阅读说明：本技术 用于燃烧含有一氧化碳的燃料气体的工艺燃烧器和方法 (Process burner and method for burning a fuel gas containing carbon monoxide ) 是由 安东尼奥·柯西亚 K·巴特尔斯 于 2021-04-27 设计创作，主要内容包括：本发明涉及一种用于用气态辅助介质燃烧多种燃料气体的工艺燃烧器,其中,这些燃料气体之一包括一氧化碳(CO)。根据本发明的工艺燃烧器包括第一燃料气体单元、第二燃料气体单元、和辅助介质单元。例如,将包含天然气的第一燃料气体经由在燃烧区区域内的第一燃料气体喷嘴被引入工艺燃烧器中。将含有一氧化碳的燃料气体经由该第二燃料气体单元引入该工艺燃烧器中,其中,用于引入含有一氧化碳的燃料气体的第二燃料气体喷嘴布置在该辅助介质单元的区域中。该辅助介质单元中与该燃烧区相比较低的温度使得能有效地减少或完全避免一氧化碳结焦而形成固体碳。(The invention relates to a process burner for combusting a plurality of fuel gases with a gaseous auxiliary medium, wherein one of the fuel gases comprises carbon monoxide (CO). The process burner according to the invention comprises a first fuel gas unit, a second fuel gas unit, and an auxiliary medium unit. For example, a first fuel gas comprising natural gas is introduced into the process combustor via a first fuel gas nozzle within the combustion zone region. Introducing a fuel gas containing carbon monoxide into the process burner via the second fuel gas unit, wherein a second fuel gas nozzle for introducing the fuel gas containing carbon monoxide is arranged in the region of the auxiliary medium unit. The lower temperature in the secondary media unit compared to the combustion zone allows for effective reduction or complete avoidance of carbon monoxide coking to form solid carbon.)

1. A process burner (100) for combusting fuel gases with a gaseous auxiliary medium, wherein one of the fuel gases comprises carbon monoxide (CO), comprises

a. A first fuel gas unit for introducing a first fuel gas, the first fuel gas unit comprising a first fuel gas conduit (110) and a first fuel gas nozzle (111), wherein the first fuel gas conduit (110) comprises a first fuel gas inlet (112) and a first fuel gas outlet (113), wherein the first fuel gas inlet (112) is fluidly connected to a first fuel gas source and the first fuel gas outlet (113) is connected to the first fuel gas nozzle (111);

b. a second fuel gas unit for introducing a second fuel gas, the second fuel gas unit comprising a second fuel gas conduit (120) and a second fuel gas nozzle (121), wherein the second fuel gas conduit (120) comprises a second fuel gas inlet (122) and a second fuel gas outlet (123), wherein the second fuel gas inlet (122) is fluidly connected with a second fuel gas source, wherein the fuel gas from the second fuel gas source comprises at least carbon monoxide (CO), and the second fuel gas outlet (123) is connected to the second fuel gas nozzle (121);

c. an auxiliary media unit comprising an auxiliary media conduit (130) and a burner plenum (131), wherein the auxiliary media conduit (130) comprises an auxiliary media inlet (132) and an auxiliary media outlet (133), wherein the auxiliary media inlet (132) is fluidly connected to an auxiliary media source and the auxiliary media outlet (133) is connected to the burner plenum (131);

d. a refractory tile (140), wherein the refractory tile (140) adjoins the burner plenum (131) and the refractory tile (140) has a refractory surface, wherein the refractory surface adjoins a combustion zone (141) of the process burner (100), wherein the refractory tile (140) and the combustion zone (141) are configured for combusting the first fuel gas and the second fuel gas with the auxiliary medium,

it is characterized in that the preparation method is characterized in that,

the first fuel gas nozzle (111) for introducing the first fuel gas is arranged within the combustion zone (141), and

the second fuel gas nozzle (121) for introducing the second fuel gas is arranged within the auxiliary medium unit.

2. The process burner (100) according to claim 1, wherein the second burner gas nozzle (121) for introducing the second burner gas is arranged within the burner plenum (131).

