SUPPLY SYSTEM FOR USE IN A VEHICLE

Abstract

A navigation mountable on-board a vehicle. The subsystem is configured to: receive a mixture including ammonia, carbon dioxide and water; generate from the mixture an ammonia rich fraction and a carbon dioxide rich fraction; the ammonia rich fraction containing a smaller weight percentage of carbon dioxide than the mixture and the carbon dioxide rich fraction containing a smaller weight percentage of ammonia than the mixture.

Claims

1-14. (canceled)

15. A subsystem mountable on-board a vehicle, the subsystem configured to: receive a mixture comprising ammonia, carbon dioxide, and water; generate from the mixture an ammonia rich fraction and a carbon dioxide rich fraction; the ammonia rich fraction containing a smaller weight percentage of carbon dioxide than the mixture and the carbon dioxide rich fraction containing a smaller weight percentage of ammonia than the mixture, wherein the subsystem is in fluid communication with an outlet of a urea decomposition unit from which the mixture comprising ammonia, carbon dioxide, and water flows out.

16. The subsystem of claim 15, comprising: a separating unit configured to separate the mixture comprising ammonia, carbon dioxide, and water into a first ammonia rich fraction and a carbon dioxide rich fraction; the first ammonia rich fraction containing a smaller weight percentage of carbon dioxide than the mixture and the carbon dioxide rich fraction containing a smaller weight percentage of ammonia than the mixture; a drying unit configured to dry the first ammonia rich fraction to obtain a second ammonia rich fraction; the second ammonia rich fraction containing a smaller weight percentage of water than the first ammonia rich fraction, and the second ammonia fraction forming the ammonia rich fraction generated by the subsystem.

17. The subsystem of claim 15, comprising a thermo-hydraulic section receiving the mixture and configured to generate a temperature difference between a first portion and a second portion of the thermo-hydraulic section, the temperature difference being capable of causing evaporation of the mixture in the first portion and of causing condensation of the mixture in the second portion such that an oscillating flow is generated between the first portion and the second portion, the second portion including an outlet for the generated the ammonia rich fraction, and the first portion including an outlet for the carbon dioxide rich fraction.

18. The subsystem of claim 15, wherein the subsystem is configured to separate carbon dioxide from the mixture by heating and pressurizing the mixture so that partial pressure of carbon dioxide in the vapors above liquid effluents is larger than 50% of total pressure, such that the carbon dioxide rich fraction can be eliminated.

19. A system for injecting an ammonia rich fraction in a component on-board a vehicle, comprising: a urea decomposition unit configured to convert a urea solution into a mixture comprising ammonia, carbon dioxide, and water; the subsystem of claim 15; an ammonia injecting module to inject or spray the ammonia rich fraction into the component at a first location.

20. The system of claim 19, wherein the component is an exhaust line, and the system further comprising a selective catalytic reduction (SCR) unit configured to convert nitrogen oxides of an exhaust gas in the exhaust line into diatomic nitrogen and water, using a catalyst; the ammonia injection module configured to inject the ammonia rich fraction into the exhaust line upstream of the selective catalytic reduction (SCR) unit.

21. The system of claim 19, wherein the component is an exhaust line, and the system further comprising a carbon dioxide injecting module to inject the carbon dioxide rich fraction into the exhaust line at a second location, the second location being upstream of the first location.

22. The system of claim 21, further comprising a carbon dioxide buffer to store the carbon dioxide rich fraction, the buffer arranged between the subsystem and the carbon dioxide injection module.

23. The system of claim 19, wherein the component is an exhaust line, and the system further comprising a diesel oxidation catalyst (DOC) unit configured to promote oxidation of exhaust gas components by oxygen, the ammonia injection module configured to inject the ammonia rich fraction into the exhaust line downstream of the diesel oxidation catalyst (DOC) unit.

24. The system of claim 19, wherein the component is a power generator or a fuel cell, the power generator configured to generate power using the ammonia rich fraction.

25. The system of claim 19, comprising a subsystem comprising: a separating unit configured to separate the mixture comprising ammonia, carbon dioxide, and water into a first ammonia rich fraction and a carbon dioxide rich fraction; the first ammonia rich fraction containing a smaller weight percentage of carbon dioxide than the mixture and the carbon dioxide rich fraction containing a smaller weight percentage of ammonia than the mixture; a drying unit configured to dry the first ammonia rich fraction to obtain a second ammonia rich fraction; the second ammonia rich fraction containing a smaller weight percentage of water than the first ammonia rich fraction, and the second ammonia fraction forming the ammonia rich fraction generated by the subsystem, wherein the ammonia injection module is configured to inject the second ammonia rich fraction in the component.

26. The system of claim 19, further comprising an ammonia buffer to store the ammonia rich fraction, the buffer arranged between the subsystem and the ammonia injection module.

