Method and apparatus for recovering energy from low energy density gas stream

Abstract

The present disclosure relates to a method and apparatus for recovering energy from a low energy density exhaust stream. The process and the apparatus allow a thermal oxidizer to oxidize the low energy density exhaust stream using a low energy density fuel gas, such as syngas, BF gas or biogas, without the need for an auxiliary high energy density source.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. non-provisional patent application No. 17 / 664,281 filed on May 20, 2022 (U.S. Patent No. 11,614,231 B1 issued on March 28, 2023), the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to methods and systems for recovering energy from low energy density gas streams. In particular, the present disclosure relates to methods and systems for efficiently thermally oxidizing low energy density gases to recover energy. Background Art

[0004] Seeking efficient energy supply solutions at a low environmental cost is a challenge faced by climate action plans around the world, from the European Commission, US business groups and the Environment and Government Association, to Japan, which is trying to replace electricity supply with nuclear energy after the Fukushima tragedy, to seven emerging economies, and as a result, member states are making efforts worldwide to combat climate change and ultimately stabilize the earth's temperature. The ultimate goal is to meet the growing demand for sustainable and renewable energy while addressing climate change to transition to a low-carbon modern economy.

[0005] Carbon dioxide (CO2) accounts for approximately 76% of global greenhouse gas emissions caused by human activities, with methane (16%), nitrous oxide (6%), and fluorinated gases (2%) accounting for the remainder (United States Environmental Protection Agency). Most CO2 comes from the burning of fossil fuels for energy production, but industrial and forestry practices also emit CO2 into the atmosphere. Reducing greenhouse gas emissions, especially CO2, is critical to halting the progression of global warming and the resulting changes in climate and weather.

[0006] It has long been recognized that catalytic processes such as the Fischer-Tropsch process can be used to convert gases containing carbon dioxide (CO2), carbon monoxide (CO) and / or hydrogen (H2), such as industrial waste gases or synthesis gas, into various fuels and chemicals. Recently, however, gas fermentation has become an alternative platform for the biological fixation of carbon in such gases. In particular, C1-fixing microorganisms have been demonstrated to be used as biocatalysts to convert substrates and / or C1 carbon sources into valuable products, such as ethanol or other alcohols.

[0007] The substrate and / or C1 carbon source can be a waste gas obtained as a by-product of an industrial process or a waste gas obtained from another source (such as burner exhaust, biogas, landfill gas, direct air capture) or electrolysis. The substrate and / or C1 carbon source can be a synthesis gas produced by pyrolysis, roasting or gasification. In other words, the waste material can be recycled by pyrolysis, roasting or gasification to produce a synthesis gas used as a substrate and / or C1 carbon source. The substrate and / or C1 carbon source can be a gas including methane, and in some embodiments, the substrate and / or C1 carbon source can be a non-waste gas.

[0008] Typically, industrial processes produce some low energy density waste gas streams that include dilute concentrations of organic pollutants such as volatile organic compounds (VOCs), volatile hazardous air pollutants (HAPs), or hydrocarbons. In order to reduce the impact of these industrial waste gas streams on the environment, the organic pollutants are converted into less harmful products by thermal oxidation at high temperatures. However, the calorific value of the waste gas stream is usually too low to support stable combustion in a typical gas burner and / or one or more oil burners, which require a minimum of 15 to 20 MJ / Nm 3 Therefore, thermal oxidation of these low energy density exhaust streams requires an auxiliary heat input such as natural gas or oil to raise the temperature of the exhaust stream to an optimal temperature that allows adequate oxidation.

[0009] Therefore, there remains a need for a method and apparatus that reduces or eliminates the need for an auxiliary high energy density source for efficient thermal oxidation of organic pollutants while recovering energy from a low energy density exhaust gas stream. Summary of the invention

[0010] The present disclosure provides a method and apparatus for recovering energy from a low energy density gas stream. The method comprises: 3 The fuel stream is delivered to a self-regenerative burner or a regenerative burner to burn the fuel stream and heat the thermal oxidizer. The energy density is about 0.5 to about 5 MJ / Nm 3At least one exhaust gas stream and a preheated combustion air stream are passed to the thermal oxidizer to oxidize the exhaust gas stream and produce hot flue gas. The thermal oxidizer can be heated sufficiently to heat the exhaust gas stream to at least its autoignition temperature or to at least 400°C above its autoignition temperature. The hot flue gas is passed to a steam boiler unit to provide heat and produce steam. The hot flue gas from the steam boiler unit is passed to an indirect heat exchanger to indirectly heat the combustion air stream to produce the preheated combustion air stream. The combustion air stream can be provided by using a combustion blower. Before being passed to the thermal oxidizer, the combustion air stream can be optionally passed to an enrichment unit to produce an oxygen-enriched combustion air stream. The enrichment unit is selected from a pressure swing adsorption unit, a membrane separation unit, a cryogenic distillation unit or any combination thereof. At least a portion of the preheated combustion air stream can be used to directly or indirectly heat the fuel stream or the exhaust gas stream to preheat the fuel stream or the exhaust gas stream. In some cases, the steam can be used in at least one gas fermentation process unit selected from a power generation unit, a product separation unit, a purification unit, a gas treatment unit, an evaporation unit, or a concentration unit, for a clean-in-place process, or any combination thereof.

[0011] The thermal oxidizer is selected from a direct-fired thermal oxidizer, a regenerative thermal oxidizer, a thermal storage thermal oxidizer, a catalytic thermal oxidizer, a flameless thermal oxidizer, or any combination thereof. In an embodiment, when the thermal oxidizer is a direct-fired, regenerative, or regenerative thermal oxidizer, the energy density can be about 1.5 MJ / Nm 3 To about 40MJ / Nm 3 Another fuel stream within the range is delivered to the self-regenerative burner or regenerative burner of the direct-fired, regenerative or regenerative thermal oxidizer.

