Classifications

• • 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
  • C01B3/386—Catalytic partial combustion
• • 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
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
  • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
  • B01D53/9404—Removing only nitrogen compounds
  • B01D53/9409—Nitrogen oxides
• • 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
  • B01J8/0207—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 flow within the bed being predominantly horizontal
  • B01J8/0221—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 flow within the bed being predominantly horizontal in a cylindrical shaped bed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
  • F01N3/0814—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
  • F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
  • F01N3/0842—Nitrogen oxides
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
  • F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
  • F01N3/206—Adding periodically or continuously substances to exhaust gases for promoting purification, e.g. catalytic material in liquid form, NOx reducing agents
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2251/00—Reactants
  • B01D2251/20—Reductants
  • B01D2251/202—Hydrogen
• • 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
  • B01J2208/00716—Means for reactor start-up
• • 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
  • C01B2203/0261—Processes for making hydrogen or synthesis gas containing a partial oxidation step containing a catalytic partial oxidation step [CPO]
• • 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
  • C01B2203/0283—Processes for making hydrogen or synthesis gas containing a CO-shift step, i.e. a water gas shift 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
  • C01B2203/0435—Catalytic purification
  • C01B2203/044—Selective oxidation of carbon monoxide
• • 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
  • C01B2203/0465—Composition of the impurity
  • C01B2203/047—Composition of the impurity the impurity being carbon monoxide
• • 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
  • C01B2203/0465—Composition of the impurity
  • C01B2203/0485—Composition of the impurity the impurity being a sulfur compound
• • 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
  • C01B2203/10—Catalysts for performing the hydrogen forming reactions
  • C01B2203/1041—Composition of the catalyst
  • C01B2203/1047—Group VIII metal catalysts
• • 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
  • C01B2203/1205—Composition of the feed
  • C01B2203/1211—Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
  • C01B2203/1235—Hydrocarbons
  • C01B2203/1247—Higher hydrocarbons
• • 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
• • 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
  • C01B2203/1288—Evaporation of one or more of the different feed components
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/04—Adding substances to exhaust gases the substance being hydrogen

Definitions

• the present invention provides a process for the production of hydrogen, a process for operating an internal combustion engine, a propulsion system, a vehicle comprising the propulsion system and use of the produced hydrogen for reducing NOx to molecular nitrogen and water.
• CPO On-board operated catalytic partial oxidation of an automotive feedstock, such as diesel feedstock, is regarded as a promising technology to supply the hydrogen required to successfully implement such an advanced NOx abatement technology.
• CPO processes are for instance employed to produce a fuel gas, typically hydrogen or a hydrogen-rich gas mixture, for fuel cells such as solid oxide feedstocks cells (SOFC) or proton exchange membrane (PEM) fuel cells.
• SOFC solid oxide feedstocks cells
• PEM proton exchange membrane
• NOx adsorbers need periodic regeneration. Hydrogen is only demanded during the regeneration of the NOx adsorber and as a result the demand for hydrogen is discontinuous. During periods wherein there is no hydrogen demand, the CPO processor should be kept in a condition, which will allow for a fast restart. According to WO2005042934 A2, the CPO processor must remain heated during the period of no hydrogen demand. Otherwise, there would be a great challenge for starting up and shutting down a CPO processor frequently. According to WO2005042934 A2, the start up and shutdown of the CPO process requires significant, complex controls, thus increasing the cost of the system. This problem is solved in WO2005042934 A2 by, at least in part, continuing the CPO operation. The produced hydrogen is diverted to the inlet of a combustion engine or discarded. Summary of the invention
• the present invention provides a process for the production of hydrogen, wherein during a first time interval a hydrocarbonaceous feedstock is converted to a hydrogen-comprising gas by mixing the feedstock with an amount of molecular oxygen to form a first mixture comprising feedstock and molecular oxygen with an overall oxygen-to-carbon ratio in the range of from 0.3 to 0.8 and contacting the first mixture with a partial oxidation catalyst and interrupting the contacting of such first mixture with the partial oxidation catalyst during a second time interval, wherein from the start and during at least part of the second time interval no hydrocarbonaceous feedstock or molecular oxygen is supplied to the partial oxidation catalyst, in which process the ratio of the first time interval over the second time interval is in the range of from 0.05 to 5.
