Gaseous and Particulate Emissions from Diesel Generators. Dongzi Zhu Desert Research Institute. Dirty Diesel engine. Non-road Diesel engine (contrary to Onroad) DPM higher than onroad diesel engines (HDDTs) contributes 44% DPM, 12% of NOx from all mobile sources nationwide (EPA)
Desert Research Institute
PM(2.5,10), NOx, SO2, CO, O3,Pb
PM most < 1mm, toxic air pollutants
NOx, precursor of O3
Hydrocarbon(HC), PAH carcinogens, precursor of SOA, O3
Tier 1 (1996-2000) (EPA,1994)
Tier 2 (2001-2006)
Tire 3 (2006-2008) (EPA,1998)
Tire 4 (2008-2015): PM, NOx reduced by 90% (EPA, 2004)
Population density and diesel BUGs location in L.A. region
% radiation reaching detector
An example of a transmission spectrumCO22500 ppm
The (sample) region to represent a NO2 concentration of 39 ppm. This is consistent with the reference spectrum concentration of 30 ppm.
H CA, using DRI’s In-Plume Emissions Testing System 2O and CO2 FTIR Spectra
Li-Cor LI-840 CO2/H2O Gas Analyzer
measures the magnitude of the shock wave when a laser beam heats up a light absorbing particle, correlated with aerosol black carbon mass
optical measurement intensity of light scattered from aerosols, aerosol concentration < 2.5 mm, or 10 mm
Electrical Low Pressure Impactor
measure of the number concentration of the particles and their aerodynamic size between 7 nm and 10 mm.
GRIMM aerosol spectrometer
measures light intensity scattered from the aerosol,
the size of the particles, number concentration of the aerosol.
Filter: Gravimetric & Chemical analysis
Table 1. CA, using DRI’s In-Plume Emissions Testing System In-Plume Sampling Test Matrix in Camp Pendleton, CA from Nov 14 to 16, 2005.
a. Unit tested five distinct loads only
b. Unit tested cold start only.
Mass of particles measured by GRIMM less sensitive to changes in the size distribution, the Grimm calculates PM2.5 mass based on an integrated measure of the particle size distribution.
. The relative fraction of black carbon to total aerosol mass can change as a function of engine, operating load, and air fuel mixture, weak correlation is expected.
DustTrak laser light wavelength of 780 nm, less sensitive to particles < 300 nm. These two measuring independent portions of particle size distribution
Moderate correlation indicates larger particles (300 nm to 1000 nm) measured by the DustTrak are generally coincident with the smaller nano particles measured by the ELPI.
size distributions overlap indicating that both measurements are physically consistent
ELPI is known to have a large bias for particles greater than 500 nm when sampling high concentration (>1 mg/m3).For PM EF calculation, ELPI PM less than 0.263 is added to DustTrak PM2.5 mass
Match test: concentration peaks shows well synchronized,
No need to subtract background since source is 2 orders higher.
EFs for the 10 kW generators were highest at the 100% load.
PM fuel based emission factors for 60 kW, 100 kW generators Camp Pendleton Generator
All but the 100 kW generator showed an increase in PM EF as load increased to 75%
100 kW unit had the highest emissions and showed a steady decrease in EF as increased load
No substantial increases in emissions were seen for the cold start tests.
BC EF Patterns are consistent with the total PM EFs. BC emissions were highest for the 10 kW generators operating at 100% load. The 100 kW generator had constant BC emissions for 10%-75% loads, but increased by a factor of 3 at the 100% load.
EF Comparison with CE-CERT MEL generator test (1) Camp Pendleton Generator
EF Comparison with CE-CERT MEL generator test (2) Camp Pendleton Generator
NOx emission factors for 13 tested generators Camp Pendleton Generator