COMBUSTION SYSTEM COMPRISING AN ANNULAR COVER BURNER

Abstract

COMBUSTION SYSTEM COMPRISING AN ANNULAR COVER BURNER. This disclosure relates to systems and methods for high flame temperature oxy-combustion that allows for the effective capture of CO2. A portion of the matter presently disclosed comprises an annular cover burner that utilizes an undiluted oxygen supply and minimal combustion gas recycling to generate a high flame temperature to maximize efficiency. The annular cover burner can supply oxygen to a combustion zone where oxygen and fuel stream mixing occurs. The recycled combustion gas from the combustion system outlet serves the dual purpose of driving coal to the reaction zone, as well as providing local cooling and protection against high incident heat fluxes through the novel cover cooling design.The annular cap burner can be configured to produce an axial jet flame that controls the oxygen-fuel mixing ratio, thus extending the heat release. Oxygen and coal can be mixed in a ratio such that the maximum flame temperatures exceed 4,500 (degrees Fahrenheit) 2,482 (degrees Celsius), while the recycled combustion gas flow is regulated to control the flame temperature and protect the burner components and surfaces near the burner.

Description

1 / 41 “COMBUSTION SYSTEM COMPRISING AN ANNULAR COVER BURNER” TECHNICAL FIELD

[0001] This disclosure relates to methods and systems for combustion and carbon capture, more particularly, methods and systems involving high-temperature flame oxy-combustion of fuel and efficient carbon dioxide capture. BACKGROUND

[0002] Fossil fuels are the main source of energy in the world today, primarily in the electricity generation, manufacturing, and transportation industries. However, due to the large CO2 production associated with the use of fossil fuels, it is also considered by many to be one of the main contributors to global warming. One of these fossil fuels is coal, where the future use of coal as fuel for power generation and industrial applications depends on the availability of new economical technologies to capture and store the CO2 emitted as a product of the combustion process. These carbon capture technologies are commonly called carbon capture and storage (CCS) and carbon capture utilization and storage (CCUS).

[0003] Some of the available technologies include air-fueled and oxy-fueled combustion technologies. In the case of air-fueled combustion (air comprises approximately 79% nitrogen and 21% oxygen), NOx and other greenhouse gases such as CO2 and SO2 are produced as a result of the combustion process. The higher percentage of impurities for air-fueled combustion makes carbon capture (such as CCS and CCUS) more complicated and expensive than that of oxy-fueled combustion. In addition to this disadvantage, air-fueled combustion suffers from lower fuel efficiency due to the amount of fuel required to heat the nitrogen present in the air.

[0004] A more advantageous system is the system of Petition 870220072537, dated 12 / 08 / 2022, p. 10 / 70 2 / 41 Oxy-fuel combustion (or oxy-combustion). In the case of oxy-combustion, oxygen that is >95% pure is used as an oxidant in the combustion process instead of air. The use of high-purity oxygen results in a significantly lower percentage of impurities and higher concentrations of CO2 and H2O, making processes such as CCS and CCUS more economical than air combustion. CO2 and H2O can be easily separated and the CO2 purified in a carbon purification unit (CPU), leaving high-purity CO2 that can be recycled, stored, or used as a valuable commodity as part of CCS or CCUS processes. This reduces the amount of greenhouse gases produced.

[0005] However, this process requires pure oxygen (O2), which is often obtained by cryogenic distillation. Cryogenic distillation is a very mature process that has been in operation since the 1930s, but it is still an expensive process. In addition to increased expense, traditional oxy-combustion suffers from other shortcomings, such as high capital costs, higher air intake and associated impurities, high oxygen requirements, and lower carbon capture, utilization, and sequestration of CO2.

[0006] Regardless of the disadvantages associated with traditional oxy-combustion of fuels, it is still an improvement over air combustion. Thus, there is a desire to replace the air-fuel combustion burners present in boilers and process heaters in existing fuel processing plants with more environmentally friendly oxy-combustion burners.

[0007] Generally, the systems in existing fuel processing plants have been configured to provide optimal performance, limiting the negative outcomes associated with air-combustion burners. Thus, replacing one burner with another is not easily accomplished, much less replacing an air-combustion process with an oxy-combustion process. The potential disadvantages associated with this type of Petition 870220072537, dated 12 / 08 / 2022, page 11 / 70 3 / 41 Changes include a significant change in heat transfer between the various systems, as well as a greater likelihood of component damage due to different heating characteristics, current flows, and current characteristics. One reason for this difficulty is the fact that an oxy-combustion burner will produce a hotter flame temperature than a traditional air-fuel burner. For example, when an existing air-fueled combustion burner is replaced with an oxy-combustion burner, the peak temperature will increase, thus increasing the amount of heat transfer (heat flow) to the components around the oxy-combustion burner. This requires modification of existing parts of the plant, a process that is both time-consuming and extremely expensive.

[0008] Reports on previous attempts to design an oxy-coal burner suitable for application in different systems comprise overly complex designs (see U.S. Patents Nos. 8,584,605, 7,028,622, and 6,843,185). This results in part from the nature of oxycombustion, which involves burning fuel using pure oxygen as an oxidant instead of air. Since the heat of combustion does not go to heating the nitrogen in the air, flame temperatures with oxycombustion increase dramatically. Others have described oxycombustion technology that uses minimal FGR and produces high-temperature flames (see Gross in U.S. Patents Nos. 6,436,337 and 6,596,220). However, the burners described in these publications have the potential to cause damage to systems surrounding the oxy-coal burner due to the nature of their designs.

[0009] Others have mitigated the temperature of the oxy-combustion flame by creating a synthetic air stream consisting of a mixture of oxygen and combustion gas recirculation (FGR), resulting in a lower flame temperature, in addition to the use of a pre-combustor (see US Patents 9,243,799, 8,689,710). Although the burners described in Petition 870220072537, dated 12 / 08 / 2022, page 12 / 70 4 / 41 US Patents Nos. 9,243,799 and 8,689,710 allow furnaces to operate at a much lower flame temperature and therefore may not necessarily cause damage to the system's surroundings; however, they do present other operational and design challenges. Large volumes of FGR may require additional energy to heat up before entering the furnace (similar to an air preheater). Air intake may also increase as the FGR increases. More FGR leads to a large volume of flue gas exiting the furnace, which necessitates larger downstream equipment (e.g., air pollution control devices, ductwork, fans, carbon capture and purification equipment).

[0010] In summary, the existing patents mentioned above do not have burner design features or operational approaches suitable for effectively utilizing and regulating heat flow to burner components and furnace walls when using a high-temperature flame oxy-combustion approach.

[0011] Thus, there is a need for an oxy-combustion incineration system that overcomes the shortcomings of the previous technique, namely, the development of a burner design capable of efficiently and economically producing and sustaining high-temperature oxy-combustion flame conditions for coal incineration. Furthermore, an oxy-combustion incineration system is needed that can replace traditional air-combustion burners in existing fuel combustion systems, while simultaneously avoiding damage to burner components and internal furnace surfaces resulting from high heat fluxes. SUMMARY

[0012] In one aspect, the subject matter described in this document is directed to a high-temperature flame oxy-combustion incineration system. More specifically, in one embodiment, the high-temperature flame oxy-combustion incineration system is a burner Petition 870220072537, dated 12 / 08 / 2022, page 13 / 70 5 / 41 annular cover comprising a quadruple concentric burner design with an O2 ring in the center, followed by a coal fuel ring, then an O2 ring and finally, an outer flue gas recirculation (FGR) ring. Additionally, positioned outside the FGR ring is a refractory brick.

[0013] The design and method of operation of the annular cap burner allows the generation of a high-temperature flame, localized towards the center of the combustion area, with a cooler gas cap at the periphery of the combustion area. Thus, the annular cap burner provides local cooling while simultaneously maintaining the high-temperature characteristics of the burner flame, thereby maximizing flame efficiency and stability.

[0014] In another embodiment, the annular cover burner having a quadruple concentric burner design has a design comprising a first, second, third and fourth conduit wherein each conduit separately injects a first, second, third and fourth flow into a first, second, third and fourth ring, wherein the first flow comprises a first oxygen source, the second flow comprises a mixture of fuel and a carrier gas to transport the fuel, the third flow comprises a second oxygen source, the fourth flow comprises FGR, wherein in the center of the annular cover burner there is an igniter and positioned outside the fourth ring is a refractory brick.

[0015] In another embodiment it is a method of combustion of fuel, the method comprising: provide an annular cover burner, provide a first stream of O2 through a Petition 870220072537, dated 12 / 08 / 2022, page 14 / 70 6 / 41 first conduit to a first ring, supply a fuel and carrier mixture through a second conduit to a second ring, supply a second stream of O2 through a third conduit to a third ring, supply FGR through a fourth conduit to a fourth ring, and ignite the flame using an igniter located in the center of the annular cap burner.

