SA93140127B1 - An endothermic reaction process - Google Patents

Abstract

Abstract: This invention relates to an endothermic reaction furnace comprising one or more longitudinal tubes within which an endothermic reaction flow path or path and a combustion flow path or path are specified to generate heat to activate the endothermic reaction. The combustion flow path is arranged so that the fuel and combustion air are heated separately by the heat inside the furnace to a temperature much higher than their self-ignition temperature before they gather in a combustion zone where they mix, self-ignite and burn.

Description

: Endothermic Reaction Process Full Description BACKGROUND The invention relates to an apparatus used to carry out endothermic reactions; It relates in particular to oil for the regeneration of light hydrocarbons; In particular mixtures of vapor and/or carbon dioxide and light hydrocarbons. o The hydrogen used in the synthesis of ammonia is produced; The synthesis of methanol or pyrocrackers is mostly in a process using the endothermic regeneration reaction: 3H, + 0Nd time and tergeon and the hydrogen can be glia which appears in the above reaction; or other light hydrocarbons or mixtures thereof, such as natural gas. These same 0 reactions can also be used when the desired product is © or both 0 © Hs . Another endothermic reaction is the conversion (thermal decomposition) of ethane to ethyleneuld, which also produces hydrogen as a by-product (Hy); And this reaction only needs heat; It is usually about m and pressure “atmosphere; But it does not need a catalyst. the catalyst on which the methane Jeli is made; For example ; It is nickel on dala inert Jie alumina” 800 and is usually found in 1 vertical tubes which are carried in a furnace often called “regeneration furnace” + a description or schematic illustration of regeneration furnaces is provided in the process flow diagrams of the US patents No. VEY 0010 “CF PAY COOL spirit. The tubes in the usual regeneration furnaces extend vertically, where the reaction materials are fed through a saturated distribution tube to one end of the tube group, and where saturated gases 0 are withdrawn with the product from the other end of the tubes. Since the regeneration reaction takes place at a high temperature YAN y and because it is endothermic; Heat must be delivered to the tubes to heat the reaction materials + and be conducted at a pressure of about 5000 in the tubes at a high temperature of about Jeli). psi 590 to 0 Many efforts have been made to improve the performance of the regeneration furnace or to improve the installation of the furnace to facilitate

A in the name of £9) 801 Oven Maintenance and Operation. and for example ; US Patent No. 0 demonstrates the use of a ceramic coating on the exposed surface of Fdnidge regeneration tubes. . J in which the reaction is; Where the coating is reflective to reduce the stress leading to gluing the pipes. She explains, and others; a regeneration device that uses the A Naito device; In the name of 16 997 US Patent No

EVY Stimulated heat generation for a very small oven size. US Patent No. et al. states; A regeneration device using heated metal regeneration tubes 5. © . Audrews as £ 81 Ve from the outside with a double passage and its ends are closed and it is also known as a shaft pipe with an exchange. Thermal controlled between the resulting gas stream and the reactant stream through the wall of the tube. There is also a well-known device that uses ceramic tubes to conduct gaseous reactions in those 7. In the name of Y 987 FAY ceramic tubes. and for example ; US Patent No. 616 et al. states; This furnace with ceramic tubes. Also, US Patent No. 2001 10 et al. states; Tubes made of a material that contains primary silicon, which is 7. Winkler in the name of 1 1 can be incorporated or inserted into other gas-tight tubes that prevent carbon build-up at . Procedure for converting the original heat to hydrocarbons 10:068:0005R1 The usual regeneration furnaces are known as huge and expensive when measured on the basis of capacity or power unit; that it includes tubes with a shorter life than desired; and exposed to carbon deposition (“Ye coking” for most Lally (and it is preferred to operate it mostly at temperatures lower than the preferred ideal values) (effective-reaction degrees) due to the occurrence of stress and corrosion in the regeneration tubes, and accordingly; the invention aims YO to provide an improved device for conducting endothermic reactions, such as light hydrocarbon regeneration, which results in improved conversions, energy performance efficiency, and improved maintenance.

YAN

¢ General Description of the Invention This invention provides a unique furnace design in which the heat required to activate the endothermic reaction is generated inside the furnace by the self-use of gaseous fuel and air. The flow paths of the endothermic reaction material and the product are arranged on the one hand, and the air, gaseous fuel and combustion products thereof on the other hand. So that the air and fuel are heated separately by the heat generated inside the furnace to a higher than their self-ignition temperature before they are collected in one or more combustion zones where they self-ignite and burn. The flow paths are also arranged so that the combustion gases, as well as the endothermic reaction product, cool down before exiting the furnace. In this way, the use of separate ignition devices is dispensed with to start the combustion of the fuel / air mixture in each combustion zone. This is particularly valuable in large multi-tube regeneration furnaces; Since it allows for close scaling of the combustion tubes to be made and also allows for the costly maintenance and repair efforts needed to service out of operation flow ignition devices.

0 and in a special embodiment; The present invention utilizes a design of a ceramic tube burner which is enclosed by a reaction vessel in which the endothermic hydrocarbon regeneration reaction takes place. This would be inconsistent with the usual prior art apparatus in which the reaction takes place in a tube and where the heat is obtained from an external source. This design allows the use of a more robust and solid device. Which can use a large number of fuel tubes with high density and can operate at 1 m at high temperatures and pressures to achieve a high conversion of hydrocarbons with a high thermal efficiency of the process. In addition ; Composition materials allow good operation with moderate vapor-to-carbon ratios and minimal coking. The device allows this design to use relatively low-temperature sealants. The reaction apparatus in this embodiment includes a reaction vessel for conducting the endothermic reaction; .+ includes an inlet for feeding the feed gas mixture into the reaction vessel; and a vacuum outlet to remove the gas produced from said reaction vessel and at least one heat-generating means for heating said reaction vessel located within said reaction vessel: The reaction vessel may contain a catalyst bed filling the YAN vessel

