SYSTEM AND PROCESS FOR HYDROGEN COMBUSTION

Abstract

The invention relates to a system and process for hydrogen combustion for industrial or steam generation applications, and more particularly to a hydrogen combustion burner or retrofit kit combustion system and process using a primary pure hydrogen fuel source. The burner or retrofit kit combustion system and process may also use one or more secondary fuels, such as natural gas, methane, propane, or the like, to reduce emissions of CO.sub.2. Additionally, the inventive burner, system and process can use a flame temperature reducing fluid for lowering the bulk flame temperature of the burner to increase equipment life and decrease equipment failure. The flame temperature reducing fluid can include flue gas recirculation (FGR), water injection, steam injection, and a combination thereof.

Claims

1. A burner or retrofit kit combustion system for industrial or steam generation applications, the burner or retrofit kit combustion system further comprising: a stream of oxidant; a stream of primary pure hydrogen (H.sub.2) fuel configured to combust with the oxidant; and at least one burner nozzle downstream from the oxidant stream and the hydrogen fuel stream, the burner configured to combust the hydrogen fuel with the oxidant.

2. The burner or retrofit kit combustion system of claim 1 wherein said burner or retrofit kit combustion system is incorporated into a boiler system.

3. The burner or retrofit kit combustion system of claim 2 wherein the boiler system is a firetube, watertube, utility, single burner, multiple-burner, side-fired, bottom-fired, roof-fired, tangentially-fired, skid-mounted, field-erected boiler, or a combination thereof.

4. The burner or retrofit kit combustion system of claim 2 further comprising at least one flow valve and control in fluid communication with the stream of hydrogen fuel.

5. The burner or retrofit kit combustion system of claim 1 wherein the burner further comprises a manifold fluidly connected to a plurality of burner nozzles.

6. The burner or retrofit kit combustion system of claim 1 further comprising a stream of secondary fuel configured to combust with the hydrogen fuel and the oxidant for reducing emissions of CO.sub.2.

7. The burner or retrofit kit combustion system of claim 6 wherein the secondary fuel is natural gas, methane, propane, or a combination or mixture thereof.

8. The burner or retrofit kit combustion system of claim 7 wherein the secondary fuel has a concentration of greater than 5% by volume of the overall burner capacity.

9. The burner or retrofit kit combustion system of claim 1 wherein the oxidant is combustion air, pure oxygen, or oxygen-enriched air.

10. The burner or retrofit kit combustion system of claim 9 wherein said oxygen-enriched air comprising an oxygen concentration greater than about 21% by volume.

11. The burner or retrofit kit combustion system of claim 1 further comprising a stream of a flame temperature reducing fluid configured to be introduced to lower the bulk flame temperature of the burner.

12. The burner or retrofit kit combustion system of claim 11 wherein the flame temperature reducing fluid is injected into the burner with the oxidant, the hydrogen fuel, the secondary fuel, or a combination thereof.

13. The burner or retrofit kit combustion system of claim 12 wherein the flame temperature reducing fluid is water, steam, flue gas recirculation, or a combination thereof.

14. The burner or retrofit kit combustion system of claim 13 wherein the steam, the water, and the flue gas recirculation each have variable flow rates to reduce the bulk flame temperature of the burner nozzle.

15. The burner or retrofit kit combustion system of claim 14 wherein the flue gas recirculation has a flow rate greater than about 45% by volume to reduce the bulk flame temperature of the combustion process.

16. The burner or retrofit kit combustion system of claim 14 wherein the steam has a flow rate greater than about 0.35 lbs. of steam/lbs. of hydrogen fuel to reduce the bulk flame temperature of the burner nozzle.

17. The burner or retrofit kit combustion system of claim 14 wherein the water has a flow rate greater than about 1.5 lbs. of water/lbs. of hydrogen fuel to reduce the bulk flame temperature of the burner nozzle.

