Classifications

• • 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
  • F01N3/2066—Selective catalytic reduction [SCR]
• • 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
• • 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
  • F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
• • 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
  • F01N2610/14—Arrangements for the supply of substances, e.g. conduits
  • F01N2610/1406—Storage means for substances, e.g. tanks or reservoirs
• • 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
  • F01N2610/14—Arrangements for the supply of substances, e.g. conduits
  • F01N2610/1433—Pumps
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
  • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the present invention relates to the trapping of ammonia in a pollution control system for reducing the amount of nitrogen oxides in the exhaust gas of a motor vehicle.
• SCR selective catalytic reduction
• NH 3 ammonia
• ammonia is produced by thermal decomposition of a precursor, usually an aqueous solution of urea.
• a precursor usually an aqueous solution of urea.
• the urea solution undergoes over time a decomposition reaction to gaseous ammonia, a reaction which increases with increasing temperature.
• the gaseous ammonia resulting from this decomposition and which is present inside the tank can pass through the wall of the urea storage tank.
• this gaseous ammonia will spread outside the tank, that is to say in the air surrounding the tank. This is particularly troublesome.
• gaseous ammonia is a source of a very pungent odor and is toxic, especially for humans, but also for the environment. It is also corrosive for some metals.
• the solution described in this document is to route the gaseous ammonia present inside the urea storage tank to a trap external to the urea storage tank, via a transport pipe.
• the disadvantage of this solution lies in the fact that there is a risk that some of the gaseous ammonia present in the tank is not conveyed to the trap. This portion of ammonia gas can therefore pass through the wall of the tank.
• the aforementioned solution is not suitable for solving this problem. More generally, the solution of the prior art described above does not allow to trap ammonia that could escape from SCR system components other than the tank, such as for example a urea injection line. . The solution of the prior art also does not make it possible to protect components of the SCR system placed in housings whose walls can be made of materials permeable to ammonia, such as, for example, a copper coil, more commonly called a winding, a motor of a urea pump.
• the invention aims to trap all or part of the gaseous ammonia generated in an SCR pollution control system wherever it may be annoying.
• the subject of the invention is a subsystem of a selective catalytic reduction pollution control system intended to reduce the quantity of nitrogen oxides in the exhaust gases of a motor vehicle, characterized in that said subsystem comprises:
• At least one chamber comprising at least one wall
• a trap configured to capture gaseous ammonia emanating from this at least one wall or which, if it were not trapped, would emanate from this at least one wall.
• the subsystem of a pollution control system means a subset of the assembly consisting of all the components of a pollution control system intended to be loaded into the vehicle.
• Chamber means a volume defined by at least one wall.
• a second wall delimits a second volume
• two chambers are delimited.
• a room is the space between the two walls.
• a second chamber corresponds to the second volume delimited by the second wall.
• wall is meant a structure that blocks (at least partially or completely) ammonia. More specifically, this structure has an ammonia permeability of less than 3 g / m 2 per day, for a thickness of 1 mm.
• the trap is integrated in the wall.
• the subsystem forms a single block which optimizes the overall volume occupied by the chamber and the trap.
• the assembly of the chamber and the trap in the pollution control system is also facilitated by this configuration in one block.
• the chamber contains the trap configured to capture ammonia gas and contains an ammonia-sensitive component.
• the ammonia-sensitive component is made of copper or one of its alloys, and preferably constitutes a coil of a motor of a urea pump.
• Ammonia corrodes copper and all its alloys.
• the onboard systems for storage, distribution and dosing of urea SCR systems can contain ammonia from the decomposition of urea and contain components containing copper. These components are placed in a housing so as not to be in contact with the urea to which they can also be sensitive.
• the wall of the protective case is not totally impervious to ammonia. This configuration of the invention makes it possible to increase the service life of these components, which makes it possible to prevent the occurrence of functional defects in the pollution control system and confers an economic advantage.
• the trap is fixedly mounted to the wall in a fixed or removable manner.
• the trap can be fixed in different modes such as gluing, welding, screwing, or others.
