JCAP Diesel WG(Oil) Report

Transcription

1 1 Further Challenge in Automobile and Fuel Technologies For Better Air Quality JCAP Diesel WG(Oil) Report Diesel WG

2 2 Activities of Oil WG STEP I Effect of oil properties on PM emission( ) STEP II Adverse effect of oil on continuously regenerating type DPF(CR-DPF)( )

3 Oil Properties and Test Matrix in STEP I Investigated the effect of oil properties(kv, NOACK, Base stock type, Ash) on PM emission using HD engine(8.2l) and LD car(2.5l). In the case of LD car, conducted an additional investigation regarding the effect of oxidation catalyst. Oil Properties Test Matrix Symbolic Viscosity KV40 KV100 VI NOACK Base S.Ash HD Engine LD car Grade mm 2 /s mm 2 /s mass% Stock mass% D13 F/F JCAP-CD Mineral 1.65 JCAP-CD10W-30L 10W Semi-Syn JCAP-CD10W-30M 10W Mineral 1.66 JCAP-CD10W-30H 10W Mineral 1.68 JCAP-CD15W-40 15W Mineral JCAP-CD10W-30PAO 10W Synthetic 1.63 JCAP-CD10W-30POE 10W Synthetic 1.62 JCAP-30MA Mineral JCAP30ZA Mineral JCAP-CD5W-30M 5W Mineral 1.64 JCAP-CD5W-30H 5W Mineral :w/o oxidation catalyst :w/ oxidation catalyst 3

4 4 Effect of oil properties on PM emission - Summary on STEP I (1) - Engine Heavy Duty DI Engine Light Duty DI Car Mode D13 mode Full/Full mode No observable effect on No observable effect on High viscosity oils could PM. PM. reduce SOF oil fraction. Effect of viscosity Effect of volatility Effect of base stock type Effect of ash Multi-grade oils can reduce PM emission by its fuel economy effect. No observable effect on PM. Synthetic oils could have positive effect to decrease SOF. No observable effect on PM. No observable effect on PM. Synthetic oils could have positive effect to decrease SOF. No observable effect on PM. High volatility oils increase SOF oil fraction. Synthetic oils have positive effect to decrease SOF. Could not conclude at this stage

5 Effect of oxidation catalyst - Summary on STEP I (2) - The amount of soluble organic fraction(sof) was largely decreased by the oxidation catalyst, resulting in a negligible effect of oil properties on SOF emission SOF oil fraction (w/o OC) SOF(w/o OC) SOF(w/ OC) SOF oil fraction(w/o OC) Min.PAO POEMin.PAO POE KV(40 o C) mm 2 /s NOACK mass% SOF oil fraction (w/ OC) w/o OC SOF w/ OC SOF oil fraction a)effect of Viscosity b)effect of volatility c)effect of base stock type 5

6 6 Adverse effect of oil on CR-DPF (STEP II) Survey for deposits in the DPFs of city busses in the field Analyzed deposit samples obtained from DPFs(Fuel Sulfur =500ppm). Oil related investigation on running test Clarify the influence of fuel sulfur on CR-DPF deposit composition by analyzing deposits in CR-DPF against varying fuel sulfur content(s=10,50,100ppm). Acceleration test for Oil Ash accumulation Analyze the quantity of ash due to oil additives(oil Ash) in CR- DPF and its adverse effect on pressure drop. Acceleration test with fuels blending oil additives.