[0012] In some cases, the waste gas stream comprises organic compounds targeted for thermal incineration. The waste gas stream may be obtained from a gas fermentation process and is selected from a tail gas stream from a bioreactor, a regeneration gas stream from an adsorption unit, a tail gas stream from a distillation unit, a biogas stream from a wastewater treatment unit, an exhaust gas stream from a purification unit, or any combination thereof. In some cases, the fuel stream comprises a byproduct gas stream obtained from at least one of an industrial process or a syngas process or a burner exhaust or direct air capture or electrolysis. The industrial process may be selected from carbohydrate fermentation, gas fermentation, cement manufacturing, pulp and paper manufacturing, steel manufacturing, oil refining, petrochemical production, coke production, anaerobic digestion, aerobic digestion, natural gas extraction, oil recovery, geological reservoirs, metallurgical processes, aluminum, copper and or ferroalloy refining for the production of aluminum, copper and or ferroalloys, or any combination thereof; or the syngas process may be selected from the gasification of coal, gasification of refinery residues, gasification of biomass, gasification of lignocellulosic materials, black liquor gasification, gasification of municipal solid waste, gasification of industrial solid waste, gasification of sewage, gasification of sludge from wastewater treatment, reforming of natural gas, reforming of biogas, reforming of landfill gas, or any combination thereof.

[0013] In some cases, the present disclosure provides for energy densities ranging from about 1.5 to about 20 MJ / Nm 3 A supplementary fuel stream is delivered to the self-regenerative burner or regenerative burner of the thermal oxidizer. The supplementary fuel stream is a gas stream generated in an industrial process, a gasification process, a gas fermentation process or a combination thereof.

[0014] The present disclosure also provides an apparatus for recovering energy from a low energy density gas stream. The apparatus comprises: a recuperative burner or a regenerative burner, positioned in a thermal oxidizer; a fuel gas conduit, fluidically connected to the recuperative burner or the regenerative burner of the thermal oxidizer; an exhaust gas conduit, fluidically connected to the thermal oxidizer; a combustion air conduit, fluidically connected to the thermal oxidizer and to an indirect heat exchanger; and a flue gas conduit, fluidically connected to the thermal oxidizer and to a steam boiler unit and the indirect heat exchanger.

[0015] In some cases, the combustion air conduit is further in fluid communication with a combustion blower. The combustion air conduit is in fluid communication with the fuel gas conduit or the exhaust gas conduit. The fuel gas conduit is further in fluid communication with a bioreactor, an extraction unit, a wastewater treatment unit, a gasifier, or any combination thereof. The exhaust gas conduit is further in fluid communication with at least one gas fermentation process unit, and the at least one gas fermentation process unit is selected from a bioreactor, an adsorption unit, a distillation unit, a wastewater treatment unit, a purification unit, or any combination thereof. The thermal oxidizer may be a direct-fired thermal oxidizer, a regenerative thermal oxidizer, a regenerative thermal oxidizer, a catalytic thermal oxidizer, a flameless thermal oxidizer, or any combination thereof.

[0016] Although the present disclosure is broadly defined above, it is not limited thereto and encompasses embodiments for which the following description provides examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings have been simplified by deleting a large amount of equipment commonly used in processes of this nature, such as vessel internals, temperature and pressure control systems, flow control valves, recirculation pumps, etc., which are not specifically required to illustrate the performance of the present invention. In addition, the description of the process of the present invention in the embodiments of the specific drawings is not intended to limit the present disclosure to the specific embodiments. Some embodiments may be described with reference to the process configurations shown in the drawings, which relate to both the equipment and methods for performing the present disclosure. Any reference to a process step includes a reference to an equipment unit or equipment suitable for performing the step, and vice versa.

[0018] Figure 1 A flow chart of a method and apparatus for recovering energy from a low energy density gas stream according to an exemplary embodiment of the present disclosure is shown.

[0019] Figure 2 A flow chart of a gas fermentation process utilizing at least one low energy density waste gas stream according to an exemplary embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0020] There is a general need to recover energy from low energy density exhaust gases while reducing reliance on auxiliary heat input for stable combustion and oxidation of organic pollutants such as volatile organic compounds (VOCs), volatile hazardous air pollutants (HAPs), or hydrocarbons in the low energy density exhaust gases. The present disclosure provides a method and system that facilitates efficient energy recovery from low energy density exhaust gas streams.

[0021] The low energy density waste gas stream includes at least one organic compound targeted for thermal incineration. The organic compounds present in the waste gas stream may include carbon monoxide, hydrogen, or methane. In embodiments, the waste gas stream may be obtained from gas fermentation of a C1 carbon source and / or substrate. The waste gas stream may contain various components that are preferably removed prior to further processing, i.e., sulfur-containing compounds such as hydrogen sulfide that may be produced, introduced, and / or concentrated by a gas fermentation bioreactor.

[0022] The gas fermentation bioreactor comprises a culture of one or more C1 fixed microorganisms having the ability to produce one or more products from a C1 carbon source. "C1" refers to a single carbon molecule, such as CO, CO2, CH4 or CH3OH. "C1 carbon source" refers to a carbon molecule that serves as a part of or the sole carbon source of the microorganism of the present disclosure. For example, the C1 carbon source may include one or more of CO, CO2, CH4, CH3OH or CH2O2. In an embodiment, the C1 carbon source includes one or both of CO and CO2. "Substrate" refers to a carbon source and / or energy source for the microorganism of the present disclosure. Typically, the substrate is gaseous and includes a C1 carbon source, such as CO, CO2 and / or CH4. The substrate may further include other non-carbon components, such as H2, N2 or electrons. Although the substrate is typically gaseous, the substrate may also be provided in an alternative form. For example, a microbubble dispersion generator may be used to dissolve the substrate in a liquid saturated with a C1 carbon source gas. As another example, the substrate may be adsorbed onto a solid carrier.

[0023] The substrate and / or C1 carbon source can be a waste gas obtained as a by-product of an industrial process or a waste gas obtained from another source (such as burner exhaust, biogas, landfill gas, direct air capture) or electrolysis. The substrate and / or C1 carbon source can be a synthesis gas produced by pyrolysis, roasting or gasification. In other words, the waste material can be recycled by pyrolysis, roasting or gasification to produce a synthesis gas used as a substrate and / or C1 carbon source. The substrate and / or C1 carbon source can be a gas including methane, and in some embodiments, the substrate and / or C1 carbon source can be a non-waste gas.

[0024] In certain embodiments, the industrial process is selected from the manufacture of ferrous metal products such as steel manufacturing, non-ferrous product manufacturing, petroleum refining, power generation, carbon black production, paper and pulp manufacturing, ammonia production, methanol production, coke manufacturing, petrochemical production, carbohydrate fermentation, cement manufacturing, aerobic digestion, anaerobic digestion, catalytic processes, natural gas extraction, cellulose fermentation, oil recovery, industrial processing of geological reservoirs, processing fossil resources such as natural gas, coal and oil, or any combination thereof. Examples of specific processing steps within the industrial process include catalyst regeneration, fluid catalyst cracking and catalyst regeneration. Air separation and direct air capture are other suitable industrial processes. Specific examples in steel and ferroalloy manufacturing include direct reduction of blast furnace gas, basic oxygen furnace gas, coke oven gas, iron furnace top gas and residual gas from ironmaking. Other general examples include flue gas and gas turbine exhaust from combustion boilers and combustion heaters (such as natural gas, oil or coal-fired boilers or heaters). In these embodiments, the substrate and / or C1 carbon source can be captured from the industrial process using any known method before it is discharged into the atmosphere.

