Chemistry of the NOx trap technology. 8 th VERT Forum: Combined particle filter and denox-technologies

Transcription

1 Chemistry of the NOx trap technology 8 th VERT Forum: Combined particle filter and denox-technologies Dübendorf, March 17, 2017

2 Blue Technology: Not green enough yet VW Skandal ( Einträge am ; 17:18) VW scandal ( hits on ; 17:17)

3 Blue Technology: Not green enough yet VW Skandal ( Einträge am ; 17:18) VW scandal ( hits on ; 17:17) GDCh/DECHEMA-Sonderkolloquium, Frankfurt, 14. Januar 2016 Stickoxide: Ist der Diesel noch zu retten? 7 th VERT-Forum, Dübendorf, March 18, 2016 Can diesel solve its NO and NO 2 problem in time? 6 th Freiburger workshop, Freiburg i.b., 6. Juni 2016 Europe s NOx problem, a consequence of inefficient diesel-converters and bad exhaust legislation 20 th ETH conference on CGN, Zürich, June 13-16, 2016 The particle-nox trade-off: Two decades of diesel converter technologies have not settled both issues? GDCh/DECHEMA/VDI-Expert Forum Frankfurt, 5-6. December 2016 Efficient filter & denox for diesel and GDI vehicles?

4 Blue Technology: Not green enough yet Will blue technology be green enough in the future?

5 Blue Technology: Not green enough yet Will diesel technology survive?

6 Chemistry of the NOx trap technology The NO x scandal (Inefficient deno x for diesel PCs since two decades!) The best deno x system on roads (Honor to whom honor is due! ) The NO x trap chemistry (Is this best available technology?) 8 th VERT Forum: Combined particle filter and denox-technologies Dübendorf, March 17, 2017

7 Mean annual NO 2 levels: City of London EU Limit Jan. 1 st, µg/m 3 DOCs and hox-dpfs substantially contribute to the NO 2 problem

8 Adverse health effects of diesel exhaust Reactive nitrogen compounds NO 2 is highly toxic (acute and chronic) (induces oxidative stress, inflammation chronic obstructive pulmonary disease) Diesel vehicles with DOCs and hox-dpfs are high NO 2 emitters! One reason for better deno x systems is the increase of NO 2 emissions due to secondary formation in DPFs

9 From chassis dynamometers to on-road measurements For example with an FT-IR at the curbside - Remote Sensing - Emissions of individual vehicles - NO, CO, HC, CO2-15 years, vehicles - Licence plate recognition - Technology assignment - Detection of high emitters - Field inspection and control Gian-Marco Alt, Michael Götsch, Valentin Delb, AWEL, Zürich Chen & Borken-Kleefeld Atm. Env. 2014, 88,

10 From chassis dynamometers to on-road measurements Appearance and reality are far apart! Diesel NO x 10x higher than gasoline vehicles NO x emissions of gasoline & diesel vehicles The NO x problem of diesel PCs & LDVs is 20 years old that s the scandal 10x 10x Chen & Borken-Kleefeld Atm. Env. 2014, 88,

11 Can diesel solve its NO and NO2 emission problem in time? NO x emissions of diesel vehicles Appearance and reality are far apart! Another 15 years to wait? The NO x problem of diesel PCs & LDVs is 20 years old that s the scandal Is it really 2030 when diesel PC and LDV reach the 3-4x depn Euro-6 level introduced in 2009?

12 Chemistry of the NOx trap technology The NOx scandal (Inefficient denox for diesel PCs since two decades!) The best denox system on roads (Honor to whom honor is due! ) The NOx trap chemistry (Is this the best available technology?)

13 The best deno x system on European roads Honor to whom honor is due Vehicle: Fuel: Catalyst: BMW 318 (1.8 l, 1995, Euro-1, mileage 70'000 km) 95 RON gasoline (specification CEF RF-08-A-85) New, original spare part TWC Two-layered Pd-CeO 2 -Al 2 O 3 /Rh-ZrO 2 -Al 2 O 3 structure 13

14 DeNO X am Pd/Rh-TWC Speed limit 120 km h -1 NO emission (BMW, 1.8 l, 1995, EURO-1) Nitrogen monoxide (Ra cycle, post-catalyst) Mass flow [mg s -1 ] That s how we drive on Swiss highways Velocity [km h -1 ] Time [s]