7 Survey for deposits in the DPFs of city busses in the field Ash deposits sampled from DPFs used in four city buses in the field were analyzed. Mileage of buses was ranging from 12,000 to 19,000km in urban area. Commercial diesel fuel (sulfur content:less than 500ppm) was used. 2 types of oil were used. Samples from field test Symbolic H1 H2 M1 M2 Vehicle Type City bus Engine Type 9.88L, DI/NA 11.15L, DI/NA DPF Type Reverse flow regeneration In-situ regeneration by heater Volume L Oil H-CF10W-30 M-CD30 Fuel Max. S=500ppm in market Mileage km 12,000 16,000 18,954 18,341 Properties of oils Symbolic H-CF10W-30 M-CD30 Quality CF,10W-30 CD,30 KV 40 o C mm 2 /s 100 o C VI TAN mgkoh/g TBN(HClO 4 ) mgkoh/g Element Ca mass% Mg max max Zn P S Sulfated Ash mass%

8 Results of survey for deposits in the DPFs of city busses in the field Majority of metal in deposits is originated from oil additives (Proportion of Ca is quite large) Oil Ash is mainly composed of CaSO 4 (70 to 80%) Components of sulfated ash(based on JIS K2272) of oil used in M1 and M2 is similar to deposits in DPF ICP analysis of DPF deposits Others Mg Al Fe P Estimated compositions of ash originated from oil Zn,P compounds ZnO Ca,P compounds 20 Zn 20 CaO 0 *1 H1 H2 M1 M2 Ca 0 H1 H2 M1 M2 S.Ash *2 CaSO 4 *1 Mg 2 Al 4 Si 5 O 18 was detected, originated from DPF *2 Sample made by laboratory method JIS K2272 8

9 Oil related investigation on running test After the tests, deposits on DPF were analyzed Specifications of test vehicles and engines and their mileages are shown below. Test fuels with 3 levels of sulfur content were provided: 10, 50, 100 ppm JCAP-CD30(S.Ash 1.65%) was used Specifications of Test Vehicle and Engines Engine Type Aftertreatment Devices XB YB YC Vehicle Engine Engine L4, 2.4L L4, 4.9L L6, 15.7L DI/TI DI/TI DI/TI CR-DPF (Fiber type) CR-DPF CR-DPF +SCR Driving Mode 11Lap JARI Engine Test Cycle Distance 30,000km 30,000km 10,000km Properties of Oil JCAP-CD30 Kinematic Viscosity 40 o C mm 2 /s 100 o C 11.4 VI 105 TAN mgkoh/g 2.03 TBN mgkoh/g HCl 10.1 HClO Elemental Analysis Ca 0.43 mass% Zn 0.12 P 0.10 S 0.34 N 0.02 Sulfated Ash mass%

10 10 Oil related investigation on running test - Component of CR-DPF deposit - Despite the differences of fuel sulfur content(s=10, 50, 100 ppm), the main component of Oil Ash is CaSO4 in every test. [mass %] XB YB YC Test Fuel 2D-21 2D-22 2D-23 2D-21 2D-22 2D-23 2D-21 2D-22 2D-23 S=10ppm S=50ppm) S=100ppm S=10ppm S=50ppm) S=100ppm S=10ppm S=50ppm) S=100ppm CaSO 4 59+/ / / /-7 85+/-6 81+/-6 69+/-5 82+/-5 89+/-6 Ca 2 P 2 O /-4 (6+/-4) (6+/-4) 12+/-4 5+/-3 (3+/-1) Ca 3 (PO 4 ) (4+/-1) (2+/-1) (3+/-1) (12+/-4) (3+/-1) (3+/-1) CaO /-1 (3+/-1) - ZnSO 4 9+/-5 9+/-4 <1 3+/-1 2+/-1 4+/-1 2+/-1 2+/-1 2+/-1 ZnO <1 <1 <1 7+/-4 2+/-1 5+/-3 3+/-1 3+/-1 2+/-1 Zn 3 (PO 4 ) <1 <1 <1 <1 <1 <1 Zn 2 P 2 O 7 - <1 - <1 1+/-1 <1 <1 1+/-1 <1 C 32+/-14 (17+/-9) (20+/-10) (<1) (<1) (<1) (<1) (<1) (<1)