[0025] The substrate and / or C1 carbon source may be a synthesis gas known as syngas, which may be obtained from a reforming, partial oxidation or gasification process. Examples of gasification processes include gasification of coal, gasification of refinery residues, gasification of petroleum coke, gasification of biomass, gasification of lignocellulosic materials, gasification of waste wood, gasification of black liquor, gasification of municipal solid waste, gasification of municipal liquid waste, gasification of industrial solid waste, gasification of industrial liquid waste, gasification of refuse derived fuels, gasification of sewage, gasification of sewage sludge, gasification of sludge from wastewater treatment, such as gasification of biogas when biogas is added to enhance the gasification of another material. Examples of reforming processes include steam methane reforming, steam naphtha reforming, natural gas reforming, biogas reforming, landfill gas reforming, naphtha reforming and dry methane reforming. Examples of partial oxidation processes include thermal and catalytic partial oxidation processes, catalytic partial oxidation of natural gas, partial oxidation of hydrocarbons. Examples of municipal solid waste include tires, plastics, and fibers such as those in shoes, clothing, and textiles. Municipal solid waste may be simple landfill type waste and may be sorted or unsorted. Examples of biomass may include lignocellulosic materials and microbial biomass. Lignocellulosic materials may include agricultural waste and forest waste.

[0026] The substrate and / or C1 carbon source may be a gas stream comprising methane. Such methane-containing gases may be obtained from fossil methane emissions, such as during hydraulic fracturing, wastewater treatment, livestock, agriculture, and municipal solid waste landfills. It is also contemplated that methane may be burned to generate electricity or heat, and the C1 byproduct may be used as a substrate or carbon source.

[0027] For reference Figure 1 and Figure 2 Some embodiments of the present disclosure are described with reference to the process configuration shown in , which relates to both the device and method for implementing the present disclosure. Any reference to a method step includes a reference to an equipment unit or device suitable for performing the step, and vice versa. The following detailed description is merely exemplary in nature and is not intended to limit the use of the present application and the described embodiments. In addition, it is not intended to be bound by any theory presented in the previous background technology or the following detailed description.

[0028] Figure 1 One embodiment of the method and apparatus of the present disclosure is described in the . However, the embodiments and drawings of the present disclosure are described by way of example, and it should be understood that a particular step or stage required in one embodiment may not be required in another embodiment. Conversely, a step or stage included in the description of a particular embodiment may be optionally advantageously used in an embodiment where the step or stage is not specifically mentioned. For example, the scope includes application to liquid fermentation processes, such as sugar-based fermentation processes. Reference Figure 1The waste gas stream may be obtained from at least one gas fermentation process unit 101. The waste gas stream may be a gas stream generated from at least one gas fermentation process unit, the waste gas stream being selected from a tail gas stream from a bioreactor, a regeneration gas stream from an adsorption unit, a tail gas stream from a distillation unit, a biogas stream from a wastewater treatment unit, an exhaust gas stream from a purification unit, or any combination thereof. The energy density of the waste gas stream may be between about 0.5 and about 5 MJ / Nm 3 In an embodiment, the energy density of the exhaust gas stream may be in the range of about 1 to about 5 MJ / Nm 3 In another embodiment, the energy density of the exhaust gas stream may be in the range of about 1 to about 2 MJ / Nm 3 within the range.

[0029] The methods and systems of the present disclosure minimize the need for auxiliary heat input, such as natural gas or oil, to raise the temperature of the exhaust gas to allow adequate oxidation. The fuel stream 100 can be used to support oxidation of the exhaust gas stream. In an embodiment, the fuel stream 100 can include a byproduct gas stream obtained from at least one selected from the group consisting of: an industrial process, a syngas process, a combustor exhaust, direct air capture, electrolysis, or any combination thereof. In some cases, the industrial process is selected from carbohydrate fermentation, gas fermentation, cement manufacturing, pulp and paper manufacturing, steel manufacturing, oil refining, petrochemical production, coke production, anaerobic digestion, aerobic digestion, natural gas extraction, oil recovery, geological reservoirs, metallurgical processes, aluminum, copper and or ferroalloy refining for the production of aluminum, copper and or ferroalloys, or any combination thereof; or the synthesis gas process is selected from coal gasification, gasification of refinery residues, gasification of biomass, gasification of lignocellulosic materials, black liquor gasification, gasification of municipal solid waste, gasification of industrial solid waste, gasification of sewage, gasification of sludge from wastewater treatment, reforming of natural gas, reforming of biogas, reforming of landfill gas, or any combination thereof. The energy density of the fuel stream can be from about 2 to about 15 MJ / Nm 3 In an embodiment, the energy density of the fuel stream may be in the range of about 4 to about 15 MJ / Nm 3 In another embodiment, the energy density of the fuel stream may be in the range of about 4 to about 7 MJ / Nm 3 within the range.

[0030] refer to Figure 1, the exhaust gas stream is delivered to the thermal oxidizer 130 via the exhaust gas conduit 120. The fuel stream 100 is delivered to the self-regenerative burner or regenerative burner 140 of the thermal oxidizer 130 via the fuel gas conduit 110. The thermal oxidizer or thermal incinerator is a combustion device that controls the emission of volatile organic compounds (VOCs), CO and volatile hazardous air pollutants (HAPs) by burning them into carbon dioxide (CO2) and water. In an embodiment, the thermal oxidizer 130 is selected from a direct-fired thermal oxidizer, a regenerative thermal oxidizer, a regenerative thermal oxidizer, a catalytic thermal oxidizer, a flameless thermal oxidizer or any combination thereof.