The reaction was carried out at least partially to facilitate the endothermic reaction to produce a product gas. The heat generating device in this embodiment includes at least one ceramic combustion tube centrally surrounding a fuel feed tube extending at least partly along and into the combustion tube. The heat generating device includes an entry device for feeding fuel gas air so that the fuel gas and air are combusted in said heat generating device and so that the heat generated from the heat generator is transferred into the reaction vessel; And an exhaust outlet to remove combustion exhaust gases from the aforementioned heat generation method. It is preferable, 0, that the mixture, the feed gas, be brought into the reaction vessel from one end, and that the feeding gas and air enter the heat generating medium from the opposite end of the feed end, so that the reaction gases and combustion gases flow together at the same time. Ve and in another embodiment; The furnace subject of the invention is designed so that the endothermic reaction takes place inside metal reaction tubes; With the occurrence of combustion of fuel and air outside the pipes. In this embodiment it is preferable that the combustion medium also use common air and fuel feed pipes in one central line; Which is best also shared in one central line with the metallic reaction tubes. This arrangement also allows for tight bracing of the tubes as well as the self-ignition of the fuel/air mixture; Both features contribute to a simple design and ease of operation. The following is a further explanation of the invention through the following description with the attached drawings. A brief explanation of the drawings: Figure 1 - A statement of a cross section of the regeneration device subject of this invention. Yo oo Fig. 7 - Indication of a cross section of the regeneration device shown in Fig. 1 taken along the lines ? . FIGURE ¥ - Indication of a cross section similar to FIG. 7 but illustrating an AT embodiment of this invention FIGURE 0; - an indication of a cross section similar to Fig. 1; An AT embodiment of the invention in which a feed tube is used shows a perforated . ‎Yo form © - an indication of a cross section of another embodiment of this invention; in which VAY | is used

+ A spear combustion tube. Figure + - a lea statement of the methane regeneration process illustrating this invention. Figure 7 - Indication of a cross section of the AT embodiment of the invention. Figure A - Schematic statement of the production and reaction gas temperatures aspects as well as the combustion tube wall of the device shown in the form of V when the flanges are stable and continuous. The following is a description of this invention with respect to the number of preferred embodiments. In one embodiment described in an earlier application with serial number 375/097 504 and filed at ¥ Apr + 0 0 - the combustion is carried out in one or more ceramic tubes; The endothermic reaction takes place in one or more of the flow paths outside the combustion tubes. In a preferred AT embodiment, it is explained lad as follows; The endothermic reaction takes place inside one or more metallic reaction tubes, where combustion occurs in one or more combustion flow paths located outside the tubes. and in both incarnations; It will also be explained in more detail below; The flow paths of the different reaction gases and product gases are arranged so that the combustion air and fuel are heated separately to +0 a temperature higher than their self-ignition point before they gather inside the furnace, where they mix together, self-ignite, and burn to produce the heat necessary to activate the endothermic reaction. Rendering of a ceramic tube Figure 01 illustrates in Fig. 1 the reaction apparatus that is generally the subject of this embodiment. Although it is shown in an upright position; However, it must be understood that it can be played in a horizontal position; Rather, it does not, + be limited to a specific situation or direction. The device includes a VY steel casing internally lined with VE heat-resistant insulation and includes a bottom plate 11 (it can also be called a tube plate) fixed by gaskets. and by screws or the like; hardcover; and a top plate (or tube top plate), which together define the reaction vessel. The lower VU plate bears a catalytic bed 01 through which one or more combustion tubes 0 pass; It is made of ceramic material and + and is firmly attached to the lower plate 11 and the upper plate 18 . The shape of the regeneration unit is generally cylindrical and can be described as somewhat similar in structure to a shell and a tubular heat exchanger. YAY

The ceramic burner tubes are fixed to plates 116 and 18 by means of a hollow screw (not shown 0): gle inside the tube plate at the tube end in conjunction with a steel compression ring which

form a graphite riveted; Which is preferably a thin spirally wrapped annular cylinder rivet

Graphite (eg Granfoil from Union Carbide). And you do this

The rivets, YY, fix the combustion tube in its place 0. Gas pressures are reserved on the side of the casing that is more

use However, it allows it to expand thermally and independently without significant current leakage

invader through the epithelium. It may also be desirable to apply an axial or compressive force

A preload on each pipe which will tend to equalize or decrease tensile stresses

axial generated by thermal fluxes; By adding a stack of Belleville springs (not shown), a set of pipe rivets, or the like. Alternatively;

The rivet can be held in place by means of a device that also generates an axial compressive force

0 The advantage of this design is that it allows the use of rivets at lower temperatures, as it is a tube or

The combustion tubes are attached to the tube plate.

The hard shell 11 includes one or more YY feed inlets for the passage of the feed gas mixture M1 - to be regenerated into the regeneration unit and down through the backing layer 01 for exit through an outlet (

outputs) one or more YE outputs. And the feed gas mixture can be; For example ; mixture

of natural gas and steam if the endothermic reaction is a methane regeneration reaction even though the mixture

It can be natural gas, a vessel that turns into steam in the reactor, or just natural gas; with

The steam produced from the water fed separately into the reactor. As understood; Other groups of feed mixtures can be added. As shown in Figure 1; The catalytic layer 71 which

may be nickel over alumina; or other suitable catalytic inert carrier; It may include a section

or inert region YT; Or the entire bed can consist of a single catalyst or combination of materials

catalytic + and in fact; The device can be operated without a catalyst for some adsorbent reactions

for heat. Yo and inside the combustion tube 0" there is a VE fuel feed tube in common with it in the same axis 0

Central, which can be made of metal alloy or ceramic material. tube is installed

‎YAY

A

By welding or using a Vo ring (on the outer plate) or a YE tube plate. Fuel is fed to the distribution tube ©1 of graphite. Fuel is fed from a circular or thin VV inlet with a rivet, and air is fed Through an air intake, TE, to the fuel feeding tube, YA, which is saturated with a fuel inlet, in the air inlet, which is specified on the outer plate © and located at a distance from Z, EY, to the distribution tube, 0, through an annular inlet, so that Tr Which is connected to the combustion tube 11 tube plate 0 and the inner wall TE The air will flow into the annular space between the outer wall of the fuel tube and the fuel feed tube 34; Vo consists of a combustion tube assembly Tr for the combustion tube The means of generating heat for the reactor and the fuel gas is any clean fuel to which sufficient water vapor has been added (as aie necessary) to prevent coking before combustion. It needs a little pre-heating to maintain the required humidity level without condensation.Z from the reactor to start the VY and uses a heating resistance coil 476 inside the outer shell wall