11 Oil related investigation on running test - Pressure drop by ash - Measured the pressure drop of burned CR-DPF after engine test using a blower Slight increase of pressure drop in XB is due to Fe 2 O 3, FeO trapped in CR-DPF. Little effect of Oil Ash on the pressure drop in these tests. Increase of pressure drop kpa XB YB YC Air Flow (m 3 /min) Air Flow (m 3 /min) Air Flow (m 3 /min) Pressure drop by ash: :2D-21(S=10ppm) :2D-22(S=50ppm) :2D-23(S=100ppm) 11

12 12 Interim conclusion The main Oil Ash component of current DPFs (Fuel sulfur = 500ppm) in the field is CaSO 4. The main Oil Ash component of CR-DPFs in the running test is also CaSO 4, irrespective of the different fuel sulfur contents(s = 10, 50, 100 ppm). In the case of this running test, little effect of Oil Ash on the pressure drop.

13 13 Acceleration test for Oil Ash accumulation Examined the adverse effect of metal additives in oil on pressure drop. Clogging of CR-DPF is accelerated by adding metal additives for oil directly to fuels.

14 Acceleration test for Oil Ash accumulation - Test design - Oil consumption was presumed to be 0.1 % of fuel consumption. Dosage of oil additives in fuel is equivalent to 25 times of the oil consumption based on standard metal content in oil as shown below. And metal content in fuel was distributed based on the design of experiment. Oil additive Type Sulfonate Metal detergent *1 Phenate Salicilate Metal type Ca or Mg Metal content in oil approx mass% Anti-wear/Antioxidant agent ZnDTP Zn(P) approx. 0.12(0.11) mass% Friction modifier MoDTC *2 Mo approx mass% *1 Ca-sulfonate is generally used in Japan. In Europe, Ca and Mg type is used. *2 It is mainly used in gasoline engine oil to improve fuel economy. 14

15 Acceleration test for Oil Ash accumulation - Test matrix and test conditions - CR-DPF was equipped in heavy duty engine(7l, DI/TI) complying with Japanese Long-term regulations. Test was conducted with 100 % of engine speed and 75 % of load(f/75). Test duration is about 20 hours corresponding to fuel consumption of 850L. Ashes equivalent to mileage of 60,000 km are emitted. Test No. Ca Mg Zn P Mo S ppm ppm ppm ppm ppm ppm Base Fuel D-06(S=50ppm) D-07(S=0ppm) D-07(S=0ppm) D-06(S=50ppm) D-06(S=50ppm) D-07(S=0ppm) D-07(S=0ppm) D-06(S=50ppm) 15

16 Acceleration test for Oil Ash accumulation - Pressure drop change during test - Pressure drops of CR-DPF increase during test, except for Test No.1(no additives included). After the tests, CR-DPF was detached, and pressure drop by ash was analyzed by measuring pressure drop before and after burning (550 C 8 hr) using a blower. CR-DPF pressure drop kpa Time hr No.4 No.8 No.7 No.5 No.2 No.6 No.3 No.1 Pressure drop by ash are analyzed 16

17 Acceleration test for Oil Ash accumulation - Details of CR-DPF pressure drop - Increase of pressure drop by ash is less than half of the total. In this test, pressure drop by ash after mileage of 60,000 km using oil of S. ash =1.65 % was calculated as 11.6 F/75. But actual running test is required for confirmation of these results. CR-DPF pressure drop kpa Test No Initial pressure Increase of pressure drop by ash Increase of pressure drop by others * *Excluded from estimation as the deposits were lacked before blower test Equivalent to 1.65% of S.ash 17

