The Effects of Engine Technology and Fuel Property on Diesel Emission

1 Further Challenge in Automobile and Fuel Technologies For Better Air Quality The Effects of Engine Technology and Fuel Property on Diesel Emission 22.2.22 Combustion Analysis WG

Positioning of Combustion Analysis Analysis,Verification 2 D.WG Tests Single Cylinder Tests Statistical Analysis Clarification of factors having influence on emission Technical trend evaluation Commission of Research

3 Contents 1. Review of Results from Diesel WG 2. Preliminary Statistical Analysis of Data Obtained from Diesel-WG 3. Organization of Issues of Combustion Analysis 4. Single Cylinder Engine Tests 5. Contribution of Engine Technologies and Fuel to Emission Reduction 6. Secondary Statistical Analysis of Data Obtained from Diesel-WG 7. Conclusion

Example of specifications of test vehicles and engines(d- WG) 4 symbol Vehicle or Engine Regulation 1) Type 2) Displacement L Intake system Combustion Injector type 3) Others A Vehicle 94 P 3. T IDI E EGR B Vehicle 94 C 2.3 NA IDI M EGR C Vehicle 94 P 2. NA IDI M EGR D Vehicle 94 C 2. NA IDI M EGR K Vehicle 98 P 3. TI DI common rail EGR+Cat. L Vehicle 98 C 2.2 NA IDI E EGR M Vehicle 98 P 2.2 T IDI E EGR+Cat. N Vehicle 98 P 2. T IDI E EGR E Engine 94 M 9.2 NA DI E - F Engine 94 L 12.1 TI DI TICS - G Engine 94 M 3.6 NA IDI M - H Engine 94 L 1.5 TI DI TICS - O Engine 98 L 21.2 NA DI TICS EGR P Engine 98 M 8.2 NA DI TICS EGR Q Engine 98 S 4.8 T DI in-line/e EGR R Engine 98 M 8. NA DI common rail -

ref.: Report 1-3-1 p.31 Table 3.3.1-5 5 Test results of Diesel WG Single regression analysis R 2 value, results of the existing step R 2 Total aromatics Distillation Cetane T9 Number Density (15deg-C) PM NOx Vehicles Engines Vehicles Engines.7 < = R 2.5 < = R 2 <.7.7 < = R 2.5 R 2 <.7.7 < = R 2.5 < = R 2 <.7.7 < = R 2.5 < = R 2 <.7 - - - G - - E,F,H,Q P C B,D,K, L,M E,H,O,P R - C,L,M,N - - L - - - - D,L,M E,P H,R C,D,L, M,N - R E,O,P - M - -

6 Contents 1. Review of Results from Diesel WG 2. Preliminary Statistical Analysis of Data Obtained from Diesel-WG 3. Organization of Issues of Combustion Analysis 4. Single Cylinder Engine Tests 5. Contribution of Engine Technologies and Fuel to Emission Reduction 6. Secondary Statistical Analysis of Data Obtained from Diesel-WG 7. Conclusion

Effects of fuel properties on PM, with stepwise method Dens (g/cm3) T9 Aromatics(vol%) CN Sul ( o C ) 1R-A 2R-A 3R-A (mass%) Base.84 35 6 35 8 2.5 Comparison.81 3 5 7 PM Reduction Rate (%) Vehicle 2-4 -8 K S T U K+K T+N U+M '98 ' 94 modified ' 98 3.,DI-TI 2.,IDI 2.,IDI-T CR Mech. M.Elec. 2.2,IDI-T Sul 3R-A 2R-A 1R-A CN T9 Existing step data added Dens Low Pt High Pt

Effects of fuel properties on NOx, with stepwise method Dens (g/cm3) T9 Aromatics(vol%) Sul ( o CN C ) 1R-A 2R-A 3R-A (mass%) Base.84 35 6 35 8 2.5 Comparison.81 3 5 8 NOx Reduction Rate (%) OCC 4-4 Vehicle Vehicle w/o Low Pt High Pt K S T U K+K T+N U+M '98 '94 modified '98 3.,DI-TI CR 2.,IDI Mech. 2.,IDI-T M.Elec. 2.2,IDI-T Existing step data added Sul 3R-A 2R-A 1R-A CN T9 Dens

9 Stepwise Analysis Diesel WG data 1st analysis Results for PM Density and 3-R aromatics are dominants. T9, D WG has pointed out, is not a major factor. for NOx T9(Vehicle),1,2-R aromatics(engine) are dominants.

