CHEMICAL CHARACTERIZATION OF PARTICULATE MATTER EMISSIONS FROM A CATALYZED TRAP EQUIPPED NATURAL GAS FUELED TRANSIT BUS Mridul Gautam, Sairam Thiagarajan, Tim Burlingame, Scott Wayne, Dan Carder Department of Mechanical and Aerospace Engineering West Virginia University Adewale Oshinuga South Coast Air Quality Management District Lisa Graham Environment Canada Ted Tadrous Lubrizol Howard Paris and Bob Kreeb Booz Allen and Hamilton
Project Objectives Reduction of exhaust emissions from current (2001 ULEV compliant) natural gas fueled vehicles Recognize the problem (PM/gaseous; regulated/unregulated) Natural gas engine designs need to focus more on cylinder materials, design of ring packs, valve stem seals, etc., to minimize oil consumption. Identify the nature of the problem by conducting a detailed speciation of the exhaust (Round 1) Design an exhaust aftertreatment system to tackle specific pollutants Install exhaust aftertreatment system on the vehicle and conduct another speciation study (Round 2) Operate the vehicle in the field for 6 months and monitor performance. Conduct speciation study after 6 months (Round 3)
Project Objectives Engine Cummins C8.3G+ (6-cylinder, 8.3 liter, 280 hp@2400 rpm) Certified with a catalyst for California ULEV levels NOx: 1.53 g/bhp-hr NMHC: 0.21 g/bhp-hr Total PM: 0.008 g/bhp-hr CO: 0.8 g/bhp-hr Vehicle Orion, standard 40-foot, high-floor design Laboratory WVU Transportable Laboratory with a dedicated Clean Tunnel with on-site GC
Chemical Characterization Particulate Matter TPM, PM 10, PM 2.5, PM 1 Volatile Organic Compounds Low molecular weight alkanes and olefins (C 2 C 5 ) Low molecular weight aromatics (BTEX) Elemental & Organic Carbon PAHs and n-pahs Hopanes and Stearanes Elemental Compounds Ionic Species Carbonyls PM Size Concentration and Distributions
Test Vehicle Installed On The Chassis Dynamometer
Clean Tunnel With Sampling Ports/Trains PM 1 Cyclone PM 2.5 Cyclone PM 2.5 Cyclone (EC/OC) Total PM PM 10 Cyclone
PM Filter followed by an Oxidation Catalyst in the Transit Bus Exhaust System
WVU/Lubrizol-ECS Catalyzed Filter and Oxidation Catalyst Diesel Particulate Filter Silicon Carbide segmented honeycomb (11.25 in x 12 in) 200 square CPI cell density Pt coated on proprietary wash-coat for passive regeneration over duty cycles producing exhaust temperature 280 o C - 320 o C for >25% of the time Oxidation Catalyst Cordierite monolith (10.5 in x 6 in) 400 square CPI cell density Pd coated on proprietary wash-coat
Tunnel Background (Round 1) Particle concentration dn/dlogdp (#/cm^3) 6x10 4 5x10 4 4x10 4 3x10 4 2x10 4 1x10 4 0 Normal background Data: BG2_B Model: Gauss 10 100 Chi^2/DoF = 101079652.46189 R^2 = 0.53704 y0 809.40262 ±3129.09373 xc 65.20498 ±2.48241 w 52.22772 ±8.15302 A 2206882.03511 ±467990.75733 Particle diameter (nm)
Sunline Transit Bus Steady State Operation 20 Mph With Oxidation Catalyst (Round 1) Particle Concentration dn/dlogdp (#/cm^3) 1.0x10 6 8.0x10 5 6.0x10 5 4.0x10 5 2.0x10 5 0.0 SS 20mph With Oxidation Catalyst--cold SS 20mph With Oxidation Catalyst--hot 10 100 Data: SS 20mph with cat cold Model: Gauss Chi^2/DoF = 14102545157.70303 R^2 = 0.86379 y0-3741.47652 ±26882.40612 xc 47.34166 ±0.76992 w 36.18543 ±2.0348 A 41264889.31164 ±2966796.1965 Data: SS 20mph with cat hot Model: Gauss Chi^2/DoF = 294888399.39383 R^2 = 0.74812 y0 5318.76959 ±3234.95684 xc 42.91572 ±0.95994 w 28.99202 ±2.35115 A 3266736.64037 ±313992.14651 Particle diameter (nm)
Tunnel Background (Round 2) Particle Concentration dn/dlogdp (#/cm^3) 3.0x10 4 2.5x10 4 2.0x10 4 1.5x10 4 1.0x10 4 5.0x10 3 0.0 Background 1 10 100 Particle diameter (nm)
