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Continuously Regenerating Particulate Filters Part 2

Performance and Durability Evaluation of Continuously Regenerating Particulate Filters on Diesel Powered Urban Buses at NY City Transit - Part II

  • Sougato Chatterjee, Ray Conway, Diesel Emission Control Systems, Johnson Matthey, CSD
  • Thomas Lanni, Shida Tang, Brian P. Frank, Division of Air Resources, New York State Department of Environmental Conservation
  • Deborah Rosenblatt, Environment Canada
  • Christopher Bush, Dana Lowell, New York City Metropolitan Transit Authority
  • James Evans, Equilon Enterprises LLC
  • Robert McLean, Corning Inc.
  • Steven Levy, Rad Energy

Summary

Particulate emission from diesel engines is one of the most important pollutants in urban areas. As a result, particulate emission control from urban bus diesel engines using particle filter technology is being evaluated at several locations in the US. A project entitled "Clean Diesel Vehicle Air Quality Project" was initiated by NY City Transit under the supervision of NYSDEC and with active participation from several industry partners.

Under this program, 25 NY City transit buses with DDC Series 50 engines were equipped with continuously regenerating diesel particulate filter systems (the CRTTM system from Johnson Matthey) and were operated with ultra low sulfur diesel (<30 ppm S) in transit service in Manhattan beginning in February 2000. These buses were previously evaluated during a baseline emissions testing period of 9 months to verify the emissions reduction capability of the continuously regenerating diesel particulate filter technology. In the second phase of the program, reported here, the buses were further evaluated over a 9 to 12 month durability testing period for operations, maintainability and durability of the particulate filter, including extensive emissions testing under transient cycles on a chassis dynamometer.

The on-road operational data over fourteen months showed stable exhaust back pressure with the diesel particle filters, indicating successful filter regeneration. No adverse operational or maintenance issues were observed which can be attributed to the filter system. The emissions results from the post durability (after 9-12 months) testing exhibited >90% reductions in CO and PM and >70% for HC, with the particulate filter. In addition, >99% reductions in carbonyls, >72% in PAH and 70-99% VOC reductions were also achieved. In this report, the post durability emissions testing data from the NY City Clean Diesel Vehicle Air Quality Project are discussed in detail. In addition, the on-road performance of the diesel particulate filter equipped buses after the durability period is also reported.

Regulated Emission Test Results for DDC S50 Powered NYCTA Buses 6019 and 6065
Bus ID Test Cycle Configuration Fuel FE
(mpg)
CO2
(g/mile)
NOx
(g/mile)
THC
(g/mile)
CO
(g/mile)
PM
(g/mile)
pre post pre post pre post pre post pre post pre post
6019 CBD OEM LSD 3.3 NA 2942 NA 25.6 NA 0.18 NA 1.8 NA 0.22 NA
6019 CBD OEM ULSD 3.4 3.2 2948 3115 25.6 27.7 0.06 0.08 1.2 1.0 0.19 0.22
6019 CBD CRDPF ULSD 3.1 3.3 3236 2922 26.5 25.3 0.03 0.04 0.16 0.16 0.04 0.03
% Reduction OEM w/LSD to CRDPF 6 -9 -3 83 91 82
% Reduction OEM w/ULSD to CRDPF 9 -3 -10 6 -3 9 50 50 87 84 79 86
6019 NYBUS OEM LSD 1.5 NA 6483 70.3 NA 0.91 NA 13.0 NA 0.65 NA
6019 NYBUS CRDPF ULSD 1.4 1.4 7177 6946 70.3 68.6 0.06 0.16 0.23 0.90 0.04 0.05
% Reduction OEM w/LSD to CRDPF 7 -11 0 93 98 94
6065 NYBUS CRDPF ULSD 1.6 6326 60.0 0.26 0.53 0.06
6065 CBD OEM LSD 3.3 3.8 2897 2562 23.3 23.0 0.26 0.22 2.1 2.5 0.21 0.23
6065 CBD OEM ULSD 3.5 3.8 2884 2596 25.1 23.0 0.04 0.17 1.6 0.92 0.14 0.11
6065 CBD CRDPF ULSD 3.7 3.9 2679 2571 23.8 20.5 bdl 0.06 0.09 0.1 0.01 0.01
% Reduction OEM w/LSD to CRDPF -12 -2 7.5 0 -2 13 100 72 96 96 95 96
% Reduction OEM w/ULSD to CRDPF -6 -2 7 1 5 13 100 65 94 89 93 91
Carbonyl and PAH Emissions test Results for DDC S50 Powered Buses 6019 and 6065
Bus ID Test Cycle Configuration Fuel Carbonyl
(mg/mile)
PAH
(g/mile)
Pre Post Pre Post
#6019 CBD OEM LSD 73 NA 62 NA
#6019 CBD OEM ULSD 66 129 49 78
#6019 CBD CRDPF ULSD bdl 10.2 14 22
% Reduction OEM w/LSD to CRDPF >99 78
% Reduction OEM w/ULSD to CRDPF >99 92 71 72
#6019 NYB OEM LSD 287 NA 201 NA
#6019 NYB CRDPF ULSD bdl 4.5 42 87
% Reduction OEM w/LSD to CRDPF >99 79
#6065 NYB CRDPF ULSD 4.9 NA
#6065 CBD OEM LSD 77 54 66 69
#6065 CBD OEM ULSD 70 52 63 75
#6065 CBD CRDPF ULSD 0.9 0.64 15 15
% Reduction OEM w/LSD to CRDPF 99 99 78 78
% Reduction OEM w/ULSD to CRDPF 99 99 76 80