[0016] Another embodiment is a high-temperature flame oxy-combustion system, comprising: at least one annular cap burner, a combustion furnace, an air separation unit, at least one duct, and a control system, wherein the annular cap burner is configured to provide a peak flame temperature of at least 4,000 °F (2,204 °C) with a heat profile signature similar to that depicted in Figure 4, so that radiant heat and potential damage to systems surrounding the annular cap burner are minimized.

[0017] In another embodiment, it is a method of operating the high-temperature flame oxy-combustion system, wherein the method comprises: To supply a substantially pure fuel, carrier, and oxygen to the annular shroud burner, to burn the substantially pure fuel, carrier, and oxygen to emit a flame, wherein the flame has a radiant heat profile signature similar to that depicted in Figure 4, to heat water in the boiler with the high-temperature flame oxy-combustion annular shroud burner to convert water into Petition 870220072537, dated 12 / 08 / 2022, page 15 / 70 7 / 41 steam.

[0018] These and other aspects are described in more detail below. BRIEF DESCRIPTION OF THE FIGURES

[0019] Figures 1A and 1B represent the annular cap burner. Figure 1A represents the general configuration of the annular cap burner. Figure 1B represents four specific areas of the annular cap burner, specifically the central O2 port, the fuel ring, the outer O2 ring, and the FGR ring for localized cooling.

[0020] Figures 2A to 2C represent different aspects of the annular cap burner.

[0021] Figure 3 shows a process flow diagram of the high-temperature flame-fired oxy system.

[0022] Figure 4 shows the gas temperature profile for the annular cap burner with a peak temperature of 4,572 °F (2,522 °C) in the incineration of bituminous coal.

[0023] Figure 5 shows the gas temperature profile for an oxy-combustion burner with discrete O2 ports where the peak temperature is 4,581 °F (2,527 °C).

[0024] Figure 6 shows the gas temperature profile for the annular cap burner with a peak temperature of 4,133 °F (2,278 °C) when incinerating sub-bituminous coal.

[0025] Figure 7 shows a model of the refractory brick surface temperature, where the refractory brick is in the annular cover burner and the burner is a single burner model.

[0026] Figure 8 shows a model of the gas temperature in a burner, where the burner is a single burner model. The reduction is 60% of a full load, but the FGR flow rate from the cover was maintained and the peak temperature is 4,251 °F (2,344 °C).

[0027] Figure 9 shows a summary of the balance sheet of Petition 870220072537, dated 12 / 08 / 2022, page 16 / 70 8 / 41 energy for the radiant and convective sections of the boiler.

[0028] Figure 10 shows a process flow diagram of the high-temperature flame oxy-combustion system that incinerates coal.

[0029] Figure 11 shows the burner sketch and geometry of a burner unit for a single-walled subcritical boiler.

[0030] Figure 12 shows the net heat flow for a single-walled subcritical boiler.

[0031] Figure 13 shows the OD surface temperature of the tube for a single-walled subcritical boiler.

[0032] Figure 14 shows the gas temperature for a single-walled subcritical boiler.

[0033] Figure 15 shows the O2 concentration for a single-walled subcritical boiler.

[0034] Figure 16 shows the CO concentration for a single-walled subcritical boiler.

[0035] Figure 17 shows the NOx concentration where NOx values ​​are not controlled (no NOx removal throughout the system) for a single-walled subcritical boiler.

[0036] Figure 18 shows the net heat flow after the reduction. DETAILED DESCRIPTION

[0037] The subject matter disclosed in this document includes a high-temperature flame oxy-coal incineration system designed to burn coal using undiluted oxygen and minimal flue gas recirculation (FGR). In one embodiment, the system comprises a quad burner capable of producing an axial jet flame with a peak temperature exceeding 4,000 °F (2,204 °C). In another embodiment, the amount of FGR distributed around the combustion zone can be Petition 870220072537, dated 12 / 08 / 2022, page 17 / 70 9 / 41 regulated to ensure optimal cooling and protection of the high-temperature flame. This FGR distribution, referred to herein as a cover, surrounds the peak flame temperature areas. This cover functions to prevent damage to burner components and surfaces near the burner due to extreme temperatures and heat fluxes, minimizing the impact on the peak flame temperature.

[0038] In another embodiment, an annular cap burner system employing undiluted directed oxygen in combination with a complex mixing strategy is effective in producing a high and stable flame temperature. Applying this technology to various systems, such as steam power generation, leads to a system with increased efficiency, lower capital costs, and improved CO2 capture and sequestration. The technology can also be used in greenfield applications and / or as an upgrade for existing steam power plants. The advantages of the technology are not limited to the power generation industry. Improving coal combustion with pure oxygen has the potential to benefit any industry that uses coal combustion or other fossil fuels as a fuel source.

[0039] The present invention can be more easily understood by reference to the following detailed description of the invention and the Examples included therein.

[0040] Before the present systems, devices and / or methods are further disclosed and described, it should be understood that they are not limited to specific methods, unless otherwise specified, as such may certainly vary. It should also be understood that the terminology used in this document is for the purpose of describing only particular aspects and is not intended to be limiting. Although any methods and materials similar or equivalent to those described in this document may be used in the practice or testing of the present invention, example systems, devices and methods are now described. Petition 870220072537, dated 12 / 08 / 2022, p. 18 / 70 10 / 41

[0041] Although aspects of the present invention may be described and claimed in a particular statutory class, such as the statutory class of the system, this is only for convenience and one skilled in the art will understand that each aspect of the present invention may be described and claimed in any statutory class. Unless expressly stated otherwise, no method or aspect set forth herein is intended to be interpreted as requiring that its steps be performed in a specific order. Consequently, where a method claim does not specifically state in the claims or descriptions that the steps must be limited to a specific order, no order is intended to be inferred in any aspect.This applies to any possible unstated basis for interpretation, including questions of logic regarding the arrangement of steps or operational flow, simple meaning derived from grammatical organization or punctuation, or the number or type of aspects described in the descriptive report.

[0042] Throughout this application, several publications are referenced. The disclosures of these publications in their entirety are incorporated herein by reference to this application in order to more fully describe the state of the art to which it refers. The disclosed references are also incorporated individually and specifically by reference herein to the material contained therein that is discussed in the sentence in which the reference is invoked. A. DEFINITIONS

[0043] Listed below are the definitions of various terms used to describe this invention. These definitions apply to the terms as they are used throughout this descriptive report, unless otherwise limited in specific cases, individually or as part of a larger group.

[0044] As used in the descriptive report and appended claims, the singular forms “a”, “an” and “the” include Petition 870220072537, dated 12 / 08 / 2022, p. 19 / 70 11 / 41 plural referents, unless the context clearly indicates otherwise.

[0045] Ranges may be expressed in this document as “about” a specific value and / or “to” another specific value. When such a range is expressed, another aspect includes a particular value and / or up to the other particular value. Similarly, when values ​​are expressed as approximations, by using the antecedent “about”, it will be understood that the particular value forms another aspect. It will also be understood that the endpoints of each of the ranges are significant in relation to the other endpoint and independently of the other endpoint. It is also understood that there are several values ​​disclosed in this document and that each value is also disclosed in this document as “about” that specific value in addition to the value itself. For example, if the value “10” is disclosed, then “about 10” will also be disclosed. It is also understood that each unit between two particular units is also disclosed.For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed. Furthermore, as used in this document, the term “approximately,” when referring to a value, is intended to encompass variations of, in some embodiments ± 20%, in some embodiments ± 15%, in some embodiments ± 10%, in some embodiments ± 5%, in some embodiments ± 1%, in some embodiments ± 0.5%, and in some embodiments ± 0.1% of the specified quantity, as such variations are appropriate for carrying out the disclosed methods or employing the disclosed compositions.

[0046] When a range of values ​​is provided, it is understood that each intermediate value, up to the tenth of a unit of the lower limit, unless the context clearly indicates otherwise, between the upper and lower limits of the range and any other stated or intermediate value in that stated range, is encompassed. The upper and lower limits of those smaller ranges that may be independently included in the smaller ranges are also encompassed, subject to any limit specifically excluded in the indicated range. Where the indicated range includes one or both limits, Petition 870220072537, dated 12 / 08 / 2022, page 20 / 70 12 / 41 ranges excluding one or both of the included limits are also included.

[0047] As used in this document, the terms “optional” or “optionally” mean that the event or circumstance described below may or may not occur, and that the description includes cases in which such event or circumstance occurs and cases in which it does not occur.

[0048] The term “compreender” (and its grammatical variations), as used in this document, is used in the inclusive sense of “to have” or “to include” and not in the exclusive sense of “to consist of”.

[0049] As used in this document, the term “fuel” refers to any fuel suitable for combustion purposes. For example, the disclosure may be used with many types of fuels, including but not limited to: natural gas, hydrogen, refinery waste gas, refinery fuel gas, blast furnace gas, propane, fuel oils, coal (such as peat, anthracite, semi-anthracite, superanthracite, bituminous, sub-bituminous, semi-bituminous and lignite); tar; bitumen; petroleum coke; paper mill sludge solids and sewer sludge solids; wood; peat; grass; and combinations and mixtures of all these fuels.