1 Contents 1. Review of Results from Diesel WG 2. Preliminary Statistical Analysis of Data Obtained from Diesel-WG 3. Organization of Issues of Combustion Analysis 4. Single Cylinder Engine Tests 5. Contribution of Engine Technologies and Fuel to Emission Reduction 6. Secondary Statistical Analysis of Data Obtained from Diesel-WG 7. Conclusion

11 Issues to be solved in Combustion Analysis 1. Clarify the contribution of engine technologies and fuel properties to emission (Single Cylinder Engine Test) 2. Analyse the fundamental phenomenon occurred in combustion (Research Commission to Univ.) 3. Point out major influencing factors to emission (Statistical Analysis)

12 Contents 1. Review of Results from Diesel WG 2. Preliminary Statistical Analysis of Data Obtained from Diesel-WG 3. Organization of Issues of Combustion Analysis 4. Single Cylinder Engine Tests 5. Contribution of Engine Technologies and Fuel to Emission Reduction 6. Secondary Statistical Analysis of Data Obtained from Diesel-WG 7. Conclusion

Single cylinder engine 13 Injection Nozzle Air Intake Exhaust High Pressure Pump Common Rail

14 Single cylinder engine system Air Conditioning Fuel Consumption Meter Turbo Motor Common Rail Injection Nozzle EGR Engine Gas Analyser Dilution Tunnel PM Sampler

15 Specification of test engine Type Bore X Stroke Displacement Compression ratio Valves per cylinder Intake system EGR Fuel injection equipment Nozzle hole diameter Number of nozzle hole Single cylinder, Direct injection 18mm X 115mm 1.53L 18. 4 NA,TC w/o,with(hot) Common rail.16.18.2.25 5

16 Test fuels (T1-T1) Base T9 Aromatics Naphthene n-paraffin/i-paraffin Fuel code T1 T9 T1 T2 T3 T4 T5 T6 T7 T8 Density (15 o C)kg/m 3 ) 788. 785.2 791.6 88.2 833.8 837.8 797.4 784.6 782. 788. Distillation(T9) o C 37. 275. 387.5 299.5 314. 313.5 34. 311. 313. 37. Cetane number 48.8 48.6 48.5 48.7 5.2 5.1 49.2 6.4 7.7 61. Composition : vol% n-paraffin 36 35 24 45 42 42 25 5 63 36 i-paraffin 57 58 7 28 33 33 47 44 32 57 Naphthene 7 7 6 7 5 5 28 6 5 7 Total aromatics 2 2 2 1Ring-aromatics 2Ring-aromatics 3Ring-aromatics 2 2 15 5

Test fuels (T12-T2) 17 tentatively synthetic Side chain structure of mono-aromatics Aromatics in constant density Fuel code T12 T14 T15 T16 T17 T18 T19 T2 Density (15 o C)kg/m 3 774.8 8.1 798.5 824.9 818.5 823.6 823.5 823.6 Distillation(T9) o C 313.5 31. 31.5 32.5 35 317 316 316 Cetane number 97.8 5.8 51.6 51.8 51.1 5.5 48.2 5.1 Composition : vol% n-paraffin 1 44 4 45 43 48 38 43 i-paraffin 29 36 28 31 22 41 32 Naphthene 7 4 7 6 5 7 6 Total aromatics 2 2 2 2 25 14 19 1Ring-aromatics 2 2 2 2 2 1 2Ring-aromatics 5 14 9 3Ring-aromatics T14:Isobutylbenzene C 4 T16:Tetralin T15:C12-alkylbenzene C12 T17:Phenylcyclohexane