• the process according to the invention allows for the intermittent production of hydrogen. During periods wherein no hydrogen supply is required, essentially no hydrogen is produced. Therefore, there is no need to redirect produced hydrogen to less favoured alternative applications or to discard the produced hydrogen.
• the process according to the invention further allows for the intermittent production of hydrogen from a hydrocarbonaceous feedstock, whereby feedstock conversion and hydrogen yield are improved compared to steady state operation of the process.
• the invention relates to a process for operating an internal combustion engine, wherein a hydrocarbonaceous feedstock is combusted with air in an internal combustion engine to produce a NOx comprising exhaust gas and wherein: i) the NOx comprising exhaust gas is passed through NOx trap comprising a NOx adsorber material to obtain adsorbed NOx and NOx depleted exhaust gas; ii) the NOx trap is regenerated by reducing the adsorbed NOx with hydrogen, produced by a process according to the invention, to obtain nitrogen and water, in which process the hydrogen is produced by catalytic partial oxidation of part of the feedstock and hydrogen is only produced during regeneration of the NOx trap.
• the invention relates in a still further aspect to the use of the hydrogen produced by a process for the production of hydrogen according to the invention for reducing NOx to molecular nitrogen and water.
• Figure 1 schematically shows a catalytic partial oxidation processor suitable for the process according to the present invention.
• Figure 2 schematically shows another catalytic partial oxidation processor suitable for the process according to the present invention.
• FIG. 3 shows a schematically representation of a propulsion system according to the invention. Detailed description of the invention
• the process according to the present invention is a process for the production of hydrogen.
• the hydrogen is produced during a first time interval, wherein a hydrocarbonaceous feedstock is converted to a hydrogen- comprising gas using a catalytic partial oxidation process.
• the feedstock is mixed with an amount of molecular oxygen to form a first mixture with an overall oxygen-to-carbon ratio in the range of from 0.3 to 0.8.
• Reference herein to oxygen-to- carbon ratio is to the ratio of oxygen molecules (O2) mixed with the feedstock and carbon atoms in the feedstock.
• the first mixture is contacted with a partial oxidation catalyst and the feedstock is catalytically partially oxidised to obtain a hydrogen-comprising gas.
• Such gas may further comprise carbon monoxide and/or carbon dioxide .
• the contacting of such first mixture with the catalyst is interrupted.
• no hydrocarbonaceous feedstock molecular oxygen or any mixtures comprising one or both thereof is supplied to the partial oxidation catalyst.
• This can be achieved by interrupting the supply of hydrocarbonaceous feedstock and molecular oxygen or by allowing such to bypass the partial oxidation catalyst.
• the supply of hydrocarbonaceous feedstock is interrupted to prevent the unnecessary consumption of the feedstock, whereas the molecular oxygen is allowed to bypass, in particular when the molecular oxygen is part of an exhaust gas.
• the duration the period wherein no hydrocarbonaceous feedstock or molecular oxygen is supplied to the partial oxidation catalyst is at least 50%, more preferably at least 80%, even more preferably at least 90% of the duration of the second time interval. As a result little to essentially no hydrogen is produced during this second time interval.
• the ratio of the first time interval over the second time interval is in the range of from 0.05 to 5.
• the ratio of the first time interval over the second time interval is in the range of from 0.05 to 1, preferably, 0.05 to 0.5, more preferably 0.05 to 0.1.
• the length of the first time interval may be determined by the hydrogen demand.
• the length of the first time interval is, typically, in the range of from 1 to 120 seconds, more preferably in the range of from 1 to 60 seconds, even more preferably in the range of from 1 to 20 seconds. It will be appreciated that, in order to prevent an unacceptable cooling of the catalyst, the second time interval should preferably not exceed 10 minutes, more preferably 5 min.
• a sequence comprising the first time interval and the second time interval is repeated one or more times, more preferably the sequence of first time interval and the second time interval is repeated continuously.
• a sequence of the first time interval and the second time interval hydrogen is produced intermittently.