Tor cold start reactor. The resistance heater preheats the immediate area to about m (which will depend to some extent on the quality of the fuel used); Which then can occur spontaneous ignition of fuel and air. It may be necessary for an air flow to be yo. 51 cll preheating When gas can be added to cause ignition in an area of \u200b\u200band it is passed out of OF in an exhaust distribution manifold “00 and the exhaust is collected from the combustion pipe. Exhaust outlet port 0 that is connected to the manifold ?* Made of sintered alumina and can be Wo and preferably a ceramic combustion tube. Made by any of the various available methods for making and forming dense ceramic particles) impermeable from the use of alumina and other ceramic compounds can be used pile Also, there will be no embarrassment

TOA. ; In the name of, PET 44 example; It was mentioned in American Patent No. dan and Ali 0. ¢ Alpha Sintered ay 8 et al. Description of a silicon carbide composition and a process for producing Coppola porcelain bodies. These may be used in the manufacture of a ceramic tube. It includes other ceramic fixtures that can be used on silicon nitride; aluminum nitride; silone and the like yo The preferred substance will depend on the substances involved in the reaction and the reaction products involved in

Ya

the operation ; In addition to temperature and pressure. It is preferable to make hard shell VY, base plate 16, top plate VA, radiators + and 07 -; the YO outer plate is of conventional pressure vessel steel which is designed and manufactured to withstand up to AH 1801; square inch or more and temperatures up to ‎a You . It is preferable that the thermal insulator (VE) be corrosion-resistant and low-conductive, such as alumina installation, with expansion joints used on demand. The thermal insulator must be prepared to withstand at least 0301 m continuously.

Figure 1 shows a cross-section of the device for processing and trimming the length of the line Y - 1 in Figure 1 - and as shown, the concentric YE fuel tube is placed inside the combustion tube Ve, which is surrounded by

0. . In turn, with a Yo catalyst cradle inside the insulated steel casing 17 . The heat will be transferred from the combustion tube Fe to the catalyst cradle 71 to bring about the endothermic reaction to process the ies mixture of steam and light hydrocarbons. The use of external pressure surrounding the combustion tube

©0 A very important advantage or benefit, which is placing the tube in a state of compressive stress, where the ceramic materials are stronger than in a state of tension. yo and as shown in the form of ©; The design can consist of more than one tube, as the figure ¥ shows seven tubes in a suitable form. The invention is not limited to the use of a tube or seven, and it is expected that 1,000 combustion tubes can be used in a treatment and refinement device of a suitable size 0 and it facilitates the use of small diameter ceramic combustion tubes and a thin graphite plug from a denser filling of the combustion tubes than what was available in prior art devices.

7 The air entering the inlet 460 may be supplied by a blower or a compressor depending on the furnace pressure required, heat transfer requirements and the process used. And the compressor will generate a higher inlet pressure than the blower; On the other hand, the cost of operating the blower is less than operating the compressor, and it may also be required to heat the air saturated before entering the means of heat generation. Although the drawing does not show a preheater, these methods are known

vo in the domain and are commercially available. and according to desire; Exhaust stream can expand (with some heat

possible) through a gas turbine to drive the air compressor. YAN

Ye. In that they are 1 for that shown in the form of Silas * and the device shown in the form of; and

YY; and have a feed slot 01; Content of 11 catalyst cradles incorporating the jacket. The difference between these two embodiments lies in the design of the heat generation means; . VE and output slot: . Although in each case it is attached to the reaction vessel, it has holes or 010 tubes to feed the Ye gas, as shown in the figure; ; The combustion tube shall be closed. In this way ; TT will have 14 holes spaced along the length of the tube; and one end of it until it exits 01 the fuel feed stream passes through the inlet 96 to the manifold 8" to the bottom of the tube and when the reactor is at operating temperature the fuel will mix with . 4 lll through | and ignite automatically TA and to the burner area £Y the air inlet through the inlet £0 to the manifold heating the reactor Note that the seal 6 does not need to resist very high temperatures and therefore 0 can be made of graphite or refractory organic cement It is also possible to use other methods, for the phased entry of fuel, and the design differs in the form of ©, in that the means of heat generation are harpoon-type means. The combustion has a closed end 18. The combustion is a closed end tube 80 that closes in the plate but can have a stopper as shown in Fig. . Fuel is fed through inlet 1 while air is fed through air inlet 876 to AE 87 fuel to the fuel feed tube

Ve and at operating temperature; The fuel ignites automatically in the flame area. AA air feed tube to produce heat for the endothermic reaction to occur and the exhaust gases will pass up the tube to the manifold 57 where they exit the device through the combustion line AY 80; As shown by arrows exhaust cof 0 and in general; In devices according to this embodiment, combustion tubes require a length ratio of . 0010 to 000 to approx. inner diameter to achieve the required heat transfer per unit flow volume of natural gas as well as steam treatment and refinement application. Higher ratios are required when the reactor is operated at Z. Low temperature 8 YO a

11 The preferred spacing between tubes in this embodiment is fairly small; For an inch. It is limited by the sizes required for the plugs and the accompanying teeth, 1.8 to 0.7, for example, and the need for a small distance between these teeth. Small distances lead to Else. Reduced pot sizes and improved heat transfer within the casing

The number of tubes inside a single reactor ranges from one tube to 00.001 or more. Large reactors require thicker pressure vessel walls but save on installation costs. The preferred tube wall thickness will depend on the tube's strength, corrosion rates, and diameter. The use of an outside compression will allow the use of relatively thin walls, as long as the ceramic materials are more tensile than compressive. 0 The preferred inner diameter of the combustion tube is usually equal to the distance between the tubes (expressed from inside tube to inside tube). And so on ; If the spacing is 1.4 inches » the preferred ID for the pipe is also +f inches for a centerline distance of 1.8 inches. It is preferable to arrange the tubes in the form of an equilateral triangle to obtain the maximum packing density

For example, a design could use 00.001 tubes of 4 in. m OD dan XID ad Ye X length on a triangular pitch of 1.8 . The diameter of the beam is 7 feet and the total internal surface area is about 00.9050 square feet. The pedestal design in this embodiment uses a fuel-air stream entering the reactor at the same end while the process gas exits and flows upstream with the exhaust gas exiting at the opposite end; Where the process feed stream enters.