Single cylinder engine testing conditions NA/TC Excess air ratio 1.4 (NA) 1.8 (TC) Boost Inj. Nozzle hole EGR Spec. of FIE Press. Press. dia. (kpa) (MPa) (mm) (%) (correspond to ) 4 (TC) 6.25 - '94 Emission Reg..16 1.18 - '98 Emission Reg..2 18 4. (NA) (TC) 1 (TC) 3.25 '94 Emission Reg. 4 5.18 6 '98 Emission Reg. 5.18 2 4

The effects of engine technologies on emission Over view.8 Fuel :T1 Load : High NA, Inj. equip.; '94ER 19 PM g/kwh.6.4.2. 2 4 6 8 1 NOx g/kwh TC, Inj. equip.; '94ER NA, Inj. equip.; '98ER TC, Inj. equip.; '98ER

Influence of aromatics on PM, ratio to base fuel, by 1% change of the content 2 4 1R-aromatics Change of PM For base fuel %/vol.% 4 2 1 2R-aromatics 3 3R-aromatics Tinj o ATDC -6-4 -2-6 -4-2 -2 2 4-2 2 4 4 4 NA/TC NA TC NA TC NA TC Noz. dia. [mm].25.18.16.18.2.16.18.2 Pinj [MPa] 6 1 FIE. correspond to '94 reg. correspond to '98 reg..16.18.2.16.18.2

Influence of aromatics on NOx, ratio to base fuel, by 1% change of the content 21 Change of NOx for base fuel %/vol.% 1-1 1 1-1 1R-aromatics 2R-aromatics 3R-aromatics Tinj o ATDC -6-4 -2-6 -4-2 -2 2 4-2 2 4 4 4 NA/TC NA TC NA TC NA TC Noz. dia. [mm].25.18.16.18.2.16.18.2 Pinj [MPa] 6 1 FIE. correspond to '94 reg. correspond to '98 reg..16.18.2.16.18.2

Influence of aromatic side chain on PM & NOx,, ratio to base fuel 22 T14:Isobutylbenzene C 4 T16:Tetralin T15:C12-alkylbenzene C12 T17:Phenylcyclohexane Change of PM, NOx for base fuel % 1 1 5 NOx PM Tinj deg ATDC -6-4 -2-2 2 4-2 2 4 NA / TC NA NA TC Noz. dia.[mm].25.18 Pinj [MPa] 6 1 FIE correspond to '94 reg. correspond to '98 reg.

Stepwise method 23 Density CN 3R-A 1R-A 1 1.8.878.948.984.989.8 R 2.6.4 R 2 final.6.4.878.2.2 Model- 1-2 -3-4 Model- 4 model -1 model -2 model -3 model -4 PM =-.583 +.798* Density PM =-.78 +.929* Density +3.54E-4* CN PM =-.579 +.771* Density +2.92E-5* CN +2.9E-3* 3R-A PM =-.563 +.75* Density +2.98E-4* CN +3.19E-3* 3R-A +2.7E-4* 1R-A

Analysis of fuel factors on each engine technology type 24 1R-A 2R-A 3R-A Naphthene i-para T9 CN Density R 2 of NOx 1.8.6.4.2 R 2 of PM 1.8.6.4.2 Inj.T TDC NA TC NA TC NA TC (Inj. P.) 6MPa 1MPa 1MPa (Noz,hole dia.).25.18.16 (Inj.Spec.) 94' Reg 98' Reg 98' Reg

25 Correlation of density between properties and composition of fuels Correlation coefficient 1..5. -.5-1. Kinetic Cetane iso-paraffin Total Density T1 T5 T9 viscosity number n-paraffin Naphthene Aromatics 1R-A 2R-A 3R-A Density 1. -.28 -.11 -.17 -.5 -.51 -.29 -.19.1.82.34.71.52

Influences of fuel density on spray and combustion Physical Droplet dia., spray angle show no big difference. Liquid phase of spray becomes longer. ( Hiroshima univ.) A/F shift (production engine) 26 Chemical Change of combustion by aromatics. (Tokyo univ.) ( Hokkaido Kogyo univ.)