18 Acceleration test for Oil Ash accumulation - Component of CR-DPF deposit - Deposits consist of ash including CaSO 4,MgSO 4.6H 2 O mainly. CaCO 3 not neutralized by sulfuric acid under the low sulfur test condition is found. [mass %] Test No CaSO 4-39+/-5 22+/-5 67+/-5 7+/-3 73+/-5 45+/-5 CaCO 3-37+/-5 3+/-2-43+/-5-16+/-5 MgSO 4-6H 2 O 62+/ 5-51+/-5 (6+/-3) (20+/-5) - 17+/-5 Mg 3 (PO 4 ) 2 (5+/-3) (<1) - - (2+/-1) - - Mg 2 P 2 O 7 (14+/-5) (<1) (10+/-3) - (2+/-1) (<1) - MgO (<1) (23+/-5) - (13+/-5) ZnO 5+/-3-2+/-1 5+/-3 <1 4+/-3 <1 Zn 2 P 2 O 7 2+/-1 <1 2+/-1 2+/-1-2+/-1 - ZnSO 4 4+/-3-5+/-3 3+/-2-4+/-3 - MoO 3 2+/-1 - <1 2+/-1 - <1 4+/-2 CaMoO 4 2+/-1 16+/ MPO 3 (M=metal) - <1 2+/-1 8+/-3-13+/-5 - more than 30% more than 10% 18

19 Acceleration test for Oil Ash accumulation - Single regression analysis- Correlation coefficient of Ca is 0.62 to ash weight, 0.90 to increase of pressure drop by ash. The correlation is high. Correlation coefficient of the sum of Ca and Mg is 0.80 to ash weight, 0.90 to increase of pressure drop by ash. The correlation is also high. Case 1: Ash weight (g) deposited on CR-DPF after burning Case 2: Increase of pressure drop by ash per blower with 15.5m3/min (kpa) [Case1] [Case2] Ash weight (g) = Coef. x Element(ppm) + P by ash@15.5m 3 /min (kpa) = Coef.x Element(ppm)+Const. Element Coef. Const. R2 Element Coef. Const. R2 Ca Ca Mg Mg Zn Zn P P Mo Mo S S Ca+Mg Ca+Mg

20 20 Acceleration test for Oil Ash accumulation - Multiple regression analysis - Multiple regression analysis method is significant only for increase of pressure drop by ash.(decision is made at 10% of significant level.) Even though the error in regression coefficient is considered, the more the quantity of Ca and Mg increases, the more pressure drop increases. Ca has a larger influence on pressure drop than Mg. Zn and Mo have little adverse effect on pressure drop. Confidence limits Const. Coeff. Coeff. Coeff. Coeff. Coeff. Ca(ppm) Mg(ppm) Zn(ppm) Mo(ppm) S(ppm) 90% upper limit % lower limit

21 Acceleration test for Oil Ash accumulation - Trap ratio of each metal - Trap ratio of each metal in CR-DPF varies by tests, however, the fact that Ca and Mg giving large adverse effect are trapped easily could not be verified. Further actual running tests will be necessary to clear the mechanism of pressure drop by ash. Test No. Trap ratio % Ca Mg Zn P Mo * *Excluded from estimation as the deposits were lacked 21

22 22 Acceleration test for Oil Ash accumulation -Summary- Increase of pressure drop in CR-DPF by ash originated from oil additives was recognised. However, the increase level should be confirmed by actual running tests. The main component of ash on CR-DPF is sulfate of Ca and Mg.(In this test, CaCO 3 is detected under lower sulfur test conditions). Ca and Mg have large adverse effect on pressure drop. On the other hand, Zn, P and Mo have little effect on pressure drop. It is observed that the trap ratio of each metal at CR- DPF is the same.

23 23 Conclusion in STEP II [CR-DPF deposits] The main Oil Ash component is CaSO 4, irrespective of the different fuel sulfur contents(s = 10, 50, 100 ppm). (In the case of oils not including Mg) [CR-DPF pressure drop] For the pressure drop, Ca and Mg have large adverse effect. And Zn, P and Mo have little effect. A part of emitted metal from oil can go through the DPF. The increase level of pressure drop should be confirmed by actual running tests at longer term.

24 24 Issues to be studied Clarify the level of ash accumulation and pressure drop by ash in CR-DPF, conducting actual running tests at longer term. Research the influence of engine test condition on ash accumulation in CR-DPF. Investigate the adverse effect of oil components on DeNOx catalyst.