Y. Another change is that the combustion gases flow in the same direction as the process gases. This method requires a hot plug on the exit end of the ceramic tubes. and that plug may be made of compact glass or ceramic cement; For example . The cold end plug may be in the form of a ©-ring or thin graphite to allow for thermal expansion of the tube.

Closed end triple concentric combustion tubes can be used with the combustion gas exit yo at the same end in the reactor dua entering air and fuel. It is illustrated in the form © and can be AA

VY

The open ends of these concentric tubes shall be at the manholes of a process or at the end of the . Exit from the process in the reactor, and the upper operating temperature in the graphic plugs is determined by oxidation with air present on one side. If a very small, controlled leakage of the working gas is allowed through the plug, this works to push the air away from the plug material, which leads to a prolongation of the sealing time ©. at high temperatures. This system can be called the plug-cleaning state. The maximum operating temperature of the reactor can vary widely; According to the request to maintain the conditions of automatic self-ignition, the dala on the other hand; If there is, according to the fuel test, (5 ©0801 reactors using a maximum operating temperature of less than require the selection of one of the jacketed burntube designs). In those cases, 0 . 2000 The maximum operating temperature is as low as . (The combustion tubes can be made of many ceramic materials depending on the conditions of use, heat, corrosion, and stresses). In addition to alumina, there are some lighter materials that can be used, such as carbide ceramic materials such as silicon carbide; or oxides of ceramic materials such as mullite; the second zirconia; or something like that. The use of an external pressure is one of the most important features in controlling the stresses collected in the ceramic tubes to acceptable rates. There are still other Ve materials that can be used, such as metal pipes, which are used in low grade applications. Heat, and if the fuel chosen is a mixture of hydrocarbons (such as natural gas alle to cause TE and steam; a catalyst for refinement placed inside the tube) can be used to partially refine the fuel while it is heated and thus absorbs more of the heat from the process gas (0) (improving cooling) and at the same time increasing the heating value of the fuel gas (improving the heating). gas (a mixture of hydrogen and carbon monoxide) mounting chips.Modifications in physical dimensions will be considered from YO

YAY

operating variables, so adjustment is necessary to achieve the same results. The schematic diagram shown in Figure 1 is provided to help understand the example presented here and the various variables involved in the process that is the subject of this invention. Example 1° A feed stream containing 7.5 vol of steam plus 01 vol of natural gas (with an assumed composition of 790 vol of CHy + 1 7 » 02011; 11277 and 00271) is set up through either a conventional trimmer or an instrument The subject of this invention is 0. The conventional device is similar to that described in the US Patent No. 177 101 9 of its owner Doerr and his colleagues with a pressure of the hot reaction zone about veo psi "; Cus the example subject of this invention uses pressure 0101 pounds / inch?. The composition of the syngas shown in Table 1 depends on the compositions of thermodynamic equilibrium at the aforementioned pressures and at a temperature of Ye less than all temperatures mentioned in Table 1. The compositions were recorded after water condensation. To 560 m 0+ the syngas compositions that were calculated The conventional irradiated device The device subject of the invention The maximum temperature in the device (°C) 850 1170 Pressure of dried sungaz (pounds / inch) Y 140 1140 cas Dry slag (mol 7 ( H, 72.49 13.74 CO, 15.97 20.56 CH, 3.60 0.96 N, 0.50 0.48 H,0 0.61 0.10 YAN:

Volume of dry gas / volume of natural gas 3.98 4.5 Methane conversion rate 84.1 95.6: According to the data shown in Table 1; the advantages of this invention lie in the pressure of syngas being Je, which helps to eliminate or reduce the need 007112 in syngas is much higher and the ratio of 007002 in syngas is also very high The new process can be operated as desired at higher temperatures to obtain a higher methane conversion rate and ef ratios for both 67112 and CO/CO2.(Sa) can also be operated at Ae or low pressures and/or high or low vapor rates. Ceramic tubes are less prone to coking than metal tubes under conditions of low vapor rates. The new invention allows for high rates of heat transfer per unit volume of the reactor vessel. For example, the average rate of heat exchange between the process gas and air/fuel/exhaust is about MW/Ya for the internal volume of the process device designed according to this invention and depends on The previous example, and that number is greater than a coefficient of 01, higher than the corresponding value in the case of the usual radioactive treatment device. Metal reaction tube embodiment. Yo as shown in Figure V The reaction apparatus of the subject of this invention generally shown in this embodiment and referred to as No. 001 comprises an elongated vessel 017 having an extension 017 (such as a metal elbow) and is specified first party or "vertical" 0154 and second party or vertical 0016; Insulation of 011 ceramic fibers and 018 interior. and for cold starts; An external burner ( 0 not shown ) is used to preheat the incoming air to a temperature of about 000 °C; This is to pre-heat the reaction to above auto-ignition temperatures 0 and the burner is closed to you as soon as the fuel ignites. YAN

1

In the interior of 0018 is an endothermic reaction tube 011 which is fixed to end plates or "tube segments" 1 0 and 111 by suitable means such as welding (not shown). As shown in Figure 7; The tubular slats 6 004 111 shall be firmly attached to the walls of the vessel 011 so that they are not subject to axial movement in said vessel with respect to the part of the vessel in which they are fixed; In the art this is called a "fixed tubular slide design" and in addition, in the embodiment described, there is no fixing fitting such as bars or baffles; on the shell side in the inner part of the vessel to hold the reaction tube 011 at the position of medium (gl) at the position of Medium to terminal) as in conventional designs to prevent lateral movement of the tube and thus twisting

under compressive loads.

