exchanger 128 (e.g., a syngas cooler) configured to cool the syngas 86 via indirect heat exchange with a thermal fluid (e.g., water) circulated through the heat exchanger 128 from a fluid input 130 to a fluid output 132, where the thermal fluid discharged from the fluid output 132 can be used for heating elsewhere in the power plant 10, for district heating applications, for combined heat and power (CHP) applications, or any combination thereof. The fuel supply system 66 may also include a compressor 134 (e.g., a syngas compressor) driven by an electric motor or a combustion engine and configured to compress the syngas 86 to a pressure suitable for storage in a storage tank 136 and / or injection into the combustor 54 of the gas turbine system 12. The storage tank 136 may function as a buffer storage tank because syngas 86 production varies throughout the operation of the power plant 10. Thus, if the biochar pyrolysis reactor 22 produces more syngas 86 than is required or needed for operation of the gas turbine system 12, the excess syngas 86 is stored in the storage tank 136 for later use if the biochar pyrolysis reactor 22 produces less syngas 86 than is required or needed for operation of the gas turbine system 12. In this manner, the storage tank 136 combined with the biochar pyrolysis reactor 22 may be configured to meet the fuel needs of the gas turbine system 12 under various operating modes, such as a startup mode, a steady-state mode, a shutdown mode, a full-load mode, or a part-load mode.

[0028] In addition to the syngas 86 used by the fuel supply system 66 of the gas turbine system 12, the biochar 28 is used by the biochar sorbent system 24 along the exhaust flow path 82 (e.g., in the exhaust stack 74) to treat and enrich the exhaust gas 34 with biochar 28. In some embodiments, the biochar sorbent system 24 can operate with biochar from various sources. Thus, the biochar sorbent system 24 may operate completely independent of the biochar pyrolysis reactor 22, or the biochar pyrolysis reactor 22 and the biochar sorbent system 24 may work together to complement each other and improve the operation of the power plant 10. For example, the biochar 28 may be produced entirely by the biochar pyrolysis reactor 22 of the power plant 10, entirely by a biochar pyrolysis reactor (or other source) independent of the power plant 10, or any combination thereof. In the illustrated embodiment, the exhaust gas 34 is purged of undesirable gases, particularly nitrogen oxides (NO ). XThe nitrogen oxides flow through one or more biochar sorbent systems 24 configured to capture nitrogen dioxide (NO) and / or nitric oxide (NO), for example. As a result, the biochar sorbent system 24 adsorbs the nitrogen oxides onto the biochar 28, which acts as an adsorbent material or medium to capture the nitrogen oxides and produce a treated gas 84 that is substantially free of nitrogen oxides, and to produce a nitrogen-rich biochar 38. The nitrogen-rich biochar 38 can then be transported via a transportation system 138 to one or more soil applications 40, such as, for example, an agricultural application, a farming application, a forestry application, or any combination thereof. The transportation system 138 can include a conveyor, a rail system, a trucking system, or any combination thereof. In some embodiments, the soil application 40 may correspond to the original source of the biomass feedstock 30. In other words, the biomass feedstock 30 may be taken from a soil application and returned to the same or a similar soil application. In certain embodiments, soil application 40 may include forestry applications, such as afforestation, reforestation, agroforestry, or forest management, etc. In certain embodiments, soil application 40 may include peatland and coastal marsh restoration, soil carbon sequestration in croplands and grasslands, biomass burial, biomass sedimentation, ocean fertilization, or any combination thereof.

[0029] In certain embodiments, one or more of the biochar sorbent systems 24 are used to remove one or more undesirable gases, such as nitrogen oxides (NO X ) (e.g., nitrogen dioxide (NO2) and / or nitric oxide (NO)), carbon oxides (CO X ) (e.g., carbon dioxide (CO2) and carbon monoxide (CO)), sulfur oxides (SO X ), (e.g., sulfur dioxide (SO), or any combination thereof. Treated gas 84 may be substantially free of undesirable gases and may be discharged to the atmosphere through exhaust stack 74. In certain embodiments, biochar system 20 may include multiple biochar sorbent systems 24 in a series configuration, a parallel configuration, or a combination thereof.

[0030] In the illustrated embodiment, the biochar sorbent system 24 includes a conveyor 140 configured to transport the biochar 28 through the exhaust flow path 82, e.g., laterally or vertically through the exhaust stack 74. The conveyor 140 may include an electric motor-driven internal conveyor, such as a belt conveyor, a screw or auger conveyor, an inclined gravity-driven conveyor, or any combination thereof. The controller 26 controls the speed (e.g., increasing or decreasing speed) of the conveyor 140 to control the residence time of the biochar 28 within the biochar sorbent system 24, thereby controlling the removal of undesirable gases (e.g., NO ) from the exhaust gas 34. X ) onto the biochar 28, thereby controlling the properties of the nitrogen-rich biochar 38 and the treated gas 84. The biochar sorbent system 24 may include a perforated metal housing or duct extending through the exhaust stack 74 with sufficient openings to allow the exhaust gas 34 to flow directly over the biochar 28 moving along the conveyor 140.

[0031] In certain embodiments, as power plant 10 changes between operating modes (e.g., startup mode, steady-state mode, shutdown mode, full load mode, or part load mode), the changing operating mode causes changes in the fluid properties (e.g., temperature, pressure, flow rate, etc.) of the heated fluids (e.g., exhaust gas 34 and / or steam 36) of biochar pyrolysis reactor 22, changes in the demand for syngas 86 produced by biochar pyrolysis reactor 22, changes in the demand for gas processing via biochar sorbent system 24, or any combination thereof. Thus, controller 26 can be configured to control biochar system 20, including both biochar pyrolysis reactor 22 and biochar sorbent system 24, in response to changes in overall power plant 10, power grid demand, syngas demand, biochar demand, and available heat source 32 to support the pyrolysis reaction.