[0031] The first type of thermal oxidizer is a direct-fired thermal oxidizer. The operating principle of a direct-fired oxidizer is to introduce a combustion process gas stream into the furnace section of a direct thermal oxidizer, where the temperature of the process gas stream is raised to or above the auto-ignition temperature and maintained in the furnace section at this temperature for the desired residence time in order to completely oxidize the VOCs and HAPs in the stream. The second type of thermal oxidizer is a regenerative thermal oxidizer (RTO). The RTO uses a ceramic bed that can be heated from a previous oxidation cycle to preheat the input gas, thereby partially oxidizing the input gas. The preheated gas enters a combustion chamber that can be heated by an external fuel source to reach a target oxidation temperature. This type of oxidizer is specifically designed for oxidizing large process gas streams with low organic compound concentrations, such as low percentage organic contaminants containing VOCs and HAPs in the process gas stream. The third type of thermal oxidizer is a regenerative thermal oxidizer. A regenerative thermal oxidizer has a primary heat exchanger and / or a secondary heat exchanger within the system. The primary heat exchanger preheats the incoming combustion air stream by recovering heat from the exhaust clean gas stream. This primary heat recovery raises the temperature of the process gas stream before it enters the combustion chamber, thereby reducing the fuel demand of the oxidizer system. Catalytic thermal oxidizers are another type of thermal oxidizer that uses a catalyst to promote oxidation. Catalytic oxidation is carried out by a chemical reaction between organic pollutants and a noble metal catalyst bed inside the oxidizer system. However, catalytic thermal oxidizers are not easily used in industry due to their high cost. Flameless thermal oxidizers are another type of thermal oxidizer that uses a refractory lined vessel filled with ceramic media for flameless oxidation. Flameless oxidation is a thermal treatment that premixes exhaust gas, ambient air, and auxiliary fuel as needed before passing the gaseous mixture through a preheated inert ceramic media bed.

[0032] The thermal oxidizer of the present disclosure includes at least one self-regenerative burner or a regenerative burner. The self-regenerative burner may include a regenerative burner integrated with the burner, which is used to preheat the incoming combustion air. The self-regenerative burner is configured to transfer a portion of the energy contained in the exhaust gas / flue gas to the feed gas and / or combustion air. This design arrangement produces a high air preheat temperature and excellent thermal efficiency. The regenerative burners are installed in pairs, one of which is used for exhaust and the other is used for combustion. During exhaust, the refractory medium recovers and stores heat from the flue gas. During combustion, heat is recovered from the medium by preheating the combustion air. The exhaust gas passes through the regenerative burner body and enters the refractory medium box containing refractory materials. The refractory medium can be heated by the exhaust gas, thereby recovering and storing energy from the flue products. When the media bed is fully heated, the currently burning regenerative burner can be closed and start to discharge the flue products. The regenerative burner with a hot media bed starts to burn. The combustion air passes through the media bed and is heated by the hot refractory material, thereby producing a high thermal efficiency.

[0033] In embodiments, where the thermal oxidizer is a direct-fired, regenerative or recuperative thermal oxidizer; another fuel stream 111 may be delivered to the recuperative burner or regenerative burner. The energy density of the additional fuel stream may be about 1.5 MJ / Nm 3 To about 56MJ / Nm 3 In another embodiment, the energy density of the additional fuel stream may be about 1.5 MJ / Nm 3 To about 5.0MJ / Nm 3 within the range.

[0034] In an embodiment, the heating of the thermal oxidizer should be sufficient to heat the exhaust gas stream to at least its auto-ignition temperature. The thermal oxidizer 130 can be heated to reach at least the auto-ignition temperature of the exhaust gas stream, thereby oxidizing the exhaust gas stream and generating hot flue gas via the flue gas duct 131. In an embodiment, the heating of the thermal oxidizer should be sufficient to heat the exhaust gas stream to above its auto-ignition temperature. The thermal oxidizer 130 can be heated to at least 400°C above the auto-ignition temperature of the exhaust gas stream. The auto-ignition temperature or flash point of a substance is the lowest temperature at which it spontaneously ignites in a normal atmosphere without the need for an external ignition source (such as a flame or spark). This temperature is required to supply the activation energy required for combustion.

[0035] In another embodiment, Figure 1 The supplemental fuel stream, shown as 112 in FIG. 1 , is delivered to a self-regenerative burner or a regenerative burner of the thermal oxidizer. The energy density of the supplemental fuel stream may be in the range of about 4 to about 20 MJ / Nm 3 In another embodiment, the energy density of the supplemental fuel stream may be in the range of about 4 to about 15 MJ / Nm 3 The supplemental fuel stream may be a gas stream generated in an industrial process, a gasification process, a gas fermentation process, or a combination thereof.

[0036] refer to Figure 1 , the hot flue gas can be transferred to the steam boiler unit 150 to generate steam 151. In an embodiment, the generated steam can be used in, but not limited to, at least one gas fermentation process unit. The steam can be used in a power generation unit for power generation. The steam can be used, for example, in a distillation unit for product separation. The steam can also be used to purify or concentrate the product, for example, for ethanol dehydration. The steam can also be used in a gas processing unit or an evaporation unit. In addition, the steam can be used in a cleaning-in-place method, for example, for cleaning a bioreactor.

[0037] The hot flue gas from the steam boiler unit 150 may be transferred to the indirect heat exchanger 160 via the flue gas duct 152. The combustion air stream from the combustion blower 170 is transferred to the indirect heat exchanger 160 via the combustion air duct 171. In an embodiment, the combustion air duct 171 may optionally be in fluid communication with the enrichment unit 190. The combustion air stream may be transferred to the enrichment unit 190 before being transferred to the indirect heat exchanger 160 to produce an oxygen-enriched combustion air stream 191. The enrichment unit may be selected from a pressure swing adsorption unit, a membrane separation unit, a cryogenic distillation unit, or any combination thereof. The enrichment unit reduces the amount of nitrogen in the combustion air, so less heat is absorbed by the nitrogen in the combustion air, thereby reducing the energy required to heat the exhaust gas and the combustion air to the furnace temperature. These higher exhaust gas flow temperatures can increase the oxidation rate, thereby improving flame stability and the acceptable range of energy content of the fuel gas stream. The oxygen-enriched combustion air stream 191 may be transferred to the indirect heat exchanger 160. As used herein, the term "enriched" may mean that the outlet stream has a greater concentration of a specified component than in the inlet stream of the vessel.

[0038] The hot flue gas from the steam boiler unit may indirectly heat the combustion air stream in the indirect heat exchanger 160 to produce a preheated combustion air stream. The preheated combustion air stream is passed to the thermal oxidizer 130 to support oxidation of the exhaust gas stream and produce hot flue gas. In an embodiment, at least a portion of the preheated combustion air stream may be used to directly or indirectly heat the fuel stream to preheat the fuel stream. In another embodiment, at least a portion of the preheated combustion air stream may be used to directly or indirectly heat the exhaust gas stream to preheat the exhaust gas stream.