1 The interior of reaction tube 011 specifies a flow path for the endothermic reaction to carry out that endothermic reaction; While the volume outside the reaction tube 0011 determines the combustion flow path to perform the Slay combustion process. The reaction tube 011 with catalyst for the endothermic reaction 111 has a suitable shape and size . In the embodiment shown, catalyst 111 consists of spheres having a diameter of about ¾ mm. In order to accelerate the heat transfer process and thus reduce thermal decomposition in a tube

The endothermic catalyst 111;11 in contact with the combustion zone 011 deli on both sides of the agent 174 YY is smaller in size, about mm in diameter. There are inert materials. ; Also to improve heat transfer, VYVE / 111 endothermic catalyst to receive a feed stream of 17" materials together with the inlet manifold 01, the Veg tube slide, the head expansion 111, the tube plate 0011, and the vertical set 18 interaction. The heat sink from the entry hole

,. 177 To discharge the endothermic reaction through the exit hole 171 A lee exit manifold to receive air from the opening 17 Air bronchi 111 With the tubular slide 17 The air head is specified;

Entry 178 and VE air tube connection; Combined in the center with the reaction tube 011 with the air manifold VET to discharge the air to the combustion zone 111 through the loop 147 . The two VEE fuel heads with the two air heads 176 define the VET fuel manifold to receive gaseous fuel from an inlet

0011 also with reaction tube 3S pall; which is the Vou orifice and the fuel tube YEA leads the fuel Yo through loop 111 to supply fuel to the combustion zone VET with the fuel manifold VE and the air tube

YAN:

YOY fuel. The flue gas header 154 with the tubular bracket 0014 sets the flue gas manifold You to discharge the flue gas produced from the combustion of fuel and air into the vessel 08 through the flue gas dda 067; formed by reaction tube 011 and discharge tube 001 concentric with it; The combustion gas outlet opening is 1548. As shown in Figure 1; The air duct 1140 and the fuel duct 1051 are designed so that the combustion zone 111 is inside the vessel 017; It shall be, as will be described below, sufficiently far from the reaction and combustion gas exit openings so that the endothermic and combustion gases are cooled before leaving the vessel. and when running; Once the equilibrium and stable state of a mixture of methane and water vapor inside inlet 178 has been reached; This is followed by the withdrawal of the endothermic product from outlet VY ; dB of fuel and air are transmitted to the fuel inlet VEA and air inlet VFA respectively; This is followed by the withdrawal of combustion gases from exit 158. This causes a reverse current to pass between the reaction gases and then to flow through the reaction tube and the combustion gases to pass through the forward 018 of vessel 017 . The flow rates of the reactants and products and the size and shape of the various tubes are chosen so that when air and fuel are mixed in the combustion zone 11”; They are at a temperature equal to or greater than their combustion temperature. Thus, mixing, ignition, and combustion occur without the need for a separate igniter such as a spark plug; glow candle and the like . The flow of endothermic reactant and combustion gases in an opposite direction of the current results in an improvement in heat transfer between the reactant and combustion gases on opposite sides of the reaction tube walls. This reduces hot spots and increases the life, + - default of the piping. This beneficial effect is shown by Figure A; Which depicts a graphic representation of the temperatures of different working gases and all surfaces of the tube walls of the 011 reaction tube of the device shown through Figure 1 and through Figure A. The axes represent the distance measurement from the VTE region (a) starting from Zero as the beginning of the combustion zone 111 . And the certainty of the coordinate vo is the temperature of the different gases and the wall of the tube. During this form; The side view, VE, represents the temperature of the endothermic reaction; The side view represents 1167 the temperature of the absorbent product

1 1171 fuel temperature; The side view, VIA, represents the side view, Jie, of temperature; while the flame temperature; The side view 177 represents the air temperature; The side view represents the reaction tube wall temperature 1178 flue gas temperature; The side view is 4

Stays the reaction tube temperature from the inside; the VAL from the outside; The side view represents “ while 111 and the endothermic catalyst 111 represent the barrier between the inert YAY and the side view 6. The autoignition temperature of a fuel/air union 4 As shown in the figure; the temperature of The flame for the combustion of gases reaches a very high level, while the temperature of the JES 011 tube walls, internal and external, is relatively low, which significantly extends the life of the tubes and allows the use of metal tubes 0 - instead of ceramic tubes in uses that require Alle temperatures and at the same time; the various gases exiting from the device; whether they are exothermic pill gases or combustion gases; of can be cooled to reasonable temperatures and at the same time inside the invented furnace; the combustion gases are heated to A temperature that exceeds the auto-ignition temperatures and at the same time the endothermic reactants are supplied with a sufficient amount of heat to carry out the required endothermic reaction 1_ Also, it is possible to avoid the problem resulting from the high thermal pressure that ceramic tubes sometimes face, according to the following mentioned later; The appropriate design characteristics of the embodiment of the metal reaction tube of the present invention are identical or similar to those previously mentioned for their counterpart ceramic tubes of their embodiment. And anyway; it is through vy, this embodiment; It is preferable that the separation distance of the pipes in the Alla multi-design is very small. It is preferable that the distance of the midline between adjacent sets of tubes (i.e. feeding tube 0 - air tube VE and test tube 011) is 1.75 times the outer diameter of the feeding tube 156 . The smaller the distances, the smaller the pot measurements. In this embodiment, tubes made of ceramic or other materials can also be used instead of metal. Jes vo In any case, it is preferable to use metal tubes over ceramic tubes in this embodiment due to the ease of obtaining them in long gauges in relation to their diameter ratios; As well as what is characterized by a