27. The system of claim 19, further comprising a tank to store an aqueous urea solution, the tank being in fluid communication with the urea decomposition unit.

28. The system of claim 19, further comprising a pump arranged in a line between the subsystem and the urea decomposition unit.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0031] The accompanying drawings are used to illustrate presently preferred non-limiting exemplary embodiments of devices of the present invention. The above and other advantages of the features and objects of the invention will become more apparent and the invention will be better understood from the following detailed description when read in conjunction with the accompanying drawings, in which:

[0032] FIG. 1 is a diagram illustrating a first embodiment of a system for injecting ammonia in an exhaust line;

[0033] FIG. 2 is a diagram illustrating a second embodiment of a system for injecting ammonia in an exhaust line;

[0034] FIG. 3 is a diagram illustrating a third embodiment of a system for injecting ammonia in an exhaust line;

[0035] FIG. 4 is a diagram illustrating a fourth embodiment of a system for injecting ammonia in an exhaust line;

[0036] FIG. 5 is a diagram illustrating a fifth embodiment of a system for injecting ammonia in an exhaust line;

[0037] FIG. 6 illustrates an embodiment of a subsystem; and

[0038] FIG. 7 illustrates a further developed embodiment of a system for injecting ammonia in an exhaust line;

[0039] FIG. 8 illustrates an embodiment of a system for injecting ammonia in a fuel cell.

DESCRIPTION OF EMBODIMENTS

[0040] FIG. 1 illustrates a first embodiment of a system for supplying ammonia in exhaust gasses. The system is aimed at providing ammonia for the NO removal from the gasses in an exhaust line 14 coming from a vehicle engine 15. The system of FIG. 1 uses a SCR (Selective Catalytic Reduction) process for converting nitrogen oxides of an exhaust gas in the exhaust line into diatomic nitrogen and water, using a catalyst through a selective catalytic reduction (SCR) unit 12 arranged in the exhaust line 14.

[0041] The system comprises a tank 1 filled with the urea solution, for example a commercially available AdBlue solution containing 32.5 weight % urea. The tank 1 is preferentially made of a plastic polymer, for example high density polyethylene, molded through an injection or blow-molding process. There is provided a urea decomposition unit 2 for converting the urea solution in the tank into a solution comprising ammonia, carbon dioxide and water. The urea decomposition unit may be integrated in tank 1 or may be provided outside tank 1. Fluidic communication between tank 1 and urea decomposition unit 2 is achieved through inlet 2a. The urea decomposition unit 2 may be a unit using for example a bio-agent 3 (preferentially an enzyme, urease) to obtain an NH3/CO2 mixture which may be an aqueous solution which may be a liquid and/or a liquid with particles in suspension. The bio-agent may be thermally activated by a heater 4. Such an example of a urea decomposition unit is disclosed in patent applications EP 13182919.4 and EP 12199278.8 in the name of the Applicant, the contents of which are included herein by reference. In those applications the Applicant has proposed two new methods for generating ammonia on board a vehicle (passenger car, truck, etc.) based on a biological catalysis. Biological catalysis comprises all forms of catalysis in which the activating species (i.e. biological catalysts) is a biological entity or a combination of such. Included among these are enzymes, subcellular organelles, whole cells and multicellular organisms. More precisely, according to a first method, a protein component is used to catalyze the hydrolysis (i.e. decomposition) of an ammonia precursor solution (for example, urea) into a mixture comprising at least ammonia, carbon dioxide and water. Such first method is described in more detail in patent application EP 13182919.4. According to a second method proposed by the Applicant, a protein component is used to catalyse the hydrolysis (i.e. decomposition) of an ammonia precursor solution (for example, urea) into ammonia gas. For example, the generated ammonia gas can be directed (i.e. transmitted) to a solid absorbing matrix where it is stored thereon by sorption. Such second method is described in more detail in patent application EP 12199278.8.

[0042] The NH3/CO2 aqueous mixture is further drawn to a subsystem in the form of a separating section 7 through a line 6 coming from the urea decomposition unit 2, e.g. by running an optional pump 5 or simply by gravity. The subsystem or separating section 7 is configured for separating the mixture comprising ammonia, carbon dioxide and water into an ammonia rich fraction and a carbon dioxide rich fraction. The ammonia rich fraction contains typically very little carbon dioxide and the carbon dioxide rich fraction contains typically the major part of the carbon dioxide from the mixture. The subsystem 7 may be heated and pressurized so that a CO2-rich stream is separated from a NH3-rich solution, and may be designed with one or more separation stages.

[0043] The NH3-rich solution is sprayed in the vehicle exhaust line 14 through an ammonia injector 11 which is positioned at a first location, upstream from the SCR unit 12. The ammonia injector 11 is configured for injecting the ammonia rich fraction into the exhaust line 14.