[0050] As used in this document, the term “oxygen” refers to an oxidant with an O2 concentration greater than about 30 mol%; typically greater than about 90 mol% and includes oxygen FGR. As used in this document, the term oxy / coal combustion refers to the combustion of coal in oxygen, the term air / coal combustion refers to the combustion of coal in air, the term oxy / fuel combustion refers to the combustion of fuel in oxygen, and the term air / fuel combustion refers to the combustion of fuel in air.

[0051] As used in this document, the term “O2 stream” refers to an oxygen (O2) stream that is at least 90 mol% oxygen.

[0052] As used in this document, the Petition 870220072537, dated 12 / 08 / 2022, p. 21 / 70 13 / 41 The term “substantially pure oxygen” refers to the degree of purity of oxygen as required to provide the correct fuel-to-oxygen ratio for combustion and desired byproducts without departing from the scope of the present invention. Non-limiting examples of substantially pure oxygen are 90% or 99% pure.

[0053] As used in this document, the term “combustion fluid” refers to a fluid formed and / or mixed with the combustion products, which can be used for radiant and convective heat transfer. The term is not limited to combustion products and may include fluids mixed with or otherwise moving through at least a portion of the combustion system.

[0054] As used in this document, the term “recycled combustion gas” or “RFG” refers to the fluid exiting at any suitable location along (including the end of) the convective section that is recirculated to any part of the system. If desired, oxygen may be added to the RFG at any suitable location (e.g., the RFG may comprise up to 30 mol% O2 before being introduced into the burner and / or pre-combustor).

[0055] As used in this document, the term “flue gas recycling” or “FGR” refers to a configuration that allows the flue fluid to be recycled into recycled flue gas. Although any suitable flue gas source may be employed (including, without limitation, flue gas from an adjacent or distinct process), typically the flue gas comprises combustion products from the use of the inventive system.

[0056] As used in this document, the term “pre-combustor” refers to an apparatus where burner streams are mixed and ignited before entering the burner or furnace. If present, the pre-combustor may be physically located before a burner. Examples of such pre-combustors are described in U.S. Patent No. Petition 870220072537, dated 12 / 08 / 2022, page 22 / 70 14 / 41 9,243,799.

[0057] As used in this document, the terms “conduit” or “pipeline” are used interchangeably and refer to a passage for conducting fuel, a stream of O2 or other material from one area to another. B. Annular Cover Burner A. BURNER DESIGN

[0058] As disclosed in this document, it is a high-temperature flame oxy-combustion burner, referred to herein as an annular cap burner. Returning to the figures, one embodiment of the annular cap burner is represented in Figures 1A and 1B. More specifically, Figure 1B shows the annular cap burner with a quadruple concentric burner design with an inner O2 ring (301), followed by a coal fuel ring (302), then an outer O2 ring (303), and finally an outer flue gas recirculation (FGR) ring (304). The outer FGR ring (304) provides local cooling while minimizing the negative impacts of the high-temperature flame. These negative impacts may include a change in flame shape or temperature. In one embodiment, the FGR ring (304) creates a gas stream, referred to herein as a cap.The annular cover burner also comprises a refractory brick (305).

[0059] The refractory brick (305) provides a key surface for heat diffusion during the combustion process. In one embodiment, the refractory brick is designed for high-temperature operations and penetrates the furnace wall through which the fuel and oxidizer are injected. The refractory brick may have a divergent conical shape extending from the burner face to the inner furnace wall. The shape of the refractory brick allows for aerodynamic flame stabilization through recirculation zones. In one embodiment, the refractory brick provides a surface for heat diffusion, resulting in reduced heat flux to surfaces. Petition 870220072537, dated 12 / 08 / 2022, page 23 / 70 15 / 41 adjacent to the burner. In one embodiment, the refractory brick provides additional protection of the surrounding materials from the high flame temperatures achieved with the annular cover burner.

[0060] As disclosed in more detail in this document, the multi-register annular cover burner allows heat release and heat flux to be extended to prevent damage to surfaces near the burner while still producing flame stability. Specifically, the outer FGR ring (304) is capable of providing adequate cooling to the burner and near-burner surfaces, maintaining surface temperatures within the tolerable limits of materials conventionally used in an industrial furnace. This annular cover burner provides high flame temperatures exceeding 4,000 °F (2,204 °C) while preventing damage to burner components and internal furnace surfaces resulting from high heat fluxes.

[0061] A functional aspect resulting from the annular cap burner is that it extracts a maximum amount of energy (in the form of heat transfer from combustion products) from the combustion process, without adversely affecting the high flame temperature or the systems around the burner. Thus, the maximum practicable use of the highest flame temperatures is achieved. For example, the annular cap burner provides a considerably higher proportion of heat transfer from the combustion products to the desired areas (such as boiler tubes and / or working fluid) without unwanted radiant heat flow to undesired areas, when compared to more traditional burner designs.

[0062] Other advantages observed with the currently disclosed annular cap burner include: ease of introduction of fuel, oxygen and combustion gas; simpler design than previous burner designs; greater ease of control of many properties, such as flow rate and gas source; high flame Petition 870220072537, dated 12 / 08 / 2022, page 24 / 70 16 / 41 temperature that improves radiant heat transfer and efficiency; a new cover cooling design to minimize the impacts of flame temperature to maximize efficiency; reduced radiant heat flux; improved flame characteristics such as peak flame temperature, flame shape and stability; and the ability to use recovered flue gas.

[0063] It is known that as the temperature increases, radiant heat transfer is proportional to T4, where T = flame temperature. Thus, as described in US Patent No. 9,353,945, radiant heat transfer increases with increasing flame temperature, thereby increasing the overall efficiency of the system.

[0064] In one embodiment, as schematically represented in Figures 2A and 2B, is the annular cap burner. Figure 2A shows an embodiment of the annular cap burner with four registers. Figure 2B shows the same annular cap burner with fuel (310), FGR (320) and O2 (331) and O2 (336). The fuel (310) flows through the FGR conduit (312) to the FGR ring (304). O2 (331) flows through the conduit (330) to the inner O2 ring (301). O2 (336) flows through the conduit (335) to the outer O2 ring (303). The FGR (320) flows through the conduit (325) to the FGR ring (304). Figure 2C shows a front view of the annular cap burner with the outlet points for fuel (310), FGR (320) and O2 (331) and O2 (336).

[0065] In one embodiment, the flow scheme of the annular cover burner is represented in Figure 3. An igniter (315) is located in the center of the burner. In one embodiment, the fuel (310), such as coal, is combined with a carrier (311) and introduced into the burner through the conduit (312), which feeds the inner ring (301). In one embodiment, the carrier (311) is recycled combustion gas. In another embodiment, the recycled combustion gas is treated recycled combustion gas, where the treated recycled combustion gas has been dehydrated and the Petition 870220072537, dated 12 / 08 / 2022, page 25 / 70 17 / 41 impurities removed as part of the CO2 capture process. In a separate portion of the annular cover burner, the FGR (320) is fed through an FGR conduit (321) which is fed through the conduit (325) to the FGR ring (304). In another embodiment, oxygen is mixed with the combustion gas.

[0066] In one embodiment, an O2 conduit provides two separate paths. One path feeds an undiluted O2 stream through the conduit (330) to the inner O2 ring (301). In the other path, an undiluted O2 stream is supplied through the conduit (335) to the outer O2 ring (303) which is immediately outside the fuel conduit (312) (leading to the fuel ring (302)). In one embodiment, the O2 streams are derived from the same source. In another embodiment, the O2 streams are derived from alternative sources. In one embodiment, the outer O2 ring (303) is located between the fuel ring (302) and the FGR ring (304). In a preferred embodiment, the O2 streams are on both sides of the fuel (310) leading to the fuel ring (302). This configuration provides greater flame stability and control.In contrast to a dilute O2 stream, the undiluted O2 streams used in one embodiment allow peak flame temperatures to exceed 4,000 °F (2,204 °C).

[0067] In one embodiment, the fuel (310) may be a fossil fuel. Fossil fuels comprise petroleum, coal, and natural gas. In one embodiment, the fuel (310) may be coal. The coal may be peat, anthracite, semi-anthracite, superanthracite, bituminous, sub-bituminous, semi-bituminous, or lignite. As a point of reference, US coal production in 2010 by coal type is described in more detail. Production by tonnage comprised 45% bituminous, 47% sub-bituminous, 7% lignite, and 0.2% anthracite. Production by total energy was 54% bituminous, 41% sub-bituminous, 4.7% lignite, and 0.3% anthracite. In one embodiment, the fuel is bituminous or sub-bituminous coal. Petition 870220072537, dated 12 / 08 / 2022, p. 26 / 70 18 / 41

[0068] Fuel, oxygen, and recycled combustion gas are connected and supplied to their respective conduits or tubes according to conventional apparatus and methods. Each stream is fed directly into the combustion zone (350) where the fuel reacts with the oxidizer and the annular cover FGR acts as a temperature shield. When the oxygen and fuel react in the annular cover burner, the fuel is burned. The oxygen-fuel reaction can be initiated by heat absorbed from an external source or by a distinct energy source, such as an igniter or pilot flame. In one embodiment, the oxygen-fuel reaction is initiated by an igniter (315). In one embodiment, the igniter (315) is located in the center of the annular cover burner.