Ya

In terms of its ability to connect and ease of closure (by welding), flexibility ¢ and low Price and resistance to thermal stress The reaction apparatus of the present invention described by this embodiment is suitable for large-scale operations such as gas synthesis on a commercial production scale by means of steam recovery of gaseous hydrocarbons; Especially methane. Celsius extraction reactions are preferred; The best is 0001 steam at high temperatures; For example, at 800 to -Tropsch °C; It is preferable to carry out the synthesis of methanol, as well as the synthesis of 171 between 870 and atmospheric pressure; And the best is 01, for example, at a pressure not less than le at Fischer pressure degrees to 00 atmosphere pressure. preferably 0 atmospheric pressure; Even better is between Te to 100 for high pressure machining and at least on the casing side; and use. High temperatures when carrying out this type of reaction Large-diameter reaction tubes are used in large-scale furnaces and for you to work at temperatures and these tubes made of porcelain or metal alloys dala high temperature and pressure ¢ and there is the boiler; where you can withstand high temperatures; It also requires that it have very thick walls and have a low internal temperature. These tubes are very expensive. Therefore, the large-scale furnaces of 10 m, which are used to extract steam at high temperatures and pressures, must be made of a large number of densely packed tubes for an economical purpose. It is possible to do dense filling of a number of tubes according to the present invention, because the tubes consist of metal; The reaction takes place inside the tubes, and due to the occurrence of self-ignition of the combustion gases, this obviates the need to use igniters and / or stoves to ensure the stability of the combustion flame. It is preferable that there is no supporting installation of the tube inside the vessel on the boiler side; But that is not a basic feature through this. Embodiment, even if its presence is auxiliary, and through this context; It is important to note the starting time of the device for this embodiment under pressure higher than atmospheric pressure on the side of the tube; For example, through an integrated operation process that includes methane reformation as a first step, followed by a high-pressure operation in the direction of the yo-stream; The tubes remain under tension. This is because the pressure on the side of the tube is created by it

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An axial force tends to push the two heads; The important properties related to the embodiment of the invention, because the tubes, especially if they are long and thin, are mainly used to reduce operating costs, and these tubes have relatively less pressure-bearing strength when compared to others, and therefore any obvious pressure load, whether axial or lateral, will spoil these tubes. In a way that does not allow them to be maintained if they are damaged or deformed.By increasing the tensile strength on the pipes, this allows them to be thinner, which makes them cheaper and increases their strength, which allows avoiding the problem of warping.And when temperatures rise during endothermic reactions, the pipes are exposed to allt, and that is _ by changing Its shape and deformation under the influence of high temperature, especially in the axial direction, for example, it can be estimated that the length of the tubes of YO feet increases in length by approximately inches during methane purification. Completely from the stabilized tube film casing and tube thermal equations causing bending of the tube film resulting in axial loads in the tubes through the tube film. NO self-expansion of axial load through pipes extends the life of the whole machine; This is because it prevents the collapse of pipes that are subjected to disproportionately high axial loads, according to what happens in designs and models in this field. By one preferred embodiment the present invention provides combustion furnaces containing at least 001; and better 501 and better than that no less than 0001 or even ... 5 0 reaction tubes; Each has an inner diameter to length ratio of #0 to 0001, best of 151 to one, and even better of 7900 to 2500 . The present invention is particularly suitable for large-format designs; Of the high-capacity furnaces containing at least 100 reaction tubes with a ratio between length and inner diameter of not less than 100. These furnaces are designed to withstand a high temperature (no less than 850 YO) and a pressure (Je) (no less than 10 atmospheric pressure). It is preferable that these furnaces contain no less than 0000 tubes. An interaction with the ratio between their respective lengths and diameters, YAY |

0 Internal no less than 700. It is preferable to carry out large-scale operations to use tube furnaces with a ratio between the length of each of them and its inner diameter of no less than 0001 containing no less than, and these furnaces are suitable for carrying out large-scale operations that are carried out under pressure. You are less than 5000 psi and high temperatures eg 5000 high; any ; no less than . ° C AVE not less than about 0 The following example provides a visualization of the embodiment of the dependent metal reaction tube: For the present invention Example? The stated temperature and flow rate. The composition of the gas output is calculated on the basis of equilibrium thermodynamics. chemical psi 577 aly at a temperature of 897°C and a pressure of 71749 and an output temperature of 590°C; While the rate of air feed in pounds per inch is 11 aly degrees Celsius and the pressure is 181 kilomol / hour at a square temperature. fuel gas contains 11 2747 ; The remainder represents other gases. The temperature of the initial heating of fuel and air is approximately 85 0 degrees Celsius, while the temperature of the initial heating of fuel and air is close to 1 . Exhaust about £90°C mole gas 0001 7 Feed gas Output gas 45.28 1.19 H2 vy, 14.93 - Co 5.66 8.18 002 6.86 30.86 CH4 4.35 6.29 | N2 27.90 53.57 H20 (pressure) psi Yo 508 638 : YAN

1) Flow rate (kmol/h) 4583 3222 Reforming tip temperature: 0 ° C 1700 : Number of combustion tubes : Internal diameter of the combustion tube oo mm 19.8 : Total length of the tube Combustion 0 mm 367 : length / diameter of the combustion tube It is clear from this that the transformations of high methane into a mixture of hydrogen and carbon monoxide Ve to achieve and absorb a lot of LAS and low temperatures in the form of le; can be achieved at Compression of commercially available high-temperature alloys, which means that the invented furnaces can be made of metal tubes instead of ceramic tubes, and also increases the life span of using these tubes even if they are used in the high conversion of methane to a mixture of hydrogen and monoxide Carbon at high pressure Ye General description applicable to embodiments The best model and operating conditions of the inventor furnace are determined using a special application that depends on several factors that will be mentioned below. For example, steam reforming - methane and most Endothermic reactions of interest) which are preferably carried out at high temperatures and low pressures. And anyway; Most of the applications of the mixture of hydrogen and 0 carbon monoxide resulting from this requires that the mixture be at high pressure. And after using compressors to do. The pressure of the aforementioned mixture is very costly in terms of capital or energy. Through this invention, it is possible to operate and produce a mixture of hydrogen and carbon monoxide at 100 atmospheric pressure using metal tubes, up to 100. Any required pressure reaches about pressure one or more atmospheres using ceramic tubes. The preferred pressure represents the lowest required pressure YO for the following uses of the resulting gas, which means that there is no need to use a gas mixture compressor

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YY

. used in this field at the present time, and the pressure of air, combustible fuels, and combustion products present in the combustion flow path can be equal to the room pressure. And when carrying out endothermic reactions at high pressure; It is preferable to maintain the pressure of the combustion gases at a high level of pressure, for example / Hamsi atmospheric pressure or more than that. Which reduces the stress of the reaction tubes. What is between 01 and ? to © . Using thin reaction tubes The preferred ratio of inner diameter to length of burner tubes as well as reaction tubes depends on the embodiment chosen; required temperature; gas pressure drops