3. The process burner (100) according to claim 1 or 2, wherein the second fuel gas conduit (120) extends at least partially through the burner plenum (131).

4. A steam reformer or steam cracker comprising a process burner according to any one of claims 1 to 3.

5. A method for combusting a plurality of fuel gases with a gaseous auxiliary medium in a process burner (100), wherein the process burner (100) comprises a first fuel gas unit, a second fuel gas unit, and an auxiliary medium unit, and wherein one of the fuel gases comprises carbon monoxide (CO), the method comprising the method steps of:

a. introducing a first fuel gas from a first fuel gas source into a first fuel gas unit, wherein the first fuel gas unit comprises a first fuel gas conduit (110) and a first fuel gas nozzle (111);

b. introducing a second fuel gas from a second fuel gas source into a second fuel gas unit, wherein the fuel gas from the second fuel gas source comprises at least carbon monoxide (CO), and wherein the second fuel gas unit comprises a second fuel gas conduit (120) and a second fuel gas nozzle (121);

c. introducing a secondary medium from a secondary medium source into a secondary medium unit, wherein the secondary medium unit comprises a secondary medium conduit (130) and a burner plenum (131);

d. introducing the first fuel gas into a combustion zone (141) of the process burner (100) via the first fuel gas nozzle (111), wherein the combustion zone (141) abuts a refractory surface of a refractory tile (140), and the refractory tile (140) abuts the burner plenum (131);

e. introducing the second fuel gas into the secondary media unit via the second fuel gas nozzle (121);

f. the first fuel gas and the second fuel gas are combusted with the auxiliary medium in a combustion zone (141) of the process burner (100).

6. A method according to claim 5, characterized in that the second fuel gas is introduced into the burner plenum (131) of the secondary media unit.

7. A method according to claim 5 or 6, wherein the fuel gas from the second fuel gas source comprises at least 50 mol% carbon monoxide, preferably at least 90 mol% carbon monoxide, and more preferably at least 95 mol% carbon monoxide.

8. A method according to any one of claims 5 to 7, wherein the source of secondary medium comprises air, oxygen or oxygen-enriched air.

9. The method according to any one of claims 5 to 8, characterized in that the second fuel gas is introduced via the second fuel gas nozzle (121) at the following temperatures: below 160 c, preferably below 140 c, more preferably below 100 c.

10. The method according to any one of claims 5 to 9, characterized in that the ratio of the volume flow of the secondary medium, in particular air, to the volume flow of the second fuel gas is 15:1 to 10:1, preferably 14:1 to 12: 1.

11. The method according to any of claims 5 to 10, characterized in that the second fuel gas is introduced into the second fuel gas unit at a temperature of 20 ℃ to 50 ℃, preferably at a temperature of 30 ℃ to 40 ℃.

12. The method according to any one of claims 5 to 11, characterized in that the auxiliary medium is introduced into the auxiliary medium unit at a temperature of 250 to 350 ℃.

13. Use of a process burner according to any of claims 1 to 4 in a method according to any of claims 5 to 12.

14. Use of a process burner according to any of claims 1 to 4 in a steam reformer or steam cracker.

Technical Field

The invention relates to a process burner for combusting a plurality of fuel gases with a gaseous auxiliary medium, wherein one of the fuel gases comprises carbon monoxide (CO). The present invention relates to a steam reformer or steam cracker comprising a process burner according to the present invention. The invention further relates to a method for combusting a plurality of fuel gases with a gaseous auxiliary medium in a process burner, wherein the process burner comprises a first fuel gas unit, a second fuel gas unit, and an auxiliary medium unit, and wherein one of the fuel gases comprises carbon monoxide (CO). The invention further relates to the use of a process burner according to the invention in a method according to the invention.

