Chassis dynamometer emissions testing of 11 heavy-duty goods movement vehicles, including diesel, natural gas, and dual-fuel technology, compliant with US-EPA 2010 emissions standard were conducted. Results of the study show that three-way catalyst (TWC) equipped stoichiometric natural gas vehicles emit 96% lower NOx emissions as compared to selective catalytic reduction (SCR) equipped diesel vehicles. Characteristics of drayage truck vocation, represented by the near-dock and local drayage driving cycles, were linked to high NOx emissions from diesel vehicles equipped with a SCR. Exhaust gas temperatures below 250 °C, for more than 95% duration of the local and near-dock driving cycles, resulted in minimal SCR activity. The low percentage of activity SCR over the local and near-dock cycles contributed to a brake-specific NOx emissions that were 5-7 times higher than in-use certification limit. The study also illustrated the differences between emissions rate measured from chassis dynamometer testing and prediction from the EMFAC model. The results of the study emphasize the need for model inputs relative to SCR performance as a function of driving cycle and engine operation characteristics.

A low-swirl burner (LSB) developed for laboratory research has been scaled to the thermal input levels of a small industrial burner. The purpose was to demonstrate its viability for commercial and industrial furnaces and boilers. The original 5.28 cm i.d. LSB using an air-jet swirler was scaled to 10.26 cm i.d. and investigated up to a firing rate of Q ‫ס‬ 586 kW. The experiments were performed in water heater and furnace simulators. Subsequently, two LSBs (5.28 and 7.68 cm i.d.) configured to accept a novel vaneswirler design were evaluated up to Q ‫ס‬ 73 kW and 280 kW, respectively. The larger vane-LSB was studied in a boiler simulator. The results show that a constant velocity criterion is valid for scaling the burner diameter to accept higher thermal inputs. However, the swirl number needed for stable operation should be scaled independently using a constant residence time criterion. NO x emissions from all the LSBs were found to be independent of thermal input and were only a function of the equivalence ratio. However, emissions of CO and unburned hydrocarbons were strongly coupled to the combustion chamber size and can be extremely high at low thermal inputs. The emissions from a large vane-LSB were very encouraging. Between 210 and 280 kW and 0.8 Ͻ Ͻ 0.9, NO x emissions of Ͻ15 ppm and CO emissions of Ͻ10 ppm were achieved. These results indicate that the LSB is a simple, low-cost, and promising environmental energy technology that can be further developed to meet future air-quality rules.

A fleet of six 2001 International Class 6 trucks operating in southern California was selected for an operability and emissions study using gas-to-liquid (GTL) fuel and catalyzed diesel particle filters (CDPF). Three vehicles were fueled with CARB specification diesel fuel and no emission control devices (current technology), and three vehicles were fueled with GTL fuel and retrofit with Johnson Matthey's CCRT™ diesel particulate filter. No engine modifications were made.Bench scale fuel-engine compatibility testing showed the GTL fuel had cold flow properties suitable for year-round use in southern California and was additized to meet current lubricity standards. Bench scale elastomer compatibility testing returned results similar to those of CARB specification diesel fuel. The GTL fuel met or exceeded ASTM D975 fuel properties.Researchers used a chassis dynamometer to test emissions over the City Suburban Heavy Vehicle Route (CSHVR) and New York City Bus (NYCB) cycles. The GTL-fueled vehicles were tested with and without the CDPFs to isolate fuel and aftertreatment effects.All emission changes are compared to the CARB specification diesel baseline. Over the CSHVR cycle, GTL fuel (no filter) reduced all regulated emissions, with oxides of nitrogen (NO x ) reductions of 8% and particulate matter (PM) reductions of 33%. Over the NYCB cycle, GTL fuel (no filter) reduced NO x and PM by 16% and 23%, respectively. Combining GTL and CDPF further reduced all regulated emissions, with NO x and PM reductions of 14% and 99%, respectively, on the CSHVR cycle. Vehicles tested over the NYCB cycle on GTL fuel and CDPF produced NO x and PM reductions of 20% and 97%, respectively.

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