L / 0, the percentage (1) that is allowed during use and operation, for example through the embodiment of the shape, ranges from L / D. It is preferable to use a ratio of 1, while during the form 000 to 40800 used ranges from 0

You between 09? to combustion tubes and the reaction is relatively small; For example, Jala preferably has a diameter of millimeters; For purposes of Vo to 11 mm; Preferably between 00 ranging from © to economical ¢, but it is possible to use pipes of any internal diameter. The small diameter requires that the pipes be thin-walled compared to the pipes of large diameter at the same temperature and different pressure, and thus the cost decreases. If the pipes are very small, the number of pipes is very large, and the cost rises again. as well as; Very small diameter tubes cause problems during catalyst filling in models that contain catalyst inside the tubes; Which leads to weak heat transfer. With regard to ceramic tubes in which combustion occurs; the small diameters cause heat transfer in the ignition area; Which may cause an increase of 0 in the wall temperature. Larger pipes cause unwanted heat leakage. radiation route and when determining the preferred number of tubes; The choice must be made between one very large reactor and several small reactors. Especially during industrial operations for processing very large volumes of operating gas, and in general there are some advantages resulting from the use of more than several thousand tubes in one reactor. It is preferable to use the least possible number of tubes when doing

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gas operation. Using the embodiment cited in Figure 7 containing reaction tubes with an inner diameter of A+ inch, the production of the mixture of hydrogen and carbon monoxide per tube by one example aly is about 7.7 kg-mol/h. The metal alloys preferred by the present invention should have a high ability to resist thermal deformation (resistance to deformation and tear) and be resistant to both oxidation and gaseous corrosion. Among the preferred alloys suitable for these uses are many nickel-containing alloys; High temperature alloys 0 is an example of this; When using the invented reaction furnace to re-form the methane vapor using nickel-based and chromium-containing alloys; Tungsten and molybdenum for example / Haynes.RTM.230(Cr22 « 14 arat M 2 and the remainder (NT) commercially available Haynes International. Inc. of Kokomo, Ind sal. 1 When needed; can be supplied Metal pipes with a suitable cover to prevent metal contamination and other forms of attack.These covers are known in the industry.The top temperature of the operation process depends on the pressure chosen;the material of the pipe;the composition of the feed mixture;and the requirements of the external operations.It is preferable to perform + operation at higher temperatures than It increases the life of the tubes to an acceptable degree under the selected conditions.In these cases, the ceramic tubes are operated at peak temperatures ranging from 151000 to more than 10110010 degrees Celsius, while it is preferable to operate the metal tubes at a level of temperatures ranging from Between about 850 to 0001 ° C. Through other cases, it is possible to achieve thermal equilibrium for higher operations with a decrease in total costs at relatively lower temperatures than previously mentioned when using metal pipes during operations when + reaches a peak The preferred temperature is between about 875 to AYO degrees Celsius. In a preferred embodiment of the invention the reaction furnace is designed and operated such that operation during the steady-state process takes place in the presence of a difference between the heating temperature of each of the fuel and air prior to their mixing in the combustion zone and the maximum endothermic reaction temperature; which is represented by the 0 + temperature DELTA mentioned by figure A; So that aly this difference is 001 degrees Celsius and it is better to be 00 degrees Celsius to 001 degrees Celsius. This is because most fuels are YAN

The known gaseous Y¢£00 self-ignites with air at temperatures in the range of 600 to 856 °C. Most of the significant endothermic reactions occur at about oY °C as well as 0" to 956 °C; this means that within Normal operation of this preferred embodiment (°C) above oes temperature air and gaseous fuel are heated to 400°C and this exposed heating results in .11” self-combustion prior to their union within the combustion zone 0 . The occurrence of intensive cooling of the resulting endothermic gases, and in the same way, it is preferable to design and operate the furnace so that the resulting combustion gases are significantly cooled before entering the furnace.When using an appropriate furnace design and operation process, it is possible to ensure that each of the combustion gases The resulting gases come out of the furnace at degrees Celsius, which provides high thermal efficiency and moderate temperatures of 00860 degrees, for example, under Ve. For different temperatures, steam regeneration of light hydrocarbons, in particular methane, ethane and natural gas; And the decomposition of Jie ¢ ethane and propane to their corresponding kinases and the transformation reaction Jie water - gas thermal potential. And so on. These processes are well known in this field YO and some of these processes can be performed without a catalyst while other processes need or usually use a suitable catalyst. when using a catalyst; It must maintain sufficient activity for a long period of time at the high temperatures that can be encountered here. The catalyst must be of sufficient strength to support the weight of the above layer. It shall also include a particle size small enough to reduce the Lay - sufficient to adequately fill the voids between the tubes but be large enough to reduce the pressure drop through the layer to an inverted value. It should not bond with some flocculation or pipes when exposed to high temperatures for a long time. The appropriate form of nickel over alumina is one. possible means; However, it was reported that there are other catalysts that are also suitable for hydrogen production. Either a high-temperature conversion catalyst and/or an optionally low-temperature conversion catalyst may be placed inside the reactor in the region where the process gas cools and this causes +

Hy indicates that most of the carbon dioxide ( 0 © ) reacts with an abundance of hydrogen 0:11 to form more A