[0069] In addition to providing the motive force for fuel transport, the FGR (320) can be directed to the FGR ring (304), which provides protection to the burner internals and near burner surfaces from the high heat fluxes produced. The inlets for each stream in the furnace are configured so that the flame produced is an axial jet that extends the mixing rate of fuel and O2 in the furnace. The resulting heat release profile is extended through elongation compared to other burner designs configured to rapidly mix fuel and oxidizer involving vortex and / or a blunt object. This extended heat release profile provides protection against the intense radiant fluxes created by the high-temperature flames.

[0070] In another embodiment, the annular cap burner comprises a control scheme that individually regulates the fuel flow, the FGR flow and the O2 flow as needed to control the FGR flow ratio to fuel flow and the fuel flow ratio to O2 flow.

[0071] The flow rate of the O2 streams is controlled so that the flow rate is in the range of about 7.62 m / s (25 ft / s) to about 38.1 m / s (125 ft / s). In one embodiment, the flow rate is Petition 870220072537, dated 12 / 08 / 2022, page 27 / 70 19 / 41 in the range of 9.144 to 33.528 m / s (30 to 110 ft / s), 12.192 to 27.432 m / s (40 to 90 ft / s), or 15.24 to 21.336 m / s (50 to 70 ft / s). In one mode, the flow rate is greater than approximately 9.144 m / s (30 ft / s), 12.192 m / s (40 ft / s), 15.24 m / s (50 ft / s), 18.288 m / s (60 ft / s), 21.336 m / s (70 ft / s), 24.384 m / s (80 ft / s), 27.432 m / s (90 ft / s), or 30.48 m / s (100 ft / s). In one mode, the flow rate is approximately 9.144 m / s (30 ft / s), 10.668 m / s (35 ft / s), 12.192 m / s (40 ft / s), 13.716 m / s (45 ft / s), 15.24 m / s (50 ft / s), 16.764 m / s (55 ft / s), 18.288 m / s (60 ft / s), 19.812 m / s (65 ft / s), 21.336 m / s (70 ft / s), 22.86 m / s (75 ft / s), 24.384 m / s (80 ft / s), 25.908 m / s (85 ft / s), 27.432 m / s (90 ft / s), 28.956 m / s (95 ft / s), 30.48 m / s (100 ft / s), 32.004 m / s (105 ft / s), or 33.528 m / s (110 ft / s).

[0072] In one embodiment, the percentage of oxygen in the O2 streams may be at least 90% oxygen. In other embodiments, the O2 stream may be at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, at least about 99.5%, at least about 99.6%, at least about 99.7%, at least about 99.8%, or at least about 99.9% oxygen. The O2 stream may contain between 90% to 100%, 95% to 100%, 97% to 100%, 98% to 100%, or 99% to 100% oxygen. In some modalities, the O2 stream can contain between 91% and 99.5%, between 92% and 99%, between 93% and 98%, or between 94% and 97% oxygen.

[0073] The percentage of oxygen in the currents of Oxygen (O2) can be adjusted to control the flame temperature. In one embodiment, the use of undiluted O2 streams allows the peak flame temperature of the annular cap burner to exceed 2204.444 °C (4,000 °F). In contrast, when an O2 stream is diluted with other gases or contains less than 90% oxygen, peak flame temperatures exceeding 2204.444 °C (4,000 °F) cannot be achieved.

[0074] The primary fuel flow rate is Petition 870220072537, dated 12 / 08 / 2022, page 28 / 70 20 / 41 controlled so that the flow rate is in the range of about 6.096 m / s (20 ft / s) to about 45.72 m / s (150 ft / s). In one embodiment, the flow rate is in the range of 9.144 to 38.1 m / s (30 to 125 ft / s), 12.192 to 30.48 m / s (40 to 100 ft / s), or 15.24 to 22.86 m / s (50 to 75 ft / s). In one mode, the flow rate is greater than approximately 9,144 m / s (30 ft / s), 12,192 m / s (40 ft / s), 15,24 m / s (50 ft / s), 18,288 m / s (60 ft / s), 21,336 m / s (70 ft / s), 24,384 m / s (80 ft / s), 27,432 m / s (90 ft / s), 30,48 m / s (100 ft / s), 33,528 m / s (110 ft / s), 36,576 m / s (120 ft / s), 39,624 m / s (130 ft / s), or 42,672 m / s (140 ft / s).In one mode, the flow rate is approximately 9.144 m / s (30 ft / s), 10.668 m / s (35 ft / s), 12.192 m / s (40 ft / s), 13.716 m / s (45 ft / s), 15.24 m / s (50 ft / s), 16.764 m / s (55 ft / s), 18.288 m / s (60 ft / s), 19.812 m / s (65 ft / s), 21.336 m / s (70 ft / s), 22.86 m / s (75 ft / s), 24.384 m / s (80 ft / s), 25.908 m / s (85 ft / s), 27.432 m / s (90 ft / s), 28.956 m / s (95 ft / s), 30.48 m / s (100 ft / s), 32.004 m / s (105 ft / s), 33.528 m / s (110 ft / s), 35.052 m / s (115 ft / s), 36.576 m / s (120 ft / s), 38.1 m / s (125 ft / s), 39.624 m / s (130 ft / s), 41.148 m / s (135 ft / s), 42.672 m / s (140 ft / s), 44.196 m / s (145 ft / s), or 45.72 m / s (150 ft / s). In one embodiment, the fuel stream flow rate is directly related to the type of fuel used. In another embodiment, the fuel flow rate may result in a change in the position from which the flame originates. In one type, the flame originates from the face of the burner.In another configuration, the flame originates from a position away from the burner face. When an annular cap burner is installed in a fuel processing plant and near a boiler, this is seen as the flame origin point moving away from the burner face towards the boiler.

[0075] In one embodiment, the percentage of oxygen in the carrier is between 0% and 30% oxygen. In other embodiments, the percentage of oxygen can be from 0% to 3%, from 3% to 10%, from 10% to 20%, or from 20% to 30%. In alternative embodiments, the percentage of oxygen is from about 3% to 25%, from about 5% to 20%, from about 10% to 15%, or from Petition 870220072537, dated 12 / 08 / 2022, page 29 / 70 21 / 41 10% to 23.5%. In embodiments, the oxygen percentage is approximately 0%, 1%, 2%, 3%, 4%, 5%, 10%, 15%, 20%, 23.5%, 25%, or 30%. In some embodiments, the oxygen percentage is at least approximately 1%, at least approximately 5%, at least approximately 10%, at least approximately 15%, at least approximately 20%, or at least approximately 23.5%. In one embodiment, the oxygen percentage is less than approximately 30%, less than approximately 23.5%, less than approximately 20%, less than approximately 15%, less than approximately 10%, less than approximately 5%, less than approximately 3%, or less than approximately 1%. The amount of oxygen present has an effect on the target peak flame temperature. In one modality, the percentage of oxygen is variable, for example, where the percentage of oxygen is 23.5% for a period of time and then the percentage of oxygen is reduced, where such a reduction can be around 0% oxygen.

[0076] The use of high-purity oxygen (>95%) has several advantages when compared to air burners. One is that, when placed in a boiler system, oxy-fuel combustion can allow the boiler to be physically smaller than a conventional boiler. That is, since oxygen instead of air is used as the oxidizing agent (combustion agent), the entirety of the oxidizing agent is available for combustion and the volume of gas entering the boiler is smaller (up to 21% smaller) than would be required if air were used as the oxidizing agent. Thus, the boiler can be considerably smaller because substantially high-purity oxygen is used instead of air.

[0077] The flow rate of the FGR (320) stream, with or without additional O2 streams, is controlled so that the flow rate is in the range of about 3.048 m / s (10 ft / s) to about 22.86 m / s (75 ft / s). In one embodiment, the flow rate is in the range of 3.048 to 9.144 m / s (10 to 30 ft / s), 9.144 to 15.24 m / s (30 to 50 ft / s) or 15.24 to 22.86 m / s (50 to 75 ft / s). In one mode, the flow rate is greater than approximately 3.048 m / s (10 ft / s), 6.096 m / s (20 ft / s), 9.144 m / s (30 ft / s), 12.192 m / s (40 ft / s), 15.24 m / s (50 Petition 870220072537, dated 12 / 08 / 2022, p. 30 / 70 22 / 41 ft / s) or 18,288 m / s (60 ft / s). In one mode, the flow rate is approximately 3.048 m / s (10 ft / s), 4.572 m / s (15 ft / s), 6.096 m / s (20 ft / s), 7.62 m / s (25 ft / s), 9.144 m / s (30 ft / s), 10.668 m / s (35 ft / s), 12.192 m / s (40 ft / s), 13.716 m / s (45 ft / s), 15.24 m / s (50 ft / s), 16.764 m / s (55 ft / s), 18.288 m / s (60 ft / s), 19.812 m / s (65 ft / s), 21.336 m / s (70 ft / s), or 22.86 m / s (75 ft / s).

