WO2006117572A1 - Appareil et procede de reformage a la vapeur d'hydrocarbures - Google Patents

Appareil et procede de reformage a la vapeur d'hydrocarbures Download PDF

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Publication number
WO2006117572A1
WO2006117572A1 PCT/GB2006/050079 GB2006050079W WO2006117572A1 WO 2006117572 A1 WO2006117572 A1 WO 2006117572A1 GB 2006050079 W GB2006050079 W GB 2006050079W WO 2006117572 A1 WO2006117572 A1 WO 2006117572A1
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Prior art keywords
heat exchange
tubes
reformer
catalyst
helical
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PCT/GB2006/050079
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English (en)
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Peter William Farnell
Bernard John Crewdson
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Johnson Matthey Plc
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Publication of WO2006117572A1 publication Critical patent/WO2006117572A1/fr

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    • 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
    • C01B3/384—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 the catalyst being continuously externally heated
    • 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
    • B01J8/008—Details of the reactor or of the particulate material; Processes to increase or to retard the rate of reaction
    • 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
    • B01J8/06—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 in tube reactors; the solid particles being arranged in tubes
    • B01J8/067—Heating or cooling the reactor
    • 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
    • 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
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00008—Controlling the process
    • B01J2208/00017—Controlling the temperature
    • B01J2208/00106—Controlling the temperature by indirect heat exchange
    • B01J2208/00168—Controlling the temperature by indirect heat exchange with heat exchange elements outside the bed of solid particles
    • B01J2208/00212—Plates; Jackets; Cylinders
    • B01J2208/00221—Plates; Jackets; Cylinders comprising baffles for guiding the flow of the heat exchange medium
    • 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
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00008—Controlling the process
    • B01J2208/00017—Controlling the temperature
    • B01J2208/00106—Controlling the temperature by indirect heat exchange
    • B01J2208/00168—Controlling the temperature by indirect heat exchange with heat exchange elements outside the bed of solid particles
    • B01J2208/00212—Plates; Jackets; Cylinders
    • B01J2208/0023—Plates; Jackets; Cylinders with some catalyst tubes being empty, e.g. dummy tubes or flow-adjusting rods
    • 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
    • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
    • B01J2208/00796—Details of the reactor or of the particulate material
    • B01J2208/00884—Means for supporting the bed of particles, e.g. grids, bars, perforated plates
    • 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
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00002—Chemical plants
    • B01J2219/00004—Scale aspects
    • B01J2219/00006—Large-scale industrial plants
    • 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
    • C01B2203/0233—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step the reforming step being a steam reforming step
    • 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
    • C01B2203/02—Processes for making hydrogen or synthesis gas
    • C01B2203/025—Processes for making hydrogen or synthesis gas containing a partial oxidation step
    • 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
    • C01B2203/06—Integration with other chemical processes
    • C01B2203/061—Methanol production
    • 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
    • C01B2203/06—Integration with other chemical processes
    • C01B2203/062—Hydrocarbon production, e.g. Fischer-Tropsch process
    • 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
    • C01B2203/06—Integration with other chemical processes
    • C01B2203/068—Ammonia synthesis
    • 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
    • C01B2203/08—Methods of heating or cooling
    • C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
    • C01B2203/0838—Methods of heating the process for making hydrogen or synthesis gas by heat exchange with exothermic reactions, other than by combustion of fuel
    • C01B2203/0844—Methods of heating the process for making hydrogen or synthesis gas by heat exchange with exothermic reactions, other than by combustion of fuel the non-combustive exothermic reaction being another reforming reaction as defined in groups C01B2203/02 - C01B2203/0294
    • 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
    • C01B2203/14—Details of the flowsheet
    • C01B2203/141—At least two reforming, decomposition or partial oxidation steps in parallel
    • 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
    • C01B2203/14—Details of the flowsheet
    • C01B2203/142—At least two reforming, decomposition or partial oxidation steps in series
    • 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
    • C01B2203/14—Details of the flowsheet
    • C01B2203/142—At least two reforming, decomposition or partial oxidation steps in series
    • C01B2203/143—Three or more reforming, decomposition or partial oxidation steps in series