[0032] In certain embodiments, the controller 26 may be configured to control the amount of undesirable gases (e.g., NO ) that are present in the power plant 10 contrary to normal operating objectives. X ), while varying the fuel-air ratio, combustion flame temperature, or a combination thereof to increase the amount of undesirable gases (e.g., NO) in the biochar sorbent system 24. X The power plant 10, and in particular the gas turbine system 12, is configured to control the power plant 10, and in particular the gas turbine system 12, to utilize the increased nitrogen (e.g., NO) to enrich the biochar 28 and produce nitrogen-rich biochar 38 for various soil applications 40. Thus, with the positive goal of enriching the biochar 28, the power plant 10 is configured to control the power plant 10, and in particular the gas turbine system 12, to utilize the increased nitrogen (e.g., NO) to enrich the biochar 28 and produce nitrogen-rich biochar 38 for various soil applications 40. X By incorporating a biochar sorbent system 24 to adsorb undesirable gases (e.g., NO), the power plant 10 can operate over a wider range of operating conditions, such as various fuel-air ratios (e.g., fuel-rich, fuel-lean, or stoichiometric), combustion flame temperatures, etc. Conventional wisdom has long suggested that undesirable gases (e.g., NO) can be adsorbed over a wider range of operating conditions, such as various fuel-air ratios (e.g., fuel-rich, fuel-lean, or stoichiometric), combustion flame temperatures, etc. X While the power plant 10 does not intentionally operate to increase the amount of undesirable gases (e.g., NO), the controller 26 may, in combination with the operation of the biochar system 20 (e.g., the biochar pyrolysis reactor 22 and the biochar sorbent system 24), increase the amount of undesirable gases (e.g., NO X ) can be included in an operating mode that specifically increases

[0033] In certain embodiments, the controller 26 controls the low NO X Operation mode, intermediate NO X Operating Mode and High NO X Operation modes can include combustion flame temperature, NO X The production and exhaust gas temperatures change from one operating mode to another, resulting in low NO X High NO from operation mode X The higher temperature of the exhaust gas 34 may help increase heat transfer and pyrolysis of the biomass feedstock 30 to produce biochar 28 in the biochar pyrolysis reactor 22, increase steam production in the steam generator 14, etc. Additionally, high NO XThe generation of different NO may help to more quickly enrich the biochar 28 in the biochar sorbent system 24 to produce nitrogen-rich biochar 38. X The operating mode may be used in combination with other operating modes, such as a start-up mode, a steady-state mode, a shutdown mode, a full load mode, or a part load mode of the gas turbine system 12. For example, the controller 26 may X , Medium NO X , or high NO X The gas turbine system 12 may be controlled to operate in a full load mode in one of the operating modes, or the controller 26 may control a low NO X , Medium NO X , or high NO X In one of the operating modes, the gas turbine system 12 may be controlled to operate in a part load mode. For example, the controller 26 may control the gas turbine system 12 to operate in a low NOx mode while in a full load mode. X The gas turbine system 12 may be operated in a partial load mode while the controller 26 controls the high NO X In some embodiments, the controller 26 may adjust the NO 2 in the exhaust gas 34 as the flow rate of the exhaust gas 34 decreases and / or the load on the gas turbine system 12 decreases. X The gas turbine system 12 may be operated to gradually increase production rate and temperature, while the controller 26 adjusts the NO 2 content of the exhaust gas 34 as the flow rate of the exhaust gas 34 increases and / or the load on the gas turbine system 12 increases. X The gas turbine system 12 can be operated to gradually reduce the production rate and temperature. X With various changes in concentration, the biochar pyrolysis reactor 22 can benefit from increased heat transfer (e.g., higher temperature and / or flow rate) to improve the pyrolysis reaction, while the biochar sorbent system 24 can improve the NO X The increased concentration can be beneficial to enrich the biochar 28 .

[0034] As shown, controller 26 includes a processor 142, a memory 144, instructions 146 stored in memory 144 and executable by processor 142 to perform various control functions of controller 26, and communication circuitry 148 for communicating with various sensors and equipment of power plant 10. Further aspects of the control are described in more detail below. Additionally, various embodiments of power plant 10 having biochar system 20 are described in more detail below.

[0035] FIG. 2 is a block diagram of one embodiment of the power plant 10 of FIG. 1 , illustrating a simple cycle configuration 150 with a biochar system 20 that uses both exhaust gas 34 and steam 36 as the heat source 32 for the biochar pyrolysis reactor 22. The power plant 10 of FIG. 2 is substantially the same as that described in detail above with reference to FIG. 1 , except for certain variations described below. Accordingly, like element numbers are used for like elements, and thus, all aspects of the illustrated power plant 10 and biochar system 20 are the same as those described above unless otherwise indicated. In the illustrated embodiment, the simple cycle configuration 150 of the power plant 10 excludes the steam turbine system 16 and the EGR system 18. Additionally, the power plant 10 excludes the nitrogen-selective membrane 118 and the duct burner 120 along the exhaust line 116, although some embodiments may include these components within the power plant 10 of FIG. 2. Additionally, the power plant 10 excludes the air compressor 60 and instead relies on the compressor 52. In other respects, the embodiment of FIG. 2 is substantially the same as the embodiment of FIG. 1.

[0036] In the illustrated embodiment, the biochar pyrolysis reactor 22 produces biochar 28 using exhaust gas 34 and / or steam 36 for direct and / or indirect heat transfer to the biomass feedstock 30. For example, the exhaust gas 34 may be directed to flow through the biochar pyrolysis reactor 22 from one or more exhaust extraction points (e.g., after one or more turbine stages of the turbine 56, or the last turbine stage), or the exhaust gas 34 may not be used as one of the heat sources 32. In certain embodiments, the exhaust gas 34 may be directed partially or completely through the biochar pyrolysis reactor 22 to provide heat transfer (e.g., direct and / or indirect heat transfer) for the pyrolysis reaction, or the exhaust gas 34 may bypass the biochar pyrolysis reactor 22 entirely. Similarly, the steam 36 may be directed to flow through the biochar pyrolysis reactor 22 from one or more steam extraction points, or the steam 36 may not be used as one of the steam sources 32. As a result of direct and / or indirect heat transfer from the heat source 32 (e.g., exhaust gas 34 and / or steam 36) to the biomass feedstock 30, the biochar pyrolysis reactor 22 produces biochar 28. In certain embodiments, all or a portion of the biochar 28 may be used for the biochar sorbent system 24, for direct soil application 40, or a combination thereof. In other words, in some embodiments, unenriched biochar 28 and / or enriched biochar 28 as nitrogen-rich biochar 38 may be transported to the soil application 40 by the transport system 138. The biochar sorbent system 24 converts undesirable gases (e.g., NO) from the exhaust gas 34 into nitrogen-rich biochar 38. X ) is adsorbed onto biochar 28 to produce treated gas 84 and nitrogen-rich biochar 38.

[0037] 2 can include all or part of the biochar system 20. For example, the power plant 10 can include only the biochar pyrolysis reactor 22, only the biochar sorbent system 24, or a combination of both the biochar pyrolysis reactor 22 and the biochar sorbent system 24. In embodiments that do not include the biochar sorbent system 24, the power plant 10 can include one or more other types of carbon capture systems (e.g., sorbent-based carbon capture and / or solvent-based carbon capture), and the biochar 28 produced by the biochar pyrolysis reactor 22 can be used for soil application 40 without enrichment in the power plant 10. In embodiments that do not include the biochar pyrolysis reactor 22, the power plant 10 can supply biochar to the biochar sorbent system 24 from a variety of external sources, possibly from other power plants that have the biochar pyrolysis reactor 22. However, in the illustrated embodiment, biochar system 20 includes a biochar pyrolysis reactor 22 and a biochar sorbent system 24 that operate to complement each other and improve the efficiency and value of power plant 10 by producing syngas 86 and nitrogen-rich biochar 38.