• the subsystem comprises two chambers, of which a first chamber contains an ammonia trap, said two chambers being separated from each other by at least one wall of a second chamber, so that ammonia contained in the second chamber, leaking by permeability or rupture of said at least one wall, can have no other destination than the first chamber.
• the ammonia trap comprises at least one of the following elements:
• a material on which ammonia can be stored by sorption more particularly a salt and even more particularly an alkaline earth metal chloride such as magnesium chloride, and
• These elements have a high absorption capacity when compared to other absorbent elements such as, for example, activated carbons.
• absorbent elements such as, for example, activated carbons.
• the use of these elements makes it possible to obtain traps of smaller volume.
• the superabsorbent polymer is in the form of a gel resulting from the absorption of water by said polymer (the ammonia being trapped by this water).
• the wall of the second chamber which separates the two chambers, is a wall common to both chambers.
• the ammonia trap is in contact with the wall common to both chambers.
• This configuration makes it possible to improve the capture of ammonia, which is, as soon as the wall separating the two chambers passes, comes into contact with the trap.
• both chambers have two contiguous walls.
• Contiguous walls are those that are side by side, separated by a specified distance.
• the second chamber is adapted to contain an ammonia precursor.
• the second chamber is adapted to contain urea.
• the second chamber consists of a urea injection line.
• the second chamber consists of a urea storage tank.
• a wall of at least one of the chambers is made of a thermoplastic material.
• the first chamber contains an ammonia sensitive component.
• the ammonia-sensitive component is made of copper or one of its alloys, and preferably constitutes a coil or winding of a motor of a urea pump.
• the second chamber is adapted to contain a compound on which ammonia can be stored by sorption.
• an alternative technique for providing ammonia in the SCR depollution systems consists in storing the ammonia by sorption on a salt, most often an alkaline earth metal chloride.
• the storage system includes a reservoir designed to enclose the salt and a heater configured to heat the salt.
• a heater configured to heat the salt.
• the invention also makes it possible to secure the SCR depollution systems having such an ammonia storage device. In fact, this configuration makes it possible to trap the ammonia which could suddenly be released from the chamber containing gaseous ammonia in the event of an accidental situation such as a defect or a rupture in the wall of this chamber, thus improving the safety of the SCR depollution system.
• the European patent application EP2574599 in the name of the applicant describes an example of a tank for storing ammonia by sorption on a salt.
• Said reservoir comprises a plurality of storage cells communicating with each other and with at least one orifice communicating with a distribution conduit.
• the cells are cavities capable of containing the compound on which the ammonia is stored by sorption.
• the subsystem comprises a cell, at least one part of which defines the second chamber.
• At least one other part of the cell defines the first chamber.
• This embodiment of the invention simplifies and speeds up the assembly because the two chambers are provided in the form of a single piece. Such a configuration also provides a more compact subsystem.
• the two chambers comprise between them fluid communication means which, in the event of overpressure in the second chamber or in the case of a desorption operation of the storage means, direct the ammonia towards the first chamber.
• An overpressure in the second chamber can be generated by excessive heating of the storage means.
• At least part of the fluidic communication means including the connection between the fluid communication means and the second chamber, is located in the first chamber. This part therefore also benefits from the security system formed by the trap.
• the fluidic communication means may also be used to evacuate the ammonia stored by sorption on the trap, in order to regenerate it.
• the trap thus fulfills three functions.
• the trap is constituted by a matrix that occupies all the free space of the first chamber.
• the space occupied by the matrix increases with the absorption of ammonia.
• the matrix is then compressed in the volume of the first chamber, thus limiting the flow of ammonia through the wall.
• the matrix makes it possible to improve the capture of the ammonia which is, as soon as the wall separating the two chambers passes, comes into contact with the trap.
• the matrix has a thermal insulation function, which prevents the urea solution from reaching a temperature too high to limit the release of ammonia due to its decomposition.
• the thermal insulation also facilitates the maintenance of the urea solution at a temperature above its crystallization temperature.
• the invention also relates to a selective catalytic reduction decontamination system comprising a subsystem as described above.
• the subject of the invention is also a housing for an ammonia sensitive component, said housing being intended to be placed in a selective catalytic reduction pollution control system intended to reduce the amount of nitrogen oxides in the gases.