Definitions

  • This invention relates to a process for steam reforming hydrocarbons to produce a synthesis gas and to apparatus for carrying out the process.
  • a process fluid i.e. a mixture of a hydrocarbon feedstock and steam, and in some cases also carbon dioxide or other components
  • a suitable heating medium generally a hot gas mixture.
  • the catalyst is normally in the form of shaped units, e.g. cylinders having a plurality of through holes, is typically formed from a refractory support material e.g. alumina, impregnated with a suitable catalytically active metal such as nickel.
  • Steam reforming reactions take place to generate a crude synthesis gas.
  • the crude synthesis gas comprises hydrogen and carbon oxides (carbon monoxide and carbon dioxide) and may contain nitrogen and other inerts such as argon and low levels of methane.
  • the synthesis gas may contain greater or lesser amounts of hydrogen and carbon oxides suited to the particular end use such as hydrogen manufacture for refineries or fuel cells, ammonia synthesis, methanol synthesis, dimethylether synthesis or the Fischer-Tropsch process for the synthesis of liquid hydrocarbons.
  • the steam reforming reactions are endothermic and heat must be supplied to the gas undergoing reforming.
  • Various reformer configurations are known.
  • the heat may be provided by 'externally-heated' hot gases, for example a flue-gas.
  • the catalyst-filled tubes may be externally heated by means of the process gas that has passed through the tubes but which has then been subjected to further processing before being used as the heat exchange medium.
  • the further processing step advantageously includes a step of partial oxidation with an oxygen- containing gas, which both provides further conversion of hydrocarbon feedstock and heats the reformed gas mixture.
  • primary catalytic steam reforming may be effected in a heat exchange reformer in which the catalyst-containing reformer tubes are heated by a secondary reformed gas.
  • a heat exchange reformer in which the catalyst-containing reformer tubes are heated by a secondary reformed gas.
  • Examples of such reformers and processes utilising the same are disclosed in for example GB1578270.
  • Heat exchange reformers are typically cylindrical and often have domed ends.
  • the tube bundle is typically supported by tube sheets at either end of the cylinder, which also act to define the inlet and outlet zones of the reformer.
  • a heat exchange reformer is mounted vertically with the hydrocarbon feedstock/steam mixture fed to an inlet zone at the top or bottom and the heat exchange medium fed to the reformer so that it flows counter-current to the flow of gases through the tubes.
  • the spacing of the tubes as measured by the tube pitch centre line to centre line measurement between adjacent tubes
  • the spacing of the tubes as measured by the tube pitch is typically no less than 1.25 times the outside tube diameter due to mechanical design and fabrication limitation on the tube sheets to which the tubes are attached.
  • the mechanical design of the tube bundle sets a characteristic free flow area around the outside of the catalyst tubes through which the heat exchange medium must flow. Typically, this will be at low velocity and with a commensurately low heat transfer coefficient. Typically, this heat transfer coefficient is too low to achieve an economically sized heat exchange reformer.
  • heat transfer enhancement means are usually provided to increase the heat transfer over and above this basic low heat transfer level. Heat exchange enhancement means include sheath tubes and transverse baffles.
  • a heat exchange reformer containing sheath tubes is described for example in EP-B-0843590.
  • the sheath tubes act to increase the axial (vertical) flow of heat exchange medium along the exterior surfaces of the tubes. While sheath tubes are useful for increasing the heat transfer to the catalyst-filled tubes to an acceptably high level, they require a separate tubesheet to support their weight and, where corrosion-resistant alloys have to be used to minimise metal dusting corrosion, can add considerably to the cost of the heat exchange reformer design. Construction can also be difficult to ensure adequate spacing of the tubes under operating conditions were they are subject to considerable thermal expansion.
  • a heat exchange reformer containing transverse baffles is described in US4127389.
  • the baffles provided comprise an alternating series of horizontal rings and discs supported in the reformer that act to displace the heat exchange medium radially as it flows through the length of the reformer. While simpler in design than sheath tubes, transverse baffles can be less effective in increasing heat transfer. Therefore there is a need to increase the heat transfer between the heat exchange medium and the catalyst-filled tubes in heat exchange reformer but avoiding the need for sheath tubes.
  • helical baffles provide such a solution to the problem of achieving a design with a suitable heat transfer coefficient, a lack of vibration and a smaller bundle with tubes within the complete cross section of the equipment.
  • the invention provides apparatus for steam reforming of hydrocarbons comprising a heat exchange reformer having disposed within a plurality of vertical catalyst-filled tubes, through which a gas mixture comprising hydrocarbon and steam may be passed, and to which heat may be transferred by means of a heat exchange medium flowing around the external tube surfaces, characterized in that one or more helical baffles are provided within the reformer such that the heat exchange medium follows a helical path through the reformer.