[0078] In one embodiment, the percentage of FGR in the FGR stream (320) may be at least 90%. In embodiments, the FGR may be at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, at least about 99.5%, at least about 99.6%, at least about 99.7%, at least about 99.8% or at least about 99.9%. The FGR stream may contain between 90% to 100%, 95% to 100%, 97% to 100%, 98% to 100% or 99% to 100% oxygen.In some models, the FGR current may contain between 91% and 99.5%, between 92% and 99%, between 93% and 98%, or between 94% and 97%.

[0079] In one embodiment, the oxygen-to-fuel ratios can vary. This ratio may depend on the purity of the oxygen supply and the nature of the fuel. For example, in an embodiment where the oxygen is 100% pure, the oxygen / fuel ratio may be about 2:1. Those skilled in the art will understand that the ratios may vary depending on the purity of the fuel and oxygen, and the ratios may be adjusted accordingly. In one embodiment, the oxygen-to-fuel ratio is about 1:1, about 1.5:1, about 2:1, about 2.5:1, or about 3:1.

[0080] The oxygen-to-fuel ratio provides a number of advantages. For example, approximately stoichiometric ratios provide complete combustion of the fuel, thus resulting in a substantially lower volume of impurities, such as NOx and other harmful emissions. Furthermore, precisely controlling the oxygen ratio... Petition 870220072537, dated 12 / 08 / 2022, page 31 / 70 23 / 41 for fuel facilitates complete combustion of the fuel.

[0081] In one embodiment, the conduits (312, 325, 330 and 335) may comprise currents different from those described above. For example, the fuel conduit (312) may comprise an O2 current instead of a fuel current. In an alternative embodiment, the O2 conduit (330) may comprise a fuel current. Such examples are not intended to be limiting, as it is possible to supply alternating currents through the various conduits in the annular cap burner.

[0082] The annular cover burner disclosed in this document provides a design that offers advantages not only in terms of simplicity, but also in the uniformity of O2 and FGR distribution. In one embodiment, the design simplifies the delivery of O2 and FGR by replacing the individual O2 and FGR ports with annular registers. Thus, in one embodiment, the annular cover burner can be described as a multi-register axial jet burner that allows heat release and heat flux to be extended to avoid damage to surfaces near the burner while still producing stable flames. Furthermore, the outer ring (304) of the FGR is capable of providing adequate cooling to the burner and near-burner surfaces, thus maintaining surface temperatures within the tolerable limits of materials conventionally used in an industrial furnace.

[0083] In another embodiment, the annular cover burner does not comprise a pre-combustor.

[0084] In an alternative embodiment, FGR can be added to any of the O2 streams.

[0085] In another modality, the currents (310, 320, 331) and / or (336) avoid the inclusion of nitrogen associated with air. In embodiments, streams (310) and (320) may comprise less than about 20% air, less than about 15% air, less than about 10% air, Petition 870220072537, dated 12 / 08 / 2022, p. 32 / 70 24 / 41 less than about 5% air or less than about 1% air. In modalities, the currents (310, 320, 331) and / or (336) comprise about 0% air. B. CHARACTERISTICS OF THE ANNULAR COVER BURNER FLAME

[0086] An incineration system designed to produce flame temperatures exceeding 4,000 °F (2,204 °C) must be configured to prevent damage to burner components and furnace interior surfaces from high heat fluxes. The currently disclosed annular shroud burner achieves this goal by surrounding the high-temperature areas of the flame with a cooler gas stream, termed the shroud. The presence of the shroud reduces the exposure of surrounding systems to the high heat flux and reduces damage when compared to traditional burner designs.

[0087] As detailed in this document, heat flux data are provided for undiluted oxygen inlets under oxy-coal combustion conditions. Design considerations for atmospheric oxy-coal systems using directed undiluted oxygen with minimum FGR should include an understanding of appropriate radiant heat transfer profiles as a function of burner aerodynamics.

[0088] This document describes models for accurately predicting heat transfer and surface temperatures in high-flame oxy-coal combustion units. Heat transfer and surface temperature are critical parameters upon which oxy-coal combustion applications depend. These predictive models allow for the evaluation of multiscale experiments coupled with the development of mechanisms and computational fluid dynamics (CFD) modeling. The models are used to characterize and predict flame behavior, heat transfer, ash deposition, and ash chemistry during high-flame oxy-coal combustion at atmospheric pressure. Petition 870220072537, dated 12 / 08 / 2022, page 33 / 70 25 / 41

[0089] The CFD predictive model was used to evaluate burner designs applied to a 30 MWt burner in various arrangements. In one embodiment, the arrangement comprises a front-wall steam boiler equipped with four such burners. The heat release profile of the annular cover burner differs from that of the discrete-ported burners.

[0090] Figures 4 and 5 show a detailed comparison of the flame shapes for the annular cover burner (Figure 4) and a more conventional burner (Figure 5) with discrete ports. As seen in Figure 4, the annular cover burner produces an elongated heat release profile, as the concentric O2, fuel, O2, and FGR registers result in slower mixing rates between the fuel and O2, while the external combustion gas recirculation register creates an outer envelope of relatively cool conditions. The resulting heat profile signature shows discrete bands with different flame temperatures, which depend on the source. For example, in one embodiment, the flame from the internal O2 stream produces the flame region (361), the fuel produces the flame region (362), the external O2 stream produces the flame region (363), and the FGR stream produces the flame region (364) (the cover). The peak flame temperature in this embodiment is 4.572 °F (2,522 °C). The temperature of the cover (364) is significantly lower, between about 2,000 °F (1,093 °C) and 3,000 °F (1,649 °C). The cover (364) surrounds the high-temperature flame regions (361), (362) and (363), thus primarily exposing any surrounding materials only to the flame region of the cooler cover (364). The exposure of such surrounding materials to a high heat flux is thus greatly reduced when compared with burners currently known in the art.

[0091] In contrast, as can be seen in Figure 5, alternating regions of high and low velocity gases at the same radial distance from the centerline of the conventional burner accelerate the mixing rate in Petition 870220072537, dated 12 / 08 / 2022, page 34 / 70 26 / 41 project with discreet doors. Specifically, the flame region (373) is a high-temperature region that extends radially away from the flame center. This radial extension increases the heat flow to surrounding systems, thus increasing damage to those systems.

[0092] The experiments described in this paper are the first to provide heat flux data for undiluted oxygen inlets under oxy-coal combustion conditions. This was performed under sufficiently well-defined conditions to allow them to be used to validate heat transfer correlations in CFD simulation codes. The CFD model predictions corroborated by radiant heat flux data for selected test conditions in the program suggest that the aerodynamic stage using axial flames with slow mixing sufficiently extends the heat released in the furnace to avoid excessive heat fluxes to the furnace walls and burner components. It was also found that delayed mixing and high peak flame temperatures are not necessarily mutually exclusive.In other words, the heat release can be extended to distribute the heat flow over larger areas of the furnace, while simultaneously achieving flame temperatures that exceed 4,000 °F (2,204 °C).

[0093] Correspondingly, the approach to modeling larger-scale systems includes quantifying radiant heat fluxes to establish a suitable design for the technology to be applied at scales far beyond those of the test furnaces. Sensitivity analyses were performed to evaluate the impacts of burner design on flame behavior and the associated profiles for heat release and heat flux. Several design configurations were simulated with varying degrees of complexity. In one case, the designs are based on an axial jet burner with an O2-enriched FGR drive used to drive the fuel along with discrete ports to introduce O2. In this system, the heat fluxes to the burner and furnace walls are unacceptably Petition 870220072537, dated 12 / 08 / 2022, page 35 / 70 27 / 41 high.

[0094] In contrast, as described in this document, it has been found that target peak temperatures above 4,000 °F (2,204 °C) can be maintained contemporaneously with reduced heat flow by introducing supplementary non-motive FGR through the use of the new shroud design. The supplementary FGR is introduced into the burner shroud to provide local cooling and prevent burner surface temperatures from exceeding tolerable limits. The ring is sized to achieve a relatively low velocity stream that would keep the recycled gas close to the burner and absorb heat radiated from adjacent hot spots.