15 DeNO x in Pd/Rh-TWC Pre-catalyst NO up to 200 mg s -1 at transient highway driving NO emission (BMW, 1.8 l, 1995, EURO-1) Nitrogen monoxide (Ra cycle, pre-catalyst) Mass flow [mg s -1 ] Velocity [km h -1 ] Time [s] Heeb et al. Atm. Env. 40 (2006) Heeb et al. Atm. Env. 40 (2006)

16 DeNO X am Pd/Rh-TWC Post catalyst less than 6 mg s -1 NO emission (BMW, 1.8 l, 1995, EURO-1) Nitrogen monoxide (Ra cycle, post-catalyst) >95% Mass flow [mg s -1 ] Velocity [km h -1 ] Time [s]

17 TWC-induced formation of ammonia No ammonia before catalyst Ammonia emissions (BMW, 1.8 l, 1995, EURO-1) Mass flow [mg s -1 ] Ammonia (Ra cycle, pre-catalyst) Velocity [km h -1 ] Time [s]

18 TWC-induced formation of ammonia Relevant ammonia emissions post catalyst Ammonia emissions (BMW, 1.8 l, 1995, EURO-1) 10 8 Ammonia (Ra cycle, post catalyst) Mass flow [mg s -1 ] Velocity [km h -1 ] Time [s] Heeb et al. Atm. Env. 40 (2006) Heeb et al. Atm. Env. 40 (2006)

19 TWC in real world application Why NH 3 and N 2 O? Which three ways to go? A new try incl. H 2, water gasshift-reactions and steam reforming Another try with H 2, N 2 O and NH 3 CO + 1/2 O 2 HC + O 2 NO + CO H 2 + 1/2 O 2 CO + H 2 O HC + H 2 O NO + H 2 NO + HC NO + 5/2 H 2 3 NO + 2 NH 3 2 NO + H 2 2 N 2 O 2 NH 3 CO 2 H 2 O + CO 2 1/2 N 2 + CO 2 H 2 O H 2 + CO 2 H 2 + CO + CO 2 1/2 N 2 + H 2 O N 2 + H 2 O + CO 2 NH 3 + H 2 O 5/2 N H 2 O N 2 O + H 2 O 2 N 2 + O 2 N H 2 19

20 Chemistry of the NOx trap technology The NOx scandal (Inefficient denox for diesel PCs since two decades!) The best denox system on roads (Honor to whom honor is due! ) The NOx trap chemistry (Is this best available technology?)

21 NOx-trap technology The first in-series GDI vehicle (Mitsubishi Carisma, 1.8 l, Euro-3) with NOx trap technology

22 NOx-trap technology NOx-trap activity in a SSC An ideal cycle to study converter chemistry at its best 120 freeway Velocity (km/h) (94 km/h) highway (61 km/h) extra-urban (45 km/h) urban (26 km/h) idle Time (min)

23 NOx-trap technology NOx-trap activity in a SSC An ideal cycle to study converter chemistry at its best 120 freeway Velocity (km/h) (94 km/h) highway (61 km/h) extra-urban (45 km/h) urban (26 km/h) idle Time (min)

24 NOx-trap chemistry Extra fuel injections (FI) about every minute! CO 2 emissions in the SSC freeway highway extra-urban urban (94 km/h) (61 km/h) (45 km/h) (26 km/h) 32 FI 25 FI 10 FI 9 FI 1/37s 1/47s 1/122s 1/136s

25 NOx-trap chemistry CO and CO 2 emissions Extra fuel injections result in extra CO emissions but only in phase 1 (94 km/h) (61 km/h) (45 km/h) (26 km/h) 32 FI 25 FI 10 FI 9 FI 1/37s 1/47s 1/122s 1/136s

26 1/37s NOx-trap chemistry Extra fuel injections result in extra CO and NH 3 emissions but only in phase 1 NH 3 and CO emissions (94 km/h) (61 km/h) (45 km/h) (26 km/h) 32 FI

27 NOx-trap chemistry NO and CO 2 emissions NOx trap at work: extra fuel injections result in extra NO emissions (94 km/h) (61 km/h) (45 km/h) (26 km/h) 32 FI 25 FI 10 FI 9 FI 1/37s 1/47s 1/122s 1/136s

28 NOx-trap chemistry NOx trap at work: extra fuel injections result in extra NO and NO 2 emissions NO and NO 2 emissions (94 km/h) (61 km/h) (45 km/h) (26 km/h) no extra NO 2 (fuel-rich) 32 FI 25 FI 10 FI 9 FI

29 NOx-trap chemistry NO 2 proportion NO 2 proportions lowest during extra fuel injections and high temperatures (94 km/h) 6 mol% (61 km/h) (45 km/h) 22 mol% 30 mol% (26 km/h) 38 mol% no extra NO 2 (fuel-rich)