Background

The process burner is used for heating equipment and heating furnaces in petrochemical and chemical processing industries. For example, process burners are used as heating devices in steam reformers for heating reaction tubes arranged vertically in a furnace. In these reaction tubes, natural gas or other suitable carbonaceous feedstock is reacted with steam over a nickel catalyst to form synthesis gas as the primary product. Syngas is a mixture of hydrogen, carbon monoxide and undesirable by-products such as carbon dioxide.

If the production synthesis gas is primarily used to produce hydrogen, the carbon monoxide is further converted to hydrogen and carbon dioxide by the known water gas shift reaction, or carbon monoxide is removed from the main synthesis gas mixture. This can be achieved, for example, using a pressure swing adsorption apparatus. In such processes, it is often necessary to recycle a portion of the carbon monoxide to the process combustor for use as fuel. A number of additional situations are envisaged in which carbon monoxide is used as fuel for the process burner.

When carbon monoxide is combusted with oxygen to produce carbon dioxide, the actual combustion reaction competes with the exothermic Boudouard reaction (also known as Boudouard equilibrium) according to the following equation:

among other things, high pressure and low temperature favor the formation of solid carbon and carbon dioxide according to Le Chatelier's principle. However, even at the high temperatures prevailing in the combustion zone in the region of the refractory tiles (also referred to as burner blocks), the process burners still suffer from the problem of coking of the fuel gas conduits, burner lances or burner nozzles due to solid carbon deposits. This is true whether the carbon monoxide is introduced into the burner system alone or mixed with other fuel gases. The aforementioned deposits result in blockages in the components, which increases maintenance costs and results in combustion inefficiencies.

For example, in EP 1736707 a2 a burner for injecting a mixed fuel of at least hydrogen and carbon monoxide into a combustion chamber of a gas turbine is described.

Thus, due to carbon deposition problems in certain burner components, there is a need for improvements in known burners using carbon monoxide as fuel and for improvements in corresponding known methods for combusting carbon monoxide containing fuel gases.

Disclosure of Invention

It is an object of the present invention to at least partly overcome the aforementioned drawbacks of the prior art.

In particular, it is an object of the present invention to provide a burner for combusting carbon monoxide-containing fuel gas, which burner is configured such that the deposition of solid carbon in certain burner components, in particular in the fuel gas conduits, burner lances and burner nozzles, is at least reduced or completely prevented in comparison with conventional burners.

It is a further object of the present invention to provide a method for combusting a fuel gas containing carbon monoxide, which method is configured such that less carbon, if any, is formed compared to the known method.

The independent claims contribute at least in part to achieving at least one of the above objects. The dependent claims provide advantageous embodiments which contribute to at least partly achieving at least one of the above objects. In the relevant cases, preferred embodiments of the components of one category according to the invention are equally preferred for the same designation or corresponding components of the corresponding other category according to the invention.

The terms "having," "including," or "containing" and the like do not exclude the presence of additional elements, components, and the like. The indefinite article "a" does not exclude the possible presence of a plurality.

The object of the invention is at least partly achieved by a process burner for combusting a plurality of fuel gases with a gaseous auxiliary medium, wherein one of the fuel gases comprises carbon monoxide (CO), the process burner comprising:

a. a first fuel gas unit for introducing a first fuel gas, the first fuel gas unit comprising a first fuel gas conduit and a first fuel gas nozzle, wherein the first fuel gas conduit comprises a first fuel gas inlet and a first fuel gas outlet, wherein the first fuel gas inlet is fluidly connected to a first fuel gas source and the first fuel gas outlet is connected to the first fuel gas nozzle;

b. a second fuel gas unit for introducing a second fuel gas, the second fuel gas unit comprising a second fuel gas conduit and a second fuel gas nozzle, wherein the second fuel gas conduit comprises a second fuel gas inlet and a second fuel gas outlet, wherein the second fuel gas inlet is fluidly connected with a second fuel gas source, wherein the fuel gas from the second fuel gas source comprises at least carbon monoxide (CO), and the second fuel gas outlet is connected to the second fuel gas nozzle;

c. a secondary media unit comprising a secondary media conduit and a burner plenum, wherein the secondary media conduit comprises a secondary media inlet and a secondary media outlet, wherein the secondary media inlet is fluidly connected to a secondary media source and the secondary media outlet is connected to the burner plenum;

d. a refractory tile, wherein the refractory tile is adjacent to the burner plenum and the refractory tile has a refractory surface, wherein the refractory surface is adjacent to a combustion zone of the process burner, wherein the refractory tile and the combustion zone are configured to combust the first fuel gas and the second fuel gas with the auxiliary medium.

