EP-4735151-A1 - METHOD AND APPARATUS FOR TREATING DIESEL EXHAUST EMISSIONS

Abstract

An apparatus for treating diesel exhaust emissions is disclosed. The apparatus includes an intake manifold in fluid communication with a diesel engine exhaust outlet, wherein the intake manifold is provided with an inlet for ingress of an ammonia gas stream in an arrangement whereby, in use, the ammonia gas stream mixes with the diesel exhaust emission to produce a gas mixture. The apparatus includes a conditioning chamber in fluid communication with the intake manifold to receive the gas mixture therefrom. The conditioning chamber is configured to pass the gas mixture to a first gas-liquid contact zone where it is reacted with a first stream of aqueous ammonia solution via a first conduit and a high pressure nozzle, thereby producing a gas-liquid mixture in the first gas-liquid contact zone. The apparatus further includes a static mixer in fluid communication with the first gas-liquid contact zone, and interposed between the first gas-liquid contact zone and a second gas-liquid contact zone. The second gas-liquid contact zone is provided with a spray head configured to spray a second stream of aqueous ammonia solution therein and an impellor to induce turbulence in the second gas-liquid contact zone. Said second stream is delivered to the spray head via a second conduit arranged in fluid communication with a launder reservoir, whereby in use, the gas-liquid mixture in the second gas-liquid contact zone separates by gravity, liquid collecting in the launder reservoir and carbon dioxide-depleted gas mixture being vented therefrom.

Inventors

• REID, TERRENCE

Assignees

• CJ REACTOR PTY LTD

Dates

Publication Date

20260506

Application Date

20240625

Claims (20)

1. 1 . A method of treating diesel exhaust emissions, the method comprising: a) contacting an ammonia gas stream with a diesel exhaust emissions stream to produce a gas mixture; b) conditioning the gas mixture in a first reactor; c) contacting the conditioned gas mixture with a first stream of aqueous ammonia solution in a first gas-liquid contact zone of the first reactor to produce a gas-liquid mixture; d) passing the gas-liquid mixture through a static mixer; and e) contacting the gas-liquid mixture from step d) with a second stream of aqueous ammonia solution in a second gas-liquid contact zone of the first reactor.
2. 2. The method of claim 1 further comprising: a) separating the resulting mixture from step e) by gravity, collecting liquid from said mixture in a launder reservoir and venting a carbon dioxide-depleted gas mixture.
3. 3. The method of claim 1 or claim 2, wherein the method comprises circulating the carbon dioxide-depleted gas mixture to a second reactor and repeating steps b) to e) prior to venting said gas mixture.
4. 4. The method of any one of claims 1 to 3, wherein prior to step e), the method comprises agitating the gas-liquid mixture after it has passed through the static mixer.
5. 5. The method according to any one of claims 1 to 4, wherein the reservoir launder contains aqueous ammonia solution.
6. 6. The method according to any one of claims 1 to 5, wherein the method further comprises circulating first and second aqueous ammonia solutions, respectively, from the launder reservoir to the first and second gas-liquid contact zones of the first reactor.
7. 7. The method according to any one of claims 1 to 6, wherein the contents of the launder reservoir are maintained below 38 °C.
8. 8. The method according to any one of claims 1 to 7, wherein conditioning the gas mixture comprises inducing high energy flow in the gas mixture and passing the gas mixture through a cyclone chamber in the first reactor in an arrangement to increase gas-solid collisions and deplete the gas mixture of one or more of particulate material, NOx and SOx.
9. 9. The method according to any one of claims 1 to 8, wherein passing said first stream through the static mixer increases the pressure of said first stream to 55- 60 psi.
10. 10. The method according to any one of claims 1 to 8, wherein the diesel exhaust emissions stream is passed through a heat exchanger before contacting said stream with the ammonia gas stream.
11. 11. An apparatus for treating diesel exhaust emissions, the apparatus comprising: a) a launder reservoir containing aqueous ammonia solution; b) an intake manifold in fluid communication with a diesel engine exhaust outlet, wherein the intake manifold is provided with an inlet for ingress of an ammonia gas stream in an arrangement whereby, in use, the ammonia gas stream mixes with the diesel exhaust emission to produce a gas mixture; c) a conditioning chamber in fluid communication with the intake manifold to receive the gas mixture therefrom, wherein the conditioning chamber is configured to pass the gas mixture to a first gas-liquid contact zone whereby the gas mixture is reacted with a first stream of aqueous ammonia delivered via a first conduit in fluid communication with the launder reservoir and a nozzle, thereby producing a gas-liquid mixture in the first gas-liquid contact zone; d) a static mixer in fluid communication with the first gas-liquid contact zone, and interposed between the first gas-liquid contact zone and a second gasliquid contact zone; e) the second gas-liquid contact zone being provided with a spray head configured to spray a second stream of aqueous ammonia solution therein, wherein said second stream is delivered to the spray head via a second conduit arranged in fluid communication with the launder reservoir, whereby in use, the gas-liquid mixture in the second gas-liquid contact zone separates by gravity, liquid collecting in the launder reservoir and carbon dioxidedepleted gas mixture being vented therefrom.
12. 12. The apparatus according to claim 11 , wherein the conditioning chamber is provided with a cyclone chamber configured in use to induce high energy flow in the gas mixture.
13. 13. The apparatus according to claim 11 or claim 12, wherein the nozzle comprises a jet nozzle or a venturi tube.
14. 14. The apparatus according to any one of claims 11 to 13, wherein the nozzle is disposed in concentric alignment with a central longitudinal axis of the cyclone chamber.
15. 15. The apparatus according to any one of claims 11 to 14, wherein the static mixer is configured to increase the pressure of said first stream to 50-60 psi.
16. 16. The apparatus according to any one of claims 11 to 15, wherein the second gasliquid contact zone comprises a cylindrical skirt having a lower end thereof immersed in the launder reservoir.
17. 17. The apparatus according to any one of claims 11 to 16, wherein the spray head may be a plurality of spray heads spaced equidistantly around and proximal to an inner surface the cylindrical skirt.
18. 18. The apparatus according to any one of claims 11 to 17, wherein the impellor is disposed in an upper portion of the second gas-liquid contact zone.
19. 19. The apparatus according to any one of claims 11 to 18, wherein the launder reservoir is provided with means to scavenge and remove sludge therefrom.
20. 20. The apparatus according to any one of claims 11 to 19, wherein the launder reservoir is provided with means to vent a head space thereof.

