Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
  • B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
  • B01D53/047—Pressure swing adsorption
  • B01D53/053—Pressure swing adsorption with storage or buffer vessel
• • 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
• • 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
  • C01B3/50—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification
  • C01B3/56—Separation of hydrogen or hydrogen containing gases from gaseous mixtures, e.g. purification by contacting with solids; Regeneration of used solids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2256/00—Main component in the product gas stream after treatment
  • B01D2256/16—Hydrogen
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2259/00—Type of treatment
  • B01D2259/40—Further details for adsorption processes and devices
  • B01D2259/40083—Regeneration of adsorbents in processes other than pressure or temperature swing adsorption
  • B01D2259/40086—Regeneration of adsorbents in processes other than pressure or temperature swing adsorption by using a purge gas
• • 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
  • C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
  • C01B2203/042—Purification by adsorption on solids
  • C01B2203/043—Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration
• • 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
  • C01B2203/0811—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel
  • C01B2203/0827—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel at least part of the fuel being a recycle stream
• • 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
  • C01B2203/16—Controlling the process
  • C01B2203/1685—Control based on demand of downstream 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
  • C01B2203/16—Controlling the process
  • C01B2203/1695—Adjusting the feed of the combustion

Definitions

• the invention relates to a method for providing a fuel gas, which is used in the regeneration of a synthesis gas for the decomposition of synthesis gas
• DWA Pressure swing adsorption
• the raw hydrogen is fed to the DWA where it flows at elevated pressure through one of several adsorbers each filled with an adsorbent material which adsorbs and holds the impurities contained in the raw hydrogen while allowing the water off to pass largely unhindered ,
• the emerging from the adsorber hydrogen therefore has a high purity of
• Impurities loaded adsorber regenerated.
• the pressure in the adsorber is lowered to the so-called regeneration pressure in order to desorb the adsorbed contaminants from the adsorber material. So that the impurities are removed as completely as possible, the adsorber during and / or after the
• residual gas gas mixture consists for the most part of combustibles and is therefore usually used as a fuel gas for firing the steam reformer. Since both the flow rate and the composition of the residual gas time strong
• From the hydrogen generator A is the one from the burner-fired
• Buffer tank P available to bridge the time to replace the residual gas by a fuel gas from an external source can.
• the pressure regulator PC1 changes the setpoint value for the flow regulator FC, which then regulates the flow rate in the fuel gas line 4
• Control valve Z1 which is usually a control valve, further opens or closes and so reduces or increases the pressure loss of the fuel gas, the fuel gas flow increases or decreases accordingly.
• the flow controller FC very slow controller parameters are set, so that only long-term trends
• control valve Z2 opens immediately and residual gas 5 to a torch (not shown) passes as soon as the pressure in the buffer tank P its set value
• Object of the present invention is therefore to provide a method of the generic type, which allows to overcome the resulting in a reduction in the Regenerier horrs according to the prior art difficulties.
• the stated object is achieved in that the control valve is positioned by specifying a particular value determined by the load of the pressure swing adsorption plant to an operating point, wherein the pressure in the buffer tank is within a defined range.
• An operating point is to be understood as meaning a position of the control valve in which the fuel gas flows from the buffer vessel to the burner with a mass flow corresponding to the load of the DWA and the pressure drop across the control valve, which is moved around the operating point for control purposes, is within one range , which allows a trouble-free execution of the control task.
• the load of the DWA is measured in temporal intervals, usually in the range of seconds, and averaged over several consecutive measured values. Between two
• the manipulated variable remains unchanged regardless of the actual load of the DWA.
• pressure fluctuations of the residual gas preferably designed as a control valve and equipped with a remote-controlled drive and a position feedback control valve is usefully controlled by a flow controller, the corresponding fast control parameters are set.
• the current residual gas quantity can be determined and compared, for example, with the residual gas quantity at nominal load. Since a direct measurement of the amount of residual gas is usually possible only with considerable errors, the current amount of residual gas is usefully not measured directly, but calculated from the amount of the synthesis gas flowing into the DWA and the known yield of the DWA. Preferably, however, to determine the DWA load, the amount of the synthesis gas flowing into the DWA is determined and compared with the amount of synthesis gas at nominal load.
• the control value of the control valve is usefully set so that sets a pressure over the entire load range of the DWA in the buffer tank, the time average is lower than in the prior art, so that a
• the time average of the pressure is between 100 and 250 mbar (g).
• Control valve is characteristic for the production unit, of which the DWA is a part. It must be determined experimentally or by simulation and is preferably stored as a curve or table electronically or otherwise.
• the size and position of the defined area in which the pressure in the buffer tank can move are also dependent on the characteristics of the production unit and their operating conditions and are predefined for the system. They are chosen so that a stable plant operation is guaranteed, as long as the pressure in the buffer tank is within the defined range.
• the synthesis gas to be separated is generated in a burner-fired steam reformer, for the heating of which the residual gas is used, the lower limit of the defined
• Pressure range between 50 and 150mbar (g) and the upper limit between 200 and 300mbar (g).
• the hydraulic balancing is preferably carried out such that the maximum pressure loss via the control valve is less than 70%, and particularly preferably less than 50%, of the total pressure drop across the controlled system. Short, in the range of seconds pressure fluctuations in the buffer tank, such as occur when switching between the adsorbers of the DWA, therefore, for example, via an acting on the control valve, operated with much faster control parameters than in the prior art flow regulator effectively in the lower DWA load range become. This is not possible in a concept according to the prior art, since the high pressure drop of the control valve system especially at a low load operation is already disturbed sensitive even at low position changes.