[0095] In modalities, the peak flame temperature is in the range of about 4,000 °F (2,204 °C) to about 5,000 °F (2,760 °C), about 4,100 °F (2,260 °C) to about 4,900 °F (2,704 °C), about 4,200 °F (2,316 °C) to about 4,800 °F (2,649 °C), 4,300 °F (2,371 °C) to about 4,700 °F (2,593 °C), or about 4,400 °F (2,427 °C) to about 4,600 °F (2,538 °C). In modalities, the peak flame temperature is in the range of about 4,000 °F (2,204 °C) to about 4,100 °F (2,260 °C), about 4,100 °F (2,260 °C) to about 4,200 °F (2,316 °C), about 4,200 °F (2,316 °C) to about 4,300 °F (2,371 °C), about 4,300 °F (2,371 °C) to about 4,400 °F (2,427 °C), about 4,400 °F (2,427 °C) to about 4,500 °F (2,482 °C), about 4,500 °F (2,482 °C) to about 4,600 °F (2,538 °C). °C), about 4,600 °F (2,538 °C) to about 4,700 °F (2,593 °C), about 4,700 °F (2,593 °C) to about 4,800 °F (2,649 °C), about 4,800 °F (2,649 °C) to about 4,900 °F (2,704 °C), around 4.900°F (2,704°C) to about 5,000°F (2,760°C). In other embodiments, the peak flame temperature is at least about 4,000 °F (2,204 °C) to about 4,100 °F (2,260 °C), about 4,100 °F (2,260 °C) to about 4,200 °F (2,316 °C), about 4,200 °F (2,316 °C) to about 4,300 °F (2,371 °C), about 4,300 °F (2,371 °C) to about 4,400 °F (2,427 °C), about 4,400 °F (2,427 °C) to about 4,500 °F (2,482 °C), about 4,500 °F. Petition 870220072537, dated 12 / 08 / 2022, p. 36 / 70 28 / 41 (2,482 °C) to about 4,600 °F (2,538 °C), about 4,600 °F (2,538 °C) to about 4,700 °F (2,593 °C), about 4,700 °F (2,593 °C) to about 4,800 °F (2,649 °C), about 4,800°F (2,649°C) to about 4,900°F (2,704°C), about 4,900°F (2,704°C) to about 5,000°F (2,760°C). In some embodiments, the peak flame temperature is approximately 4,000 °F (2,204 °C), approximately 4,050 °F (2,232 °C), approximately 4,100 °F (2,260 °C), approximately 4,150 °F (2,288 °C), approximately 4,200 °F (2,316 °C), approximately 4,250 °F (2,343 °C), approximately 4,300°F (2,371°C), about 4,350°F (2,399°C), about 4,400°F (2,204°C), about 4,450°F (2,454°C), about 4,500°F (2,482°C), about 4,550°F (2,510°C), about 4,600 °F (2,538 °C), about 4,650 °F (2,566 °C), about 4,700 °F (2,593 °C), approximately 4,750 °F (2,621 °C), approximately 4,800 °F (2,649 °C), approximately 4,850 °F (2,677 °C), approximately 4,900 °F (2,704 °C), approximately 4,950 °F (2,732 °C), or approximately 5,000 °F (2,760 °C). In one embodiment, the peak flame temperature is approximately 4,572 °F (2,522 °C), 4,581 °F (2,527 °C), 4,133 °F (2,278 °C), 4,251 °F (2,344 °C), or 4,033 °F (2,223 °C). C. PHYSICAL CHARACTERISTICS OF THE ANNULAR COVER BURNER

[0096] As disclosed in this document, it is an annular cap burner configured in dimensions and composition suitable for use in the system in which it is employed. The following dimensions and compositions are provided merely as examples and are not intended to be limiting for the annular cap burner as disclosed in this document.

[0097] The igniter (315) has an outer diameter of about 5.08 to about 15.24 cm (2 to about 6 inches). In one embodiment, the igniter has an outer diameter of about 10.16 cm (4 inches).

[0098] The inner ring O2 (301) has an inner diameter and an outer diameter. In embodiments, the inner diameter is in the range of about 10.16 to about 15.24 cm (4 to about 6 inches) and the outer diameter Petition 870220072537, dated 12 / 08 / 2022, page 37 / 70 The outside diameter of a 29 / 41 shoe is in the range of about 12.7 to about 17.78 cm (5 to about 7 inches), provided the outside diameter is larger than the inside diameter. In the models, the inside diameter is about 12.7 or 13.462 cm (5 or 5.3 inches) and the outside diameter is about 15.24 or 16.002 cm (6 or 6.3 inches).

[0099] The fuel ring (302) has an inner diameter and an outer diameter. In embodiments, the inner diameter is in the range of about 25.4 to about 38.1 cm (10 to about 15 inches) and the outer diameter is in the range of about 30.48 to about 43.18 cm (12 to about 17 inches), provided that the outer diameter is greater than the inner diameter. In embodiments, the inner diameter is about 33.02, 34.29, 34.544 or 35.56 cm (13, 13.5, 13.6 or 14 inches) and the outer diameter is about 35.56, 36.83, 37.084 or 38.1 cm (14, 14.5, 14.6 or 15 inches).

[0100] The outer ring O2 (303) has an inner diameter and an outer diameter. In embodiments, the inner diameter is in the range of about 38.1 to about 48.26 cm (15 to about 19 inches) and the outer diameter is in the range of about 40.64 to about 50.8 cm (16 to about 20 inches), provided the outer diameter is greater than the inner diameter. In embodiments, the inner diameter is about 43.18 cm (17 inches) and the outer diameter is about 45.72 cm (18 inches).

[0101] The FGR ring (304) has an inner diameter and an outer diameter. In embodiments, the inner diameter is in the range of about 45.72 to about 55.88 cm (18 to about 22 inches) and the outer diameter is in the range of about 48.26 to about 58.42 cm (19 to about 23 inches), provided the outer diameter is greater than the inner diameter. In embodiments, the inner diameter is about 50.8 cm (20 inches) and the outer diameter is about 53.34 cm (21 inches).

[0102] In any of the above configurations, the igniter and ring sizes follow the order from smallest diameter to largest diameter of the igniter (315) < inner O2 ring (301) < fuel ring (302) < Petition 870220072537, dated 12 / 08 / 2022, page 38 / 70 30 / 41 outer ring O2 (303) < ring (304).

[0103] In the embodiments, the annular cover burner has a specified length. The length can be configured to dimensions suitable for use in the system in which it is employed.

[0104] There is a relationship between burner size and fuel flow rate, O2 current and FGR. Specifically, the higher the fuel flow rate, the larger the burner.

[0105] In embodiments, the annular cover burner is manufactured from materials suitable for use in the system in which it is employed. In one embodiment, the annular cover burner may be manufactured from stainless steel. Stainless steel is commonly classified according to a standard alloy numbering system for steel grades maintained by SAE International. Stainless steel grades are separated into separate series, where the series include the 100, 200, 300, 400, 500, 600, and 900 series. Within each series, variations are specified, called stainless steel types. For example, in the 200 series there are types 201, 202, 205, 253, and 254. Non-limiting examples of suitable stainless steel include types 253, 309, and 310.

[0106] In embodiments, the dimensions of the annular cap burner are modified to obtain desired properties, such as flame characteristics, incineration rate, velocities or flow rates that may vary with the type of fuel and heating value. In one embodiment, variations in the size of the annular cap burner may vary based on the burner's incineration rate, fuel type and heating power.

[0107] As disclosed in this document, in one embodiment, there is an annular cover burner having a quadruple concentric burner design wherein the design comprises a first, second, third and fourth conduit wherein each conduit injects separately Petition 870220072537, dated 12 / 08 / 2022, pp. 39 / 70 31 / 41 a first, second, third and fourth flows in a first, second, third and fourth rings, wherein the first flow comprises a first oxygen source, the second flow comprises a mixture of fuel and a carrier, the third flow comprises a second oxygen source, the fourth flow comprises FGR, wherein in the center of the annular cover burner there is an igniter, and positioned outside the fourth ring is a refractory brick.

[0108] As in any above embodiment, an annular cover burner in which the first and second oxygen sources are undiluted oxygen sources.

[0109] As in any embodiment above, an annular cover burner in which the first and second oxygen sources have an oxygen content of at least about 90%.

[0110] As in any of the above forms, an annular cover burner in which the carrier is FGR.

[0111] As with any of the above configurations, an annular cover burner in which the cover cooling design minimizes damage to burner components and furnace surfaces near the burner when compared to traditional burner configurations.

[0112] As in any embodiment above, an annular cover burner in which the annular cover burner is made of stainless steel.

[0113] As in any above embodiment, an annular cover burner in which the steel is a series type stainless steel Petition 870220072537, dated 12 / 08 / 2022, pp. 40 / 70 32 / 41 200 or 300.

[0114] As in any embodiment above, an annular cover burner further comprising a combustion zone on the face of the annular cover burner.

[0115] As in any embodiment above, an annular cap burner in which the peak flame temperature is at least 4,000 °F (2,204 °C). In another embodiment, an annular cap burner in which the peak flame temperature is at least about 4,300 °F (2,371 °C).