Description

“Method and apparatus for treating diesel exhaust emissions" Technical Field [0001 ] The disclosure relates to a method and apparatus for treating diesel exhaust emissions, in particular a method and onboard apparatus for treating diesel exhaust emissions from vehicles. Background [0002] The discussion of the background to the disclosure is intended to facilitate an understanding of the disclosure. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application. [0003] The transportation sector, is a major contributor to CO2 emissions. In particular, heavy vehicles, rail and marine transport are reliant on diesel fuel. The composition of diesel exhaust emissions are about 12% CO2 and 1% pollutants such as CO, nitrous oxides (NOX), sulphur oxides (SOX) and particulates. [0004] Electrification of vehicles is one option to reduce CO2 emissions. However, adoption of battery technology is disadvantaged by increased payload weight (in comparison with hydrocarbon fuel) and prolonged charging times. [0005] There is a need to integrate onboard apparatus to treat exhaust emissions by capturing CO2 and converting NOX and SOX to useful byproducts. [0006] Amine absorption, membrane separation, cryogenic separation and adsorption are well understood technologies for treatment of flue gases to remove pollutants, such as particulates, heavy metal compounds, NOX and SOX to comply with regulations for environmental control. Absorbents and membranes, however, require regular regeneration which has an energy cost associated therewith. Solvent absorbents such as monoethanolamine (MEA) and other primary amines, in particular are subject to corrosion and solvent degradation over time. [0007] The present disclosure provides a method and apparatus for treating diesel exhaust emissions to overcome at least some of the disadvantages discussed above, with the additional potential to manufacture saleable byproducts. Summary [0008] The disclosure provides a method and apparatus for treating diesel exhaust emissions, in particular a method and onboard apparatus for treating diesel exhaust emissions from vehicles. [0009] In one aspect the disclosure provides a method of treating diesel exhaust emissions, the method comprising: a) contacting an ammonia gas stream with a diesel exhaust emissions stream to produce a gas mixture, and passing the gas mixture to a first reactor arranged to perform the following steps: b) conditioning the gas mixture; c) contacting the conditioned gas mixture with a first stream of aqueous ammonia solution in a first gas-liquid contact zone to produce a gas-liquid mixture; d) passing the gas-liquid mixture through a static mixer; and e) contacting the gas-liquid mixture from step d) with a second stream of aqueous ammonia solution in a second gas-liquid contact zone. [0010] In one embodiment, the method further comprises: f) separating the resulting mixture from step e) by gravity, collecting liquid from said mixture in a launder reservoir and venting a carbon dioxide-depleted gas mixture. [0011] In one embodiment, the method comprises circulating the carbon dioxide- depleted gas mixture to a second reactor and repeating steps b) to e) prior to venting said gas mixture. [0012] In one embodiment, prior to step e), the method comprises agitating the gasliquid mixture after it has passed through the static mixer. [0013] In one embodiment the launder reservoir contains aqueous ammonia solution. [0014] In one embodiment, the method further comprises circulating first and second aqueous ammonia solutions, respectively, from the launder reservoir to the first and second gas-liquid contact zones of the first reactor. [0015] In one embodiment, the contents of the launder reservoir are maintained below 38 °C. [0016] In one embodiment, conditioning the gas mixture comprises inducing high energy flow in the gas mixture and passing the gas mixture through a cyclone chamber in the first reactor in an arrangement to increase gas-solid collisions and deplete the gas mixture of one or more of particulate material, NOx and SOx. [0017] In one embodiment, passing said first stream through the static mixer increases the pressure of said first stream to 55-60 psi. [0018] In one embodiment, the diesel exhaust emissions stream is passed through a heat exchanger before contacting said stream with the ammonia gas stream. [0019] In another aspect the disclosure provides an apparatus for treating diesel exhaust emissions, the apparatus comprising: a launder reservoir containing aqueous ammonia solution; an intake manifold in fluid communication with a diesel engine exhaust outlet, wherein the intake manifold is provided with an inlet for ingress of an ammonia gas stream in an arrangement whereby, in use, the ammonia gas stream mixes with the diesel exhaust emission to