Brian P. Frank

Particulate Emissions from in-use Commercial Aircraft

Particulate emission indices (per kg fuel) have been determined by sampling the advected plumes of in-use commercial aircraft at two different airports using a novel approach. Differences are observed in the number, magnitude, and composition of the particle emissions between idle and take-off. At the first airport, Electrical Low Pressure Impactor (ELPI) data indicate that number based emission indices (EI n ) vary by an order of magnitude for take-off plumes from different aircraft. Additionally, EI n values for idle plumes are greater than take-off. At the second airport, EI n values derived from condensation particle counter (CPC) measurements span ∼ an order of magnitude (3–50 × 10 15 particles per kg fuel). The median values of the idle and take-off plumes were 1.8 × 10 16 and 7.6 × 10 15 particles per kg fuel, respectively. For take-off plumes, the magnitude of the particulate emission index is not correlated with NO x at either airport. The surface properties of the particulate emissions in take-off and idle plumes differ significantly as measured by diffusion charging (DC) and photoelectric aerosol sensor (PAS) instruments. Results indicate that take-off plumes are characterized by particles with photoelectric-active surfaces, presumably elemental carbon, whereas idle plumes are composed of non-photoelectric-active constituents and coated soot particles. Measurements of the particulate size distribution (ELPI) show evidence for two modes, one at ∼ 90 nm aerodynamic diameter and a second mode at or below the instrument cutoff ( < 30 nm).

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

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 Demonstration Program” has been initiated by NY City Transit under the supervision of NY State DEC and with active participation from several industrial partners. Under this program, several NY City transit buses with DDC Series 50 engines have been equipped with continuously regenerating diesel particulate filter system and are operating with ultra low sulfur diesel ( 90% reductions in CO, HC and PM with the particulate filter. In addition, >99% reductions in Carbonyls and up to 80% PAH and 94% NO2-PAH destructions were also achieved.

Performance and Emissions Evaluation of Compressed Natural Gas and Clean Diesel Buses at New York City's Metropolitan Transit Authority

The New York City Metropolitan Transit Authority (MTA) has initiated a program to utilize various diesel emission control, alternative fuel, and hybrid electric drive technologies as part of its ongoing effort to provideenvironmentally friendly bus service. The New York State Department of Environmental Conservation (DEC) has joined with the MTA and Environment Canada in evaluating this program, and has established a protocol for measuring both regulated and unregulated emissions, as well as other operational parameters. This paper compares and contrasts the emissions of buses powered by Detroit Diesel Series 50 diesel engines and Series 50G Compressed Natural Gas (CNG) engines. All buses have been tested for regulated emissions at the Emissions Research and Measurement Division of Environment Canada, in Ottawa, Ontario. Unregulated emissions measurements, including particle size distributions and chemical analysis, have been supported by DEC staff. The various measured quantities are presented in order to facilitate useful comparisons among the different transit bus technologies.

The effect of fuel type and aftertreatment method on ultrafine particle emissions from a heavy-duty diesel engine

Two potential strategies for reducing diesel emissions are exhaust aftertreatment and the use of reformulated or alternative fuels. Little is yet known about the impact on ultrafine particle emissions of combining exhaust aftertreatment with such increasingly common fuels. This paper reports ultrafine particle size distribution measurements for a study in which the impact of such fuels on emissions from a heavy duty diesel engine employing different aftertreatment configurations was evaluated. Eight different fuels were tested: Canadian No. 1 and No. 2 diesel; low sulfur diesel fuel; two different ultra low sulfur diesel fuels (< 30 ppm S); Fischer-Tropsch diesel fuel; 20% biodiesel blended with ultra low sulfur diesel fuel; and PuriNOx™. The fuels were tested in combination with four exhaust configurations: engine out, diesel oxidation catalyst (DOC), continuously regenerating diesel particle filter (CRDPF), and engine gas recirculation with CRDPF (EGR-DPF). In general, aftertreatment configuration was found to have a greater impact on ultrafine particle size distributions than fuel composition, and the effects of aftertreatment tended to be uniform across the entire particle size distribution. Steady state tests revealed complex behavior based on fuel type, particularly for PuriNOx. This behavior included bimodal particle size distributions with modes as low as 8–10 nm for some fuels. Unlike previous results for gravimetric PM from this study, no significant correlation for ultrafine emissions was found for fuel properties such as sulfur level.

Field Evaluation of a TSI Model 3034 Scanning Mobility Particle Sizer in New York City: Winter 2004 Intensive Campaign

A new “single box” Scanning Mobility Particle Sizer (TSI SMPS Model 3034) was deployed and operated during a period of four weeks as a part of the PMTACS-NY Winter 2004 intensive study in Queens College, New York City. The SMPS 3034 is an alternative to a conventional multi-component TSI SMPS and houses a Differential Mobility Analyzer and butanol-based Condensation Particle Counter in one cabinet. The SMPS 3034 operates at a fixed 1 l/min sample flow rate (4 l/min sheath flow rate) and measures size distributions within a 10–487 nm size range. One size scan is produced every 3 minutes. Four other measurement systems (a conventional TSI SMPS with a Nano Differential Mobility Analyzer, an Aerodynamic Particle Sizer, a stand-alone Condensation Particle Counter, and an R&P Inc. Filter Dynamic Measurement System (FDMS) TEOM mass monitor) were operated side-by-side with the SMPS 3034. It is shown that total particle number concentrations measured by the SMPS 3034 are highly correlated with those from the conventional Nano SMPS, the Condensation Particle Counter and the FDMS TEOM monitor, and that the number median diameters measured by the SMPS 3034 and the Nano SMPS agree within 3 nm.