• the catalyst is not contacted with the first mixture. Also from the start and during at least part of the second time interval all hydrocarbonaceous feedstock, amounts of molecular oxygen or any mixtures comprising one or both thereof are allowed to bypass around the partial oxidation catalyst. Generally, the catalyst arrangement is insulated and the temperature loss of the catalyst is predominantly governed by the heat radiation. However, when during the second period the hydrocarbonaceous feedstock, amounts of molecular oxygen or any mixtures comprising one or both thereof are passed over the catalyst partial oxidation catalyst a significant temperature loss may be induced by heat convection.
• the catalyst may be contacted with a second amount of molecular oxygen.
• amounts of carbon- comprising residue may be deposited on the catalyst. These carbon-comprising residues may result in catalyst deactivation and are therefore preferably removed.
• carbon-comprising residues may be oxidised and subsequently removed from the catalyst. Additionally, the exothermic oxidation of the carbon-comprising residues may provide heat to the catalyst during the second time interval.
• the gas hourly space velocity of the second amount of molecular oxygen contacting the catalyst does not exceed the gas hourly space velocity at which the first amount of molecular oxygen mixed with the feedstock in the first time interval. This may allow for the use of the same means for supplying the first and second amount of molecular oxygen .
• the second amount of molecular oxygen is comprised in a second mixture of the feedstock and molecular oxygen with an overall oxygen-to- carbon ratio in the range of from 1.0 to 10, more preferably of from 2 to 5.
• the second mixture comprises oxygen in excess of the stoichiometric ratio.
• the exothermic oxidation of the feedstock may provide heat to the catalyst during the second time interval.
• the presence of oxygen in excess of the stoichiometric ratio will allow the oxidative removal of carbon-comprising residues, which may be present on the catalyst surface.
• the catalyst is contacted with the second mixture directly preceding the step of contacting the catalyst with the first mixture.
• heat may be generated and the inlet temperatures of the feedstock and molecular oxygen-comprising gas during the first time interval may be lower .
• the catalyst is exposed to the heat generated by the exothermic partial oxidation reaction.
• the temperature of the catalyst may have reached temperatures in the range of from 700 to 1500 0 C.
• the second mixture may ignite spontaneously.
• the second mixture is ignited prior to contacting the catalyst. Ignition is effected e.g. by a spark plug or a glow element.
• the hydrocarbonaceous feedstocks that are suitable for the process according to the invention include gaseous and liquid feedstocks. Where gaseous feedstocks generally mix easily with the molecular oxygen, it may be preferred that the liquid feedstock is first evaporated. The heat necessary to evaporate the feedstock may be provided by the molecular oxygen-comprising gas. If the temperature of the molecular oxygen-comprising gas is high enough, it may be used to cause the feedstock to evaporate when it is contacted or mixed with the molecular oxygen-comprising gas. Alternatively, part of the feedstock may be combusted to generate the heat necessary for evaporating the feedstock.
• liquid feedstock is mixed in the first time interval with a first part of the amount of molecular oxygen to form an intermediate mixture comprising feedstock and molecular oxygen.
• the intermediate mixture is ignited, causing the feedstock to react exothermically with the molecular oxygen.
• the heat generated by the exothermic reaction causes the feedstock in the intermediate mixture to evaporate.
• the evaporated feedstock is then mixed with a second part of the amount of molecular oxygen, to form the first mixture comprising evaporated feedstock and molecular oxygen.
• the oxygen-to-carbon ratio in the intermediate mixture is preferably in the range of from 0.01 to 0.4, more preferably of from 0.01 to 0.15, even more preferably of from 0.02 to 0.10.
• the overall oxygen-to-carbon ratio in the first mixture is in the range of from 0.3 to 0.8, preferably of from 0.40 to 0.75, more preferably of from 0.45 to 0.65. It will be clear that the oxygen-to-carbon ratio in the intermediate mixture cannot exceed the overall oxygen-to-carbon ratio of the first mixture. Preferably, the oxygen-to-carbon ratio in the intermediate mixture does not exceed 50% of the overall oxygen-to-carbon ratio. Therefore, preferably, the intermediate mixture comprises no more than half of the amount of molecular oxygen .
• the molecular oxygen-containing gas may comprise water. It will be appreciated that depending on the temperature the water will either be in a liquid or vapour phase.