The influence of aromatic content on flame temperature and soot formation (Tokyo univ.) 27 26 + 25 + 24 + 23 + 22 + 21 + 2 + 1 MPa Nozzle Hole dia.18 TC Condition 1.95ms After Injection 1. +.8 +.6 +.4 +.2 +. + Temperature (K) KL Factor Standard Aromatics High Standard Aromatics High

28 Soot formation process Fuel Dehydrogenation Naphthenes Acetylenes Aromatics Olefins Condensation Polyacetylenes Polycondensation Condensed saturated unsaturated Carbon Particles SOF

PM ratio T3/T1 Survey on influence of density change of fuels 2.5 2. 1.5 1..5 λ Adjusted ρ.79.83 NA TC Const.Vol 2.5 2. 1.5 1..5 λ Adjusted Const.Vol 29. 1 1.2 1.4 1.6 1.8 2. 1 1.2 1.4 1.6 1.8 2 2.2 T1 setting excess air ratio

Definition of residual density 3 Regression Density =.774937 x n-para +.789286 x i-para +.835134 x Naphthene +.9998 x 1R-A + 1.3527 x 2R-A + 1.11527 x 3R-A Residual density = Measured dens. - Regression dens. Measured density Regression density Residual density Measured and Regression density (g/cm 3 ).87.86.85.84.83.82.81.8.79.78.77 Base Low-T9 High-T9 Mid n-p High n-p Base+C.I. 1R-Aroma 2R-Aroma 2R+3R- Aroma naphthene n-p 1% i-c4 Bz C12 Bz Tetralin PhcycHexane.2.1 -.1 -.2 -.3 -.4 -.5 Residual density (g/cm3) T1 T9 T1 T6 T7 T8 T2 T3 T4 T5 T12 T14 T15 T16 T17

31 Analysis with residual density (PM) R 2 of PM 1.8.4 Existing Analysis 1R-A 2R-A 3R-A Naphthene i-para T9 CN Density Residual.Dens. Introduced 1R-A 2R-A 3R-A Naphthene i-para T9 CN Residual Den 1 High load.8.4 High load Tinj [ o ATDC] -6-4 -2-6 -4-2 -2 2 4-2 2 4 4 4 NA/TC NA TC NA TC NA TC.25 Noz. Dia [mm] Pinj [MPa] 6 1 correspond to '94 reg. correspond to '98 reg..18.16.18.2.16.18.2.16.18.2.16.18.2

Analysis with residual density (NOx,PM; High load) 32 1R-A 2R-A 3R-A Naphthene i-para T9 CN Res.Dens R 2 of NOx R 2 of PM Inj.T TDC 1.8.6.4.2 1.8.6.4.2 NA TC NA TC NA TC Inj. P. 6MPa 1MPa 1MPa Noz,hole dia..25.18.16 Inj.Spec. 94' Reg 98' Reg 98' Reg

Analysis with residual density (NOx,PM; Low load) 33 R 2 of NOx R 2 of PM 1.8.6.4.2 1.8.6.4.2 Inj.T.3deg BTDC 1R-A 2R-A 3R-A Naphthene i-para T9 CN Res.Dens NA TC NA TC NA TC NA TC w/o EGR w/o EGR EGR=4% w/o EGR 3MPa 5MPa 6MPa.25mm.18mm 94' Reg 98' Reg

Fuel properties with constant density and changed aromatics composition 34 Fuel code Distillation(T9) : o C o Density : (15 Cetane number n-paraffin C)kg/m3 i-paraffin Naphthene Total aromatics 1R-aromatics 2R-aromatics 3R-aromatics Constant density Existing Aroma Series T18 T19 T2 T1 T2 T3 823.6 823.5 823.6 788. 88.2 833.8 317 316 316 37. 299.5 314. 5.5 48.2 5.1 48.8 48.7 5.2 Composition : vol.% 48 38 43 36 45 42 22 41 32 57 28 33 5 7 6 7 7 5 25 14 19 2 2 2 1 2 5 14 9 2

Fuels of changed aromatics composition, ratio to base fuel, by 1% change of the content. fuels with existing properties an with constant density 35 Change of PM for base fuel %/vol.% Change of PM for base fuel %/vol.% 6 4 2 6 4 2 Calculated from T18,T19,T2 Calculated from T1,T2,T3 1R-Aromatics 2R-Aromatics Tinj [ o ATDC] -2 2 4-2 2 4-6 3-6 3 NA/TC NA TC NA TC Noz. dia. [mm].18 Pinj [MPa] 1 Load High Low Fuel inj. equip. correspond to '98 reg.