  • helical baffle we mean a baffle that forms a helical flow path for the heat exchange medium within the reformer, i.e. has surfaces defining a helical flow path around the axis of the tube bundle within the reformer.
  • the helix may be defined as having a pitch of 400mm to 1600m, i.e. the distance between adjacent baffles in the same single helical path a 360° turn apart, such spacings covering the anticipated commercial scales of heat exchange reformers from the smallest to the largest.
  • a helical spacing of 1600mm tube vibration may still be a problem due to the large unsupported span length.
  • two or more identical helical baffle sets may be installed equally spaced to provide adequate support of the tube bundle, forming for example a double or triple helix, each helix spaced 200mm to 800mm apart from the adjacent helix, but each helix maintaining a 400mm to 1600mm pitch.
  • the baffle may be continuous or discontinuous, i.e. more than one helical baffle may be present.
  • the turn of the helix may be clockwise or anticlockwise around the axis of the tube bundle, i.e. the rotation of the heat exchange medium as it flows through the reformer may comprise flow in a clockwise or anticlockwise direction.
  • the helical flow is provided by a plurality of shaped baffles.
  • baffles segments Preferably 1-8 baffles segments, more preferably 4-6 baffle, especially 6 segments are provided for each helical rotation and the number of rotations may be from 1 to 50 depending on the size of the reformer.
  • the use of 6 baffle segments per turn is advantageous as the tubes are typically disposed upon an equilateral triangular pattern with a tube at the centre of the tube bundle.
  • the tube layout will have inherent hexagonal symmetry making each of the 6 baffle segments identical.
  • the central tube may well act as a dummy support tube and not have through flow of process gas but acts only as a tube to which the baffle segments are mechanically attached such as by bolting or welding.
  • This central tube may be increased in size to provide further mechanical strength to the bundle fabrication by taking up the space that would have otherwise been used by the 7 central tubes.
  • a process fluid i.e. the hydrocarbon/steam mixture
  • a process fluid feed zone i.e. the hydrocarbon/steam mixture
  • heat exchange tubes containing a particulate catalyst disposed within a heat exchange zone defined by a cylindrical casing through which a heat exchange medium passes, and then into a process fluid off-take zone.
  • Means, such as tube- sheets, are provided to separate the zones.
  • a tube-sheet may separate the heat exchange zone through which the heat exchange medium passes from a zone, such as a plenum chamber, communicating with the interior of the heat exchange tubes to permit feed of process fluid to the tubes or off-take of process fluid from the tubes.
  • a zone such as a plenum chamber
  • An alternative arrangement involves the use of header pipes disposed within the heat exchange zone to define the process fluid feed zone: the process fluid is fed to the header pipes from whence it flows into and through the heat exchange tubes.
  • header pipes may be provided for the off-take of process fluid from the tubes.
  • the process fluid may be fed to the heat exchange tubes from a plenum chamber separated from the heat exchange zone by a tube-sheet while header pipes are provided disposed within the heat exchange zone for off-take of process fluid from the tubes.
  • Such tube-sheets or headers may be termed boundary means as they define boundaries between the heat exchange zone and the process fluid feed and off-take zones. Howsoever the boundary means are disposed, the one or more helical baffles are located in the heat exchange zone within the reformer.
  • the heat exchange tubes may have a circular, oval or polygonal cross section, typically have a length of 5 to 15 m and preferably a diameter in the range 7 to 20 cm.
  • the wall thickness of the tubes may be 1->10 mm, but is preferably 2-10 mm.
  • the heat-exchange tubes preferably have a circular cross-section.
  • the circular cross-section of the heat-exchange tubes better allows them to withstand the pressure differential between the pressure of the process fluid within the tubes and the pressure of the heating medium.
  • the tubes are typically fabricated from suitable steels are preferably coated on their external surfaces with a 40-60% (Ni) nickel- chrome alloy, preferably having an iron content below 3% wt, preferably below 1% wt. Such coatings advantageously reduce the susceptibility of the tubes to metal dusting corrosion caused by the heat exchange medium.
  • the heat-exchange tubes are heated to a high temperature, typically to a temperature in the range 650 0 C to ⁇ 900°C.
  • This heating necessarily means that the tubes are subject to thermal expansion, both longitudinally and radially, as the tubes are heated from ambient temperature to the operating temperature and likewise to thermal contraction as the tube is cooled upon shut down of the process.
  • the heat-exchange tubes are of considerable length, the tubes can expand longitudinally by an amount, often 10 cm or more, relative to the casing to which the boundary means is fastened.
  • the heat- exchange tubes are moveably attached to at least one of the boundary means.
  • the term “moveably attached” we mean that the tube is attached to the boundary means by means that allow for the thermal expansion and contraction of the heat-exchange tubes.
  • the heat-exchange tubes are preferably moveably attached to one boundary means and non-moveably attached to the other.
  • the heat- exchange tubes preferably extend from a first boundary means to which they are non-moveably attached, through the heat exchange zone, and are moveably attached by means of e.g. pigtails, bellows or venturi seal tubes, to a second boundary means.