[0038] FIG. 3 is a block diagram of one embodiment of the power plant 10 of FIG. 1 , illustrating a simple cycle configuration 170 with a biochar system 20 that uses exhaust gas 34 as the heat source 32 for the biochar pyrolysis reactor 22. The power plant 10 of FIG. 3 is substantially the same as that described in detail above with reference to FIGS. 1 and 2 , except for certain variations described below. Accordingly, like element numbers are used for like elements, and thus, all aspects of the illustrated power plant 10 and biochar system 20 are the same as those described above unless otherwise indicated. In the illustrated embodiment, the simple cycle configuration 170 of the power plant 10 excludes the steam turbine system 16 and the EGR system 18. Additionally, the power plant 10 excludes the nitrogen-selective membrane 118 and the duct burner 120 along the exhaust line 116, although some embodiments may include these components within the power plant 10 of FIG. 3 . Additionally, the power plant 10 excludes the air compressor 60 and instead relies on the compressor 52. In other respects, the embodiment of FIG. 3 is substantially the same as the embodiment of FIG. 1 . Additionally, the embodiment of FIG. 3 is substantially the same as the embodiment of FIG. 2, except that the embodiment of FIG. 3 includes only exhaust gas 34 as the heat source 32.

[0039] In the illustrated embodiment, the biochar pyrolysis reactor 22 operates with heat provided solely by the exhaust gas 34 as the heat source 32. Thus, the exhaust gas 34 directly and / or indirectly transfers heat to the biomass feedstock 30 within the biochar pyrolysis reactor 22, thereby producing syngas 86 for the combustor 54 and biochar 28 for the biochar sorbent system 24. In the illustrated embodiment, the exhaust gas 34 may flow directly through an internal flow path 102 along a conveyor 104 inside the biochar pyrolysis reactor 22. The exhaust stream 34 may be in the same flow direction, counter-flow direction, and / or cross-flow direction relative to the biomass feedstock 30 moving along the conveyor 104. However, direct contact and direct heat transfer between the exhaust gas 34 and the biomass feedstock 30 may allow for a relatively simple design of the biochar pyrolysis reactor 22. In some embodiments, the exhaust gas 34 may flow through separate conduits, flow paths, and / or heat exchangers for indirect heat transfer with the biomass feedstock 30 in the biochar pyrolysis reactor 22. All other aspects of the power plant 10 are the same as those described above with reference to Figures 1 and 2.

[0040] FIG. 4 is a block diagram of one embodiment of the power plant 10 of FIG. 1 , illustrating a simple cycle configuration 190 with a biochar system 20 that uses steam 36 as the heat source 32 for the biochar pyrolysis reactor 22. The power plant 10 of FIG. 4 is substantially the same as that described in detail above with reference to FIGS. 1 and 2 , except for certain variations described below. Accordingly, like element numbers are used for like elements, and thus, all aspects of the illustrated power plant 10 and biochar system 20 are the same as those described above unless otherwise indicated. In the illustrated embodiment, the simple cycle configuration 190 of the power plant 10 excludes the steam turbine system 16 and the EGR system 18. Additionally, the power plant 10 excludes the nitrogen-selective membrane 118 and the duct burner 120 along the exhaust line 116, although some embodiments may include these components within the power plant 10 of FIG. 4 . Additionally, the power plant 10 excludes the air compressor 60 and instead relies on the compressor 52. In other respects, the embodiment of FIG. 4 is substantially the same as the embodiment of FIG. 1 . Additionally, the embodiment of FIG. 4 is substantially the same as the embodiment of FIG. 2, except that the embodiment of FIG. 4 includes only steam 36 as the heat source 32.

[0041] In the illustrated embodiment, the biochar pyrolysis reactor 22 operates with heat provided solely by steam 36 as the heat source 32. Thus, the exhaust gases 34 transfer heat to water in the steam generator 16 to produce steam 36, which is then used by the biochar pyrolysis reactor 22. In this manner, the heat source 32 still comes from the combustion process of the gas turbine system 12, which produces the exhaust gases 34. However, the steam 36 is used to transfer heat directly and / or indirectly to the biomass feedstock 30 in the biochar pyrolysis reactor 22, thereby producing syngas 86 for the combustor 54 and biochar 28 for the biochar sorbent system 24. All other aspects of the power plant 10 are the same as those described above with reference to FIGS. 1 and 2.

[0042] FIG. 5 is a block diagram of one embodiment of the power plant 10 of FIG. 1 , illustrating a stoichiometric exhaust gas recirculation (SEGR) configuration with a biochar system 20, in which the heat source 32 for the biochar pyrolysis reactor 22 is exhaust gas 34 and a duct burner 120 is downstream of the biochar pyrolysis reactor 22. The power plant 10 of FIG. 5 is substantially the same as that described in detail above with reference to FIG. 1 , except for a few variations described below. Accordingly, like element numbers are used for like elements, and thus, all aspects of the illustrated power plant 10 and biochar system 20 are the same as those described above unless otherwise indicated. In the illustrated embodiment, the SEGR configuration 210 of the power plant 10 excludes the nitrogen-selective membrane 118 along the exhaust line 116. Additionally, the power plant 10 excludes steam 36 as one of the heat sources 32 and instead relies on exhaust gas 34 for heat source 32. In other respects, the embodiment of FIG. 5 is substantially the same as the embodiment of FIG. 1 .

[0043] In the illustrated SEGR configuration 210, the power plant 10 is configured to operate with the EGR system 18 using stoichiometric combustion in the combustor 54 of the gas turbine system 12. Accordingly, the compressor 52 is configured to compress the exhaust gas 34 recirculated to the air inlet 50 to deliver the compressed exhaust gas to the combustor 54, and the air compressor 60 is configured to separately deliver compressed air 64 to the combustor 54. The fuel supply system 66 also supplies the syngas 86 as fuel to the combustor 54. The controller 26 is configured to control the combustion of the syngas 86 with the air and the recirculated exhaust gas, thereby providing a substantially stoichiometric ratio of fuel (e.g., the syngas 86) to air, resulting in substantially stoichiometric combustion. One measure of stoichiometric combustion is the equivalence ratio, or phi (φ), which is the ratio of the actual fuel / oxidant ratio to the stoichiometric fuel / oxidant ratio. An equivalence ratio greater than 1.0 results in fuel-rich combustion of the fuel and oxidizer, while an equivalence ratio less than 1.0 results in fuel-lean combustion of the fuel and oxidizer. In contrast, an equivalence ratio of 1.0 results in combustion that is neither fuel-rich nor fuel-lean, thereby consuming substantially all of the fuel and oxidizer in the combustion reaction. In the context of embodiments of the present disclosure, the terms stoichiometric or substantially stoichiometric may refer to an equivalence ratio of about 0.95 to about 1.05. However, embodiments of the present disclosure may also include equivalence ratios of 1.0 ± 0.01, 0.02, 0.03, 0.04, 0.05, or greater. Stoichiometric combustion of the fuel and oxidizer in the combustor 54 can result in products of combustion or exhaust gas 34 that are substantially free of unburned fuel or oxidizer. Therefore, exhaust gas 34 (e.g., substantially free of unburned fuel or oxidizer) may be particularly well-suited for the biochar system 20 of FIG. 5.