[0039] In an embodiment, at least a portion 172 of the combustion air stream is blended with the exhaust gas stream, and the blended stream may be passed to the self-regenerative burner or regenerative burner 140. In another embodiment, the non-productive flue gas stream 161 in the indirect heat exchanger 160 may be passed to the flue unit 180 to discharge a clean, cooler, and environmentally friendly flue gas stream 181. The methods and apparatus of the present disclosure allow a thermal oxidizer to oxidize a low energy exhaust gas stream by using a low energy density fuel gas such as syngas, BF gas, or biogas without the need for an external high energy density stream.

[0040] exist Figure 2 An embodiment of the method and apparatus of the present disclosure is described in Figure 1 The energy recovery device 250 utilizes a gas fermentation process of at least one low energy density waste gas stream. However, the embodiments and drawings of the present disclosure are described by way of example, and it should be understood that a step or stage required in one embodiment may not be required in another embodiment. Conversely, a step or stage included in the description of a particular embodiment may be optionally advantageously used in an embodiment in which the step or stage is not specifically mentioned.

[0041] Figure 2 A schematic flow chart of a process for utilizing energy from at least one low energy density waste gas stream from a gas fermentation process as an exemplary embodiment of the present disclosure is shown. The gas fermentation process can be a platform for biological fixation of carbon in byproduct gases (including carbon dioxide (CO2), carbon monoxide (CO) and / or hydrogen (H2)) using C1 fixing microorganisms as biocatalysts to convert substrates and / or C1 carbon sources into valuable products, such as ethanol or other alcohols.

[0042] "C1 fixed microorganism" is a microorganism that can produce one or more products from a C1 carbon source. Typically, the microorganism of the present disclosure is a C1 fixed bacteria. A "microorganism" or "biocatalyst" is a microscopic organism, particularly a bacterium, an archaea, a virus or a fungus. The microorganism of the present disclosure is typically a bacterium. As used herein, references to "microorganisms" should be considered to cover "bacteria". "Surviving microorganisms" or "survival rate of microbial biomass" and the like refer to the ratio of living microorganisms that are able to survive, develop or reproduce to microorganisms that are unable to survive, develop or reproduce. The present disclosure can be designed to maintain the survival rate of the microbial biomass at a minimum survival rate.

[0043] The microorganism in the bioreactor can be modified from a naturally occurring microorganism. A "parent microorganism" is a microorganism used to produce the microorganism of the present disclosure. The parent microorganism can be a naturally occurring microorganism (referred to as a wild-type microorganism) or a previously modified microorganism (referred to as a mutant or recombinant microorganism). The microorganism of the present disclosure can be modified to express or overexpress one or more enzymes that are not expressed or overexpressed in the parent microorganism. Similarly, the microorganism of the present disclosure can be modified to contain genes that are not contained in one or more parent microorganisms. The microorganism of the present disclosure can also be modified to not express or express a lower amount of one or more enzymes expressed in the parent microorganism. In one embodiment, the parent microorganism is Clostridium autoethanogenum, Clostridium jundal or Clostridium ragbelloides. In an embodiment, the parent microorganism is Clostridium autoethanogenum LZ1561, which was deposited on June 7, 2010 at the Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH (DSMZ) at Inhoffenstraβe 7B, D-38124 Braunschweig, Germany under the terms of the Budapest Treaty on June 7, 2010 and was granted accession number DSM 23693. This strain is described in International Patent Publication No. WO 2012 / 015317.

[0044] The microorganisms of the present disclosure can be cultured with substrates and / or C1 carbon sources in gas fermentations to produce one or more products. For example, the microorganisms of the present disclosure can produce or can be engineered to produce ethanol (WO 2007 / 117157), acetate (WO 2007 / 117157), butanol (WO 2008 / 115080 and WO 2012 / 053905), butyrate (WO 2008 / 115080), 2,3-butanediol (WO 2009 / 151342 and WO 2016 / 094334), lactate (WO 2011 / 112103), butene (WO 2012 / 024522), butadiene (WO 2012 / 024522), methyl ethyl ketone (2-butanone) (WO 2012 / 024522 and WO 2013 / 185123), acetone (WO 2012 / 115527), isopropanol (WO 2012 / 115527), and 1,2-diol (WO 2012 / 151342 and WO 2016 / 094334). 2012 / 115527), lipids (WO 2013 / 036147), 3-hydroxypropionate (3-HP) (WO 2013 / 180581), terpenes, including isoprene (WO 2013 / 180584), fatty acids (WO 2013 / 191567), 2-butanol (WO 2013 / 185123), 1,2-propylene glycol (WO 2014 / 036152), 1-propanol (WO 2014 / 0369152), chorismate derivatives (WO 2016 / 191625), 3-hydroxybutyrate (WO 2017 / 066498), 1,3-butanediol (WO 2017 / 066498), 2-hydroxyisobutyrate or 2-hydroxyisobutyric acid (WO 2017 / 066498), isobutylene (WO 2017 / 066498), adipic acid (WO 2017 / 066498), 1,3-hexanediol (WO 2017 / 066498), 3-methyl-2-butanol (WO 2017 / 066498), 2-butene-1-ol (WO 2017 / 066498), isovalerate (WO 2017 / 066498), isopentanol (WO 2017 / 066498) and / or monoethylene glycol (WO 2019 / 126400), except 2-phenylethanol (WO 2021 / 188190).

[0045] refer to Figure 2, a fuel stream produced as a byproduct gas stream is obtained from an industrial process 210. At least a portion 212 of the fuel stream is passed to an energy recovery device 250. A portion 211 of the fuel stream can be passed to an adsorption unit 220 to produce a gaseous feed substrate and a first waste gas stream. The gaseous feed substrate 221 can be passed to at least one bioreactor 230, the at least one bioreactor comprising a culture of at least one C1 fixed microorganism. The culture is fermented to produce a fermentation broth comprising one or more fermentation products.