  • the catalyst- filled tubes are moveably attached to the reformer at one end by means of venturi seal tubes.
  • venturi-seal designs as described in the aforesaid EP-B-0843590 are employed.
  • the invention further provides a process for steam reforming of hydrocarbons to generate a reformed gas mixture, including the steps of (i) passing a gas mixture, comprising hydrocarbon and steam through a plurality of catalyst-filled tubes disposed vertically within a heat exchange reformer, and (ii) transferring heat to the mixture undergoing reforming by means of a heat exchange medium flowing around the external surfaces of said tubes, characterized in that one or more helical baffles are provided within the reformer such that the heat exchange medium follows a helical path through the reformer.
  • the hydrocarbon feedstock may be methane, natural gas or naphtha, and is preferably a natural gas containing a high (i.e. >90%) methane content.
  • a high (i.e. >90%) methane content Prior to reforming the hydrocarbon feedstock is preferably desulphurised e.g. by passing the hydrocarbon though a bed of a suitable sulphur compound absorbent such as zinc oxide.
  • the steam reforming catalyst is normally in the form of shaped units, e.g. cylinders, rings, saddles, and cylinders having a plurality of through holes, and are typically formed from a refractory support material e.g. alumina, calcium aluminate cement, magnesia or zirconia impregnated with a suitable catalytically active metal such as nickel.
  • a refractory support material e.g. alumina, calcium aluminate cement, magnesia or zirconia impregnated with a suitable catalytically active metal such as nickel.
  • a refractory support material e.g. alumina, calcium aluminate cement, magnesia or zirconia impregnated with a suitable catalytically active metal such as nickel.
  • a refractory support material e.g. alumina, calcium aluminate cement, magnesia or zirconia impregnated with a suitable catalytic
  • the shaped units are prevented from falling out of the tubes by a mesh or grill suitably fixed at the bottom of the tube above the pigtail, bellows or venturi seal.
  • methane reacts with steam to produce hydrogen and carbon oxides. Any hydrocarbons containing two or more carbon atoms that are present are converted to methane, carbon monoxide and hydrogen, and in addition, the reversible water-gas shift reactions occur.
  • the reformer is a heat exchange reformer in which the heat exchange medium is a flue gas or other suitable hot gas.
  • the heat exchange medium is the partially reformed gas leaving the tubes of the heat exchange reformer that has been subjected to a further process step.
  • a preferred process for steam reforming comprises the steps of (i) passing a gas mixture, comprising hydrocarbon and steam through a plurality of vertical catalyst-filled tubes to which heat is transferred by means of a heat exchange medium flowing around the external surfaces of said tubes within a heat exchange reformer, to generate a partially reformed gas mixture, (ii) subjecting the partially reformed gas mixture to a further process step in which the temperature of the resulting gas mixture is increased, and (iii) passing said resulting gas mixture to the heat exchange reformer as the heat exchange medium wherein one or more helical baffles are provided within the reformer such that the heat exchange medium follows a helical path through the reformer.
  • the further process step (ii) may be a step of heat exchange in which the partially reformed gas is heated by suitable means.
  • the further process step (ii) comprises a step of partial oxidation of the partially reformed gas mixture with an oxygen containing gas such as oxygen, air or oxygen-enriched air.
  • the further step comprises a step of secondary reforming in which the partially reformed gas mixture is subjected to a step of partial oxidation with an oxygen containing gas such as oxygen, air or oxygen-enriched air, optionally with steam, and the resulting partially combusted gas mixture, which is heated by the exothermic oxidation reactions, is passed through a bed of steam reforming catalyst that brings the gas composition towards equilibrium.
  • Steam reforming reactions take place in the tubes over the steam reforming catalyst at temperatures above 35O 0 C and typically the process fluid exiting the tubes is at a temperature in the range 650 - 95O 0 C.
  • the heat exchange medium flowing around the outside of the tubes may have a temperature in the range 900 -1300 0 C.
  • the differential pressure between the heating medium and the process fluid is preferably 0.5 to 10 bar.
  • the tubes may have a zone of lower heat exchange extending from the bottom of the catalyst up to 25% of the catalyst depth.
  • lower heat exchange we mean that the heat exchange is 50% or less in this zone of the heat exchange above it. The effect of this is to provide cooler tube surfaces at the bottom of the tubes where catalyst debris can accumulate, which might otherwise lead to reduced tube lifetimes.
  • the lower heat exchange zone is preferably ⁇ 20%, more preferably ⁇ 15% of the catalyst depth.
  • the zone of lower heat exchange comprises at least 5% of the catalyst depth.
  • the zone of lower heat exchange may be provided by omitting baffles from the lower 25% of the catalyst depth
  • the lower heat transfer zone may also be achieved by providing heat transfer reducing means that mask, protect or insulate the portion of the tube in the zone of lower heat transfer.