[0044] For example, the exhaust gas 34 (e.g., substantially free of unburned fuel or oxidizing materials) may be particularly well suited for direct heat transfer with the biomass feedstock 30 moving through the biochar pyrolysis reactor 22 via the conveyor 104. The exhaust gas 34 can transfer heat directly to the biomass feedstock 30 without substantial contamination caused by unburned fuel or oxidizing materials, thereby facilitating the pyrolysis reaction of the biomass feedstock 30 via direct heat transfer. As a result, syngas is produced or directly mixed with the exhaust gas 34 flowing through the biochar pyrolysis reactor 22, and the mixture of the discharged syngas 86 and the exhaust gas 34 exits the biochar pyrolysis reactor 22 along the exhaust line 116. As described above with reference to FIG. 1 , the duct burner 120 is configured to combust the syngas mixed with the exhaust gas 34, thereby further heating the exhaust gas 34 upstream of the steam generator 14. The heat added by duct burner 120 serves to increase steam production in steam generator 14 for use in steam turbine system 16 and / or elsewhere in power plant 14. As a result, duct burner 120 serves to improve the efficiency of power plant 10. After steam generator 14, exhaust gas 34 flows through exhaust stack 74 for treatment by biochar sorbent system 24, as described in detail above.

[0045] Additionally, the biochar pyrolysis reactor 22 may output a syngas 86 (or a mixture of the syngas 86 and the exhaust gas 34) for use as fuel in a fuel supply system 66 coupled to the gas turbine system 12. In some embodiments, assuming the power plant 10 is operating with the EGR system 18, the mixture of the syngas 86 and the exhaust gas 34 is cooled by the heat exchanger 128, compressed by the compressor 134, stored by the storage tank 136, and used as fuel in the combustor 54 without separating the exhaust gas 34 from the syngas 86. In some embodiments, the fuel supply system 66 may be configured to separate the syngas 86 from the exhaust gas 34 for storage in at least the storage tank 136. In some embodiments, the fuel supply system 66 may be used when operating the biochar pyrolysis reactor 22 in an indirect heat transfer mode, where the exhaust gas 34 indirectly transfers heat to the biomass 30 moving along the conveyor 104 in the biochar pyrolysis reactor 22.

[0046] As will be appreciated, NO in the exhaust gas 34 X The concentration may depend on the combustion flame temperature, the fuel-air ratio or equivalence ratio, and the amount of diluent (e.g., exhaust gas recirculated via the EGR system 18). Accordingly, the controller 26 may control one or more operating parameters of the gas turbine system 12 (e.g., the combustion flame temperature, the fuel-air ratio or equivalence ratio, the amount of diluent (EGR flow), or any combination thereof) to achieve various NO concentrations as described above. X Mode NO X In certain embodiments, the controller 26 controls the biochar sorbent system 24 to control the NO concentration. X and enriching the biochar 28 to produce a nitrogen-rich biochar 38 while controlling one or more operating parameters of the gas turbine system 12 to increase the NO X Therefore, NO XThe increased concentration is a beneficial advantage in biochar system 20, which produces useful products (e.g., nitrogen-rich biochar 38) for use in various soil applications 40. When operating in part-load mode, gas turbine system 12 may not be producing power for the power grid, but gas turbine system 12 still produces useful products (e.g., nitrogen-rich biochar 38). In certain embodiments, while operating in part-load mode, power plant 10 may operate in a manner that maximizes the production of biochar 28, syngas 86, and / or nitrogen-rich biochar 38.

[0047] FIG. 6 is a block diagram of one embodiment of the power plant 10 of FIG. 1 , showing a stoichiometric exhaust gas recirculation (SEGR) configuration with a biochar system 20, in which the heat source 32 for the biochar pyrolysis reactor 22 is exhaust gas 34, and a nitrogen-selective membrane 118 is downstream of the biochar pyrolysis reactor 22. The power plant 10 of FIG. 6 is substantially the same as that described in detail above with reference to FIGS. 1 and 5, except for a few variations described below. Accordingly, like element numbers are used for like elements, and thus, all aspects of the illustrated power plant 10 and biochar system 20 are the same as those described above unless otherwise indicated. In the illustrated embodiment, the SEGR configuration 230 of the power plant 10 excludes the duct burner 120 and includes a nitrogen-selective membrane 118 along the exhaust line 116. Additionally, the power plant 10 excludes steam 36 as one of the heat sources 32, instead relying on exhaust gas 34 for heat source 32. In other respects, the embodiment of FIG. 6 is substantially the same as the embodiment of FIG. 1. Additionally, the embodiment of Figure 6 is substantially the same as the embodiment of Figure 5, except that the embodiment of Figure 6 includes a nitrogen-selective membrane 118 rather than a duct burner 120. While the embodiment of Figure 6 includes a steam generator 14 and a steam turbine system 16, in certain embodiments of the SEGR configuration 230 of Figure 6, the steam generator 14 and / or the steam turbine system 16 may be excluded.

[0048] As described above, the SEGR configuration 230 operates with substantially stoichiometric combustion, resulting in exhaust gas 34 that is substantially free of unburned fuel or oxidants. The exhaust gas 34 is well suited for direct heat transfer with the biomass feedstock 30 in the biochar pyrolysis reactor 22, without substantial contamination caused by unburned fuel or oxidants, thereby facilitating the pyrolysis reaction of the biomass feedstock 30 via direct heat transfer. As a result, syngas is formed or directly mixed with the exhaust gas 34 flowing through the biochar pyrolysis reactor 22, and the exhausted syngas and exhaust gas 34 mixture exits the biochar pyrolysis reactor 22 along the exhaust line 116. As described above with reference to FIG. 1 , the nitrogen-selective membrane 118 separates nitrogen oxides (NO ) from the exhausted syngas and exhaust gas 34 mixture. X ), thereby producing nitrogen 122 and syngas 86 (e.g., colorific syngas) along syngas line 124. Thus, fuel supply system 66 can use the syngas 86 produced by nitrogen-selective membrane 118 for use in combustor 54 of gas turbine system 12.