[0046] Fermentation, including "fermentation", "fermentation process" or "fermentation reaction", etc., covers both the growth phase of the microorganism and the product biosynthesis phase. The fermentation process can be described as "batch" or "continuous". "Batch fermentation" is used to describe the following fermentation process: wherein the bioreactor is filled with raw materials (such as a carbon source) and microorganisms, wherein the product remains in the bioreactor until the fermentation is completed. In a batch process, after the fermentation is completed, the product is extracted and the bioreactor is cleaned before the next batch begins. "Continuous fermentation" is used to describe the following fermentation process: wherein the fermentation process extends for a long period of time, and the product and / or metabolites are removed during the fermentation. The present disclosure is most advantageous in a continuous fermentation process, but it is also conceivable to be applicable to batch fermentation.

[0047] Fermentation culture is usually maintained in an aqueous medium, and the aqueous medium contains nutrients, vitamins and / or minerals that are enough to allow microbial growth. In an embodiment, the aqueous medium is an anaerobic microbial growth medium, such as a minimal anaerobic microbial growth medium. Suitable culture medium is well-known in the art. The term "fermentation broth" or "broth" is intended to encompass a component mixture comprising a nutrient medium, a culture of one or more microorganisms, water and one or more products. The terms microorganism, bacterium and biocatalyst are used interchangeably throughout this disclosure.

[0048] The fermentation process should be carried out under appropriate conditions for producing the target product. Typically, fermentation is carried out under anaerobic conditions. The reaction conditions to be considered include pressure or partial pressure, temperature, gas flow rate, liquid flow rate, medium pH, medium redox potential, stirring rate (if a continuous stirred tank reactor is used), inoculum level, the maximum gas substrate concentration for ensuring that the gas in the liquid phase does not become restricted, and the maximum product concentration for avoiding product inhibition. Specifically, the introduction rate of the substrate or components in the substrate can be controlled to ensure that the concentration of the gas in the liquid phase is not restricted, because under gas-restricted conditions, the product may be consumed by the culture.

[0049] Operating the bioreactor under boost allows for an increase in the rate of gas mass transfer from the gas phase to the liquid phase. Therefore, one embodiment is cultured / fermented at a pressure higher than atmospheric pressure. Similarly, since a given gas conversion rate is partly a function of the substrate retention time and the retention time indicates the desired volume of the bioreactor, the use of a pressurized system can greatly reduce the volume of the required bioreactor, and thus reduce the capital cost of the culture / fermentation equipment. This also means that when the bioreactor is maintained at high pressure rather than atmospheric pressure, the retention time (defined as the liquid volume in the bioreactor divided by the input gas flow rate) can be reduced. The most preferred reaction conditions will depend in part on the specific microorganism used. In one embodiment, the fermentation can be operated at a pressure higher than atmospheric pressure. Similarly, since a given gas conversion rate varies in part with the substrate retention time, and achieving the desired retention time will affect the desired volume of the bioreactor, the use of a pressurized system can greatly reduce the desired bioreactor volume, and thus reduce the capital cost of the fermentation equipment.

[0050] Fermented broth is produced in a bioreactor comprising a fermentation unit consisting of one or more containers and / or towers or pipeline arrangements. Examples of bioreactors include continuous stirred tank reactors (CSTRs), immobilized cell recirculation (ICRs), trickle bed reactors (TBRs), bubble towers, gas lift fermenters, static mixers, circulating loop reactors, membrane reactors (such as hollow fiber membrane bioreactors (HFM-BRs)) or other units or other devices suitable for gas-liquid contact. The reactor may be suitable for receiving gaseous substrates including CO and / or CO or H or mixtures thereof. The reactor may include multiple reactors (stages) in parallel or in series. For example, the reactor may include a first growth reactor for culturing bacteria and a second fermentation reactor to which a fermentation broth from a growth reactor may be fed and to which a majority of fermented products may be produced.

[0051] Fermentation broth produced from a bioreactor encompasses a mixture of components comprising a nutrient medium, a culture medium for one or more microorganisms, and one or more products. "Nutrient media" or "nutrient medium" is used to describe a bacterial growth medium. Typically, this term refers to a culture medium containing nutrients and other components suitable for the growth of a microbial culture. The term "nutrient" includes any substance that can be used in the metabolic pathways of a microorganism. Exemplary nutrients include potassium, vitamin B, trace metals, and amino acids.

[0052] The target fermentation product can be separated from the fermentation broth using any method or combination of methods known in the art, including, for example, fractionation, evaporation, pervaporation, gas stripping, phase separation, extractive separation (including, for example, liquid-liquid extraction). In certain embodiments, the target product is recovered from the fermentation broth by continuously removing a portion of the culture broth from the gas fermentation bioreactor, first separating the microbial cells from the culture broth, and then separating the target product from the aqueous remainder. Alcohol and / or acetone can be recovered, for example, by distillation. Acid can be recovered, for example, by adsorption on activated carbon. The separated microbial biomass can be recycled to the gas fermentation bioreactor. The remaining solution after removing the target product can also be recycled to the gas fermentation bioreactor. Additional nutrients can be added to the recycled solution before the recycled solution returns to the gas fermentation bioreactor to replenish the culture medium. Known separation techniques can be used in the separator. For example, the separator can use vacuum distillation as discussed in WO2018 / 175481, or the separator can use filtration techniques, such as membrane filtration. In membrane filtration, the membrane retains the biocatalyst cells, and the permeate passing through the membrane is substantially free of biocatalyst cells.

[0053] refer to Figure 2 , the fermentation broth produced in the bioreactor 230 can be transferred to a separator to produce a product substrate including one or more fermentation products and a second waste gas stream. The product substrate 231 can be transferred to the distillation unit 240. At least one fermentation product and the third waste gas stream are separated in the distillation unit 240. At least one fermentation product is collected via a conduit 241. One or more of the first waste gas stream 222, the second waste gas stream 232, and the third waste gas stream 242 are transferred to the device 250. At least one of the waste gas streams is oxidized in the device 250 and steam is generated. At least a portion 251 of the steam can pass through the distillation unit 240 and be used in the distillation unit 240. At least a portion 252 of the steam can be used to generate electricity.

[0054] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0055] Unless otherwise indicated herein or clearly contradicted by the context, in the context of describing the present disclosure (especially in the context of the following claims), the use of the terms "a" and "an" and "said" and similar references are interpreted to cover both the singular and the plural. Unless otherwise indicated, the terms "including", "having", "including" and "containing" are interpreted as open terms, i.e., meaning "including but not limited to". Unless otherwise specified, the description of the value range herein is intended only to serve as a shorthand method for individually referring to each independent value within the range, and each independent value is incorporated into this specification as if individually listed herein. Unless otherwise specified herein or clearly contradicted by the context, all methods described herein can be performed in any suitable order. Unless otherwise required, the use of any and all examples or exemplary language is intended only to better illustrate the present disclosure and does not limit the scope of the present disclosure. The language in this specification should not be interpreted as indicating that any non-claimed element is essential to the practice of the present disclosure.