According to the invention, it is provided that,

the first fuel gas nozzle for introducing the first fuel gas is arranged within the combustion zone, and

the second fuel gas nozzle for introducing the second fuel gas is disposed in the auxiliary medium unit.

In the process burners known from the prior art, the fuel gas nozzles are in a combustion zone in the region of the refractory tiles, which combustion zone forms part of the head or neck of the process burner. In the process burner according to the invention, the second fuel gas nozzle is arranged within the secondary media unit. The second fuel gas nozzle introduces or injects the second fuel gas comprising or consisting of carbon monoxide into the process combustor. According to the invention, this is not done in the combustion zone in the region of the hot burner head/hot burner neck, but in the secondary media unit in the significantly cooler region of the process burner, due to the arrangement of the second fuel gas nozzles. The fuel gas of the first fuel gas unit is mixed with the even colder fuel gas of the second fuel gas unit and is combusted only in the region of the combustion zone. Thus, on the way to the combustion zone, the second fuel gas comprising or consisting of carbon monoxide is only very late in contact with the first fuel gas (if it occurs). On the way to the combustion zone, the second fuel gas is only in contact with the auxiliary medium, wherein combustion of the second fuel gas has not yet taken place due to the lower temperature in the auxiliary medium conduit. It has now been found that, surprisingly, the arrangement of the second fuel gas nozzle within the secondary media unit results in less solid carbon deposits being formed in the region of the fuel gas nozzle or in the upstream thereof, for example in the region of the fuel gas conduit.

The first fuel gas unit includes at least one first fuel gas conduit. The first fuel gas conduit is configured as a riser conduit and provides a first fuel gas from a first fuel gas source that is introduced into the process burner via a first fuel gas nozzle in the region of the secondary media unit but not in the region of the refractory tile or the combustion zone. The first fuel gas conduit has an inlet and an outlet. The inlet of the first fuel gas conduit is connected to a first fuel gas source. The first fuel gas from the first fuel gas source contains little, if any, carbon monoxide. For example, the first fuel gas from the first fuel gas source comprises less than 10 mol% carbon monoxide, or less than 5 mol%, or less than 2 mol%, or less than 1 mol%, or less than 0.5 mol%. It is particularly preferred that the fuel gas from the first fuel gas source is free of carbon monoxide. In one example, the first fuel gas from the first fuel gas source comprises natural gas, hydrogen, and/or exhaust gas from a pressure swing adsorption apparatus. The first fuel gas conduit may comprise a so-called fuel gas lance, which opens into the first fuel gas nozzle. In this case, the fuel gas lance comprises an outlet of the first fuel gas conduit.

The second fuel gas unit includes at least one second fuel gas conduit. The second fuel gas conduit is configured as a lift conduit and provides a second fuel gas from a second fuel gas source, which is introduced into the process burner via a second fuel gas nozzle in the region of the combustion zone. The second fuel gas conduit has an inlet and an outlet. The inlet of the second fuel gas conduit is connected to a second fuel gas source. The second fuel gas from the second fuel gas source comprises at least carbon monoxide (CO) which is combusted in the combustion zone of the process burner by means of an auxiliary medium to produce carbon dioxide (CO)₂). The second fuel gas is preferably rich in carbon monoxide, or contains carbon monoxide as a main component. For example, the second fuel gas comprises at least 50 mol% carbon monoxide, or at least 75 mol% carbon monoxide, or at least 90 mol% carbon monoxide, or at least 95 mol% carbon monoxide, or at least 99 mol% carbon monoxide. In one example, the second fuel gas is composed of carbon monoxide and a small proportion of unavoidable impurities.