[0044] The CO2-rich fraction is introduced in the exhaust line 14, downstream from a DOC (Diesel Oxidation Catalyst) unit 13 through an injection module 9, e.g. in the form of a jet, via a line 8 between the subsystem 7 and the exhaust line 14. The carbon dioxide injecting module 9 is configured for injecting the carbon dioxide rich fraction into the exhaust line 14 at a second location. The second location is upstream of the first location where the NH3-rich fraction is injected. The diesel oxidation catalyst (DOC) unit 13 is configured to promote oxidation of exhaust gas components by oxygen. The diesel oxidation catalyst (DOC) is configured to promote oxidation of several exhaust gas components by oxygen, which is present in sufficient quantities in diesel exhaust gasses. When passed over an oxidation catalyst, certain diesel pollutants in the exhaust gasses can be oxidized to harmless products. By choosing a second location upstream of said first location the temperature of the exhaust line will be typically higher because it is located closer to the engine, so that the risk on deposits is reduced or eliminated.

[0045] Optionally there may be provided a buffer 20 for storing the ammonia rich fraction before being injected into the exhaust gasses, and/or a buffer 21 for storing the carbon dioxide rich fraction before being injected in the exhaust gasses.

[0046] The entire system may be controlled by an electronic unit (not shown in FIG. 1). The electronic unit may be configured to operate the ammonia injection module 11 and/or the carbon dioxide injection module 9 at particular moments in time. Preferably the carbon dioxide injection module 9 only injects when the exhaust line 14 is at a sufficiently high temperature in order to avoid deposits.

[0047] FIG. 2 illustrates a second exemplary embodiment in which similar components have been indicated with the same reference numerals. This embodiment is similar to the first embodiment with this difference that the injection module 9, typically a jet, for injecting carbon dioxide in the exhaust line 14 is located in a second location, upstream of the diesel oxidation catalyst (DOC) unit 13, so that the CO2-reach stream is introduced upstream from the DOC unit 13. In that way the carbon dioxide rich fraction is injected closer to the engine 15 where higher temperatures are available and solid deposits can be easily avoided. Also, if water is present in the carbon dioxide rich fraction, this water will evaporate more easily in view of the higher temperature closer to the engine.

[0048] FIG. 3 illustrated a third exemplary embodiment in which similar components have been indicated with the same reference numerals. In the third embodiment the subsystem 7 comprises a separating unit 17 and a drying unit 16. The separating unit 17 is configured for separating the solution comprising ammonia, carbon dioxide and water into a first ammonia rich fraction and a carbon dioxide rich fraction; and the drying unit 16 is configured for drying said first ammonia rich fraction in order to obtain a second dried ammonia rich fraction, typically a gas fraction; said second ammonia rich fraction containing a smaller weight percentage of water than said first ammonia rich fraction. The ammonia injection module 11 is arranged for injecting said second ammonia rich fraction in the exhaust line 14.

[0049] The water extracted from the first ammonia rich fraction flows back to the urea decomposition unit 2 through line 19, to further dilute the ammonia precursor coming from tank 1. If the urea decomposition unit 2 uses an enzyme, the returned water may further promote the enzymatic activity. In another non-illustrated variant, the line 19 may be connected to the tank 1, so that the water flow is used to dilute the content of tank 1. Further, there may be provided a drainage valve 22 to avoid that too much water is returned to the tank 1 or to the urea decomposition unit 2.

[0050] FIG. 4 illustrates a fourth exemplary embodiment in which similar components have been indicated with the same reference numerals. The fourth embodiment is similar to the third embodiment with this difference that the second dried ammonia rich fraction, typically a gaseous fraction is absorbed in an absorbing/desorbing unit 20 which functions as a buffer which is able to provide the second dried ammonia rich fraction to the injector 11 for SCR purposes. The water flow resulting from the drying of the first ammonia rich fraction in the drying unit 16 may be drained via line 19. Optionally line 19 may be connected to tank 1 or to the decomposition unit 2, as described above in connection with FIG. 3.

[0051] FIG. 5 illustrates a fifth exemplary embodiment in which similar components have been indicated with the same reference numerals. The fifth embodiment is similar to the fourth embodiment with this difference that the injection module 9 for injecting the CO2-rich stream is now arranged between the outlet of engine 15 and the inlet of DOC unit 13.