[0116] As in any embodiment above, an annular cover burner in which the annular cover burner has a heat profile signature as represented in Figure 4. In another embodiment, the heat profile signature has a cooler outer layer. In another embodiment, the heat profile signature has one, two, or more high-temperature areas surrounded by a cooler area. In another embodiment, there are two high-temperature areas surrounded by a cooler area.

[0117] As in any embodiment above, an annular cover burner in which the fuel conduit comprises at least one fuel selected from the group consisting of natural gas, hydrogen, refinery waste gas, refinery fuel gas, blast furnace gas, propane, fuel oils, anthracite, bituminous, sub-bituminous and lignite coals, tar, bitumen, petroleum coke, paper mill sludge solids and sewage sludge solids, wood, peat and grass. In another embodiment, the fuel is selected from the group consisting of bituminous, sub-bituminous and lignite coals.

[0118] As in any embodiment above, an annular cover burner in which the burner dimensions are sufficient to achieve a flow rate for the fuel in the range of about 6.096 m / s (20 ft / s) to about 45.72 m / s (150 ft / s). Petition 870220072537, dated 12 / 08 / 2022, p. 41 / 70 33 / 41 D. METHODS OF USING THE ANNULAR COVER BURNER

[0119] In one aspect, a method for fuel combustion using an annular cover burner as described in this document is disclosed. Variations in flow rates, fuel mixtures, oxygen content, fuel type, and many other variables are disclosed in this document and should not be considered limiting.

[0120] In another embodiment, the method for fuel combustion comprises the following steps: To provide an annular cap burner, supply a first stream of O2 through a first conduit to a first ring, supply a mixture of fuel and carrier through a second conduit to a second ring, supply a second stream of O2 through a third conduit to a third ring, supply FGR through a fourth conduit to a fourth ring, and ignite the flame using an igniter located in the center of the annular cap burner.

[0121] In one embodiment, the method further comprises the steps of controlling the flow rate of the O2 streams so that the flow rate is in the range of about 7.62 m / s (25 ft / s) to about 38.1 m / s (125 ft / s), and controlling the flow rate of the primary fuel so that the flow rate is in the range of about 6.096 m / s (20 ft / s) to about 45.72 m / s (150 ft / s).

[0122] As in any embodiment above, the method that produces a peak flame temperature of at least about Petition 870220072537, dated 12 / 08 / 2022, p. 42 / 70 34 / 41 4,000 °F (2,204 °C).

[0123] As with any embodiment above, the method produces a peak flame temperature of at least about 4,300 °F (2,371 °C).

[0124] As in any of the above modes, the method in which the flame has a heat profile signature as represented in Figure 4. C. THE COMBUSTION AND RECYCLING SYSTEM

[0125] The annular cap burner described herein can be incorporated into a boiler unit that may also form part of a technical system, such as a fossil fuel power generation plant. In one embodiment, the annular cap burner design provides a heat release profile in a conventional front-wall steam boiler configuration that substantially reduces the peak heat flux incident on the burner components and furnace front walls. The annular cap burner further regulates the amount of FGR distributed in the combustion zone to prevent damage to burner components and surfaces near the burner due to extreme temperatures and heat fluxes, minimizing the impact on peak flame temperature.

[0126] The advantages associated with a system comprising the annular cap burner described herein include: a much higher flame temperature than conventional air / fuel and other patented oxy / fuel systems; a more targeted heat release profile with less radiant heat; a novel cap cooling design to eliminate damage to components around the burner and furnace surfaces near the burner; and easy replacement of pre-existing air combustion burners with the annular cap burner.

[0127] Represented in Figure 10 is a process flow scheme of an embodiment of a single-wall subcritical boiler plant comprising the annular cover burner disclosed in Petition 870220072537, dated 12 / 08 / 2022, page 43 / 70 35 / 41 present document. As seen in Figure 10, the fuel (202) flows through the mill (206) to the annular cover burner (207), which is connected to the furnace (201). The water (208) flows into the furnace (201) and flows out as steam (209).

[0128] Additional components may also flow into the burner. For example, primary FGR (PRI FGR) (204) may flow into the mill (206) where it is mixed with fuel (202) before being introduced into the burner (207). The oxidant (203) (which may be substantially pure oxygen) may flow along several different paths. In one embodiment, the oxidant (203) flows into the mill (206) where it may mix with fuel (202) and / or PRI FGR (204) before being introduced into the burner (207). The oxidant (203) may also flow into the burner (207) or furnace (201). An alternative source of FGR may also be present, called secondary FGR (SEC FGR) (205). The SEC FGR (205) may flow into the burner (207) and / or furnace (208).

[0129] From the furnace, there are at least two output streams, steam (209) and hot combustion gas (FG) (210). The steam (209) flows out of the furnace to other parts of the system, such as a turbine / generator assembly which are not described here, which operate to provide power generation. Another possible output stream, hot FG (210) flows to the air heater (211). In one capacity, the cold FG (212) flows to the air heater (211), which heats the cold FG (212) and provides hot FG (213). In another capacity, the air heater (211) provides an output of hot FG (214), which flows to the coils (215).

[0130] The coils (215) can receive cold feedwater (FW) (216), heat the water and supply hot FW (217) as a result. The flow can continue from the coils (215) to the electrostatic precipitator (ESP) (218), for flue gas desulfurization (FGD) (220). After flue gas desulfurization, the FGD output (221) can flow as secondary FGR (222) to the air heater (AH) or flow to a direct contact cooler polishing scrubber (DCCPS) (223). From Petition 870220072537, dated 12 / 08 / 2022, page 44 / 70 36 / 41 of DCCPS (223), the FGR can flow as primary FGR (224) to the air heater or flow as FG to CO2 processing (225).

[0131] Because the annular cap burner produces a high flame temperature, heat transfer in the overall system is very efficient. Further modifications to the overall system can increase this efficiency even more. Such modifications include changes to the boiler geometry (e.g., direct flame exposure of the boiler tubes) which further increases heat transfer by maximizing the metal surface area over which heat transfer from the flame to the metal occurs. As a result, the boilers used can be physically smaller than a conventional boiler with a conventional burner.

[0132] Also shown in Figures 11 to 18 are results of models of the annular cover burner operated within a single-wall subcritical boiler system.

[0133] In one embodiment, as disclosed in this document, there is a high-temperature flame oxy-combustion system comprising: at least one annular cap burner, a combustion furnace, an air separation unit, at least one duct, and a control system, wherein the annular cap burner is configured to provide a peak flame temperature of at least 4,000 °F (2,204 °C) with a heat profile signature similar to that depicted in Figure 4, so that radiant heat and potential damage to systems surrounding the annular cap burner are minimized.

[0134] In one embodiment, as disclosed in this document, there is a method of operating an oxy-combustion system, wherein the method comprises: to provide a fuel, carrier and oxygen Petition 870220072537, dated 12 / 08 / 2022, pp. 45 / 70 37 / 41 substantially pure to the annular cap burner, burn the fuel, carrier and substantially pure oxygen to emit a flame, wherein the flame has a radiant heat profile signature similar to that represented in Figure 4, heat water in the boiler with the high-temperature flame annular cap burner to convert water into steam. D. EXAMPLES

