Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J4/00—Feed or outlet devices; Feed or outlet control devices
  • B01J4/001—Feed or outlet devices as such, e.g. feeding tubes
  • B01J4/002—Nozzle-type elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/30—Injector mixers
  • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
  • B01F25/313—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/30—Injector mixers
  • B01F25/31—Injector mixers in conduits or tubes through which the main component flows
  • B01F25/313—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit
  • B01F25/3133—Injector mixers in conduits or tubes through which the main component flows wherein additional components are introduced in the centre of the conduit characterised by the specific design of the injector
  • B01F25/31331—Perforated, multi-opening, with a plurality of holes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
  • B01J8/04—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds
  • B01J8/0446—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical
  • B01J8/0449—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical in two or more cylindrical beds
  • B01J8/0453—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical in two or more cylindrical beds the beds being superimposed one above the other
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
  • B01J8/04—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds
  • B01J8/0492—Feeding reactive fluids
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
  • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
  • C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
  • C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
  • C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
  • C01B3/382—Multi-step processes
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
  • C01B2203/02—Processes for making hydrogen or synthesis gas
  • C01B2203/0205—Processes for making hydrogen or synthesis gas containing a reforming step
  • C01B2203/0227—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step
  • C01B2203/0244—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step the reforming step being an autothermal reforming step, e.g. secondary reforming processes
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
  • C01B2203/12—Feeding the process for making hydrogen or synthesis gas
  • C01B2203/1276—Mixing of different feed components
  • C01B2203/1282—Mixing of different feed components using static mixers

Definitions

• Light hydrocarbons are converted to synthesis gas by reaction with oxygen and/or oxygen-containing compounds, such as water.
• a natural gas feed may be converted to synthesis gas by reaction with an oxygen-containing gas.
• water usually present as steam, is used to oxidize, otherwise known as "reforming," the light hydrocarbon feed, it contributes both oxygen and hydrogen to the product mix.
• the contribution of hydrogen and the subsequent shift conversion of product CO by residual water produces a synthesis gas having relatively high ratios of hydrogen to CO.
• steam reforming of light hydrocarbons is favored for the production of hydrogen. Reforming of light hydrocarbons with water is endothermic. Heat must be added to sustain reaction temperature. Reactor designs feature heat transfer tubing containing reforming catalyst and operating at high temperatures.
• Partial oxidation of light hydrocarbons by molecular oxygen contributes oxygen, but not hydrogen or carbon, to the product mix. It yields a synthesis gas having a H 2 to CO ratio lower than that of steam reforming and higher than that of CO 2 reforming.
• partial oxidation of light hydrocarbons by molecular oxygen is well suited to the production of synthesis gas for use in Fischer Tropsch and methanol syntheses.
• the partial oxidation reaction is exothermic.
• the exothermic nature of the reaction leads to the concept of "auto-thermal" reforming.
• auto-thermal reforming partial oxidation of the feedstock provides much of the heat needed to raise the temperature of the products. Oxidation products that would be lost in flue gas if formed external to the reaction environment become part of the product stream.
• the synergy of feed and fuel is further enhanced by the ability to achieve high reaction temperatures without the need for high heat transfer equipment. High temperatures favor the conversion of light hydrocarbons to product CO.
• the invention relates to a device which mixes light hydrocarbons, steam, and air and delivers the mixture to an active catalyst.
• the invention further relates to a process for optimizing the size and orientation of air and/or oxygen injection nozzles of the mixing device.
• the device and processes of the invention are well suited for use with the devices and process described in U.S. patent application Serial No. 10/924,174, Publication No. 2005/0063899 and Serial No. 10/923,931, Publication No. 2005/0066577, which are incorporated herein by reference in their entirety.
• the process is conducted on a once-through basis, without recycle, at a high temperature, and at an elevated pressure.
• Such conditions generally utilize a feed mixture that has a tendency to self heat and autoignite.
• the mixing of the natural gas and steam mixture with the oxygen-containing gas is complete before the three component gas mixture contacts an inert solid material.
• uniform mixing is achieved by conducting the mixing at high gas velocity, by uniform distribution of the openings, and by providing adequate axial length to the mixing zone.
• the mixture of natural gas, steam and oxygen-containing gas contacts the active catalyst at a sufficiently low velocity to prevent high pressure loss and catalyst erosion.
• the three component gas mixture is decelerated in an expansion zone.
• the expanding mixture does not form macroturbulent eddies nor are large void volumes and associated long duration deceleration times incurred.
• Figure 1 is a schematic diagram illustrating an axial cross section of a first symmetric embodiment of the mixer.
• Figures IA and IB are schematics illustrating a transverse cross section of a first symmetric embodiment of the mixer.
• Figure 2 is a schematic illustrating an axial cross section of a second symmetric embodiment of the mixer.
• Figure 2A is a schematic illustrating a transverse cross section of a second symmetric embodiment of the mixer.