The secondary media unit comprises at least one secondary media conduit and a burner plenum (also referred to as a windbox). The secondary media conduit has an inlet and an outlet. The inlet of the secondary medium conduit is connected to a secondary medium source. The auxiliary medium is typically a gas or gas mixture that assists in the combustion of the fuel gas. Ideally, the carbonaceous fuel gas is completely combusted with the aid of the auxiliary medium to produce carbon dioxide. Ideally, the hydrogen fuel gas is completely combusted with the aid of an auxiliary medium to produce water, wherein the water is present as steam in the combustion zone of the process burner. The auxiliary medium source provides an auxiliary medium which is conveyed to the burner gas chamber via an auxiliary medium conduit (riser). A control device for controlling the volume flow of the secondary medium can be arranged in the secondary medium unit, in particular in the secondary medium conduit. In one example, such a control device includes a plurality of movable air slots and/or one or more air control flaps.

A burner plenum connected to the secondary medium outlet delivers the secondary medium into the burner tip, the refractory tiles and the combustion zone are arranged in the tip region and dampen the noise from the surrounding firing space. The burner plenum is disposed adjacent to the refractory tile, either directly adjacent thereto or indirectly via another component. The secondary media conduit may further comprise an additional absorber (sound absorber) adjacent the burner plenum.

The refractory tiles have refractory surfaces. In one example, the refractory surface is comprised of a ceramic. The refractory surface of the tile is directly adjacent to the combustion zone of the process burner, which is operated at temperatures up to 2000 ℃. The combustion zone is at least partially formed by the flame of the process burner.

Typically, an ignition burner or pilot burner for starting the combustion reaction is arranged in the region of the burner head (often also referred to as burner neck or burner block).

A preferred embodiment of the process burner according to the invention is characterized in that the second burner gas nozzle for introducing the second burner gas is arranged in the burner plenum.

A preferred embodiment of the process burner according to the invention is characterized in that the second fuel gas duct extends at least partially through the burner plenum.

The object of the invention is further at least partly achieved by a steam reformer or steam cracker comprising a process burner according to the invention.

The object of the invention is further at least partly achieved by a method for combusting a plurality of fuel gases with a gaseous auxiliary medium in a process burner, wherein the process burner comprises a first fuel gas unit, a second fuel gas unit, and an auxiliary medium unit, and wherein one of the fuel gases comprises carbon monoxide (CO), the method comprising the following method steps, which method steps are not necessarily performed in a given order:

a. introducing a first fuel gas from a first fuel gas source into the first fuel gas unit, wherein the first fuel gas unit comprises a first fuel gas conduit and a first fuel gas nozzle;

b. introducing a second fuel gas from a second fuel gas source into the second fuel gas unit, wherein the fuel gas from the second fuel gas source comprises at least carbon monoxide (CO), and wherein the second fuel gas unit comprises a second fuel gas conduit and a second fuel gas nozzle;

c. introducing a secondary medium from a secondary medium source into a secondary medium unit, wherein the secondary medium unit comprises a secondary medium conduit and a burner plenum;

d. introducing the first fuel gas into a combustion zone of the process burner via the first fuel gas nozzle, wherein the combustion zone is adjacent a refractory surface of a refractory tile and the refractory tile is adjacent the burner plenum;

e. introducing the second fuel gas into the secondary media unit via the second fuel gas nozzle;

f. the first fuel gas and the second fuel gas are combusted with the auxiliary medium in a combustion zone of the process burner.

In contrast to the known method, the second fuel gas is not introduced into the combustion zone of the process burner but into the secondary medium unit of the process burner via the second fuel gas nozzle. As is known from prior art process burners, a first fuel gas is introduced into the combustion zone of the process burner via a first fuel gas nozzle. Only in the combustion zone, the second fuel gas comprising carbon monoxide (CO) is contacted with the first fuel gas and combusted using the auxiliary medium. On the way to the combustion zone, the second fuel gas is only or almost only in contact with the secondary medium. It has now been found that this type of process management results in less solid carbon deposits being formed in the region of the fuel gas nozzle or upstream thereof, for example in the region of the fuel gas conduit.