• the overall water-to-carbon ratio is preferably in the range of from 0.0 to 3.0, more preferably of from 0.0 to 1.5, even more preferably of from 0.0 to 1.0. Reference herein to the overall water- to-carbon ratio is to the ratio of water molecules mixed with the feedstock and carbon atoms in the feedstock.
• the process according to the invention is especially suitable for mixing the feedstock with molecular oxygen that has a temperature up to 400 0 C.
• the heat comprised in the molecular oxygen is not sufficient to evaporate the feedstock.
• the amount of the molecular oxygen mixed with the feedstock has a temperature in a range of from ambient to 500 0 C, more preferably in the range of from 200 0 C to 500 0 C.
• the first mixture is preferably contacted with the catalyst at a gas hourly space velocity in the range of from 1,000 to 10,000,000 Nl/l/h (normal litres of gaseous feed mixture per litre of catalyst per hour), more preferably in the range of from 5,000 to 2,000,000 Nl/l/h, even more preferably in the range of from 10,000 to 1,000,000 Nl/l/h.
• Reference herein to normal litres is to litres at Standard Temperature and Pressure conditions, i.e. 0 0 C and 1 atm.
• the first mixture, second mixture and/or second amount of molecular oxygen are preferably contacted with the catalyst at a pressure up to 100 bara, preferably in the range of from 1 to 50 bara, more preferably of from 1 to 10 bara.
• the catalyst may be any catalyst suitable for catalytic partial oxidation. Such catalysts are known in the art and typically comprise one or more metals selected from Group VIII of the Periodic Table of the Elements as catalytically active material on a catalyst carrier .
• Suitable catalyst carrier materials are well known in the art and include refractory oxides, such as silica, alumina, titania, zirconia and mixtures thereof, and metals.
• Preferred refractory oxides are zirconia-based, more preferably comprising at least 70% by weight zirconia, for example selected from known forms of (partially) stabilised zirconia or substantially pure zirconia.
• Most preferred zirconia-based materials comprise zirconia stabilised or partially-stabilised by one or more oxides of Mg, Ca, Al, Y, La or Ce.
• Preferred metals are alloys, more preferably alloys containing iron, chromium and aluminium, such as fecralloy-type materials .
• the catalytically active material comprises one or more Group VIII noble metals, more preferably rhodium, iridium, palladium and/or platinum, even more preferably rhodium and/or iridium.
• the catalyst comprises the catalytically active material in a concentration in the range of from 0.02 to 10% by weight, based on the total weight of the catalyst, preferably in the range of from 0.1 to 5% by weight.
• the catalyst may further comprise a performance-enhancing inorganic metal cation selected from Al, Mg, Zr, Ti, La, Hf, Si, Ba, and Ce which is present in intimate association supported on or with the catalytically active metal, preferably a zirconium cation.
• any suitable igniter known in the art may be used to ignite the second mixture and/or the intermediate mixture.
• the second mixture and/or the intermediate mixture are ignited using a spark plug that is placed in the flow path of the mixture.
• Suitable spark plugs are typically operated at a voltage in a range from 9 to 13 Volt, which is sufficient to ignite the mixture.
• the second mixture and/or the intermediate mixture are ignited using glow element, which reaches into the mixture.
• a suitable glow element is for instance an electrical resistor comprising a metal spiral.
• Such a glow element may for instance be powered at 12 V and 17A, constituting a power output of approximately 200 W.
• the metal spiral is coated with an oxidation catalyst .
• Suitable hydrocarbonaceous feedstocks for the process according to the invention comprise hydrocarbons, oxygenates or mixtures thereof. Oxygenates are defined as molecules containing apart from carbon and hydrogen atoms at least one oxygen atom, which is linked to either one or two carbon atoms or a carbon atom and a hydrogen atom.
• the hydrocarbonaceous feedstock is a hydrocarbon comprising feedstock such as natural gas, liquefied petroleum gas, gasoline or diesel.
• the hydrocarbonaceous feedstock may be a liquid hydrocarbonaceous feedstock.
• Reference herein to a liquid hydrocarbonaceous feedstock is to a feedstock that is liquid at 20 0 C and atmospheric pressure.
• such a liquid feedstock has a final boiling point up to 400 0 C, more preferably in the range of from 250 to 400 0 C.