• exhaust system of a motor vehicle said housing being characterized in that it comprises at least one wall and a trap configured to capture ammonia gas emanating from this at least one wall or which, if it was not trapped, emanating from this at least one wall.
• An optional feature of the housing is that it contains an ammonia sensitive device (eg pH paper), so as to reveal that the trap has been served, which can be a way of easily verifying that the component is still protected during a maintenance operation.
• an ammonia sensitive device eg pH paper
• caulking agent commonly referred to as "caulking agent”
• FIG. 1 is a diagrammatic representation of an SCR depollution system comprising a urea storage tank.
• FIG. 2 is a view of a urea storage tank of an SCR depollution system according to a first embodiment of the invention.
• FIG. 3 is a view of a urea storage tank of an SCR depollution system according to a second embodiment of the invention.
• FIG. 4 is a view of a urea storage tank of an SCR depollution system according to a third embodiment of the invention.
• FIG. 5 is a view of a portion of a urea injection line of an SCR depollution system according to a fourth embodiment of the invention.
• FIG. 6 is a section along IV - IV of FIG. 7 and FIG. 7 is a section along V - V of FIG.
• Fig. 8 is a section of a urea storage tank according to a sixth embodiment.
• FIG. 9 is a schematic representation of a SCR depollution system comprising a gaseous ammonia storage system.
• Figure 10 is a view of an ammonia gas storage system according to a seventh embodiment of the invention.
• Figure 11 is a view of a gaseous ammonia storage system according to an eighth embodiment of the invention.
• Figure 12 is a view of a gaseous ammonia storage system according to a ninth embodiment of the invention.
• FIG. 1 shows a nitrogen oxides treatment system present in the exhaust line 2 of a vehicle engine 1.
• the nitrogen oxides are directed to a catalyst 8 in which is placed Selective catalytic reduction SCR.
• Selective catalytic reduction is achieved by adding ammonia to the exhaust gas.
• the ammonia necessary for the reduction comes from a solution of urea 4 which is stored in a urea storage tank 3.
• the urea storage tank 3 is connected to the exhaust line 2 by a urea injection line 5.
• the urea present in the tank 3 is conveyed to the urea injection line 5 thanks to the action of a urea pump 6 present inside the urea storage tank 3.
• urea injector 7 Under the action of a urea injector 7, the urea is injected into the exhaust line 2. With time and variations in temperature, part of the urea contained in the tank 3 decomposes into ammonia gaseous. The gaseous ammonia of the reservoir is likely to come into contact with ammonia sensitive components present in the urea storage tank 3.
• FIG. 2 shows a first embodiment of the invention.
• a urea storage tank 3 contains a component 9 sensitive to ammonia. This component is placed in a housing 10 delimited by a wall 17 and a cover 11. The wall 17 of the housing and the lid 11 being porous with ammonia, an ammonia trap 12 was placed in the wall 17 of the housing and that of the lid 11 in order to maintain the ammonia concentration below the housing.
• a threshold value capable of causing corrosion of the component can be determined according to the nature of the component, the temperature or the duration of exposure. This threshold value or these threshold values can be obtained as a result of experiments.
• the subsystem is constituted by the entire housing 10 which corresponds to the chamber comprising two walls, namely the wall 17 of the housing and the cover 11.
• Trap 12 is configured to capture ammonia gas emanating from wall 17 or lid 11.
• the trap can be placed in one or other of the walls of the housing and the cover.
• the trap 12 is in the form of magnesium chloride particles integrated in the wall 17 of the housing and the cover 11 made of polymer.
• the wall 17 of the housing has for example a thickness of about 2 mm and has a permeability equal to about 1.25 g / m 2 / day at 80 ° C.
• the housing 10 has for example a total area of about 300 cm 2 .
• the protection of the component is ensured by 3 to 6 g of magnesium chloride.
• FIG. 3 shows a second embodiment of the invention.
• An ammonia-sensitive component 9 ' is placed in a housing 10' equipped with a lid 11 'and placed close to a urea storage tank 3 delimited by a wall 18.