Sunline Transit Bus Steady State Operation 25 Mph with PM Filter Only No Oxidation Catalyst (Round 2) Particle Concentration dn/dlogdp (#/cm^3) 5x10 6 4x10 6 3x10 6 2x10 6 1x10 6 0 1 10 100 Particle Diameter (nm) Steady State 25Mph Cold Steady State 25Mph Hot Data: Steady State Cold Model: Gauss Chi^2/DoF = 3572981174.48617 R^2 = 0.94352 y0 12292.20008 ±7627.46749 xc 57.19985 ±0.39402 w 25.32478 ±0.8411 A 26114214.0915 ±875462.32399 Data: Steady State Hot Model: Gauss Chi^2/DoF = 45250324274.3747 R^2 = 0.97051 y0 124246.57048 ±25723.0407 xc 13.34646 ±0.05907 w 5.24218 ±0.12387 A 28190677.16038 ±655746.44917
Particle concentration dn/dlogdp (#/cm^3) Sunline Transit Bus Steady State Operation 25 Mph with PM Filter and Oxidation Catalyst (Round 2) 6x10 4 5x10 4 4x10 4 3x10 4 2x10 4 1x10 4 Steady state 25Mph with Oxidation Catalyst and Trap 0 20 40 60 80 100 120 140 160 180 Particle diameter (nm)
Comparison of Particle Size Distributions LNG-fueled and Diesel-fueled Transit Buses 1.00E+09 1.00E+08 1.00E+07 1.00E+06 GMD ~ 49 nm (Diesel) GMD ~ 30 nm (LNG) 1999 Study Diesel fueled M11-1 Diesel fueled M11-2 LNG fueled L-10-1 LNG fueled L-10-2 LNG fueled L-10-3 dn/dlogdp 1.00E+05 1.00E+04 1.00E+03 1.00E+02 1.00E+01 1.00E+00 1 10 100 1000 Dp (nm) M. Gautam and S. Mehta, West Virginia University
Sunline Transit Bus Transient Operation Quad CBD; PM Filter Only (Round 2) Normalized particle concentration N/dlog Dp (#/cm^3) 1.00E+08 1.00E+07 1.00E+06 1.00E+05 1.00E+04 1.00E+03 1.00E+02 1.00E+01 1.00E+00 0 200 400 600 800 1000 1200 1400 1600 1800 13.29 nm Time (sec)
Transit Bus Transient Operation Quad CBD; PM Filter and Oxidation Catalyst (Round 2) Normalized concentration dn/dlog Dp (#/cc) 1.00E+04 1.00E+03 1.00E+02 1.00E+01 1.00E+00 0 100 200 300 400 500 600 700 800 900 1000 Time (sec) 18.8 nm
Transit Bus Transient Operation Quad CBD; PM Filter Only (Round 2) Normalized particle concentration dn/dlog Dp (#/cm^3) 1.00E+06 1.00E+05 1.00E+04 1.00E+03 1.00E+02 1.00E+01 1.00E+00 0 200 400 600 800 1000 1200 1400 1600 1800 Time (sec) 53.3 nm
Normalized particle concentration dn/dlog Dp (#/cm^3) 1.00E+05 1.00E+04 1.00E+03 1.00E+02 1.00E+01 1.00E+00 Transit Bus Transient Operation Quad CBD; PM Filter and Oxidation Catalyst (Round 2) 46.49nm 0 500 1000 1500 2000 2500 Time (sec)
Regulated Emissions 40 35 37.7 32.8 C8.3G+ (No Cat) C8.3G+ (With Cat) Emissions, g/mile 30 25 20 15 13.2 21 21.9 C8.3G+ (With WVU-Lubrizol Trap & Cat) 15.8 11.8 10 5 0 3.9 1.5 0.380.13 0.07 CO NOX1 FIDHC PM (x100) West Virginia University, Bars are Average of 3 Replicate Runs
Total PM Emissions 0.04500 0.04000 0.03500 0.0331 0.0404 C8.3G+ (Without Oxy Cat) C8.3G+ (With Oxy Cat) C8.3G+ (WVU-Lubrizol Trap & Oxy Cat) 0.0388 Emissions, g/mile 0.03000 0.02500 0.02000 0.01500 0.01000 0.0095 0.0158 0.0327 0.0112 0.0151 0.00500 0.00000 0.0000 0.0000 0.0007 PM1 PM2.5 PM10 TPM West Virginia University, Bars are Average of 3 Replicate Runs
Methane and Non-Methane Hydrocarbons 25.00 23.80 20.00 21.90 20.56 20.91 C8.3G+ (No Cat) C8.3G+ (With Cat) Emissions, g/mile 15.00 10.00 15.80 11.80 14.94 10.00 C8.3G+ (With WVU- Lubrizol Trap & Cat) C8.3G+ (WVU-Lubrizol Trap Only) 5.00 0.00 1.14 0.54 0.13 FIDHC CH4 NMHC 1.67 West Virginia University, Bars are Average of 3 Replicate Runs
Carbonyls 14 12.7651 12 Emissions, g/mile 10 8 6 C8.3G+ (Baseline) C8.3G+ (With OEM Cat) C8.3G+ (WVU-Lubrizol Trap & Cat)X100 4 2 0 2.5364 2.2053 1.0999 0.7771 0.3944 0.3352 0.1914 0.0218 0.0140 formaldehyde acetaldehyde acetone propionaldehyde West Virginia University,
XRF Chemical Elements C8.3G+ (with WVU-Lubrizol Trap & OC: Non-Detectable) 7.500E-03 6.000E-03 Na Mg Al Si P S Cl K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Rb Sr Y Zr Nb Mo Pd Ag Cd In Sn Sb Te I Cs Ba La Ce Pr Nd W Hg Pb Emissions, g/mile 4.500E-03 3.000E-03 1.500E-03 0.000E+00 Background C8.3G+ (With Oxy Cat) C8.3G+ (Without Oxy Cat) West Virginia University, Bars are Average of 3 Replicate Runs
Acknowledgements Funding for the study was provided by: South Coast Air-Quality Management District The Gas Company West Virginia University,
West Virginia University,