A Study of PGM-Free Oxidation Catalyst YMnO3 for Diesel Exhaust Aftertreatment

2012 ◽  
Author(s):  
Keita Ishizaki ◽  
Naoki Mitsuda ◽  
Naoki Ohya ◽  
Hiroshi Ohno ◽  
Takahiro Naka ◽  
...  
Keyword(s):  
Diesel Exhaust ◽  
Oxidation Catalyst ◽  
Exhaust Aftertreatment ◽  
Free Oxidation

scholarly journals Impact of aftertreatment devices on primary emissions and secondary organic aerosol formation potential from in-use diesel vehicles: results from smog chamber experiments

2010 ◽  
Vol 10 (6) ◽  
pp. 16055-16109 ◽  
Author(s):  
R. Chirico ◽  
P. F. DeCarlo ◽  
M. F. Heringa ◽  
T. Tritscher ◽  
R. Richter ◽  
...  
Keyword(s):  
Urban Areas ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Oxidation Catalyst ◽  
Particulate Filter ◽  
Exhaust Aftertreatment ◽  
Smog Chamber ◽  
Aerosol Formation ◽  
Diesel Particulate ◽  
Diesel Vehicles

Abstract. Diesel particulate matter (DPM) is a significant source of aerosol in urban areas and has been linked to adverse health effects. Although newer European directives have introduced increasingly stringent standards for primary PM emissions, gaseous organics emitted from diesel cars can still lead to large amounts of secondary organic aerosol (SOA) in the atmosphere. Here we present results from smog chamber investigations characterizing the primary organic aerosol (POA) and the corresponding SOA formation at atmospherically relevant concentrations for three in-use diesel vehicles with different exhaust aftertreatment systems. One vehicle lacked exhaust aftertreatment devices, one vehicle was equipped with a diesel oxidation catalyst (DOC) and the final vehicle used both a DOC and diesel particulate filter (DPF). The experiments presented here were obtained from the vehicles at conditions representative of idle mode, and for one car in addition at a speed of 60 km/h. An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was used to measure the organic aerosol (OA) concentration and to obtain information on the chemical composition. For the conditions explored in this paper, primary aerosols from vehicles without a particulate filter consisted mainly of black carbon (BC) with a low fraction of organic matter (OM, OM/BC<0.5), while the subsequent aging by photooxidation resulted in a consistent production of SOA only for the vehicles without a DOC and with a deactivated DOC. After 5 h of aging ~80% of the total organic aerosol was on average secondary and the estimated "emission factor" for SOA was 0.23–0.56 g/kg fuel burned. In presence of both a DOC and a DPF, primary particles with a mobility diameter above 5 nm were 300±19 cm−3, and only 0.01 g SOA per kg fuel burned was produced within 5 h after lights on. The mass spectra indicate that POA was mostly a non-oxidized OA with an oxygen to carbon atomic ratio (O/C) ranging from 0.097 to 0.190. Five hours of oxidation led to a more oxidized OA with an O/C range of 0.208 to 0.369.

scholarly journals Size-resolved physico-chemical characterization of diesel exhaust particles and efficiency of exhaust aftertreatment

2020 ◽  
Vol 222 ◽  
pp. 117021
Author(s):  
Soheil Zeraati-Rezaei ◽  
Mohammed S. Alam ◽  
Hongming Xu ◽  
David C. Beddows ◽  
Roy M. Harrison
Keyword(s):  
Diesel Exhaust ◽  
Chemical Characterization ◽  
Diesel Exhaust Particles ◽  
Exhaust Aftertreatment ◽  
Physico Chemical ◽  
Exhaust Particles

Effects of Diesel Exhaust Aftertreatment Devices on Concentrations and Size Distribution of Aerosols in Underground Mine Air

2009 ◽  
Vol 43 (17) ◽  
pp. 6737-6743 ◽  
Author(s):  
Aleksandar D. Bugarski ◽  
George H. Schnakenberg, Jr. ◽  
Jon A. Hummer ◽  
Emanuele Cauda ◽  
Samuel J. Janisko ◽  
...  
Keyword(s):  
Size Distribution ◽  
Diesel Exhaust ◽  
Underground Mine ◽  
Exhaust Aftertreatment

scholarly journals Effects of Renewable Diesel Exhaust on Lung Function and Self-rated Symptoms for Healthy Volunteers in a Human Chamber Exposure Study 