• the control valve expediently has sufficient distance to its end positions over the entire load range of the DWA in their respective operating point.
• the control valve is at full load in its operating point preferably 70 to 90% open, the pressure in the buffer tank a distance of 30 to 50mbar to the upper end of defined area.
• the pressure in the buffer tank is 30 to 50 mbar from the lower end of the defined range, and the control valve is 20 to 40% open.
• Buffer tank is not a controlled variable. At least with unchanged load of the DWA, the control valve remains under these conditions at its operating point. Only when the pressure reaches the limits of the defined range, additional high and low pressure regulators become active.
• the proposed method can be realized in different ways. Preferably, the position of the control valve via a flow controller is changed, which is coupled to a position analysis controller.
• the position analysis controller which sets the operating point derived from the stored curve or table as a control value dependent on the load of the DWA, compares this with the actual position value of the control valve and determines a setpoint for the flow controller from the deviation of the two values.
• the flow controller also compensates for short-term pressure fluctuations in the buffer tank, for which purpose it is set much faster control parameters than the position analysis controller.
• Another possibility is to dispense with the position analysis controller and instead to control the flow controller via a pressure regulator, which monitors the pressure in the buffer tank and its setpoint from the stored curve or table is given as a function of the current load of the DWA ,
• the setpoint for the pressure regulator can also be determined via a load-dependent calculation, in which, for example, the desired pressure drop over the
• a line is opened by the high pressure regulator, can flow through the residual gas from the buffer tank.
• the high-pressure regulator keeps the line open until the pressure in the buffer tank falls below the upper limit of the defined pressure range again.
• the line is preferably a connecting line to a torch, in which the residual gas flowing out of the buffer tank is disposed of by combustion.
• the buffer tank is operated in particular at partial load of the DWA with a pressure only slightly above the ambient pressure and correspondingly reduced storage effect. To ensure that the buffer tank can be used in all operating conditions meaningful as a volume storage, it is therefore intended to open by a low-pressure regulator a line through which a combustible gas in the
• conduit is a bypass conduit via which synthesis gas or a synthesis gas obtained by decomposition
• Gas mixture such as raw hydrogen is diverted upstream of the DWA and introduced in the bypass to this in the buffer tank.
• the direct supply of synthesis gas or raw hydrogen into the buffer container makes it possible, in the event of a malfunction of the DWA and a resulting interruption of the residual gas supply, to use the entire residual gas present in the buffer container. This stands for the Provision of a substitute gas from an external fuel gas source a much longer compared to the prior art time available.
• FIG. 2 shows a production plant for hydrogen with a burner-fired steam reformer for the production of synthesis gas
• the residual gas is used according to a preferred variant of the invention for heating the steam reformer. Same
• Hydrogen generator A is separated from a synthesis gas raw hydrogen 1 to the pressure swing adsorption D to get pure hydrogen 2 and a residual gas 3, which is temporarily stored in the buffer tank P and then the burners B of the steam reformer S zugnosti as fuel gas 4.
• the position of the control valve Z1 is changed during normal operation of the system via the flow controller FC, which is coupled to a position analysis controller ZC.
• the actual value 7 for the fuel gas flow with the current fuel gas density 10 can be corrected, which is determined by means of the density analyzer Ql.
• the position analysis regulator ZC to which the operating point dependent on the load of the pressure swing adsorption system D, specified from a stored curve or table for control valve Z1, is compared with the position actual value of control valve Z1 and determined from the deviation of both values a setpoint 9 for the flow controller FC. If the operating point for the control valve Z1 is smaller than the actual position value, the control valve Z1 is thus opened further than required, the currently valid setpoint value for the flow controller FC is reduced so that the control valve Z1 moves in the closing direction. On the other hand, if the position analysis shows that the control valve Z1 is currently closed too far, the
• Flow controller FC a higher setpoint specified, whereby the control valve Z1 continues to open.
• the flow controller FC is set fast control parameters, so that it is able to compensate for short-term pressure fluctuations in the buffer tank P caused flow changes of the fuel gas 4.
• the pressure in the buffer container P is not a controlled variable in normal operation and can fluctuate freely in a defined range, which preferably extends between 100 and 250 mbar (g).
• the system is designed with a PC2 high-pressure regulator and a PC3 intakes pressure regulator.
• the obturator Z2 is opened by the high pressure regulator PC2, so that residual gas from the buffer tank P via the torch lead 5 to a torch (not shown) can flow, where it is disposed of by combustion.
• High pressure regulator PC2 keeps the torch lead 5 open until the pressure in the
• Buffer tank P falls below the upper limit of the defined pressure range again.
• the obturator Z3 is opened by the low pressure regulator PC3, so that raw hydrogen 1 via the line 6 in the bypass to
• Pressure swing adsorption D is introduced directly into the buffer tank P.
• the intakes PC3 keeps the line 6 open until the pressure in the
• Buffer container P again exceeds the lower limit of the defined range or a replacement gas for the residual gas 3 is provided from an external source.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Inorganic Chemistry (AREA)
• Combustion & Propulsion (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• General Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Hydrogen, Water And Hydrids (AREA)
• Separation Of Gases By Adsorption (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=62167270

Family Applications (1)

Country Status (6)

Family Cites Families (10)

• 2017
  • 2017-05-04 DE DE102017004326.4A patent/DE102017004326A1/de not_active Withdrawn
• 2018
  • 2018-04-27 EP EP18724775.4A patent/EP3619162A1/de not_active Withdrawn
  • 2018-04-27 CA CA3060001A patent/CA3060001A1/en active Pending
  • 2018-04-27 CN CN201880029493.8A patent/CN110621614A/zh active Pending
  • 2018-04-27 US US16/610,140 patent/US20200070085A1/en not_active Abandoned
  • 2018-04-27 WO PCT/EP2018/000226 patent/WO2018202329A1/de unknown

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