[0135] The following preparations and examples are given to enable those skilled in the art to understand more clearly and practice the present invention. They should not be considered as limiting the scope of the invention, but merely illustrative and representative. Petition 870220072537, dated 12 / 08 / 2022, pp. 46 / 70 38 / 41 EXAMPLE 1: COMPARISON OF AIR AND COMBUSTION AÓXI Air-fired Grams in MW 112.0 Net in MW 105.67 Firing Rate (thermal inlet HHV), MMBtu / h 1138.6 Net Heat Rate, Btu / kWh 10775 Coal Rate, kg / h (lb / h) 63639.9167 (140.302) Total Air Flow, kg / h (lb / h) 424875.437 (936.690) Overall Stoichiometric Ratio 1.1036 Excess O2 in FG at furnace outlet, % wet volume 1.72 Excess O2 in FG at furnace outlet, % dry volume 2.0 FG temperature at eucon outlet (AH inlet), C (F) 364.444 (688) FG temperature at AH outlet, C (F) 139.444 (283) Atmospheric pressure, psia 12.1 Burners in operation 12 Mills in service 8, 10, 11, 12 Primary Gas / Coal 1.95 Primary Gas Flow, kg / h (lb / h) 124098.337 (273.590) Primary gas temperature entering the mill, C (F) 305.556 (582) Primary gas temperature entering the boiler, C (F) 57.2222 (135) Vaporized coal moisture in the mill, % 60 Secondary temperature entering the tank, C (F) 304.444 (580) Petition 870220072537, dated 12 / 08 / 2022, pp. 47 / 70 39 / 41 Triggered by oxy Firing Rate (thermal inlet HHV), MMBtu / h 1138.6 Coal Rate, kg / h (lb / h) 63639.9167 (140.302) Total O2 Flow, kg / h (lb / h) 93425.0597 (205.967) Total FGR Flow, kg / h (lb / h) 238520.187 (525.847) Secondary FGR Flow, kg / h (lb / h), external to burner 301975 (57.4% of total FGR) FGR Cover Flow, kg / h (lb / h) 12409.8337 (27.359) (5.2% of total FGR) Overall Stoichiometric Ratio 1.054 Excess O2 in FG at the outlet of Furnace, % wet volume 1.31 Excess O2 in FG at furnace outlet, % dry volume 1.94 Atmospheric pressure, psia 12.1 Burners in operation 12 Mills in service 7, 8, 9, 12 Primary Gas / Coal 1.75 (1.68 eq of air, 22.86 m / s (4,500 ft / min) coal piping) Gas Flow Rate, kg / h (lb / h) 111370.081 (245.529) Primary FGR Flow, kg / h (lb / h) 89136.79741 (196.513) (37.4% of total FGR) Primary O2 Flow, kg / h (lb / h) 22233.284 (49.016) Primary O2 Gas Concentration, % 23.5 Primary gas temperature entering the mill, C (F) 285 (545) Primary gas temperature entering the boiler, C (F) 56.6667 (134) Vaporized coal moisture in the mill, % 45 O2 temperature entering the boiler, C(F) 20 (68) Secondary FGR temperature entering the boiler, C (F) 340.556 (645) FG Recycling Rate, % by mass of FG furnace outlet flow 61 O2 Overall in O2 / FGR mixture, % 30.6. Petition 870220072537, dated 12 / 08 / 2022, pp. 48 / 70 40 / 41 The following steam conditions were used to define the tuning parameters in the air-based SGE process modeling. Once defined, the parameters were kept constant to predict steam conditions during oxy-oxide incineration. Air-fired SH flow, kg / h (lb / h) 341394.483 (752.646) SH final pressure, psig 1.449 SH final temperature, C (F) 540 (1.004) SH sprayer, kg / h (lb / h) 10832.239 (23.881) Primary SH outlet temperature, C (F) 374.444 (706) Drum pressure, psig 1.615 Saturation temperature, C (F) 319.444 (607) Econ out temperature, C (F) 280.556 (537) FW to economizer temperature, C (F) 243.889 (471) Sprayer and Econ inlet pressure, psig 1.826 RH flow, kg / h (lb / h) 304604,967 (671.539) Final RH pressure, psig 472 Final RH temperature, C (F) 537,778 (1.000) Sprayer RH, kg / h (lb / h) 39340,973 (86.732) Inlet RH temperature, C (F) 388,333 (731) Inlet RH pressure, psig 513 Sprayer temperature, C (F) 150,556 (303) Overall results comparing air and oxygen burners. Petition 870220072537, dated 12 / 08 / 2022, pp. 49 / 70 41 / 41 CFD fired by air CFD fired by oxy FEGT (°F) 1.724 1.693 Peak Gas Temperature in the Domain (°F) 1838.333 (3341) 2264.444 (4108) CO at Furnace Outlet (ppmv, wet) 2.131 5.314 O2 at Furnace Outlet (% by volume, wet) 2.16 2.51 Peak Net Heat Flux (kW / m2) 210 262 Average Net Heat Flux, All Surfaces (kW / m2) 60.0 60.7 Average Net Heat Flux, Surfaces below the nose (kW / m2) 115.9 125.0 Peak Incident Heat Flux (kW / m2) 406 507 DO Temperature of Peak Tube Temperature (°F) 406.111 (763) 430 (806) Burnout (%) 99.15 99.44 Carbon in Ash (%) 5.6 <0.1 Ash Residue (%) 93.7 97.6 NOx at economizer outlet (ppmv, wet) 183 602 NOx at economizer outlet (lb / MMBtu) 0.23 0.62 NOx Emissions at Stack / CPU Inlet (ppmv, wet)1 180 713 NOx Emissions at Stack / CPU Inlet (lb / MMBtu)1 0.28 0.24 * The oven outlet is located between the SSH board and the RH1 pendant. From the process modeling

[0136] It will be evident to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or essence of the invention. Other aspects of the invention will be evident to those skilled in the art from consideration of the descriptive report and practice of the invention disclosed herein. The descriptive report and examples are intended to be considered merely illustrative, the true scope and essence of the invention being indicated by the following claims. Petition 870220072537, dated 12 / 08 / 2022, pages 50 / 70

Claims

1 / 4 CLAIMS 1. Annular cover burner, characterized in that it comprises: a refractory brick (305), wherein the refractory brick (305) has a divergent conical shape that is positioned to extend along a central geometric axis and defines a combustion zone (350) radially inward and downstream of a radially inner surface of the refractory brick (305), wherein the refractory brick (305) extends from a face of the burner to an inner wall of the furnace; a first conduit (301), the first conduit (301) positioned so as to extend along the central geometric axis and configured to provide a first oxygen stream (331) to the combustion zone (350) on the face of the burner;a second conduit (312), the second conduit (312) positioned so as to extend along the central geometric axis, radially outward from the first conduit (301) and configured to supply a mixed stream of a fuel (310) and a carrier (311) to the combustion zone (350) on the burner face; a third conduit (335), the third conduit (335) positioned so as to extend along the central geometric axis, radially outward from the second conduit (312) and configured to supply a second stream of oxygen (336) to the combustion zone (350) on the burner face;and a fourth flue (325), the fourth flue (325) positioned so as to extend along the central geometric axis, radially outward from the third flue (335) and configured to provide a stream of recycled combustion gas (320) in the form of a conical cover extending along the inner surface of the refractory brick (305), from the burner face to the inner wall of the furnace, the stream of recycled combustion gas (320) encircling a peak flame temperature region within the combustion zone (350), wherein the burner is a quadruple burner consisting of four flues.

2. Annular cover burner, according to claim 1, characterized in that the first oxygen stream (331) and the second oxygen stream (336) comprise undiluted oxygen.

3. Annular cover burner, according to claim 1, characterized in that the first oxygen stream (331) and the second oxygen stream (336) comprise an oxygen content of at least about 90%.

4. Annular cover burner, according to claim 1, characterized in that the carrier (311) comprises recycled combustion gas (320).

5. Annular cover burner, according to claim 1, characterized in that the first oxygen stream (331) and the second oxygen stream (336) comprise an oxygen content of at least about 95%.

6. Annular cap burner, according to claim 1, characterized in that a peak flame temperature within the combustion zone (350) is at least 4,000 °F (2,204 °C).

7. Annular cover burner, according to claim 1, characterized in that the fuel (310) is selected from the group consisting of natural gas, hydrogen, refinery waste gas, refinery fuel gas, blast furnace gas, propane, fuel oils, anthracite, bituminous, sub-bituminous and lignite coals, tar, bitumen, petroleum coke, paper mill sludge solids and sewage sludge solids, wood, peat and grass.

8. Annular cover burner, according to claim 1, characterized in that the fuel (310) is selected from the group consisting of bituminous, sub-bituminous and lignite coals. Petition 870260034550, dated 13 / 04 / 2026, page 26 / 32 3 / 4 9. Method of combustion of a fuel in an annular cover burner having a refractory brick (305), wherein the refractory brick (305) has a divergent conical shape that is positioned so as to extend along a central geometric axis and defines a combustion zone (350) radially inward and downstream of a radially inner surface of the refractory brick (305), wherein the refractory brick (305) extends from a burner face to an inner furnace wall, wherein the method is characterized in that it comprises: supplying a first oxygen stream (331) to the combustion zone (350) through a first conduit (301), the first conduit (301) positioned so as to extend along the central geometric axis and configured to open into the refractory brick (305) on the burner face;to provide a mixed stream of fuel (310) and a carrier (311) to the combustion zone (350) by means of a second conduit (312), the second conduit (312) positioned so as to extend along the central geometric axis, radially outward from the first conduit (301) and configured to open into the refractory brick (305) on the face of the burner; to provide a second stream of oxygen (336) to the combustion zone (350) by means of a third conduit (335), the third conduit (335) positioned so as to extend along the central geometric axis, radially outward from the second conduit (312) and configured to open into the refractory brick (305) on the face of the burner;and provide a recycled combustion gas stream (320), which encircles a portion of the combustion zone (350), through a fourth conduit (325), the fourth conduit (325) positioned so as to extend along the central geometric axis, radially outward from the third conduit (335) and configured to provide the recycled combustion gas stream (320) in the form of a conical cover extending along the inner surface of the refractory brick (305), from the burner face to the inner wall of the furnace, wherein the recycled combustion gas stream (320) encircles a peak flame temperature area within the combustion zone (350).

10. Annular cover burner, according to claim 1, characterized in that it further comprises an igniter (315) located in the center of the annular cover burner. Petition 870260034550, dated 13 / 04 / 2026, p. 28 / 32

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