[0049] In certain embodiments, the exhaust gas 34 exiting the nitrogen-selective membrane 118 may be directed through the steam generator 14 (if included) and then through the exhaust stack 74, or the exhaust gas 34 exiting the nitrogen-selective membrane 118 may be directed to the exhaust stack 74 without generating steam. Again, certain embodiments of the SEGR configuration 230 may exclude the steam generator 14 and / or the steam turbine system 16. The biochar sorbent system 24 operates in substantially the same manner as discussed in detail above.

[0050] FIG. 7 is a schematic diagram of one embodiment of the biochar pyrolysis reactor 22 of the biochar system 20 of FIGS. 1-6 , further illustrating an indirect heat transfer configuration 250, in which a heat transfer fluid or heat source 32 (e.g., exhaust gas 34 and / or steam 36) facilitates the pyrolysis of the biomass feedstock 30 via indirect heat transfer. In the illustrated embodiment, the indirect heat transfer configuration 250 isolates the biomass feedstock 30 within the inner tube 252 of the double-tube heat exchanger 254 from the heat source 32 within the outer shell 256 of the double-tube heat exchanger 254. Thus, the products of the pyrolysis of the biomass feedstock 30 (e.g., biochar 28 and syngas 86) are contained within the inner tube 252 and do not mix with the heat source 32 within the outer shell 256 (e.g., annular chamber 258 between the inner tube 252 and the outer shell 256). In such an embodiment, the heat source 32, syngas 86, and biochar 28 may be separately exited from the biochar pyrolysis reactor 22 through a heat transfer fluid outlet 260 (e.g., exhaust gas outlet 94 and / or steam outlet 96), a syngas outlet 98, and a biochar outlet 100, respectively. In the illustrated embodiment, the heat source 32 transfers heat indirectly to the biomass feedstock 30 through the wall (e.g., annular wall) of the inner tube 252. However, any suitable configuration of the biochar pyrolysis reactor 22 in the indirect heat transfer configuration 250 is within the scope of embodiments of the present disclosure.

[0051] FIG. 8 is a schematic diagram of one embodiment of the biochar pyrolysis reactor 22 of the biochar system 20 of FIGS. 1-6 , further illustrating a direct heat transfer configuration 270, in which a heat transfer fluid or heat source 32 (e.g., exhaust gas 34 and / or steam 36) facilitates the pyrolysis of the biomass feedstock 30 via direct heat transfer. In the illustrated embodiment, the direct heat transfer configuration 270 allows the heat transfer fluid 32 to flow directly across the biomass feedstock 30 in tubes 272 to transfer heat. The products of the pyrolysis of the biomass feedstock 30 (e.g., biochar 28 and syngas 86) are directly mixed with the heat source 32 flowing through the biochar pyrolysis reactor 22, producing a mixture 274 of the syngas 86 and the heat source 32, which is discharged through a mixture outlet 276. The mixture 274 can then be separated and / or used together as described above. For example, a separator, a heat exchanger (e.g., a condenser or cooler), or any combination thereof, can be used to separate the steam 36 from the syngas 86. In a further example, a burner (e.g., duct burner 120) can be used to combust syngas 86 in mixture 274, thereby increasing the temperature of heat source 32 (e.g., exhaust gas 34 and / or steam 36) in mixture 274. In a further example, nitrogen-selective membrane 118 can be used to separate syngas 86 and nitrogen 122 from heat source 32 (e.g., exhaust gas 34 and / or steam 36) in mixture 274. However, any suitable configuration of biochar pyrolysis reactor 22 in direct heat transfer configuration 270 is within the scope of embodiments of the present disclosure.

[0052] FIG. 9 is a flow chart of one embodiment of a process 290 for operating the biochar system 20 in the power plant 10 of FIGS. 1-6. In the illustrated embodiment, the process 290 includes transporting biomass feedstock (e.g., 30) from a biomass source to the power plant (e.g., 10) (block 292). The biomass source may include an agricultural field, a farm, a forest, an industrial facility, a waste treatment facility, or any combination thereof. The biomass feedstock may include industrial waste and by-products, food waste, agricultural residues (e.g., wheat straw), plants (e.g., corn, switchgrass, miscanthus, and bamboo), energy crops, wood, wood residues, or any combination thereof in various forms (e.g., pellets). The power plant may be a coal plant, a gas turbine power plant, or a power plant that uses fuel to produce undesirable gases (e.g., NO). X The process 290 may include any heat-driven power plant that produces exhaust gases including ethane (e.g., 22). Next, the process 290 may feed the biomass feedstock to a biochar pyrolysis reactor (e.g., 22) (block 294). For example, feeding the biomass feedstock may include using a conveyor to move the biomass feedstock vertically, horizontally, and / or inclined to the biomass inlet of the biochar pyrolysis reactor. Next, the process 290 may supply heat to the biochar pyrolysis reactor via heat transfer from a heat source of the power plant (e.g., exhaust gas 34 and / or steam 36) (block 296). The heat may be transferred directly and / or indirectly via one or more internal flow paths (e.g., 102) through the biochar pyrolysis reactor. The heat may come from the combustion of fuel in the power plant, and thus, the heat is generated integrally with the operation of the power plant. The process 290 may then produce a syngas (e.g., 86) and a biochar (e.g., 28) via pyrolysis of the biomass feedstock in a biochar pyrolysis reactor (block 298). The process 290 may then deliver the produced syngas to a combustor (e.g., 54) of a power plant (block 300). The process 290 may then extract nitrogen oxides (NO ) from the exhaust gas. X) onto the biochar to produce a NOx-lean exhaust gas (e.g., treated gas 84) and nitrogen-rich biochar (e.g., 38) (block 302). Finally, process 290 may transport the nitrogen-rich biochar from the power plant to one or more soil applications (e.g., 40) (block 304). For example, the soil applications may include various sustainable soil sinks, such as agriculture, forestry, farming, etc. The aforementioned process 290 may be controlled by controller 26 or any other suitable processor-based controller or system. Furthermore, the aforementioned process 290 may include any and all aspects of the control and operation of power plant 10, as described in detail above with reference to FIGS. 1-8.