• Figure 3 is a schematic illustrating an axial cross section first asymmetric embodiment of the mixer.
• Figure 4 is a schematic illustrating a first symmetric embodiment of the mixer further illustrating an inert solids zone and an inlet portion of an active catalyst zone.
• Figure 5 illustrates the results of a computational fluid dynamics analysis of an asymmetric mixer embodiment.
• Figure 6 illustrates the results of a computational fluid dynamics analysis of a symmetric mixer embodiment.
• Fig. 7 is a graph of temperature vs. time for a specific reactor configuration and feed gas composition.
• homogeneous reaction means ignition and/or decomposition of C 2 + hydrocarbons.
• FIG. 1 a first symmetric embodiment of the mixer of the invention is illustrated in axial cross section.
• Fig. 1 more specifically illustrates the oxygen-containing gas inlet portion of the mixer.
• An inner tube 100 has a plurality of openings 110 and a gas inlet 120.
• a shell tube 130 has a plurality of openings 180.
• the space between inner tube 100 and shell tube 130 forms annular space 140.
• a gas inlet 170 is located at or near a top portion of the annular space 140.
• a jacket 150 having a gas inlet 160 surrounds at least a portion of shell tube 130.
• an oxygen-containing gas feed is passed through gas inlet 120 into inner tube 100 and through openings 110 into annular space 140.
• an oxygen-containing gas is also passed into gas inlet 160 and passes through openings 180 into annular space 140.
• a mixture natural gas and steam enters annular space 140 through gas inlet 170.
• the term "symmetric" refers to mixers in which the oxygen-containing gas injection is symmetric relative to the centerline of natural gas and steam flow. That is, the embodiment shown in Fig. 1 is considered symmetric because as natural gas and steam flows axially through the annular space 140, an oxygen-containing gas is injected from into the annular space 140 from both sides perpendicular to the direction of flow.
• FIGs. IA and IB illustrate transverse cross sectional views of the inner tube 100 and shell tube 130.
• the openings 110 and 180 are aligned.
• Fig. IB the openings 110 and 130 are offset from each other.
• Fig 2 illustrates a second symmetric embodiment of the mixer of the invention.
• an inner tube 200 having a plurality of openings 210 and a gas inlet 220 is shown in axial cross section, hi some embodiments of the invention, a natural gas and steam mixture passes through gas inlet 220 into inner tube 200.
• a shell tube 230 surrounds inner tube 200 forming an annular space 240.
• Annular space 240 has a gas inlet 250 at or near the top of the annular space 240.
• an oxygen-containing gas is passed through gas inlet 250 into annular space 240, through openings 210 and into inner tube 200.
• FIG. 2A a transverse cross section showing the inner tube 200, including openings 210, and shell tube 230 is shown.
• FIG. 3 a first asymmetric embodiment of the mixer is shown.
• An inner tube 300 having a plurality of openings 310 and a gas inlet 320 is shown in axial cross section.
• a shell tube 330 surrounds inner tube 300 thereby forming an annular space 340.
• a gas inlet 350 is located at or near a top portion of annular space 340.
• a natural gas and steam mixture passes through gas inlet 350 into annular space 340.
• an oxygen-containing gas passes through gas inlet 320, into inner tube 300, and through openings 310 into annular space 340.
• a symmetric embodiment of the mixer of the invention is illustrated upstream of and fluidly connected to a burnerless autothermal reactor with which the mixer is well suited for use.
• An inner tube 100 having a plurality of openings 110 and a gas inlet 120 is surrounded by a shell tube 130 having a plurality of openings 180 thereby forming an annular space 140.
• As gas inlet 170 is located at or near a top portion of annular space 140.
• a jacket 150 having two gas inlets 160 surrounds a portion of shell tube 130.
• Inner tube 100 terminates in a tapered cone-shaped end portion 190.
• shell tube 130 flares slightly outwardly.
• the area between point D and E is called an expansion zone in which the volume available for the gas increases, thereby allowing the gas velocity to slow.
• the diameter of the imier tube may be decreased, also resulting in an expanded volume for the gas, as is shown between points C and D of Fig. 4. It will be understood that a variety of configurations may be used with more or less rapid flaring or tapering of the shell tube or inner tube respectively, to achieve the desired expanded volume and decrease in gas velocity.
• inner tube 100 has no gas outlet and the air injected into inner tube 100 must pass through openings 110 and into annular space 140.
• inert solid material zone between points E and F is an inert solid material zone.
• the inert solid material prevents the transfer of radiant heat between the expansion zone and the active partial oxidation/reforming catalyst.
• a number of known inert solids may be used in the inert solid material zone.
• the inert solid material is randomly packed and is a catalytically inert ceramic capable of exposure to temperatures in excess of 2200 0 F without substantial chemical or physical degradation.
• an active catalyst zone is shown beginning at point F. It is noted that only an inlet portion of the active catalyst zone of an autothermal reactor is shown in Fig 4.
• a natural gas and steam mixture is premixed and injected into gas inlet 170.