18. The burner or retrofit kit combustion system of claim 1 having jet stabilization only.

19. A process for industrial applications or steam generation using the burner or retrofit kit

1. on system of claim 1.

20. A burner or retrofit kit combustion system for industrial or steam generation applications, the burner or retrofit kit combustion system further comprising: a stream of oxidant; a stream of primary pure hydrogen (H.sub.2) fuel configured to combust with the oxidant; a stream of secondary fuel configured to combust with the hydrogen fuel and the oxidant for reducing emissions of CO.sub.2; a stream of a flame temperature reducing fluid configured to be introduced to lower the bulk flame temperature of the burner; and a plurality of burner nozzles downstream from the oxidant stream, the hydrogen fuel stream, the secondary fuel stream, and the flame temperature reducing fluid stream, the burners configured to combust the hydrogen fuel with the oxidant and the secondary fuel stream.

21. The burner or retrofit kit combustion system of claim 20 wherein said burner or retrofit kit combustion system is incorporated into a boiler system.

22. The burner or retrofit kit combustion system of claim 21 wherein the boiler system is a firetube, watertube, utility, single burner, multiple-burner, side-fired, bottom-fired, roof-fired, tangentially-fired, skid-mounted, field-erected boiler, or a combination thereof.

23. The burner or retrofit kit combustion system of claim 20 further comprising at least one flow valve and control in fluid communication with the stream of hydrogen fuel.

24. The burner or retrofit kit combustion system of claim 20 wherein the burner further comprise a manifold fluidly connected to the plurality of burner nozzles.

25. The burner or retrofit kit combustion system of claim 20 wherein the secondary fuel is natural gas, methane, propane, or a combination or mixture thereof.

26. The burner or retrofit kit combustion system of claim 25 wherein the secondary fuel has a concentration of greater than 5% by volume of the overall burner capacity.

27. The burner or retrofit kit combustion system of claim 20 wherein the oxidant is combustion air, pure oxygen, or oxygen-enriched air.

28. The burner or retrofit kit combustion system of claim 27 wherein said oxygen-enriched air comprising an oxygen concentration greater than about 21% by volume.

29. The burner or retrofit kit combustion system of claim 20 wherein the flame temperature reducing fluid is injected into the burner with the oxidant, the hydrogen fuel, the secondary fuel, or a combination thereof.

30. The burner or retrofit kit combustion system of claim 29 wherein the flame temperature reducing fluid is water, steam, flue gas recirculation, or a combination thereof.

31. The burner or retrofit kit combustion system of claim 30 wherein the steam, the water, and the flue gas recirculation each have variable flow rates to reduce the bulk flame temperature of the burner nozzle.

32. The burner or retrofit kit combustion system of claim 31 wherein the flue gas recirculation has a flow rate greater than about 45% by volume to reduce the bulk flame temperature of the combustion process.

33. The burner or retrofit kit combustion system of claim 31 wherein the steam has a flow rate greater than about 0.35 lbs. of steam/lbs. of hydrogen fuel to reduce the bulk flame temperature of the burner nozzle.

34. The burner or retrofit kit combustion system of claim 31 wherein the water has a flow rate greater than about 1.5 lbs. of water/lbs. of hydrogen fuel to reduce the bulk flame temperature of the burner nozzle.

35. The burner or retrofit kit combustion system of claim 20 having jet stabilization only.

36. A process for industrial applications or steam generation using the burner or retrofit kit combustion system of claim 21.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] These and further aspects of the invention are described in detail in the following examples and accompanying drawings.

[0024] FIG. 1A is a flame profile of a prior art diffusion-style burner illustrating the fuel leaving the nozzle forming a turbulent jet with vortices on its shear layer where mixing with co-flowing air, and/or internal flue gases, occurs.

[0025] FIG. 1B is a closeup of view of area 1B of the temperature and flow profile from FIG. 1A pinpointing the location within the vortices where the fuel/air equivalence ratio is close to 1.0.