[0053] 1-6. In the illustrated embodiment, process 320 includes monitoring and obtaining feedback (block 322) on operational parameters of the power plant (e.g., 10), energy demand, and the biochar system (e.g., 20) having a biochar pyrolysis reactor (e.g., 22) and a biochar sorbent system (e.g., 24). The power plant operational parameters include combustion parameters (e.g., fuel-air ratio, equivalence ratio, combustion flame temperature), EGR parameters (e.g., EGR flow rate, temperature, gas composition, etc.), undesirable gases in the exhaust gas (e.g., NO ), and the like. XThe energy demand may include emission levels of CO, CO, CO2, etc., exhaust gas temperature and flow rate, steam parameters (e.g., steam production temperature, pressure, flow rate, etc.), or any combination thereof. The energy demand may correspond to the demand for electricity on the power grid, which may fluctuate between peak demand during the hottest hours of the day and minimum demand at night. Thus, the energy demand may affect the operation and power generation by the power plant. The operating parameters of the biochar system may include the flow rate, temperature, pressure, and / or heat transfer characteristics of the thermal fluid (e.g., exhaust gas and / or steam) used in the biochar pyrolysis reactor, the feed / transport rate of the biomass feedstock through the biochar pyrolysis reactor, the production rate of syngas production, the gas composition of the syngas, the production rate of biochar production, biochar characteristics (e.g., the quality or other indicator of the pyrolysis reaction as indicated by the biochar products), the quality and availability of the biomass feedstock, the upper and lower thresholds of the pyrolysis reaction (e.g., temperature, residence time of the biomass in the presence of heat, etc.), or any combination thereof. Control of the power plant and biochar system according to process 320 of FIG. 10 can use a variety of feedbacks, including all of the aspects described in detail above with reference to FIGS.

[0054] Process 320 may then proceed to control the operating conditions and operating mode (e.g., startup mode, steady-state mode, shutdown mode, full load mode, or part load mode) of the power plant based at least in part on the feedback (block 324). For example, fluctuations in energy demand may be at least an operating parameter that process 320 can use to increase or decrease the load on the power plant. In certain embodiments, process 320 may control the power plant to change from full load mode during peak energy demand by the power grid to part load mode during lower or minimum energy demand. Similarly, process 320 may adjust the operating mode (e.g., part load mode, full load mode, etc.) depending on the need and the value generated by operating the biochar system.

[0055] The process 320 may further control the amount and transport rate of the biomass feedstock (e.g., 30) and the temperature within the biochar pyrolysis reactor to produce biochar (e.g., 28) and syngas (e.g., 86) based at least in part on the feedback and the power plant's operating mode (block 326). For example, the transport rate of the biomass feedstock through the biochar pyrolysis reactor may be increased to shorten the residence time or slowed down to increase the residence time within the biochar pyrolysis reactor. The amount of biomass feedstock (combined with the transport rate) passing through the biochar pyrolysis reactor may be used to vary the overall rate of biochar production by the biochar pyrolysis reactor. The temperature of the biochar pyrolysis reactor may be increased to increase the pyrolysis rate or decreased to decrease the pyrolysis rate of the biomass feedstock within the biochar pyrolysis reactor. The amount, transport rate, and temperature may be controlled based on the operating mode (e.g., full load vs. part load), the temperature and flow rate of the exhaust gas, and the amount of undesirable gases in the exhaust gas (NO). X The amount of biomass feedstock may be increased or decreased depending on the concentration of sulphur dioxide (S), the demand for syngas by the power plant, or any combination thereof. For example, process 320 can control (e.g., vary, increase, or decrease) the production of biochar and syngas based at least in part on the available heat source (e.g., exhaust gas 34 and / or steam 36) used to control the temperature within the biochar pyrolysis reactor. In certain embodiments, process 320 can increase the amount and / or transport rate of biomass feedstock when the heat source is available at a higher temperature, higher flow rate, and / or higher pressure, such as when the exhaust flow rate is higher during full-load conditions. Similarly, process 320 can decrease the amount and / or transport rate of biomass feedstock when the heat source is available at a lower temperature, lower flow rate, and / or lower pressure, such as when the exhaust flow rate is lower during part-load conditions. In general, process 320 can control the biochar pyrolysis system to respond to various operating conditions and produce a desired output of syngas and biochar.

[0056] Process 320 may control the flow rate, temperature, and pressure of syngas from the biochar pyrolysis reactor to the power plant's combustor (e.g., 54) based at least in part on the feedback and the operating mode (block 328). For example, process 320 may control the cooling of the syngas in a heat exchanger (e.g., 128), the compression of the syngas in a compressor (e.g., 134), the storage of excess syngas in a tank (e.g., 136), and / or the flow to the combustor via one or more valves. Additionally, process 320 may control syngas production by the biochar pyrolysis reactor by controlling the pyrolysis reaction. For example, process 320 may increase syngas production by increasing the pyrolysis reaction, such as by increasing the amount and / or transport rate of biomass feedstock and / or by increasing the temperature and / or flow rate of the thermal fluid (e.g., exhaust gas 34 and / or steam 36). In a further example, process 320 can decrease syngas production by decreasing pyrolysis reactions, such as by decreasing the amount and / or transport rate of biomass feedstock and / or decreasing the temperature and / or flow rate of the thermal fluid (e.g., exhaust gas 34 and / or steam 36). For example, process 320 can decrease syngas production during part load mode and increase syngas production during full load mode.

[0057] The process 320 controls the amount and transport rate of biochar through the biochar sorbent system (e.g., 24) to remove nitrogen oxides (NO) from the exhaust gas. X ) was adsorbed onto biochar to remove NO X The lean exhaust gas (e.g., treated gas 84) and the nitrogen-rich biochar (e.g., 38) emission concentrations may be controlled (block 330). For example, process 320 may increase the amount of biochar in the biochar sorbent system and / or decrease the transport rate of biochar to remove more NO from the exhaust gas. XIn a further example, process 320 can reduce the amount of biochar in the biochar sorbent system and / or increase the transport rate of biochar to remove less NO from the exhaust gas. X In a further example, process 320 can adjust the flow rate, temperature, and / or concentration of undesirable gases (e.g., NO) of the exhaust gas being treated by the biochar sorbent system. X The amount and / or transport rate of biochar in the biochar sorbent system can be varied depending on the flow rate (concentration). As will be appreciated, higher flow rates may occur during full load and lower flow rates may occur during partial load of the power plant. As the flow rate and load vary, the amount and / or transport rate of biochar in the biochar sorbent system can be adjusted by process 320 to maintain a sufficiently high threshold concentration of nitrogen and NO in the nitrogen-rich biochar. X Undesirable gases in lean exhaust gas (NO X For example, process 320 may be used with higher flow rates of exhaust gases, higher NO in the exhaust gases, or a combination of both. X For higher NO concentrations and higher loads on the power plant, the amount of biochar in the biochar sorbent system can be increased and / or the transport rate can be reduced. In a further example, process 320 can be used to achieve lower flow rates of exhaust gases, lower NO concentrations in the exhaust gases, and lower NO concentrations in the power plant. X For higher concentrations, and lower loads on the power plant, the amount of biochar in the biochar sorbent system can be reduced and / or the transport rate can be increased.