A preferred embodiment of the method according to the invention is characterized in that the second fuel gas is introduced into the burner plenum of the secondary media unit.

A preferred embodiment of the method according to the invention is characterized in that the fuel gas from the second fuel gas source comprises at least 50 mol% carbon monoxide, preferably at least 90 mol% carbon monoxide, and more preferably at least 95 mol% carbon monoxide.

A preferred embodiment of the method according to the invention is characterized in that the auxiliary medium source comprises air, oxygen or oxygen-enriched air.

A preferred embodiment of the method according to the invention is characterized in that the second fuel gas is introduced via the second fuel gas nozzle at the following temperatures: below 160 ℃, preferably below 140 ℃, especially preferably below 135 ℃ and more preferably below 100 ℃.

The activation energy of the carbon formation reaction from carbon monoxide is typically between 150 and 400kJ/mol, depending on whether the activation energy is reduced by the catalyst, according to the budoal balance. For the uncatalyzed reaction, which must be assumed for the introduction of carbon monoxide into the process burner, the maximum permissible temperature was determined in a computer simulation using the procedure Aspen +. The maximum allowable temperature must not be exceeded in the region of the second fuel gas nozzle to suppress the formation of solid carbon from carbon monoxide. In particular, it has been found that the temperature must not exceed 140 ℃, more preferably the temperature must not exceed 135 ℃, wherein even lower temperatures, in particular below 100 ℃ are more preferred.

A preferred embodiment of the method according to the invention is characterized in that the ratio of the volume flow of the auxiliary medium, in particular air, to the volume flow of the second fuel gas is 15:1 to 10:1, preferably 14:1 to 12: 1.

It has been found that, in particular at the aforementioned ratio of the volume flow of the auxiliary medium relative to the volume flow of the second fuel gas, a maximum permissible temperature in the region of the second fuel gas nozzle can be observed.

A preferred embodiment of the method according to the invention is characterized in that the second fuel gas is introduced into the second fuel gas unit at a temperature of 20 ℃ to 50 ℃, preferably at a temperature of 30 ℃ to 40 ℃.

It is further preferred that the auxiliary medium is introduced into the auxiliary medium unit at a temperature of 250 ℃ to 350 ℃.

Especially when the secondary medium is preheated to the highest possible temperature and the second fuel gas is introduced into the secondary medium unit via the second fuel gas nozzle at the lowest possible temperature, carbon formation reactions can be avoided without exceeding the aforementioned maximum permissible temperature.

The object of the invention is further at least partly achieved by the use of a process burner according to the invention in a method according to the invention.

The object of the invention is further at least partly achieved by the use of a process burner according to the invention in a steam reformer or steam cracker.

Exemplary embodiments

Hereinafter, the present invention is explained more specifically by exemplary embodiments and numerical examples. In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as "top," "bottom," "front," "back," etc., is used with reference to the orientation of the figures being described. Because components of embodiments can be positioned in a number of orientations, the directional terminology is used for purposes of illustration and is in no way limiting. Those skilled in the art will recognize that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the embodiments is defined by the appended claims. Unless otherwise noted, the drawings are not to scale.

FIG. 1 shows

The process burner 100 of the present invention has a first fuel gas unit, a second fuel gas unit, and an auxiliary media unit.

The process burner 100 according to fig. 1 is configured to operate in a steam reformer and by operating with natural gas as the first fuel gas and carbon monoxide (purity > 99% by weight) as the second fuel gas. Ambient air is used as the auxiliary medium.

The process burner 100 is fixed via a steel structure 101 located outside the combustion space of the steam reformer. The flame of the process burner 100 is radiated downwardly into the radiant space of the steam reformer, which is bounded externally by refractory walls 102. A plurality of nickel catalyst filled reaction tubes are arranged in the radiant space of the steam reformer, which are heated by a plurality of the depicted process burners 100. Within these reaction tubes, the natural gas reacts with steam, while synthesis gas is provided in an endothermic reaction.