• suitable feedstocks for use in the process according to the invention are gasoline, naphtha, or diesel feedstocks, preferably diesel feedstocks.
• Diesel feedstocks typically comprise at least 90% (v/v) hydrocarbons with carbon numbers in the range of from c 10 ⁇ c 28' preferably C]_2 ⁇ C24' more preferably C]_2 ⁇ C 15-
• the molecular oxygen may be comprised in any suitable molecular oxygen-containing gas known in the art.
• the molecular oxygen mixture is comprised in air, exhaust gas or a mixture thereof, preferably the exhaust gas is diesel exhaust gas.
• Reference herein to diesel exhaust gas is to the exhaust gas generated by an internal combustion engine running on diesel feedstock. It will be appreciated that a molecular oxygen-containing gas like diesel exhaust gas will typically already comprise water. It will be further appreciated that the molecular oxygen-comprising gas may be different depending on whether it is, the first or second part of, the first amount of molecular oxygen or, the first part or remainder of, the second amount of molecular oxygen.
• the hydrogen-comprising gas obtained with the present invention may be fed e.g. to an absorber for hydrogen sulphide or undergo one or more water-gas shift conversions, e.g. low or high temperature water-gas shifts, followed by preferential oxidation of carbon monoxide in the hydrogen-comprising gas .
• the use of hydrogen produced by a process according to the invention is in particular suitable for reducing NOx, such as the NOx comprised in diesel exhaust, to molecular nitrogen and water .
• An internal combustion engine may be operated according to a process wherein NOx is reduced using hydrogen.
• Reference herein to an internal combustion engine is to an engine, which, in use, is driven by combusting a hydrocarbonaceous feedstock or fuel .
• the NOx may produced when combusting a hydrocarbonaceous feedstock, such as diesel fuel, with air.
• a hydrocarbonaceous feedstock is combusted with air in an internal combustion engine, producing a NOx comprising exhaust gas.
• the NOx comprising exhaust gas is passed through a NOx trap comprising a NOx adsorber material and advantageously a NOx reducing catalyst.
• the NOx is retained in the N0x-trap as adsorbed NOx and the NOx depleted exhaust gas is discarded.
• the NOx trap is regenerated by reducing the absorbed NOx with hydrogen to obtain nitrogen and water.
• the hydrogen is produced by catalytic partial oxidation of part of the hydrocarbonaceous feedstock. Hydrogen is produced only during the regeneration of the NOx trap. It will be appreciated that the production of hydrogen may begin shortly before the regeneration of the NOx trap, in order to allow for the transport of the hydrogen to the NOx trap .
• the hydrogen is produced according to a process for the production of hydrogen according to the invention .
• the hydrogen produced by the process according to the invention may be used to fuel a propulsion system.
• a propulsion system comprises a catalytic partial oxidation reactor set to operate the process for producing hydrogen according to the invention.
• the propulsion system may further comprise a fuel cell, electric engine and/or internal combustion engine, preferably an internal combustion engine. More preferably, the propulsion system comprises an internal combustion engine, which is set to operate the process for operating a combustion engine according to the invention and further comprises one or more NOx traps.
• Processor 1 comprises housing 2.
• Housing 2 contains sections 2a, for mixing feedstock and molecular oxygen-comprising gas and 2b for collection of the hydrogen-comprising gas.
• Housing 2 further comprises inlet 3 for supplying feedstock and inlet 4 for supplying molecular oxygen-comprising gas and outlet 5 for the hydrogen-comprising gas.
• Partial oxidation catalyst 6 is disposed in housing 2 on the intersection between sections 2a and 2b. Igniter 7, for example a glow element is located upstream from catalyst 6.
• FIG. 2 schematically shows a catalytic partial oxidation processor suitable for processing a liquid feedstock.
• Housing 2 now further comprises a section 2c for evaporating the liquid feedstock.
• Section 2c comprises additional inlet 8 for supplying molecular oxygen-comprising gas.
• air-assisted nozzle 9 may be present to introduce the liquid feedstock and the molecular oxygen-comprising gas into section 2c.
• Igniter 10 for example a spark plug or a glow element is located upstream from inlet 8.
