Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4439884 | Atmospheric Environment | 2011 | 7 Pages |
Training on US military bases involves nonroad diesel vehicles with emissions that can affect base personnel, nearby communities, and attainment of air quality standards. Nonroad diesel engines contribute 44% of diesel PM and 12% of total NOx emissions from mobile sources nationwide. Although military sector fuel use accounts for only ≈0.4% of distillate fuel use in US, emissions factors measured for these engines improve the representation of the relatively small (as compared to onroad sources) database of nonroad emission factors. Heavy-duty multi-axle, all-wheel drive military trucks are not compatible with regular single-axle dynamometers and their emissions cannot be measured under standard laboratory conditions. We have developed a novel in-plume technique to measure in-use emissions from vehicles with elevated stack. Real-world gaseous and particulate matter (PM) emission factors (EFs) from ten 7-ton 6-wheel drive trucks and two 8-wheel drive heavy tactical Logistics Vehicle System (LVS) vehicles were measured using in-plume sampling. The EFs of these trucks are comparable to those of onroad trucks while the PM EFs of 2-stroke LVS are ≈10 times higher than those of onroad vehicles. Lower EC/PM ratio was observed for LVS compared with MTVR. PM number emission factors were 5.9 × 1014 particles km−1 for the trucks and 2.5 × 1016 particles km−1 for the LVSs, three orders of magnitude higher than the proposed European Union standard of 6 × 1011 particles km−1. The EFs sampled can be extended to engines used in the broader nonroad sector including agriculture and mining and used as inputs to the NONROAD model.
► Novel in-plume measurement of in-use emissions from heavy-duty nonroad vehicles. ► PM EFs of diesel 2-stroke engines are ≈10 times higher than 4-stroke engines. ► Nonroad trucks EFs are similar to those of onroad trucks of similar size. ► Measured EFs can be used as inputs for EPA’s NONROAD model where data is sparse.