• the natural gas and steam mixture has substantially fully developed axial flow, that is, with only insubstantial backflow or eddying, prior to reaching point A.
• An oxygen-containing gas is injected into inner tube 100 through gas inlet 120.
• the oxygen-containing gas passes through openings 110 and into annular space 140 wherein the natural gas and steam mixture contacts and begins mixing with the oxygen-containing gas.
• Oxygen-containing gasses useful in the invention include air, oxygen-enriched air and oxygen.
• Oxygen-containing gas also enters through one or both of gas inlets 160 into jacket 150, through openings 180 and into annular space 140 wherein such oxygen-containing gas also contacts the natural gas and steam mixture.
• Mixing of the natural gas and steam with the oxygen-containing gas begins as the oxygen-containing gas passes through openings 110 and 180 and continues as the as mixture flows through annular space 140 and through the expansion zone.
• the natural gas, steam and oxygen-containing gasses are substantially uniformly mixed prior to contact with the inert solid material at point E.
• the diameters of the inner tube 100 and shell tube 130 are selected to yield a velocity at the inlet of the expansion zone, i.e., point D, of at least about 100 feet per second and more preferably at least about 300 feet per second.
• the length of the inner tube 100 is selected to yield a mixing time of at least about 10 milliseconds, more preferably at least about 30 milliseconds, but generally not greater than about 200 milliseconds.
• the flow volume of the natural gas, steam and oxygen-containing gas may be increased over the length of the oxygen-containing gas injection so as to partially or wholly offset the velocity increase with the incremental oxygen- containing gas injection.
• Direct impingement or opposition of openings 110 and 180 may be used in some embodiments. In preferred embodiments, however, openings 110 and 180 are offset from each other.
• the quantity of steam mixed with the light hydrocarbon feed is between about 2% and about 160% by volume of the hydrocarbon portion of the light hydrocarbon feed. More preferably, the quantity of steam is 22-36%.
• the pressure maintained in the mixing device is 0 to 300 psig, more preferably 100 to 200 psig.
• the duration of time from final mixing of the oxygen-containing gas with the light hydrocarbon, e.g., natural gas, to contacting the catalyst is less than about 1000 milliseconds, more preferably less than about 300 milliseconds.
• the inert solid material prevents radiation of heat from the active catalyst zone to the natural gas, steam and oxygen-containing gas mixture.
• the inert solid material may further provide, in some embodiments, torturous passages, thereby preventing convective heat transfer.
• the velocity of the natural gas, steam and oxygen- containing gas mixture does not exceed 100 ft/sec as it contacts the surface of the active catalyst at the top of the partial oxidation and reforming section, shown in fig. 4 as point F. More preferably, this velocity does not exceed 45 ft /sec.
• a process for optimizing the size and location of openings connecting the oxygen-containing gas and the natural gas and steam mixture and other process conditions is provided.
• Figs. 5-6 illustrate the flow patterns obtained through computational fluid dynamic analysis.
• the upper portion of the colored pattern corresponds to the pre-openings, pre-oxygen-containing gas injection, flow.
• the openings through which an oxygen-containing gas is simulated as entering an annular space are simulated along with the mixing zone of the annular space of the mixer.
• the expansion zone is also illustrated at the lower portion of the colored diagrams.
• Fig. 5 illustrates the results of one computational fluid dynamics process in which an asymmetric mixer configuration was used. As can be seen from Fig. 5, significant areas of negative flow, indicated by the two darkest blue regions, developed leading to poor and inadequate mixing.
• FIG. 6 illustrates the computational fluid dynamics results for a symmetric mixer configuration. As can be seen from Fig. 6, no negative flow developed. [045] While the invention has been described with a limited number of embodiments, these specific embodiments are not intended to limit the scope of the invention as otherwise described and claimed herein. Modification and variations from the described embodiments exist. For example, an oxygen-containing gas could be injected into a natural gas and steam mixture along the entire length of the mixer, that is, through the entire pre-partial oxidation volume, and not just in an upper portion thereof as illustrated in the Figures. Therefore, materials which do not fulfill the selection criteria under one set of process conditions may nevertheless be used in embodiments of the invention under another set of process conditions.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Inorganic Chemistry (AREA)
• Hydrogen, Water And Hydrids (AREA)
• Accessories For Mixers (AREA)

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• 2005
  • 2005-12-12 WO PCT/US2005/044968 patent/WO2006065766A2/en active Application Filing
  • 2005-12-12 CN CNA2005800471935A patent/CN101111304A/zh active Pending
  • 2005-12-12 AU AU2005316638A patent/AU2005316638A1/en not_active Abandoned
  • 2005-12-12 EP EP05853797A patent/EP1835988A2/de not_active Withdrawn
  • 2005-12-13 MY MYPI20055849A patent/MY139265A/en unknown
  • 2005-12-14 PE PE2005001455A patent/PE20060805A1/es active IP Right Grant

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