  • Heat transfer reducing means include insulating means such as ceramic fibre blankets or refractory layers known to those skilled in the art. It is also possible to blank off portions of the tubes with tube plates or open-ended shrouds that prevent access of heating medium to the tube surfaces and allow for thermal expansion and contraction. In particular it is possible to combine both heat exchange reducing means in the zone of lower heat exchange with heat exchange enhancing means above this zone to maximise reforming efficiency whilst protecting the tubes from increased wall temperatures.
  • the apparatus and process of the present invention may be used as part of a process for the manufacture of hydrogen, methanol, dimethylether, ammonia, urea or hydrocarbon liquids, e.g. diesel fuels, obtained by the Fischer-Tropsch synthesis.
  • the reformed gas mixture obtained using the apparatus or in the process of the present invention may be subjected to further process steps including a step of methanol synthesis or a step of ammonia synthesis or a step of hydrocarbon liquid synthesis.
  • the process is part of a process for the manufacture of methanol, ammonia or hydrocarbon liquids.
  • Figure 1 is a cross-sectional view of a heat exchange reformer arranged vertically having a helical baffle arrangement in the heat exchange zone of the reformer.
  • Figure 2 is a cross- sectional view of the reformer viewed across its diameter.
  • Figure 3 depicts a process flow sheet according to a preferred embodiment in which the partially reformed gas mixture is subjected to a stage of secondary reforming and used as the heat exchange medium.
  • arrows illustrate the flow of heating gases in the heat exchange zone.
  • FIG. 1 there is shown a heat exchange reformer, having an outer insulated cylindrical pressure shell 10 enclosing three zones 11 , 12, 13, defined by the shell walls and tube sheets 14 and 15.
  • Zone 11 a process fluid feed zone, is defined by the shell walls and tube sheet 14.
  • It is provided with a process fluid supply conduit 16 and has a plurality of heat exchange tubes, 17 fastened to, and extending downwards from, tube sheet 14.
  • the number of tubes employed will depend on the scale of operation: although only five tubes are shown there may be typically be 50 or more such tubes.
  • the tubes 17 will be filled from a position near the bottom of the tubes to the top of the tubes with shaped units of a suitable steam reforming catalyst, for example nickel on alumina.
  • Zone 12 a heat exchange zone, is defined by the shell walls and tube sheets 14 and 15.
  • Heat exchange tubes 17 extend through zone 12 and are moveably attached by venturi seals 20 to tube sheet 15.
  • Heat exchange zone 12 is fed with heating medium, e.g. hot gases, via conduit 35 positioned in wall 10 near the bottom of tubes 17.
  • the heating medium passes upward in heat exchange zone where it exchanges heat with the tubes 17 and is then removed via conduit 36 positioned in wall 10 near the top of tubes 17.
  • a plurality of baffle segments 37 are positioned within the heat exchange zone 12 and cause the heat exchange medium entering via conduit 35 to pass up through said heat exchange zone 12 in an anti-clockwise helical flow path 40 before being removed near the top of the tubes via conduit 36.
  • the baffle segments 37 act to divert the heating medium helically through the reformer and enhance its heat exchange with the tubes.
  • Zone 13 the process fluid off-take zone, is defined by the walls of shell 10 and the tube sheet 15.
  • the venturi seals 20 are open-ended and extend below tube sheet 15 into off-take zone 13.
  • the reformed gases pass from tubes 17 through venturi seals 20 and into zone 13 from which they are removed by process fluid off-take conduit 38.
  • a process fluid comprising hydrocarbon and steam is fed at elevated temperature and pressure through conduit 16 to zone 11 and thence downward through catalyst-filled tubes 17. Heat is exchanged with heating medium in heat exchange zone 12 and reforming reactions take place.
  • the gases undergoing reforming pass through the tubes 17 and thence though venturi seals 20 to zone 13 from which it is removed by conduit 38.
  • FIG. 2 depicts a cross-sectional view of the reformer at line C-C situated just below boundary means 14.
  • the baffle segments 37a, 37b, 37c, 37d, 37e and 37f are in the shape of 60° segments and thus 6 segments are used for each rotation 40 of the heat exchange medium.
  • the catalyst-filled tubes (not shown) pass through the baffle segments.
  • FIG. 3 depicts a process for the steam reforming of a hydrocarbon feedstock.
  • Process fluid comprising a mixture of a hydrocarbon feedstock and steam is fed via line 60 to a heat exchange reformer 10 having a process fluid feed zone 11 , a heat exchange zone 12, a process fluid off-take zone 13 and first 14 and second 15 boundary means separating said zones from one another.
  • the process fluid is subjected to steam reforming in a plurality of heat exchange tubes 17 containing a steam reforming catalyst to give a primary reformed gas stream.
  • the primary reformed gas stream passes from said heat exchange tubes 17 to the process fluid off-take zone 13, and thence via line 61 to further processing.
  • the further processing comprises partial combustion in a secondary reforming vessel 62 with an oxygen- containing gas, supplied via line 63, above a bed of secondary reforming catalyst 64, for example nickel supported on calcium aluminate or alumina.
  • the resultant partially combusted gas passes through the bed of reforming catalyst and is then passed from the vessel 62 via line 65 to heat exchange zone 12 as the heat exchange medium.
  • the heat exchange medium passes up through the spaces between the heat-exchange tubes and exits the reformer 10 via line 66.