• the walls 17' of the housing and 18 of the urea storage tank 3 may be a single wall common to both chambers. These two walls being porous with ammonia, a 12 'ammonia trap was placed inside the tank 3, near the location of the housing 10' to maintain in the housing ammonia concentration below a threshold value capable of causing corrosion component.
• This threshold value can be determined according to the nature of the component, the temperature or the duration of exposure. This threshold value or these threshold values can be obtained as a result of experiments.
• the subsystem is constituted by the assembly of the urea storage tank 3 which corresponds to the chamber comprising the wall 18.
• the trap 12 ' is configured to capture ammonia gas which, if was not trapped, emanating from the wall 18.
• the trap is provided with a protection 19 limiting the direct contact between the ammonia trap and the liquid phase of the ammonia precursor.
• the trap 12 ' is mounted integral with the wall 18.
• the protection of the component is provided for example by 1 to 2 g of magnesium chloride.
• the walls 17 'of the housing 10' and 18 of the urea storage tank 3 have a total thickness of 2 mm and a permeability equal to 1.25 g / m 2 / day at 80 '. vs.
• This common wall has for example a surface of 100 cm 2 , or in the case of two superimposed walls, they can be superimposed on a surface of 100 cm 2 .
• FIG. 4 shows a third embodiment of the invention.
• a urea storage tank 3 contains an ammonia sensitive component 9. This component is placed in a housing 10 "having a wall 17" and equipped with a lid 11 ". The wall 17 “of the housing and the lid 11" being porous with ammonia, an ammonia trap 12 "was placed in the lid 11" of the housing in order to keep the ammonia concentration below the housing threshold value capable of causing corrosion of the component.
• This threshold value can be determined according to the nature of the component, the temperature or the duration of exposure. This threshold value or these threshold values can be obtained as a result of experiments.
• the subsystem is constituted by the entire housing 10 "which corresponds to the first chamber and the urea storage tank 3 which corresponds to the second chamber.
• the two chambers are separated from each other. on the wall 17 "of the housing 10" which corresponds to a wall of the second chamber
• the trap 12 " is in the form of a buffer composed of an open cell foam made by example polyethylene, impregnated with magnesium chloride.
• the wall of the housing 10 has for example a thickness of about 1 mm and has a permeability equal to about 2.5 g / m 2 / day at 80 ° C.
• the housing 10 has for example a total surface of about 300 cm 2 .
• FIG. 5 shows a fourth embodiment of the invention.
• a urea injection line 5 contains an ammonia sensitive component 9.
• the component 9 "' is placed in a housing 10"' having a wall 17 "', equipped with a lid 11 "'An ammonia trap 12"' was placed in the housing cover.
• the subsystem is constituted by the entire housing 10 "'which corresponds to the first chamber and the urea injection line 5 which corresponds to the second chamber.
• the trap 12 "' is in the form of a buffer composed of an open cell foam made by example polyethylene, impregnated with magnesium chloride.
• the wall 17 "'of the housing 10"' is constituted by polyphthalamide (PPA), for example having a thickness of 1 mm and having an ammonia permeability at ⁇ ' ⁇ of about 1 at 2.5 g / m 2 / day.
• the casing 10 has, for example, a total area of 300 cm 2.
• the protection of the component for 40 days is ensured by 2 to 6 g of chloride. magnesium.
• FIGS. 6 and 7 show a fifth embodiment of the invention.
• a urea injection line 5 is surrounded over part of its length by a sleeve 13 containing an ammonia trap 14.
• the subsystem is constituted by the whole of the sleeve 13 which corresponds to the first one. chamber and the urea injection line 5 which corresponds to the second chamber.
• the two chambers are separated from each other by the wall of the urea injection line 5 which corresponds to the wall of the second chamber.
• the trap consists of magnesium chloride crystals.
• the wall is made of polyamide 66 (PA 66) and has, for example, an ammonia permeability of about 0.5 g / m 2 / day at 40% for a thickness of about 1 mm.
• the coated surface is about 125 cm 2 .
• about 0.25 g of ammonia is emitted in 40 days (about 1000 hours) through the wall of the urea injection line.
• about 0.25 g of magnesium chloride can entrap this amount of ammonia.
• the amount of magnesium chloride forming the trap in such an embodiment is about 0.5 to 2 g.