[0026] FIG. 2 is a schematic diagram of an example of a hydrogen combustion burner or retrofit kit combustion system having a burner nozzle that combusts a primary pure hydrogen fuel stream with an oxidant in accordance with an illustrative embodiment of the invention disclosed herein.

[0027] FIG. 3 is a schematic diagram of an example of a hydrogen combustion burner or retrofit kit combustion system having a manifold connected to a plurality of burner nozzles for combusting a primary pure hydrogen fuel stream with an oxidant in accordance with an illustrative embodiment of the invention disclosed herein.

[0028] FIG. 4 is a schematic diagram of an example of a hydrogen combustion burner or retrofit kit combustion system having a burner nozzle that combusts a primary pure hydrogen fuel stream with an oxidant and one or more secondary fuels in accordance with an illustrative embodiment of the invention disclosed herein.

[0029] FIG. 5 is a schematic diagram of an example of a hydrogen combustion burner or retrofit kit combustion system having a primary fuel manifold connected to a plurality of primary fuel burner nozzles and a secondary fuel manifold connected to a plurality of secondary fuel burner nozzles for combusting a primary pure hydrogen fuel stream, an oxidant, and a secondary fuel in accordance with an illustrative embodiment of the invention disclosed herein.

[0030] FIG. 6 is a schematic diagram of an example of a hydrogen combustion burner or retrofit kit combustion system having a primary fuel manifold connected to a plurality of primary fuel burner nozzles and a secondary fuel manifold connected to a plurality of secondary fuel burner nozzles for combusting a primary pure hydrogen fuel stream, an oxidant, and a plurality of secondary fuels in accordance with an illustrative embodiment of the invention disclosed herein.

[0031] FIG. 7 is a schematic diagram of an example of a hydrogen combustion burner or retrofit kit combustion system having a burner nozzle that combusts a primary pure hydrogen fuel stream with an oxidant and at least one flame temperature reducing fluid in accordance with an illustrative embodiment of the invention disclosed herein.

[0032] FIG. 8 is a schematic diagram of an example of a hydrogen combustion burner or retrofit kit combustion system having a primary fuel manifold connected to a plurality of primary fuel burner nozzles, a secondary fuel manifold connected to a plurality of secondary fuel burner nozzles, and a stream of flame temperature reducing fluid for combusting a primary pure hydrogen fuel stream, an oxidant, a secondary fuel, and the flame temperature reducing fluid in accordance with an illustrative embodiment of the invention disclosed herein.

DETAILED DESCRIPTION OF THE INVENTION

[0033] While this invention is susceptible of embodiment in many different forms, there is shown in the drawings, and will herein be described hereinafter in detail, some specific embodiments of the instant invention. It should be understood, however, that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to the specific embodiments so described.

[0034] This invention relates generally to a system and process for hydrogen combustion, and more particularly to a combustion burner or retrofit kit combustion system and process having at least one burner nozzle using pure hydrogen as a primary fuel source. Pure hydrogen herein as used herein means H.sub.2 with a purity higher than 99%. The inventive system and process may also use the primary pure hydrogen fuel with one or more secondary fuels and/or a flame temperature reducing fluid for lowering a bulk flame temperature of the burner or retrofit kit combustion system. The inventive combustion burner or retrofit kit combustion system and process reduce emissions of CO.sub.2, NO.sub.x, and other greenhouse gases into the atmosphere and reduce bulk flame temperatures to increase equipment life and decrease equipment failure. The combustion burner or retrofit kit combustion system and process can be incorporated into a boiler system of any type of design, such as firetube, watertube, utility, single burner, multiple-burner, side-fired, bottom-fired, roof-fired, tangentially-fired, either skid-mounted or field-erected, or a combination thereof.