[0052] FIG. 6 illustrates a possible implementation of a subsystem 7 in the form of a thermo-hydraulic section configured for generating a temperature difference between a first portion and a second portion of said thermo-hydraulic section, said temperature difference being capable of causing evaporation in said first portion and of causing condensation in said second portion such that an oscillating flow is generated between said first portion and said second portion. A thermo-hydraulic oscillation is obtained by causing an oscillating flow due to the action of the thermo-hydraulic unit comprising a heating device 71 and a cooling device 72. The heating device 71 can be e.g. the exhaust line, the internal combustion engine itself, a derivation or the main stream of the cooling circuit of the internal combustion engine, etc. Preferably, the heating device 71 is a component that heats up and needs to be cooled, or a component from which heat may be removed advantageously. The cooling device 72 of the thermo-hydraulic unit can be e.g. the environment, or a derivation or the main stream of an air conditioning system. The cooling device 72 may further comprise known heat transfer devices and thermo-insulating materials to enhance the cooling. In the subsystem 7 successive vaporisation and condensation occurs in the heating and cooling devices 71, 72, causing the oscillating flow. The fluid vaporizing in the heating device 71 may be forced to flow towards the cooling device 72 due to the presence of a check valve 74 in line 6, between the urea decomposition unit 2 and the subsystem 7. The check valve 74 is configured for blocking the flow from the subsystem 7 back to the urea decomposition unit 2, whilst allowing a flow from the urea decomposition unit 2 to the subsystem 7. The vaporization due to the presence of the heating device 71 will also pressurize the fluid in line 10. The fluid condenses in the cooling device 72 generating a relative vacuum at the heating device 71, so that fluid from the urea decomposition unit 2 is sucked again in the subsystem 7. Typically the fluid entering the subsystem 7 is a NH.sub.3/CO.sub.2 aqueous mixture. When the mixture is heated, the CO.sub.2 escapes through the gas release valve 73, to line 8 which may be connected to an exhaust line as in previous embodiments. The gas release valve 73 is configured such that only gas can escape, and no liquid can escape. In addition, neither gas nor liquid can enter the subsystem 7 through the release valve 73. The liquid phase which is transferred to the exhaust line is the NH.sub.3-rich fraction. In a further developed (not illustrated) embodiment the subsystem 7 could function both as a separator stage and as a pumping stage because of the presence of the check valve 74, so that pump 5 may be omitted in the embodiments of FIGS. 1-5.

[0053] FIG. 7 illustrates a further developed embodiment of a system of the invention. The system comprises a tank 1 and a loop circuit 60 which are connected through a connecting tube 6. The connecting tube 6 is provided with an orifice valve 25, and the loop circuit 30 is provided with an orifice valve 26, a check valve 31, a thermo-hydraulic unit 30, and a buffer 40 between two control valves 23, 24. An injector 11 is connected to the buffer 40 for injecting fluid into an exhaust line 14. Further, there may be provided control means configured for controlling the positions of control valves 23, 24. A subsystem 7 is added between the connecting tube 6 and the loop circuit 60. The fluid delivered by the buffer 2 is a NH.sub.3/CO.sub.2 aqueous mixture. The subsystem 7 is configured to extract a CO.sub.2-rich stream from a NH.sub.3-rich solution. The CO.sub.2-rich stream is eliminated, e.g. sent to an injector for injecting the CO2-rich fraction into the exhaust line 14 at a second location upstream of injector 11, and the NH.sub.3-rich solution constitutes the fluid flow of the loop circuit 60. The subsystem 7 can be placed at the intersection of the main flow line and the return line as in FIG. 7, or can be located on the main flow line before the return line, i.e. in the connecting tube 6 (not illustrated), or after the return line, i.e. between the intersection and the thermo-hydraulic unit 30 (not illustrated). Alternatively, the subsystem 7 can be combined in the thermo-hydraulic unit 30 similarly to the configuration of FIG. 6.

[0054] FIG. 8 illustrated a further exemplary embodiment in which similar components have been indicated with the same reference numerals. The system of FIG. 8 injects an ammonia rich fraction in a fuel cell 80. The subsystem 7 is identical to the subsystem of FIG. 3 and reference is made to the description of the subsystem of FIG. 3 above. The second dried ammonia rich fraction leaving the drying unit 16 is sent to the fuel cell 80 via line 18. The fuel cell is arranged for using the ammonia rich fraction to generate power, e.g. as described in patent application PCT/EP2013/077851 in the name of the Applicant. The carbon dioxide rich fraction may flow via line 8 to a different location.

[0055] As in the embodiment of FIG. 3 the water extracted from the first ammonia rich fraction flows back to the urea decomposition unit 2 through line 19, to further dilute the ammonia precursor coming from tank 1. In another non-illustrated variant, the line 19 may be connected to the tank 1, so that the water flow is used to dilute the content of tank 1. Further, there may be provided a drainage valve 22 to avoid that too much water is returned to the tank 1 or to the urea decomposition unit 2. In yet another non-illustrated variant the water flow may be drained as in the embodiment of FIG. 4.

[0056] Whilst the principles of the invention have been set out above in connection with specific embodiments, it is to be understood that this description is merely made by way of example and not as a limitation of the scope of protection which is determined by the appended claims.