[0056] After reading the above description, the changes of the embodiments disclosed herein may become apparent to those of ordinary skill in the art. It is expected that those skilled in the art will adopt such variations as needed, and may practice the present disclosure in a manner different from that specifically described herein. Therefore, where applicable law permits, the present disclosure includes all modifications and equivalents of the subject matter recited in the appended claims. In addition, unless otherwise provided herein or otherwise clearly contradictory to the context, the present disclosure encompasses any combination of the above elements in all possible variations thereof. Unless otherwise stated, all pressures disclosed herein are absolute. Unless otherwise stated, all temperatures are degrees Celsius.

[0057] Embodiments of the present disclosure

[0058] Example 1. A method for recovering energy from a low energy density gas stream, comprising: 3 The fuel stream is delivered to a self-regenerative burner or a regenerative burner of the thermal oxidizer to burn the fuel stream and heat the thermal oxidizer; the energy density is about 0.5 to about 5 MJ / Nm 3 At least one exhaust gas stream and a preheated combustion air stream are passed to the thermal oxidizer to oxidize the exhaust gas stream and produce hot flue gas; the hot flue gas is passed to a steam boiler unit to provide heat and produce steam; and the hot flue gas from the steam boiler unit is passed to an indirect heat exchanger to indirectly heat the combustion air stream and produce the preheated combustion air stream.

[0059] Embodiment 2. The method according to embodiment 1, wherein the thermal oxidizer is selected from a direct-fired thermal oxidizer, a regenerative thermal oxidizer, a regenerative thermal oxidizer, a catalytic thermal oxidizer, a flame thermal oxidizer or any combination thereof.

[0060] Embodiment 3. The method according to embodiment 1 or 2, wherein the thermal oxidizer is a direct-fired, regenerative or regenerative thermal oxidizer, and the method further comprises setting the energy density to about 1.5 MJ / Nm 3 To about 20MJ / Nm 3 Another fuel stream within the range is delivered to the self-regenerative burner or the regenerative burner of the direct-fired, regenerative or regenerative thermal oxidizer.

[0061] Embodiment 4. The method of any one of embodiments 1 to 3, wherein the waste gas stream comprises organic compounds targeted for thermal incineration.

[0062] Embodiment 5. A method according to any one of embodiments 1 to 4, wherein the waste gas stream comes from a gas fermentation process and is selected from a tail gas stream from a bioreactor, a regeneration gas stream from an adsorption unit, a tail gas stream from a distillation unit, a biogas stream from a wastewater treatment unit, an exhaust gas stream from a purification unit, or any combination thereof.

[0063] Embodiment 6. The method of any one of embodiments 1 to 5, wherein the fuel stream comprises a byproduct gas stream obtained from at least one selected from the group consisting of: an industrial process, a syngas process, combustor exhaust, direct air capture, electrolysis, or any combination thereof.

[0064] Embodiment 7. A method according to any one of embodiments 1 to 6, wherein the industrial process is selected from carbohydrate fermentation, gas fermentation, cement manufacturing, pulp and paper manufacturing, steel manufacturing, oil refining, petrochemical production, coke production, anaerobic digestion, aerobic digestion, natural gas extraction, oil production, geological reservoirs, metallurgical processes, aluminum, copper and or ferroalloy refining for the production of aluminum, copper and or ferroalloys, or any combination thereof; or the synthesis gas process is selected from the gasification of coal, gasification of refinery residues, gasification of biomass, gasification of lignocellulosic materials, black liquor gasification, gasification of municipal solid waste, gasification of industrial solid waste, gasification of sewage, gasification of sludge from wastewater treatment, reforming of natural gas, reforming of biogas, reforming of landfill gas, or any combination thereof.

[0065] Embodiment 8. The method according to any one of embodiments 1 to 7, further comprising: 3 A supplementary fuel stream is delivered to the self-regenerating burner or the regenerative burner of the thermal oxidizer; wherein the supplementary fuel stream is a gas stream generated in an industrial process, a gasification process, a gas fermentation process or a combination thereof.

[0066] Embodiment 9. The method according to any one of embodiments 1 to 8, wherein the combustion air flow is provided via a combustion blower.

[0067] Embodiment 10. The method according to any one of embodiments 1 to 9 further comprises passing the combustion air flow to an enrichment unit before passing it to the thermal oxidizer; wherein the enrichment unit is selected from a pressure swing adsorption unit, a membrane separation unit, a cryogenic distillation unit or any combination thereof.

[0068] Embodiment 11. The method of any one of embodiments 1 to 10, wherein the heating of the thermal oxidizer is sufficient to heat the exhaust gas stream to at least its auto-ignition temperature.

[0069] Embodiment 12. The method of any one of embodiments 1 to 11, wherein the heating of the thermal oxidizer is sufficient to heat the exhaust gas stream to at least 400° C. above its autoignition temperature.

[0070] Embodiment 13. A method according to any one of embodiments 1 to 12, wherein the steam is used in a power generation unit or in at least one gas fermentation process unit selected from a product separation unit, a purification unit, a gas processing unit, an evaporation unit, a concentration unit, for an in-situ cleaning method, or any combination thereof.

[0071] Embodiment 14. The method according to any one of embodiments 1 to 13 further comprises directly or indirectly heating the fuel flow or the exhaust gas flow with at least a portion of the preheated combustion air flow to preheat the fuel flow or the exhaust gas flow; or both.

[0072] Embodiment 15. A device for recovering energy from a low energy density gas flow, comprising: a reheat burner or a regenerative burner positioned in a thermal oxidizer; a fuel gas conduit fluidly connected to both the reheat burner or the regenerative burner of the thermal oxidizer and a low energy density source; an exhaust gas conduit fluidly connected to the thermal oxidizer; a combustion air conduit fluidly connected to the thermal oxidizer and to an indirect heat exchanger; and a flue gas conduit fluidly connected to the thermal oxidizer and to a steam boiler unit and the indirect heat exchanger.

[0073] Embodiment 16. The apparatus of embodiment 15, wherein the combustion air conduit is further in fluid communication with a combustion blower.

[0074] Embodiment 17. The apparatus of embodiment 15 or 16, wherein the combustion air conduit is in fluid communication with the fuel gas conduit or the exhaust gas conduit.