30 NOx-trap chemistry Not funny, extra fuel injections also result in extra N 2 O emissions N 2 O emissions (94 km/h) (61 km/h) (45 km/h) (26 km/h) 32 FI 25 FI 11 FI 9 FI 1/37s 1/47s 1/122s 1/136s

31 NOx-trap chemistry How much fuel penalty per injection or per store & release cycle? CO 2 at 26 km/h 4.6% extra fuel per cycle

32 NOx-trap chemistry How much deno activitiy per injection deno activity at 26 km/h η: + 2% NO (no net NO conversion)

33 NOx-trap chemistry deno and deno 2 activity at 26 km/h How much deno activitiy per injection η: + 2% NO (no net NO conversion) η: -14% NO 2

34 NOx-trap chemistry NO 2 proportion drops during fuel injection NO 2 proportion at 26 km/h from 38% to 18% NO 2

35 NOx-trap chemistry N 2 O and NH 3 at 26 km/h No NH 3 formation, but secondary N 2 O formation during fuel injection extra N 2 O

36 NOx-trap chemistry How much fuel penalty per injection CO 2 at 94 km/h (fuel rich conditions) 12.4% extra fuel per cycle

37 NOx-trap chemistry deno and deno 2 activity at 94 km/h η: - 26% NO How much deno activitiy per injection η: - 42% NO 2

38 NOx-trap technology Low NO x storage capacity, not very sulfur tolerant, its more a SO x than a NO x trap NOx-trap cycle NO, O 2 NO 2 NO 2 CO 2 λ > 11 (llllllll) 1. NO- & NO 2 -oxidation to NO 3-2. Store as Ba(NO 3 ) 2 λ < 11 (rrrrrrrr) 3. Post injections of fuel T: C T: C 4. NO 3 - reduction with H 2, HC etc. HC Pt Ce 2 O 3 BaCO 3 Pt Ce 2 O 3 Ba(NO 3 ) 2 NO 2, CO, H 2 CO 2 N CO, H 2, CO NO 2 Pt Ce 2 O 3 BaCO 3 Pt Ce 2 O 3 Ba(NO 3 ) 2.. Similar chemistry in the NO x trap with Secondary formation of N 2 O and NH 3

39 Road vehicles on earth From 0.1 to 1 billion in 60 years (3800 as I spoke, this morning) From 310 to 410 ppm in 60 years 90 million new vehicles / y (3 vehicles / s) Kyoto (in force 2005) Kyoto (in force 2005) (1.6 ppm CO 2 / y) 12.5 Gt CO 2 / y

40 CO 2 in earth atmosphere From 345 to 400 ppm in 30 years From 310 to 410 ppm in 60 years Kyoto (in force 2005) (1.6 ppm CO 2 / y) 12.5 Gt CO 2 / y Kyoto (in force 2005) (1.6 ppm CO 2 / y) 12.5 Gt CO 2 / y

41 CO 2 and N 2 O in earth atmosphere From 345 to 400 ppm in 30 years From 303 to 328 ppb in 30 years CO 2 Proportion (ppm) Kyoto (in force 2005) (1.6 ppm CO 2 / y) 12.5 Gt CO 2 / y N 2 O Proportion (ppb) (1.0 ppb N 2 O / y) 7.8 Mt N 2 O / y

42 Blue Technology: Not green enough yet VW Skandal ( Einträge am ; 17:18) VW scandal ( hits on ; 17:17) Will blue technology be green enough in the future? There s quite some work ahead of us! 8 th VERT Forum: Combined particle filter and denox-technologies Dübendorf, March 17, 2017

43 GASOMEP: Current status and new concepts of gasoline vehicle emission control Thanks to Al Davide Bleiner, Lukas Emmenegger, Regula Haag, Peter Honegger, Joachim Mohn, Maria Munoz, Juanfernando Angel Ramelli, Cornelia Seiler, Peter Schmid, Heinz Vonmont, Adrian Wichser, Kerstin Zeyer, Empa Jan Czerwinski, Pierre Comte, Benjamin Fröhlich, Stefan Germann, Philipp Wili, Yan Zimmerli, Adrian Braun, Thomas Egli, Joel Delgado, Elia Limarzo, UASB Heinz Burtscher, Alejandro Keller, UASNWS Urs Baltensberger, Andre Prevot, Simone Pieber, Nivedita Kumar, PSI Urs Debrunner, Hans Jäckle, Intertek Andreas Mayer, TTM P