The process burner 100 includes a first fuel gas unit including at least one first fuel gas conduit 110, a first fuel gas nozzle 111, a flow controller 114, a flange 115, and a lance 116. The first fuel gas conduit 110 includes a first fuel gas inlet 112 and a first fuel gas outlet 113. The first fuel gas inlet 112 is fluidly connected to a first fuel gas source (not shown). The first source of fuel gas is natural gas. The flow rate of the first fuel gas (natural gas), that is, the volume flow rate of the first fuel gas is changed via the flow rate controller 114. A portion of the first fuel gas conduit 110 is a burner lance 116 that is connected to an upper section of the fuel conduit 110 via a flange 115. The burner lance 116 (thus forming part of the first fuel gas conduit 110) extends partially through the burner plenum 131 and opens into the first fuel gas nozzle 111, via which the first fuel gas is introduced into the process burner 100, more specifically into the combustion space 141 of the process burner 100.

The process burner 100 further comprises a second fuel gas unit comprising at least one second fuel gas conduit 120 and a second fuel gas nozzle 121. The second fuel gas conduit 120 may also include a flow controller (not shown) for the second fuel gas. The second fuel gas conduit 120 includes a second fuel gas inlet 122 and a second fuel gas outlet 123. The second fuel gas inlet 122 is fluidly connected to a second fuel gas source (not shown). The second fuel gas source is pure carbon monoxide (purity of at least 99% by weight). The second fuel gas nozzle 121 is connected to a second fuel gas conduit via a second fuel gas outlet 123. The second fuel gas nozzle is arranged within the secondary media unit, more specifically within the secondary media conduit 130. The portion of the second fuel gas conduit 120 that opens into the second fuel gas nozzle 121 may also be configured as a burner lance.

The process burner 100 further comprises a secondary media unit comprising at least one secondary media conduit 130, a sound absorber 134, and a burner plenum 131 (windbox). The secondary medium conduit 130 comprises a secondary medium inlet 132 and a secondary medium outlet 133. The auxiliary medium inlet 132 is fluidly connected to an auxiliary medium source (not shown). The secondary medium from the secondary medium source is ambient air. The secondary media outlet 133 is connected to the burner plenum 131 at least in fluid connection with the burner plenum 131. The burner plenum 131 conducts and distributes the secondary medium (air) in the direction of the burner tip or burner neck (lower part of the process burner). Part of the secondary medium conduit 130 is a sound absorber 134, which here comprises a secondary medium outlet 133 and opens into the burner plenum 131. The sound absorber 134 absorbs sound from an adjacent reformer.

Adjoining the burner plenum 131 is a refractory tile 140, which is configured here as a hollow cylindrical refractory tile 140 and has a refractory surface (not shown) at least on its inner side. In other embodiments, the burner plenum 131 may be fluidly connected only to the refractory tiles 140 without a direct connection between the burner plenum 131 and the refractory tiles 140. The combustion space 141 of the process burner 100, in which the first and second fuel gases are actually combusted with the auxiliary medium (air), is adjacent to the refractory surface of the refractory tile 140. A portion of the first fuel gas conduit 110 (here, the burner lance 116) and the first fuel gas nozzle 111 extend into the combustion space. The flame generated in the combustion space 141 is radiated downward into the radiation space of the steam reformer.

The process burner 100 of the present invention may comprise a plurality of first and/or second fuel gas units. In one example, the first fuel gas unit may be centrally disposed and surrounded by a plurality of additional first fuel gas units. Thus, the inventive process burner 100 may be configured as a fuel staged or air staged process burner. In these configurations known to those skilled in the art, the combustion reaction is retarded, thereby reducing undesirable NO_XAnd (5) discharging. In addition, the inventive process burner includes a pilot or start-up burner in the region of the refractory tile 140 to initiate the combustion reaction within the combustion zone 141.