[0058] Technical effects of embodiments of the present disclosure include integrating a biochar system having a biochar pyrolysis reactor and / or a biochar sorbent system with an industrial plant, such as a power plant having a gas turbine system. The biochar pyrolysis reactor is integrated with an available heat source in the power plant to drive the pyrolysis reaction, thereby producing both biochar and syngas. The syngas can be further used as fuel in the power plant's combustor, such as the combustor of a gas turbine system. Biochar can be a valuable resource in soil applications, with or without the biochar sorbent system. However, the biochar sorbent system adds more value to the power plant by using biochar as a sorbent material to adsorb undesirable gases from exhaust gases while simultaneously enriching the biochar for greater value in soil applications. For example, biochar can absorb nitrogen oxides (NO) from exhaust gases. X ), thereby enriching the biochar with nitrogen to produce nitrogen-rich biochar for soil applications. The biochar system can be operated in a variety of modes: part load mode, full load node, start-up mode, steady state mode, EGR mode, SEGR mode, variable NO X The biochar system can continue to operate at various operating conditions of the power plant, including fuel-rich, fuel-lean, and / or stoichiometric modes, or any combination thereof. For example, if the power plant is changed from full load mode to part load mode due to low energy demand on the power grid, the biochar system can continue to add value to the power plant by producing syngas and biochar in part load mode. In a further example, the biochar system can provide greater flexibility in controlling the power plant in fuel-rich, fuel-lean, and / or stoichiometric modes, which can reduce NO X In certain embodiments, power plants benefit from increased NO production, which would normally be contrary to conventional wisdom and emission requirements. X Using a biochar sorbent system to intentionally control NO production X and enrich biochar to produce nitrogen-rich biochar for soil applications.

[0059] The subject matter described in detail above may be defined by one or more of the following clauses:

[0060] The system includes a controller having a processor, a memory, and instructions stored in the memory and executable by the processor, the controller controlling a biochar pyrolysis reactor to heat the biomass feedstock using heat from the power plant to cause a pyrolysis reaction of the biomass feedstock to produce biochar and syngas, and controlling a biochar sorbent system to adsorb undesirable gases from the power plant exhaust gas onto the biochar to produce enriched biochar and treated gas.

[0061] 10. The system of claim 9, wherein the power plant includes a generator driven by a gas turbine system having a compressor, a combustor, and a turbine, and the controller is configured to control the power plant to combust the synthesis gas to produce the exhaust gas.

[0062] 7. The system of any preceding clause, wherein the undesirable gases comprise nitrogen oxides, the enriched biochar comprises nitrogen-rich biochar, and the enriched biochar is configured to support one or more soil applications.

[0063] 10. The system of any preceding clause, wherein the controller is configured to control the combustion process of the power plant to increase the concentration of nitrogen oxides in the exhaust gas, and wherein the controller is configured to control the biochar sorbent system to use the increased concentration of nitrogen oxides to increase the nitrogen concentration in the nitrogen-rich biochar.

[0064] 10. The system of any preceding clause, wherein the controller is configured to control the biochar pyrolysis reactor to vary biochar and syngas production based on at least an operating mode of the power plant.

[0065] 10. The system of any preceding claim, wherein the operating modes of the power plant include a part load mode and a full load mode.

[0066] 10. The system of any preceding clause, wherein the controller is configured to increase syngas and / or biochar production during part load mode during periods of low power demand at the power plant.

[0067] 10. The system of any preceding clause, wherein the controller is configured to control the biochar sorbent system to vary adsorption of undesirable gases from the exhaust gas onto the biochar to produce enriched biochar and treated gas based on at least an operating mode of the power plant.

[0068] 10. The system of any preceding claim, wherein the operating modes of the power plant include a part load mode and a full load mode.

[0069] The operating mode of the power plant is such that the combustion process of the power plant generates multiple nitrogen oxides (NO X 13. The system of any preceding claim, including a .) mode.

[0070] 10. The system of any preceding clause, wherein the controller is configured to control the biochar pyrolysis reactor to produce biochar by the biochar sorbent system at a production rate between upper and lower demand rate thresholds.

[0071] 10. The system of any preceding clause, wherein the controller is configured to control the biochar pyrolysis reactor to produce syngas by the power plant at a production rate between upper and lower demand rate thresholds.

[0072] 10. The system of any preceding clause, wherein the controller is configured to control the production of biochar and syngas by at least controlling the exhaust flow of exhaust gases to the biochar pyrolysis reactor, the steam flow of steam generated from the heat of the exhaust gases, or a combination thereof, to control the heat supplied to the biomass feedstock, and controlling the transport rate of the biomass feedstock through the biochar pyrolysis reactor.

[0073] 10. The system of any preceding clause, wherein the controller is configured to control adsorption of undesirable gases onto the biochar to produce enriched biochar and treated gas by at least controlling a transport rate of biochar through the biochar sorbent system across the exhaust flow path of the exhaust gas and controlling a concentration of undesirable gases in the enriched biochar between upper and lower thresholds.

[0074] The method includes controlling a biochar pyrolysis reactor to heat a biomass feedstock using heat from a power generation plant to cause a pyrolysis reaction of the biomass feedstock to produce biochar and syngas.

[0075] The method of any preceding paragraph, including controlling the biochar pyrolysis reactor to vary the production of biochar and syngas based at least on the operating mode of the power plant.

[0076] 10. The method of any preceding clause, comprising controlling a biochar sorbent system to adsorb undesirable gases from the power plant exhaust gas onto the biochar to produce enriched biochar and treated gas.

[0077] 10. The method of any preceding clause, comprising controlling a biochar pyrolysis reactor to produce biochar with a biochar sorbent system at a biochar production rate between upper and lower threshold biochar demand rates.

[0078] A method comprising controlling a biochar sorbent system to adsorb undesirable gases from an exhaust gas of a power plant onto biochar to produce enriched biochar and treated gas.

[0079] The method of any preceding paragraph, including controlling the biochar sorbent system to vary the adsorption of undesirable gases from the exhaust gas onto the biochar to produce enriched biochar and treated gas based on at least an operating mode of the power plant.

