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NOx-Conversion and Activation Temperature of a SCR-Catalyst Whilst Using a Novel Biomimetic Flash-Boiling AdBlue Injector on a LD Engine

Larsson, Peter LU ; Lennard, Will; Dahlström, Jessica LU ; Andersson, Oivind LU and Tunestal, Per LU (2016) In SAE Technical Papers 2016-Octobeer.
Abstract

Yearly 3.3 million premature deaths occur worldwide due to air pollution and NOx pollution counts for nearly one seventh of those [1]. This makes exhaust after-treatment a very important research and has caused the permitted emission levels for NOx to decrease to very low levels, for EURO 6 only 0.4 g/kWh. Recently new legislation on ammonia slip with a limit of 10 ppm NH3 has been added [2], which makes the SCR-technology more challenging. This technology injects small droplets of an aqueous Urea solution into the stream of exhaust gases and through a catalytic reaction within the SCR-catalyst, NOx is converted into Nitrogen and Water. To enable the catalytic reaction the water content in the Urea solution needs to be... (More)

Yearly 3.3 million premature deaths occur worldwide due to air pollution and NOx pollution counts for nearly one seventh of those [1]. This makes exhaust after-treatment a very important research and has caused the permitted emission levels for NOx to decrease to very low levels, for EURO 6 only 0.4 g/kWh. Recently new legislation on ammonia slip with a limit of 10 ppm NH3 has been added [2], which makes the SCR-technology more challenging. This technology injects small droplets of an aqueous Urea solution into the stream of exhaust gases and through a catalytic reaction within the SCR-catalyst, NOx is converted into Nitrogen and Water. To enable the catalytic reaction the water content in the Urea solution needs to be evaporated and the ammonia molecules need to have sufficient time to mix with the gases prior to the catalyst. The μMist® platform technology, inspired by nature, uses heat in order to increase the fluid temperature above the required saturation temperature within its constant volume chamber. When the outlet valve is opened the liquid breaks up into small droplets which eject and mix with the gases. This paper presents an investigation on how these heated droplets with SMD around 20μm affect the catalytic conversion and achieve high conversion whilst the ammonia slip is kept to a minimum for a few different mass flows. Injected pre-heated small droplets shows over 95 % catalytic conversion of NOx at exhaust temperatures around 200°C. During continuous operation at catalyst temperatures around 350°C - 370°C several test points reaching from 0.7 kg/h to 1.1 kg/h of AdBlue mass flow, achieved EURO VI legislation at the selected experimental conditions, not included in the WHSC (World Harmonized Steady-State Cycle), for both NOx and ammonia with higher than 98 % conversion efficiency.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
SAE Technical Papers
volume
2016-Octobeer
publisher
Society of Automotive Engineers
external identifiers
  • scopus:85019589922
ISSN
0148-7191
DOI
10.4271/2016-01-2212
language
English
LU publication?
yes
id
b7191f02-8506-4dfb-9547-40054136bf4b
date added to LUP
2017-06-09 11:48:37
date last changed
2017-06-09 11:48:37
@article{b7191f02-8506-4dfb-9547-40054136bf4b,
  abstract     = {<p>Yearly 3.3 million premature deaths occur worldwide due to air pollution and NOx pollution counts for nearly one seventh of those [1]. This makes exhaust after-treatment a very important research and has caused the permitted emission levels for NOx to decrease to very low levels, for EURO 6 only 0.4 g/kWh. Recently new legislation on ammonia slip with a limit of 10 ppm NH<sub>3</sub> has been added [2], which makes the SCR-technology more challenging. This technology injects small droplets of an aqueous Urea solution into the stream of exhaust gases and through a catalytic reaction within the SCR-catalyst, NOx is converted into Nitrogen and Water. To enable the catalytic reaction the water content in the Urea solution needs to be evaporated and the ammonia molecules need to have sufficient time to mix with the gases prior to the catalyst. The μMist<sup>®</sup> platform technology, inspired by nature, uses heat in order to increase the fluid temperature above the required saturation temperature within its constant volume chamber. When the outlet valve is opened the liquid breaks up into small droplets which eject and mix with the gases. This paper presents an investigation on how these heated droplets with SMD around 20μm affect the catalytic conversion and achieve high conversion whilst the ammonia slip is kept to a minimum for a few different mass flows. Injected pre-heated small droplets shows over 95 % catalytic conversion of NOx at exhaust temperatures around 200°C. During continuous operation at catalyst temperatures around 350°C - 370°C several test points reaching from 0.7 kg/h to 1.1 kg/h of AdBlue mass flow, achieved EURO VI legislation at the selected experimental conditions, not included in the WHSC (World Harmonized Steady-State Cycle), for both NOx and ammonia with higher than 98 % conversion efficiency.</p>},
  author       = {Larsson, Peter and Lennard, Will and Dahlström, Jessica and Andersson, Oivind and Tunestal, Per},
  issn         = {0148-7191},
  language     = {eng},
  publisher    = {Society of Automotive Engineers},
  series       = {SAE Technical Papers},
  title        = {NOx-Conversion and Activation Temperature of a SCR-Catalyst Whilst Using a Novel Biomimetic Flash-Boiling AdBlue Injector on a LD Engine},
  url          = {http://dx.doi.org/10.4271/2016-01-2212},
  volume       = {2016-Octobeer},
  year         = {2016},
}