Summary, single cylinder engine test (Engine technologies) 1.By introducing 98 regulation (Japan Long Term) conforming type FIE, (high pressure,small nozzle hole), PM has been remarkably reduced. 2.Turbo-charging (TC) reduces PM further, especially in high load. 3.EGR changes NOx and PM in trade-off relation. ( data omitted) 4.With density change in D-WG fuels,if the A/F shifts, the effect of density to PM become larger in rich side operation. 36

Summary, single cylinder engine test (Fuel) 37 1.Correlation between fuel density and aromatic contents is high.the influence of density on PM emission can be represented by aromatics. 2.for PM; 1,2.3-R aromatics are major influencing factors. for NOx; 1,2-R aromatics are major influencing factors. 3.Number of aromatic ring increased, the effects become higher. 4. 1-R aromatics with naphthene side chain leads PM increase.

38 Contents 1. Review of Results from Diesel WG 2. Preliminary Statistical Analysis of Data Obtained from Diesel-WG 3. Organization of Issues of Combustion Analysis 4. Single Cylinder Engine Tests 5. Contribution of Engine Technologies and Fuel to Emission Reduction 6. Secondary Statistical Analysis of Data Obtained from Diesel-WG 7. Conclusion

39 Impacts for emission, by engine technology and by range of fuel properties change in market place * Data of NA inj. Equip. '94 Reg.,-4 o ATDC are canceled PM (g/kwh) 1.4 1.2 1..8.6 X D1 D2 D3 D4 D5 Variation by Fuel: D1-D5 Variation by Inj. Timing NA,Inj.Equip.; 94 Reg. High Load.4 NA,Inj.Equip.; 98 Reg..2 TC,Inj.Equip.; 94 Reg. 2 4 6 8 1 NOx (g/kwh) TC,Inj.Equip.; 98 Reg.

Contribution to emission reduction by engine technologies and by range of fuel properties change in market place 4 2.5 X D1 D2 D3 D4 D5 Low Load PM (g/kwh) 2. 1.5 1..5 Variation by Fuel: D1-D5 Variation by Inj. Timing TC,Inj.Equip.; 94 Reg. 2 4 6 8 1 12 14 NOx (g/kwh) NA,Inj.Equip.; 94 Reg. NA,Inj.Equip.; 98 Reg. TC,Inj.Equip.; 98 Reg.

Explanation of the figures Impacts of fuel properties to emission 41 1 D=D5-D1 2% PM [g/kwh].8.6.4.2 PM D / D1 % 15% 1% 5% % 5% -.2 D1 D5 1% 1R-A 2R-A 3R-A Naphthene i-para T9 CN Res.Dens

Impacts, by range of fuel properties change in market place D5 fuel High Aroma., High T9 42 NOx [ D/D1 %] 1R-A 2R-A 3R-A Naphthene i-para T9 CN Res.Dens 6% 4% 2% % -2% PM [ D/D1 %] 15% 1% 5% % -5% -4-3 -6-4 -3-6 98' Reg 94' Reg 98' Reg 94' Reg 98' Reg 94' Reg 98' Reg 94' Reg High Low High Low NA TC

Impacts, by range of fuel properties change in market place D2 fuel Low Aroma., Low T9 43 NOx D/D1 %] 1R-A 2R-A 3R-A Naphthene i-para T9 CN Res.Dens 2% % -2% -4% -6% PM [ D/D1 %] % -5% -1% -15% -2% -4-3 -6-4 -3-6 98' Reg 94' Reg 98' Reg 94' Reg 98' Reg 94' Reg 98' Reg 94' Reg High NA Low High TC Low