[0035] The hydrogen combustion burner or retrofit kit combustion system has a primary pure hydrogen fuel stream delivered to at least one burner nozzle where it burns with an oxidant. The burner or retrofit kit combustion system can be configured for use with various oxidants, such as combustion air, pure oxygen to avoid NO.sub.x emissions, or oxygen-enriched air (i.e., oxygen concentration greater than about 21% by volume) with the objective of reducing overall oxygen cost or in case pure oxygen is not available to satisfy the combustion capacity needs. In an exemplary embodiment of the system and process, the primary hydrogen fuel is combusted with air, pure oxygen, oxygen-enriched air, oxy-fuel, or a combination thereof to reduce greenhouse gas emissions. The inventive hydrogen combustion burner or retrofit kit combustion system can include one or more flow valves and controls as needed to selectively control fluid flow through the inventive system and process.

[0036] Referring now to the FIGS. 2 through 8, wherein like numerals of reference designate like elements throughout the several views, and initially to FIG. 2, the illustrated hydrogen combustion burner or retrofit kit combustion system 200 utilizes a single burner nozzle 210 for combusting the primary pure hydrogen fuel 202 and the oxidant 204 (e.g., air, pure oxygen, oxygen-enriched air). A primary fuel flow valve 206 and control 208 selectively controls the primary fuel 202 fluid flow to burner 200 for combustion with the oxidant 204.

[0037] As illustrated in FIG. 3, the hydrogen combustion burner or retrofit kit combustion system 300 includes a primary fuel manifold 212 connected to a plurality of burner nozzles 210 where the primary pure hydrogen fuel 202 is combusted with the oxidant 204. The primary fuel flow valve 206 and control 208 selectively controls the primary fuel 202 fluid flow to the hydrogen combustion burner or retrofit kit combustion system 200 for combustion with the oxidant 204.

[0038] As exemplified in FIGS. 4, 5 and 6, the hydrogen combustion burner or retrofit kit combustion system 400/500/600 includes the primary fuel manifold 212 connected to the plurality of burner nozzles 210 where the primary pure hydrogen fuel 202 is combusted with the oxidant 204. In addition to the primary pure hydrogen fuel 202, the hydrogen combustion burner or retrofit kit combustion system 400 includes one or more secondary fuels 214 that mix and combust with the primary hydrogen fuel 202 and oxidant 204 to further reduce emissions of CO.sub.2. The secondary fuel(s) 214 can include any hydrocarbon fuel, such as natural gas, methane, propane, or mixtures thereof in compositions greater than 5% by volume of the overall burner capacity. A secondary fuel flow valve 216 and control 218 selectively controls the secondary fuel 214 fluid flow to the hydrogen combustion burner or retrofit kit combustion system 400 for combustion with the oxidant 204. The secondary fuel 214 stream can be separate and independent from the primary hydrogen fuel 202 stream. Moreover, the secondary fuel(s) 214 can be introduced to the burner 400 in individual fluid stream(s) (FIG. 4), introduced to the burner 500 through a secondary fuel manifold 220 connected to a plurality of secondary fuel burner nozzles 222 (FIG. 5), or introduced to the burner 600 as a single mixed secondary fuel fluid stream 224 before injection into the secondary fuel burner nozzles 222 (FIG. 6).

[0039] Turning now to FIGS. 7 and 8, the inventive system and process can use at least one flame temperature reducing fluid 226 to lower the bulk flame temperature of the burner or retrofit kit combustion system 700/800. The flame temperature reducing fluid 226 can be water or steam input from a suitable source or flue gas recirculated from combustion and mixed with the oxidant 204 or otherwise injected into the burner 700/800, or a combination thereof. A flame temperature reducing fluid flow valve 228 and control 230 controls in the injection flow rate of the flame temperature reducing fluid 226 to the hydrogen combustion burner or retrofit kit combustion system 700/800 to selectively lower the flame temperature during combustion of the primary pure hydrogen fuel 202 (and the secondary fuel(s) 214 if present).