• FIG. 8 A urea storage tank 3 is surrounded by an envelope containing an ammonia trap 16.
• the subsystem is constituted by the assembly of the casing 15 which corresponds to the first chamber and the reservoir 3.
• urea storage that corresponds to the second chamber.
• the two rooms are separated from each other by the wall urea storage tank 3 which corresponds to the wall of the second chamber.
• the trap consists of a matrix of magnesium chloride.
• the wall is made of high density polyethylene (HDPE) and has, for example, an ammonia permeability at 80 ° C. of approximately 1.5 g / m 2 / day for a thickness of about 1 mm.
• HDPE high density polyethylene
• the protection for 40 days can be provided for example by 14 g of magnesium chloride.
• the trap contains for example 15 to 25 g of magnesium chloride.
• FIG. 9 shows schematically an example of a selective catalytic reduction scrubber system SCR comprising a gaseous ammonia storage system.
• the invention is not limited to such an example of a gas storage SCR system.
• the engine 21 of the vehicle is controlled by an electronic computer 22.
• the engine 21 cooperates with an SCR system 23.
• the exhaust gases 41 are directed to an ammonia injection module 31, in which the ammonia 72 is mixed with the exhaust gases 41.
• the ammonia / exhaust gas mixture 43 then passes through an SCR catalyst 32 which allows the reduction of nitrogen oxides (NOx) by ammonia.
• the exhausted exhaust gas 44 is then directed to the exhaust outlet.
• NOx nitrogen oxides
• the SCR system 23 includes an ammonia storage system.
• the storage system 25 comprises a cell 54 in which is stored a compound 52, for example a solid (and preferably a salt).
• the ammonia is stored by sorption on the solid 52.
• the storage system 25 also includes a control device 24 in charge of controlling a heater 53 for heating the solid 52 so as to release the ammonia.
• the cell 54 is connected to a metering module 51, via a distribution conduit 27.
• the metering module 51 is controlled by the control device 24.
• the control device 24 is able to estimate the ammonia pressure in the storage system 25. If a difference is found between the estimated pressure and a set pressure supplied by the electronic computer 22, the control device 24 can adjust the heating power of the heater 53 to compensate for this difference.
• the tank 54 is equipped with a temperature measuring device 26.
• FIG. 10 shows a seventh embodiment of the invention in a selective catalytic reduction scrubber system SCR comprising a gaseous ammonia storage system.
• a cell 54 which contains a compound 52 on which the ammonia is stored by sorption, is surrounded by an envelope 63 which defines a chamber according to the invention which contains an ammonia trap 62.
• a distribution duct 27 connected to the cell 54 leads to a three-way valve 60.
• the excess ammonia is diverted to a conduit 61 which is connected to the envelope 63 which contains the trap 62.
• the subsystem consists of the entire envelope 63 which corresponds to the first chamber and the cell 54 which corresponds to the second chamber. .
• the envelope 63 and the cell 54 are separated from each other by the wall of the cell 54 which corresponds to the wall of the second chamber.
• the distribution duct 27, the three-way valve 60 and the duct 61 constitute fluid communication means within the meaning of the invention.
• the cell 54 has a volume of 500 ml.
• Trap 62 is constituted by a matrix of magnesium chloride.
• the thermal activation of the desorption results in the emission of about 1 g of ammonia, which results in an overpressure of about 4 bars in the cell 54.
• the system is closed, all of the desorbed ammonia is directed to the trap.
• 0.93 g of magnesium chloride is required for trapping about 1 g of ammonia. Nevertheless it is for example advantageous to provide the trap with 5 g of magnesium chloride in order to effectively absorb all of the ammonia discharged abruptly.
• desorption of ammonia is carried out with a rate of about 3.5 mg / s about 12.6 g of ammonia in 1 hour.
• about 11.9 g of magnesium chloride are required to absorb this amount of ammonia.
• a trap containing 12 g of magnesium chloride provides protection against such an accidental situation for about 1 hour.
• FIG. 11 shows an eighth embodiment of the invention in a selective catalytic reduction abatement system SCR comprising a gaseous ammonia storage system.