Yo. (as a “by-product”) which is called a “water-gas conversion reaction” with CO. Several variations can be made in the preferred embodiments of this invention as aforementioned, for example; Also, these flow paths do not need to be annular and co-centered with their reaction tubes as shown but can be in any arrangement that allows the fuel and air to be heated separately to higher temperatures and ignite. Also, it does not require the use of a separate heat generation method for each reaction tube, as it is sufficient to conduct sufficient heat from one or more heat generation methods inside the furnace to conduct the endothermic reaction. It is possible to work on the flow of combustion gases on the one hand, and the endothermic reaction gases on the other hand, together in one stream instead of flowing opposite each other, as desired. Other changes. For example, it is possible to process in the form of many different types, including gases, liquids in the state of boiling, normal liquids, or slurry slurries containing fine solids. Condensation of a gas into a liquid may also occur as desired in the cooler region of the reactor. In addition ; 1 Preheating of the cold reactor for start-up may alternatively be done by another means than an electric resistance heater. and for example ; Hot combustion gases may be added through additional nozzles in the reactor and circulated through the desired region. And also ; Many different types of thermal insulation can be used inside the pressure vessel. In addition to yours; 7. The maximum temperature of the combustion gases inside the combustion tubes can be varied or changed by embodying the ceramic tubes and outside the tubes in the embodiment of the metal reaction tube by adjusting the fuel composition and the flow rates of fuel and air. In addition, the gradual increase in the air flow rate above the elemental union ratio will lead to a gradual decrease in the maximum local temperatures. Steam additions can be performed. also to the fuel to lower extreme temperatures and in the end; if syngas is desired for the synthesis of ammonia; It is possible to add an appropriate ratio of Yo (usually small) from compressed air to natural gas and steam; So that the gas

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YH

And I will. (V iV) to l. Normally the resulting synthetic Ho will contain the desired proportion of this addition of air reacts in the catalyst bed during heating; But it will be low and the interaction will remain. Sufficient to not result in a severe local increase in temperature in the endothermic aggregate layer. This method of making ammonia synthesis gas does not require the addition of any oxygen besides what is produced from the air itself; This is a desirable cost saving compared to some operations. competition requiring separation of oxygen from air and all such changes are intended to be included within the scope of this invention; which. It is limited only by the included safeguards

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Claims (1)

for alc | protection -1 1 A process for carrying out an endothermic reaction in an endothermic reaction apparatus including a vessel; In this process, an endothermic reactant is heated by an exothermic reaction of two substances © . Two exothermics in the flow path of an exothermic reaction and you have to convert the sale of the endothermic reaction? to an endothermic product and includes: ° forcing the endothermic reactant to flow through a set of endothermic reaction tubes > where the endothermic reactant of the endothermic reaction passes; Where the endothermic reaction tubes extend through the endothermic reaction chamber; A The removal of the endothermic reaction product from said vessel after flow through the ald oq reaction tubes for the exothermic; 0 - Feeding the first and second endothermic reaction materials separately to the path of 585 reaction 4 endothermic reaction inside the spherical endothermic reaction chamber where the reaction products flow 10" | exothermic in a direction extending from an upper end to a lower end of the chamber exothermic reaction. Vv is the removal of the exothermic reaction products from said vessel after passing along the flow path yo _ said exothermic reaction; In which: The aforementioned separate feeding step includes the passing of the first exothermic reaction materials 10 and the second to the outside along the aforementioned endothermic reaction tubes through the Grae VA heating zone inside the aforementioned vessel, whereby heat is transferred to the said exothermic reactants. ge 14 said endothermic reaction product to preheat said exothermic reaction material prior to 0 mixing and reaction and to cool said said endothermic reaction product prior to removal from said vessel; YY Whereas, for each of the said endothermic reaction tubes n, one of the said exothermic materials Jeli YY YY is passed through an annular passage formed between the lower part of the said reaction tube vy to one of the said exothermic reaction materials to be heated before mixing and reacts with 0 YE the other exothermic reactant mentioned; and where for each Galil the sorbent reaction is YAN YA for said temperature; The aforementioned other exothermic reaction material is passed through an annular passage Yo formed between the aforementioned first feeding tube and another feeding tube to transfer heat from the aforementioned endothermic reaction product YX Z to the aforementioned exothermic reactants to heat them before mixing and reaction YY With each other ; Where the aforementioned exothermic reaction materials are preheated so that they are YA when mixed together in the aforementioned exothermic reaction chamber, the mixture of the aforementioned reaction materials > 4 . Exothermic is at or above the ignition temperature ©. ; Where each of the materials of the first reaction 1 ?- an endothermic reaction process according to element 1 and the second mentioned exothermic are heated to a temperature higher than a temperature sufficient to maintain . z © auto-ignition; Where an endothermic reaction catalyst is used in 1 endothermic reaction process according to the element -* 1 . A ¥ the aforementioned endothermic reaction tubes; Where the said set of tubes 1 is an endothermic reaction according to element dee 4 -1 . Endothermic Reaction Straight and Parallel " Endothermic Reactant and Cum Product Flow; 1 Endothermic According to Element Jeli Process #1 Endothermic Reaction Reverses the Flow of Exothermic Reactants and Exothermic Reaction Products _ . Exothermic An endothermic reaction process according to the element © ; Where the vessel is longitudinal and where the 1+1 endothermic reaction material and endothermic reaction product flow in a first longitudinal direction and where the exothermic reaction materials and endothermic reaction products flow in a second anti-directional longitudinal direction _ © . ; . The aforementioned first longitudinal; where the aforementioned endothermic reaction 1 performs an endothermic reaction process according to element 7-1 to the maximum temperature in the aforementioned endothermic reaction tubes and where the aforementioned exothermic materials are heated by heat exchange with a product The endothermic reaction deliv z °C below the maximum temperature in the reaction tubes Yoo .to a temperature not less than < . _ said endothermic reaction before being mixed and reacted exothermic reaction 0 includes with respect to In each of the reaction tubes, 1 is an endothermic reaction process according to the element =A) a | v mentioned; The step of pushing the exothermic reaction products leaving the exothermic reaction chamber of said v to flow around and along the top of the endothermic reaction tube:; Said exothermic at a speed greater than the velocity of said exothermic reaction products through said exothermic reaction chamber M to activate the heat JE from said exothermic products to said > upper portions of said endothermic reaction tubing to heat the endothermic reaction material 0” of the heat flowing through the portion The above mentioned endothermic reaction tube. 1 4- An endothermic reaction process according to element A; where ; Lad relates to each of the said endothermic ¥ reaction tubes; Said payment step includes; Passage of the products of the exothermic reaction 0” through an annular passage surrounding the aforementioned upper part of the aforementioned endothermic reaction tube. -01 y an endothermic reaction process according to item 1; Cua The ratio of the length of each endothermic Y tube to its inner diameter is 0 0 to 0 01 . 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