[0075] Embodiment 18. The apparatus of any one of embodiments 15 to 17, wherein the fuel gas conduit is further in fluid communication with a bioreactor, an extraction unit, a wastewater treatment unit, a gasifier, or any combination thereof.

[0076] Embodiment 19. An apparatus according to any one of embodiments 15 to 18, wherein the exhaust gas conduit is further connected to at least one gas fermentation process unit fluid, and the at least one gas fermentation process unit is selected from a bioreactor, an adsorption unit, a distillation unit, a wastewater treatment unit, a purification unit or any combination thereof.

[0077] Embodiment 20. The apparatus of any one of embodiments 15 to 20, wherein the thermal oxidizer is a direct-fired thermal oxidizer, a regenerative thermal oxidizer, a regenerative thermal oxidizer, or any combination thereof.

Claims

1. A method for recovering energy from a low energy density gas stream, comprising: a. The energy density is about 1.5 to about 15 MJ / Nm 3 a fuel stream passing to a self-regenerating burner or a regenerative burner of a thermal oxidizer to combust the fuel stream and heat the thermal oxidizer; b. The energy density is about 0.5 to about 5 MJ / Nm 3 passing at least one of a flue gas stream and a preheated combustion air stream to said thermal oxidizer to oxidize said flue gas stream and produce hot flue gas; c. transferring the hot flue gas to a steam boiler unit to provide heat and generate steam; as well as d. Transferring the hot flue gas from the steam boiler unit to an indirect heat exchanger to indirectly heat a combustion air stream and produce the preheated combustion air stream.

2. The method according to claim 1, wherein the thermal oxidizer is selected from a direct-fired thermal oxidizer, a regenerative thermal oxidizer, a regenerative thermal oxidizer, or any combination thereof.

3. The method of claim 2, wherein the thermal oxidizer is a direct-fired, regenerative or regenerative thermal oxidizer, and the method further comprises setting the energy density to about 1.5 MJ / Nm 3 To about 20MJ / Nm 3 Another fuel stream within the range is delivered to the self-regenerative burner or the regenerative burner of the direct-fired, regenerative or regenerative thermal oxidizer.

4. The method of claim 1, wherein the waste gas stream includes organic compounds targeted for thermal incineration.

5. The method according to claim 1, wherein the waste gas stream is from a gas fermentation process and is selected from a tail gas stream from a bioreactor, a regeneration gas stream from an adsorption unit, a tail gas stream from a distillation unit, a biogas stream from a wastewater treatment unit, a discharge gas stream from a purification unit, or any combination thereof.

6. The method of claim 1, wherein the fuel stream comprises a byproduct gas stream obtained from at least one selected from the group consisting of an industrial process, a syngas process, a combustor exhaust, direct air capture, electrolysis, or any combination thereof.

7. The method of claim 6, wherein the industrial process is selected from carbohydrate fermentation, gas fermentation, cement manufacturing, pulp and paper manufacturing, steel manufacturing, oil refining, petrochemical production, coke production, anaerobic digestion, aerobic digestion, natural gas extraction, oil recovery, geological reservoirs, metallurgical processes, aluminum, copper and or ferroalloy refining for the production of aluminum, copper and or ferroalloys, or any combination thereof; or the synthesis gas process is selected from the gasification of coal, gasification of refinery residues, gasification of biomass, gasification of lignocellulosic materials, gasification of black liquor, gasification of municipal solid waste, gasification of industrial solid waste, gasification of sewage, gasification of sludge from wastewater treatment, reforming of natural gas, reforming of biogas, reforming of landfill gas, or any combination thereof.

8. The method of claim 1, further comprising applying an energy density of about 1.5 to about 20 MJ / Nm 3 A supplementary fuel stream is delivered to the self-regenerating burner or the regenerative burner of the thermal oxidizer; wherein the supplementary fuel stream is a gas stream generated in an industrial process, a gasification process, a gas fermentation process or a combination thereof.

9. The method of claim 1, wherein the combustion air flow is provided via a combustion blower.

10. The method of claim 9, further comprising passing the combustion air stream to an enrichment unit prior to passing to the thermal oxidizer; wherein the enrichment unit is selected from a pressure swing adsorption unit, a membrane separation unit, a cryogenic distillation unit, or any combination thereof.

11. The method of claim 1 wherein the heating of the thermal oxidizer is sufficient to heat the exhaust gas stream to at least its autoignition temperature.

12. The method of claim 1 wherein the heating of the thermal oxidizer is sufficient to heat the exhaust gas stream to at least 400°C above its autoignition temperature.

13. The method of claim 1, wherein the steam is used in a power generation unit or in at least one gas fermentation process unit selected from a product separation unit, a purification unit, a gas treatment unit, an evaporation unit, a concentration unit, for a clean-in-place process, or any combination thereof.

14. The method of claim 1, further comprising directly or indirectly heating the fuel stream or the exhaust stream with at least a portion of the preheated combustion air stream to preheat the fuel stream or the exhaust stream; or both.

15. An apparatus for recovering energy from a low energy density gas stream, comprising: i. Regenerative burners or regenerative burners located in the thermal oxidizer; ii. a fuel gas conduit in fluid communication with both the recuperative burner or regenerative burner and the low energy density source of the thermal oxidizer; iii. an exhaust gas conduit in fluid communication with said thermal oxidizer; iv. a combustion air conduit in fluid communication with said thermal oxidizer and in communication with an indirect heat exchanger; and v. A flue gas duct in fluid communication with the thermal oxidizer and in communication with a steam boiler unit and the indirect heat exchanger.

16. The apparatus of claim 15, wherein the combustion air conduit is further in fluid communication with a combustion blower.

17. The apparatus of claim 16, wherein the combustion air conduit is in fluid communication with the fuel gas conduit or the exhaust gas conduit.

18. The apparatus of claim 15, wherein the fuel gas conduit is further in fluid communication with a bioreactor, an extraction unit, a wastewater treatment unit, a gasifier, or any combination thereof.

19. The apparatus of claim 15, wherein the exhaust gas conduit is further fluidly connected to at least one gas fermentation process unit, the at least one gas fermentation process unit being selected from a bioreactor, an adsorption unit, a distillation unit, a wastewater treatment unit, a purification unit, or any combination thereof.

20. The apparatus of claim 15, wherein the thermal oxidizer is a direct-fired thermal oxidizer, a recuperative thermal oxidizer, a regenerative thermal oxidizer, or any combination thereof.

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