• Three identical cells 54a, 54b and 54c of 500 ml each are all surrounded by a single envelope 59 which contains an ammonia trap 58.
• the first consists of the entire envelope 59 which corresponds to the first chamber and the cell 54a which corresponds to the second chamber.
• the second is constituted by the entire envelope 59 which corresponds to the first chamber and the cell 54b which corresponds to the second chamber.
• the third is constituted by the entire envelope 59 which corresponds to the first chamber and the cell 54c which corresponds to the second chamber.
• the envelope 59 is separated from the cells 54a, 54b and 54c by the walls of the latter, which correspond for each subsystem, to the wall of the second chamber.
• a distribution duct 27 connected to the cells 54a, 54b and 54c is equipped with a pressure relief valve 56.
• the excess ammonia is diverted to a conduit 57 which is connected to the envelope 59 which contains the trap 58.
• the distribution duct 27, the pressure relief valve 56 and the duct 57 constitute means of fluid communication in the sense of the invention. As for the previous figure, we find the three functions of the trap.
• Trap 58 is constituted by a matrix of magnesium chloride.
• the thermal activation of the desorption results in the emission of about 1 g of ammonia into each cell 54a, 54b and 54c, which results in an overpressure of about 4000 hPa in each cell.
• the system is closed, all of the desorbed ammonia is directed to the trap.
• About 2.79 g of magnesium chloride are necessary for trapping about 3 g of ammonia from the three cells.
• the desorption of the ammonia is carried out with a flow rate of approximately 3.5 mg / s about 12.6 g of ammonia in 1 hour.
• a flow rate of approximately 3.5 mg / s about 12.6 g of ammonia in 1 hour.
• 11.9 g of magnesium chloride are needed to absorb this amount of ammonia.
• a trap containing approximately 12 g of magnesium chloride makes it possible, for example, to protect against such an accidental situation for approximately 1 hour.
• FIG. 12 depicts a ninth embodiment of the invention in a selective catalytic reduction pollution control system SCR comprising a gaseous ammonia storage system.
• One cell 70 contains two compartments 74 and 73 separated from each other by a partition 71.
• the compartment 74 contains a compound 52 on which the ammonia is stored by sorption.
• a distribution duct 27 connected to the compartment 74 leads to a three-way valve 60.
• the excess ammonia is diverted to a duct 61 which is connected to the compartment 73 which contains a trap 62.
• the subsystem is constituted by the whole of the compartment 73 which corresponds to the first chamber and compartment 74 which corresponds to the second chamber.
• the compartment 74 has a volume of 500 ml.
• Trap 62 is constituted by a matrix of magnesium chloride.
• the thermal activation of the desorption results in the emission of about 1 g of ammonia, which results in an overpressure of about 4000 hPa in the compartment 74.
• the system is closed , all of the desorbed ammonia is directed to the trap.
• 0.93 g of magnesium chloride are necessary for trapping about 1 g of ammonia.
• the desorption of the ammonia is carried out with a flow rate of approximately 3.5 mg / s or approximately 12, 6 g of ammonia in 1 hour.
• a flow rate of approximately 3.5 mg / s or approximately 12, 6 g of ammonia in 1 hour.
• 11.9 g of magnesium chloride are needed to absorb this amount of ammonia.
• a trap containing about 12 g of magnesium chloride provides protection against such an accidental situation for about 1 hour.
• the embodiments may also be modified in the form of the trap (matrix, salt in crystalline form, etc.).
• the trap may contain another salt such as, for example, strontium chloride or calcium chloride. It can alternatively be constituted by super-absorbent polymers filled with water.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Exhaust Gas After Treatment (AREA)

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• 2013
  • 2013-03-18 FR FR1352387A patent/FR3003184B1/fr not_active Expired - Fee Related
• 2014
  • 2014-03-18 CN CN201480016354.3A patent/CN105518264A/zh active Pending
  • 2014-03-18 US US14/777,646 patent/US20160290203A1/en not_active Abandoned
  • 2014-03-18 WO PCT/FR2014/050626 patent/WO2014147335A1/fr active Application Filing
  • 2014-03-18 EP EP14716884.3A patent/EP2976514A1/de not_active Withdrawn

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