44 Residual.density value 1R-Aroma,Side Chain Diesel WG Fuel Residual Density.2.15.1.5 -.5 -.1 -.15 T1 T9 T1 T6 T7 T8 T2 T3 T4 T5 T12 T14 T15 T16 T17 D2 D3 D4 D5 Fuel D1

Contribution of engine technologies and fuel to emission reduction (1) 45 1.PM is substantially lowered by the TC, improved fuel injection system. In this case, impacts of fuel property change to emission become smaller. 2.Aromatics are factor with the closest relation to PM and NOx emission, and have larger Influence on PM. 3. T9, next to aromatics, contributes to NOx and PM emission.

Contribution of engine technologies and fuel to emission reduction (2) 46 4.Impacts of fuel on total emission, by range of fuel properties change in market place, regardless the Inj. Equip.or TC condition, On single cylinder, hot stable for PM;1% for NOx;2%roughly 5.Providing engine precise control, the case residual density remained as the factor, the effects of 1-R aromatics with side chain,or another unknown fuel components to residual density value should be considered.

47 Contents 1. Review of Results from Diesel WG 2. Preliminary Statistical Analysis of Data Obtained from Diesel-WG 3. Organization of Issues of Combustion Analysis 4. Single Cylinder Engine Tests 5. Contribution of Engine Technologies and Fuel to Emission Reduction 6. Secondary Statistical Analysis of Data Obtained from Diesel-WG 7. Conclusion

Detailed analysis of Diesel WG results, introduction of residual density 48 for PM 1R-A 2R-A 3R-A Sulfur T9 CN Residual Dens. D2 / D1 % 2-2 -4 K M(U) N(T) O(Y) R(X) D5 / D1 % K M(U) N(T) O(Y) R(X) '98,V 3.,DI-TI '98,V 2.2,IDI-T '98,V 2.,IDI-T CR M.Elec. Ox.Cat. Ox.Cat. D2 / D1 D5 / D1 '98,E '98,E 21.2,DI 8.,DI TICS CR No EGR 1R- 2R- 3R- Aromatics Aromatics Aromatics Sulfur T9 Cetane Residual Number Density

Detailed analysis of Diesel WG results, Introduction of residual density for NOx 1R-A 2R-A 3R-A Sulfur T9 CN Residual Dens. 49 K M(U) N(T) O(Y) R(X) K M(U) N(T) O(Y) R(X) D2 / D1 % 1-1 D5 / D1 % -2 '98,V 3.,DI-TI CR Ox.Cat. '98,V 2.2,IDI-T M.Elec. Ox.Cat. '98,V 2.,IDI-T D2/D1 D5/D1 '98,E '98,E 21.2,DI 8.,DI TICS CR No EGR 1R- 2R- 3R- Aromatics Aromatics Sulfur T9 Cetane Residual Aromatics Number Density

5 Secondary Statistical Analysis of Data Obtained from Diesel-WG 1.Secondary analysis showed Aromatics and T9 are major influencing factors to emissions, as like single cylinder engine analysis, except the case residual density remains as the factor. 2.With the vehicle and engine, the case residual density remained as the factor, A/F ratio or injection timing change etc. resulted from fuel property change, otherwise unknown factors such, contents of isoparaffins,naphthenes,or equivalence of double bond etc, could have contributed to emission.

51 Contents 1. Review of Results from Diesel WG 2. Preliminary Statistical Analysis of Data Obtained from Diesel-WG 3. Organization of Issues of Combustion Analysis 4. Single Cylinder Engine Tests 5. Contribution of Engine Technologies and Fuel to Emission Reduction 6. Secondary Statistical Analysis of Data Obtained from Diesel-WG 7. Conclusion

52 Conclusion 1. TC, high pressure injection vastly reduces PM. 2. Aromatics and secondary T9 are clarified to be the major influencing fuel factors to emission. 3. Analysis considering future engine, aftertreatment system and fuel concept will be requested.