In an alternative embodiment, the second fuel gas nozzle 121 may also be arranged in the sound absorber 134 or the burner plenum 131 (both of which form part of the secondary media unit). In the combustion zone 141, temperatures of about 1500 ℃ to 2000 ℃ may prevail. In contrast, the temperature in the auxiliary media unit is several times lower. In particular, the process burner 100 of the present invention may be configured such that the temperature at the outlet of the second fuel gas nozzle 121 is below 200 ℃ or even below 100 ℃. This effectively prevents the occurrence of an undesirable budoal reaction of two moles of carbon monoxide to one mole of solid carbon (graphite) and carbon dioxide at the outlet of the second fuel gas nozzle 121 because the activation energy of the reaction cannot be obtained. Thus, the second fuel gas unit is not affected by carbon deposit clogging. Although the temperature of the second fuel gas does then continue to rise in the direction of the burner dome 131 and the second fuel gas does eventually also "see" the high temperature in the combustion zone 141, the first fuel gas is diluted there and there is little likelihood that carbon formed in the combustion zone 141 will deposit on the inside of the first fuel gas nozzles 111. This is because there is a certain pressure drop in the first fuel gas nozzles 111 in the direction of the combustion space, which ensures that carbon particles do not enter the interior of the second fuel gas nozzles 121 but are entrained with the fuel gas in the direction of the radiant space of the reformer.

The following table reports four inventive examples 1 to 4, the data of which were determined by computer simulation using the software Aspen +.

Pure carbon monoxide was used as the second fuel gas and was introduced into the process burner via a second fuel gas nozzle in the region of the auxiliary medium unit at a temperature of 35 ℃ and a pressure of 3 barg. The secondary medium (in this case preheated air) passes through the secondary medium conduit at a temperature of 310 ℃. The flow rate of carbon monoxide introduced into the process burner via the second fuel gas nozzle in the region of the secondary medium unit and the diameter of the second fuel gas conduit at the carbon monoxide outlet (second fuel gas outlet) opening into the second fuel gas nozzle are varied.

The arrangement of the second fuel gas nozzle in the region of the secondary media unit is such that, when the flow rate of carbon monoxide is suitably high (examples 1 and 3), it is expected that the temperature in the region of the second fuel gas nozzle will be significantly below 200 ℃, advantageously below 100 ℃. The low temperature at the outlet of the second fuel gas conduit is effective to suppress carbon monoxide formation into carbon in this region, especially at high CO flow rates. At the high flow rates of examples 1 and 3, it can be assumed that the formation of solid carbon from CO is suppressed particularly effectively, since at temperatures below 135 ℃, it can be assumed that the activation energy of the budoal reaction, which produces one mole of solid carbon (graphite) and carbon dioxide (uncatalyzed case) from two moles of carbon monoxide, cannot be obtained at least in the outlet region of the second fuel gas conduit.

The following table shows two further inventive examples 5 and 6. Here, the temperature of the auxiliary medium (air) is slightly lower, and the volume flow rate of the auxiliary medium is adjusted so that the ratio of the volume flow rate of the auxiliary medium to the volume flow rate of carbon monoxide (second fuel gas) is about 13: 1. In both examples, the temperature is in turn determined to be significantly below 135 ℃ in the outlet region of the second fuel gas duct, and it can therefore be assumed that activation energy for the carbon formation reaction is not available at least in the outlet region of the second fuel gas duct.

List of reference numerals

100 process burner

101 steel structure

102 reformer wall

110 first fuel gas conduit

111 first fuel gas nozzle

112 first fuel gas inlet

113 first fuel gas outlet

114 flow controller

115 flange

116 burner lance

120 second fuel gas conduit

121 secondary fuel gas nozzle

122 second fuel gas inlet

123 second fuel gas outlet

130 auxiliary medium conduit

131 burner gas chamber

132 auxiliary media inlet

133 auxiliary medium outlet

134 sound absorber

140 refractory tile

141 combustion zone