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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)

Abstract

L'invention concerne un appareil de reformage à la vapeur d'hydrocarbures, comprenant un reformeur à échange de chaleur dans lequel est disposée une pluralité de tubes verticaux remplis de catalyseur, à travers lesquels un mélange gazeux comprenant des hydrocarbures et de la vapeur peut passer, et auxquels de la chaleur peut être transférée au moyen d'un milieu d'échange de chaleur situé autour de la surface externe des tubes, caractérisé en ce que le reformeur comprend un ou plusieurs déflecteurs hélicoïdaux, de façon à ce que le milieu d'échange de chaleur suive un chemin hélicoïdal à travers le reformeur. L'invention concerne également un procédé de reformage à la vapeur d'hydrocarbures utilisant ledit appareil.
PCT/GB2006/050079 2005-04-29 2006-04-06 Appareil et procede de reformage a la vapeur d'hydrocarbures WO2006117572A1 (fr)

Applications Claiming Priority (2)

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GB0508740.8 2005-04-29
GB0508740A GB0508740D0 (en) 2005-04-29 2005-04-29 Steam reforming

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2932173A1 (fr) * 2008-06-05 2009-12-11 Air Liquide Procede de reformage a la vapeur avec ecoulement des fumees ameliore
WO2010114844A1 (fr) * 2009-03-30 2010-10-07 Lawrence Clawson Reformeur à vapeur doté d'éléments passifs de régulation du flux de chaleur
KR101038465B1 (ko) * 2010-06-15 2011-06-01 김현영 열분해 개질기
WO2012140994A1 (fr) * 2011-04-12 2012-10-18 千代田化工建設株式会社 Procédé de fabrication n'émettant pas de co2 pour gaz de synthèse
DE102011084476A1 (de) * 2011-10-13 2013-04-18 Man Diesel & Turbo Se Rohrbündelreaktor
DE102013214313A1 (de) * 2013-07-22 2015-01-22 Bayerische Motoren Werke Aktiengesellschaft Reaktor zur Freisetzung von Wasserstoff aus flüssiger Verbindung
DE102013214314A1 (de) * 2013-07-22 2015-01-22 Bayerische Motoren Werke Aktiengesellschaft Reaktor zur Freisetzung von Wasserstoff aus einer flüssigen Verbindung
CN110052224A (zh) * 2019-06-10 2019-07-26 大连海事大学 气体分布器、固定鼓泡床反应器
WO2022162051A1 (fr) 2021-01-28 2022-08-04 Topsoe A/S Réacteur d'échange de chaleur catalytique à écoulement hélicoïdal