[0080] Examples are used herein to disclose the invention, including the best mode, and to enable any person skilled in the art to practice the invention, including making and using any devices or systems, and performing any methods incorporated therein. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims. [Explanation of symbols]

[0081] 10 Power Plant 12 Gas Turbine System 14 Steam generator 16 Steam Turbine System 18 Exhaust Gas Recirculation System 20 Biochar Systems 22 Biochar pyrolysis reactor 24 Biochar Adsorbent System 26 Controller 28 Biochar 30 Biomass raw materials 32 Heat source 34 Exhaust gas 36 Steam 38 Nitrogen-rich biochar 40 Soil Use 50 Air intake 52 Compressor 54 Combustor 56 Turbine 58 Load 60 Air Compressor 62 Air 64 Compressed Air 66 Fuel Supply System 68 Steam 70 Return Flow 72 Load 74 Exhaust stack 76 Heat exchanger 78 Fluid Input 80 fluid output 82 Exhaust flow path 84 Treated Gas 86 Syngas 88 Raw material inlet 90 Exhaust gas inlet 92 Steam inlet 94 Exhaust gas outlet 96 Steam outlet 98 Syngas outlet 100 Biochar Outlet 102 Internal flow path 104 Conveyor 106 Raw Material Supply System 108 Exhaust supply line 110 Steam supply line 112 Steam supply line 114 Exhaust bypass line 116 Exhaust line 118 Nitrogen-selective membrane 120 Duct Burner 122 Nitrogen 124 Syngas Line 126 Steam Line 128 Heat exchanger 130 Fluid Input 132 Fluid Output 134 Compressor 136 Storage Tank 138 Transportation Systems 140 Conveyor 142 processors 144 memory 146 Command 148 Communication Circuits 150 cycle configuration 230 SEGR configuration 250 Indirect Heat Transfer Configuration 252 Inner tube 254 Double tube heat exchanger 256 Shell 258 Annular Chamber 260 Heat transfer fluid outlet 270 Direct Heat Conduction Configuration 272 tube 274 mixture 276 Mixture outlet 290 Process 292 Transporting biomass feedstock from biomass sources to power plants 294 Feeding biomass feedstock into the biochar pyrolysis reactor 296 Heat is supplied to the biochar pyrolysis reactor via heat transfer from the power plant heat source (e.g., exhaust gas, steam, etc.). 298 Producing syngas and biochar via pyrolysis in a biochar pyrolysis reactor 300 Syngas is fed to the combustor of a power plant 302 Nitrogen oxides (NOX) from exhaust gas are adsorbed onto biochar to produce NOX-lean exhaust gas and nitrogen-rich biochar. 304 Transporting Nitrogen-Rich Biochar from Power Plants to Soil Applications 320 Process 322 Monitor the operating parameters of the power plant, energy demand, and biochar system with biochar pyrolysis reactor and biochar sorbent system to obtain feedback. 324 Controlling the operating conditions and operating modes (e.g., startup, steady state, shutdown, full load, or part load) of the power plant based at least in part on the feedback. 326. Controlling the amount and transport rate of biomass feedstock and the temperature within the biochar pyrolysis reactor based at least in part on the feedback and the operating mode to produce biochar and syngas. 328. Controlling the flow rate, temperature, and pressure of syngas from a biochar pyrolysis reactor to a power plant combustor based at least in part on feedback and operating modes. 330 Controlling the amount and transport rate of biochar through the biochar adsorbent system allows nitrogen oxides (NOX) from exhaust gases to be adsorbed onto biochar, thereby controlling the NOX-lean exhaust gas and nitrogen-rich biochar emission concentrations.

Claims

1. 1. A system comprising: A controller (26) having a processor (142), a memory (144), and instructions (146) stored in the memory (144) and executable by the processor (142), the controller (26) controlling a biochar pyrolysis reactor (22) to heat a biomass feedstock (30) using heat from the power plant (10) to cause a pyrolysis reaction of said biomass feedstock (30) to produce biochar (28) and syngas (86); controlling a biochar sorbent system (24) to adsorb undesirable gases from an exhaust gas (34) of the power plant (10) onto the biochar (28) to produce enriched biochar and treated gas (84); system.

2. 2. The system of claim 1, wherein the power plant comprises a generator driven by a gas turbine system having a compressor, a combustor, and a turbine, and the controller is configured to control the power plant to combust the synthesis gas to produce the exhaust gas.

3. 10. The system of claim 1, wherein the undesirable gases comprise nitrogen oxides, the enriched biochar comprises a nitrogen-rich biochar (38), and the enriched biochar is configured to support one or more soil applications (40).

4. 4. The system of claim 3, wherein the controller is configured to control a combustion process of the power plant to increase a concentration of the nitrogen oxides in the exhaust gas, and the controller is configured to control the biochar sorbent system to use the increase in the concentration of the nitrogen oxides to increase a nitrogen concentration in the nitrogen-rich biochar.

5. 2. The system of claim 1, wherein the controller is configured to control the biochar pyrolysis reactor to vary production of the biochar and the syngas based on at least an operating mode of the power plant.

6. The system of claim 5 , wherein the operating modes of the power plant (10) include a part load mode and a full load mode.

7. 6. The system of claim 5, wherein the controller is configured to increase production of the syngas and / or the biochar during the part load mode while the power plant has low power demand.

8. 2. The system of claim 1, wherein the controller is configured to control the biochar sorbent system to vary adsorption of the undesirable gases from the exhaust gas onto the biochar to produce the enriched biochar and the treated gas based on at least an operating mode of the power plant.

9. The system of claim 8 , wherein the operating modes of the power plant (10) include a part load mode and a full load mode.

10. The operating mode of the power plant (10) is to reduce the number of nitrogen oxides (NO Ｘ 9. The system of claim 8, further comprising a .) mode.

11. 2. The system of claim 1, wherein the controller is configured to control the biochar pyrolysis reactor to produce the biochar at a production rate between upper and lower demand rate thresholds.

12. 2. The system of claim 1, wherein the controller is configured to control the biochar pyrolysis reactor to produce the syngas at a production rate between upper and lower threshold demand rates by the power plant.

13. The controller (26) includes at least controlling the exhaust flow of the exhaust gas (34), the steam flow of steam (68) generated from the heat of the exhaust gas (34), or a combination thereof, to the biochar pyrolysis reactor (22) to control the heat supplied to the biomass feedstock (30); and Controlling the transport rate of the biomass feedstock (30) through the biochar pyrolysis reactor (22).

2. The system of claim 1, configured to control production of the biochar (28) and the syngas (86) by:

14. The controller (26) includes at least controlling the transport rate of the biochar (28) through the biochar sorbent system (24) across an exhaust flow path (82) of the exhaust gas (34); and Controlling the concentration of the undesirable gas in the enriched biochar between an upper threshold and a lower threshold.

2. The system of claim 1, configured to control adsorption of the undesired gases onto the biochar (28) to produce the enriched biochar and the treated gas (84) by:

15. 1. A method comprising: controlling a biochar pyrolysis reactor (22) to heat a biomass feedstock (30) using heat from the power plant (10) to induce a pyrolysis reaction of said biomass feedstock (30) to produce biochar (28) and syngas (86); A method comprising:

Images