[0040] The flame temperature reducing fluid 226 can be used separately (FIG. 7) or in conjunction with the secondary fuel source 214 (FIG. 8). The flame temperature reducing fluid 226 can also be separately or concurrently injected into one or more of the burners 700/800 configured to combust pure oxygen or oxygen-enriched air as the oxidant 204. In the exemplary embodiment of the system and process for hydrogen combustion shown in FIG. 8, the primary hydrogen fuel source 202 and the secondary fuel source 214 are combusted with pure oxygen or oxygen-enriched air 204 while the bulk flame temperature is lowered using the flame temperature reducing fluid 226 to reduce CO.sub.2 and NO.sub.x emissions and to increase equipment life and decrease equipment failure.

[0041] It is to be understood that the terms “including”, “comprising”, “consisting of” and grammatical variants thereof do not preclude the addition of one or more components, features, steps, or integers or groups thereof and that the terms are to be construed as specifying components, features, steps or integers.

[0042] If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element.

[0043] It is to be understood that where the claims or specification refer to “a” or “an” element, such reference is not to be construed that there is only one of that element.

[0044] It is to be understood that where the specification states that a component, feature, structure, or characteristic “may”, “might”, “can” or “could” be included, that particular component, feature, structure, or characteristic is not required to be included.

[0045] Where applicable, although state diagrams, flow diagrams or both may be used to describe embodiments, the invention is not limited to those diagrams or to the corresponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described.

[0046] Systems and processes of the instant disclosure may be implemented by performing or completing manually, automatically, or a combination thereof, selected steps or tasks.

[0047] The term “process” may refer to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the art to which the invention belongs.

[0048] For purposes of the instant disclosure, the term “at least” followed by a number is used herein to denote the start of a range beginning with that number (which may be a range having an upper limit or no upper limit, depending on the variable being defined). For example, “at least 1” means 1 or more than 1. The term “at most” followed by a number is used herein to denote the end of a range ending with that number (which may be a range having 1 or 0 as its lower limit, or a range having no lower limit, depending upon the variable being defined). For example, “at most 4” means 4 or less than 4, and “at most 40%” means 40% or less than 40%. Terms of approximation (e.g., “about”, “substantially”, “approximately”, etc.) should be interpreted according to their ordinary and customary meanings as used in the associated art unless indicated otherwise. Absent a specific definition and absent ordinary and customary usage in the associated art, such terms should be interpreted to be ±10% of the base value.

[0049] When, in this document, a range is given as “(a first number) to (a second number)” or “(a first number)-(a second number)”, this means a range whose lower limit is the first number and whose upper limit is the second number. For example, 25 to 100 should be interpreted to mean a range whose lower limit is 25 and whose upper limit is 100. Additionally, it should be noted that where a range is given, every possible subrange or interval within that range is also specifically intended unless the context indicates to the contrary. For example, if the specification indicates a range of 25 to 100 such range is also intended to include subranges such as 26-100, 27-100, etc., 25-99, 25-98, etc., as well as any other possible combination of lower and upper values within the stated range, e.g., 33-47, 60-97, 41-45, 28-96, etc. Note that integer range values have been used in this paragraph for purposes of illustration only and decimal and fractional values (e.g., 46.7-91.3) should also be understood to be intended as possible subrange endpoints unless specifically excluded.

[0050] It should be noted that where reference is made herein to a process comprising two or more defined steps, the defined steps can be carried out in any order or simultaneously (except where context excludes that possibility), and the process can also include one or more other steps which are carried out before any of the defined steps, between two of the defined steps, or after all of the defined steps (except where context excludes that possibility).

[0051] Still further, additional aspects of the instant invention may be found in one or more appendices attached hereto and/or filed herewith, the disclosures of which are incorporated herein by reference as if fully set out at this point.

[0052] Thus, the invention is well adapted to carry out the objects and attain the ends and advantages mentioned above as well as those inherent therein. While the inventive concept has been described and illustrated herein by reference to certain illustrative embodiments in relation to the drawings attached thereto, various changes and further modifications, apart from those shown or suggested herein, may be made therein by those of ordinary skill in the art, without departing from the spirit of the inventive concept the scope of which is to be determined by the following claims.