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113457583B (zh) * 2021-07-16 2023-09-15 浙江理谷新能源有限公司 一种甲醇重整制氢反应器及其制氢方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2491618A (en) * 1943-07-30 1949-12-20 Standard Oil Co Catalytic contacting apparatus
US4113441A (en) * 1976-03-09 1978-09-12 Director-General Agency Of Industrial Science And Technology Steam reforming reactor
US4127389A (en) * 1977-04-04 1978-11-28 Pullman Incorporated Exchanger reactor
EP0171786A2 (fr) * 1984-08-16 1986-02-19 Air Products And Chemicals, Inc. Appareil de reformage avec échange de chaleur accrue et procédé y afférent
EP0334792A2 (fr) * 1988-03-21 1989-09-27 International Fuel Cells Corporation Dispositif de transfert de chaleur pour tube de réacteur de reforming
WO2003031050A1 (fr) * 2001-10-09 2003-04-17 Jonhson Matthey Plc Reacteur echangeur de chaleur
WO2004059232A1 (fr) * 2002-12-31 2004-07-15 Dana Canada Corporation Reacteur de conversion de carburant

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2491618A (en) * 1943-07-30 1949-12-20 Standard Oil Co Catalytic contacting apparatus
US4113441A (en) * 1976-03-09 1978-09-12 Director-General Agency Of Industrial Science And Technology Steam reforming reactor
US4127389A (en) * 1977-04-04 1978-11-28 Pullman Incorporated Exchanger reactor
EP0171786A2 (fr) * 1984-08-16 1986-02-19 Air Products And Chemicals, Inc. Appareil de reformage avec échange de chaleur accrue et procédé y afférent
EP0334792A2 (fr) * 1988-03-21 1989-09-27 International Fuel Cells Corporation Dispositif de transfert de chaleur pour tube de réacteur de reforming
WO2003031050A1 (fr) * 2001-10-09 2003-04-17 Jonhson Matthey Plc Reacteur echangeur de chaleur
WO2004059232A1 (fr) * 2002-12-31 2004-07-15 Dana Canada Corporation Reacteur de conversion de carburant

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2932173A1 (fr) * 2008-06-05 2009-12-11 Air Liquide Procede de reformage a la vapeur avec ecoulement des fumees ameliore
WO2010001011A1 (fr) * 2008-06-05 2010-01-07 L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Procede de reformage a la vapeur avec ecoulement des fumees ameliore
US8845997B2 (en) 2008-06-05 2014-09-30 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Steam reforming process with improved flue gas flow
WO2010114844A1 (fr) * 2009-03-30 2010-10-07 Lawrence Clawson Reformeur à vapeur doté d'éléments passifs de régulation du flux de chaleur
KR101038465B1 (ko) * 2010-06-15 2011-06-01 김현영 열분해 개질기
WO2012140994A1 (fr) * 2011-04-12 2012-10-18 千代田化工建設株式会社 Procédé de fabrication n'émettant pas de co2 pour gaz de synthèse
DE102011084476A1 (de) * 2011-10-13 2013-04-18 Man Diesel & Turbo Se Rohrbündelreaktor
DE102013214313A1 (de) * 2013-07-22 2015-01-22 Bayerische Motoren Werke Aktiengesellschaft Reaktor zur Freisetzung von Wasserstoff aus flüssiger Verbindung
DE102013214314A1 (de) * 2013-07-22 2015-01-22 Bayerische Motoren Werke Aktiengesellschaft Reaktor zur Freisetzung von Wasserstoff aus einer flüssigen Verbindung
US10196264B2 (en) 2013-07-22 2019-02-05 Bayerische Motoren Werke Aktiengesellschaft Reactor for release of hydrogen from a liquid compound
CN110052224A (zh) * 2019-06-10 2019-07-26 大连海事大学 气体分布器、固定鼓泡床反应器
WO2022162051A1 (fr) 2021-01-28 2022-08-04 Topsoe A/S Réacteur d'échange de chaleur catalytique à écoulement hélicoïdal

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