• FIG 3 shows a schematically representation of a propulsion system according to the invention which is suitable for operating the process for operating an internal combustion engine according of the invention.
• propulsions system 100 comprising internal combustion engine 110.
• internal combustion engine 110 is comprised of a combustion chamber 120 and one or more NOx traps 130.
• fuel for example diesel fuel
• the exhaust gas from combustion chamber 120 is supplied via line 122 to NOx traps 130 wherein the NOx is adsorbed.
• the NOx depleted exhaust gas leaves internal combustion engine 110 via line 135.
• Propulsion system 100 further comprises catalytic partial oxidation processor 1.
• processor 1 can be used to produce a hydrogen-comprising gas suitable for regenerating NOx traps 130.
• Processor 1 is set to produce a hydrogen-comprising gas by the catalytic partial oxidation of a fuel, which is supplied via lines 102 and 106.
• Oxygen optionally in combination with water (not shown), is supplied to processor 1 via line 12, for example in the form of air.
• the exhaust gas of the internal combustion engine as well as the NOx depleted exhaust gas may comprise oxygen and water, part or all of the exhaust gas may be used to supply oxygen to processor 1 via line 124 or line 135 (not shown) .
• the produced hydrogen-comprising gas may be directed to saturated NOx traps via line 16 for regeneration of said NOx traps 130.
• Example 1 (not according to the invention) A diesel fuel (ARCO Ultra Low Sulphur Diesel #2) was converted to a hydrogen-comprising gas over a partial oxidation catalyst .
• Molecular oxygen was supplied comprised in a gas with a composition resembling diesel exhaust gas, the composition is shown in table 1.
• Hydrogen yield was followed for different durations of the on-period (first time interval) .
• Diesel fuel and exhaust gas were supplied to the catalyst with an oxygen- to-carbon ratio of 0.53 [-] .
• the off-period (second time interval) the flow of diesel was switched off.
• the gas inlet temperature was 420 0 C and the fuel was in the vapour phase .
• Table 2 shows the obtained hydrogen yield as well as the steady state yield. It will be clear from table 2 that when operating the process at short on-times in the on/off operation a significant drop in diesel conversion and hydrogen yield is observed. Table 1:
• a diesel fuel (ARCO Ultra Low Sulphur Diesel #2) was converted to a hydrogen-comprising gas over a partial oxidation catalyst .
• Molecular oxygen was supplied comprised in a gas with a composition resembling diesel exhaust gas, the composition is shown in table 1. Hydrogen yield and diesel conversion were followed for different durations of the on-period (first time interval) . Diesel fuel and exhaust gas were supplied to the catalyst with an oxygen-to-carbon ratio of 0.53 [-] . During the off-period (second time interval) the flow of diesel fuel and exhaust gas was allowed to bypass the catalyst.
• the gas inlet temperature was 420 0 C and the fuel was in the vapour phase .
• Table 3 shows the obtained hydrogen yield as well as the steady state yield. It will be clear from table 3 that when operating the process at even at short on-times in the on/off operation according to the invention the hydrogen yield is maintained.
• a diesel fuel (ARCO Ultra Low Sulphur Diesel #2) was converted to a hydrogen-comprising gas over a partial oxidation catalyst .
• Hydrogen yield was observed as function of the inlet temperature of diesel and exhaust gas (gas inlet temperature) for the duration of the on- period (first time interval) .
• the duration of the on- period was 6 seconds.
• Diesel fuel and exhaust gas were supplied to the catalyst with an oxygen-tot-carbon ratio of 0.53.
• both the diesel fuel and exhaust gas were allowed to bypass the catalyst for a period of 55 seconds.
• a mixture of diesel and exhaust gas having an oxygen-to-carbon ratio of 3.7 was ignited using a glow element powered at 12 V and 17 A. The catalyst was brought into contact with the ignited mixture for a period of 5 seconds.
• Table 4 shows the obtained hydrogen yield as well as the steady state yield. It will be clear from table 4 that the on/off operation according to the invention shows improved hydrogen yields compared to steady state operation also at very low gas-inlet temperatures.

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• 2007
  • 2007-10-31 WO PCT/EP2007/061722 patent/WO2008053006A1/en active Application Filing
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