2021 ◽  
Author(s):  
Louise Gren ◽  
Katrin Dierschke ◽  
Fredrik Mattsson ◽  
Eva Assarsson ◽  
Annette M. Krais ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Healthy Volunteers ◽  
Diesel Exhaust ◽  
Oxidation Catalyst ◽  
Particulate Filter ◽  
Forced Oscillation Technique ◽  
Nasal Patency ◽  
Renewable Diesel ◽  
Road Vehicles ◽  
Aftertreatment System

Abstract Background: Diesel engine exhaust causes adverse health effects. Meanwhile, the impact of renewable diesel exhaust on human health is less known. In this study, nasal patency, pulmonary function, and self-rated symptoms were assessed in 19 healthy volunteers after two separate 3-hour exposures to renewable diesel (hydrotreated vegetable oil [HVO]) exhaust, and exposure to filtered air (FA) for comparison. The HVO exposures were generated with two modern non-road vehicles (2019) having either: 1) no aftertreatment system (HVOPM+NOx), or 2) an aftertreatment system containing a diesel oxidation catalyst and a diesel particulate filter (HVONOx). The exposure concentrations complied with current EU occupational exposure limits (OELs) of NO, NO2, formaldehyde, polycyclic aromatic hydrocarbons (PAHs), and future OELs of elemental carbon (EC) from 2023. Results: Exposure to HVOPM+NOx consisted of PM1 (≈90 µg m-3, 54 µg m-3 EC) and NOx (NO 3.4 ppm, NO2 0.6 ppm). The average total respiratory tract deposition of PM1 was 27 µg h-1. The deposition fraction of HVO PM1 was 40-50% higher compared to diesel exhaust PM1 from an older vehicle, due to smaller particle sizes of the HVOPM+NOx exhaust. Exposure to HVONOx consisted mainly of NOx (NO 2.0 ppm, NO2 0.7 ppm) with low level of PM1 (~1 µg m-3). Compared to filtered air, exposure to HVOPM+NOx and HVONOx caused higher incidence of self-reported symptoms (78%, 63%, respectively, vs. 28% for FA, p<0.03). Especially, exposure to HVOPM+NOx showed 40-50% higher eye and throat irritation symptoms. Compared to filtered air, a decrement in nasal patency was found for the HVONOx exposures (-18.1, 95%CI: -27.3 to -8.8 L min-1), and for the HVOPM+NOx (-7.4 (-15.6 to 0.8) L min-1). Overall, no change was indicated in the pulmonary function tests (spirometry, peak expiratory flow, forced oscillation technique), except a slight increase in FEV1/FVC after exposure to HVONOx.Conclusion: Short-term exposure to HVO exhaust below the EU OELs did not cause severe pulmonary function changes in healthy subjects. However, an increase in self-rated mild irritation symptoms, and mild decrease in nasal patency after two HVO exposures may indicate irritative effects from exposure to HVO exhaust from modern non-road vehicles below future OELs.

Method and Detailed Analysis of Individual Hydrocarbon Species From Diesel Combustion Modes and Diesel Oxidation Catalyst

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Manbae Han ◽  
Dennis N. Assanis ◽  
Timothy J. Jacobs ◽  
Stanislav V. Bohac
Keyword(s):  
Detailed Analysis ◽  
Diesel Exhaust ◽  
Soot Formation ◽  
Soot Oxidation ◽  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Diesel Combustion ◽  
Flame Ionization ◽  
Accuracy And Precision ◽  
Combustion Processes

An undiluted exhaust hydrocarbon (HC) speciation method, using flame ionization detector gas chromatographs, is developed to investigate HC species from conventional and low-temperature premixed charge compression ignition (PCI) combustion pre- and postdiesel oxidation catalyst (DOC) exhaust. This paper expands on previously reported work by describing in detail the method and effectiveness of undiluted diesel exhaust speciation and providing a more detailed analysis of individual HC species for conventional and PCI diesel combustion processes. The details provided regarding the effectiveness of the undiluted diesel exhaust speciation method include the use of a fuel response factor for HC species quantification and demonstration of its linearity, detection limit, accuracy, and precision. The listing of individual HC species provides not only the information needed to design surrogate exhaust mixtures used in reactor tests and modeling studies but also sheds light on PCI combustion and DOC characteristics. Significantly increased engine-out concentrations of acetylene, benzene, and toluene support the theory that net soot reduction associated with PCI combustion occurs due to the reduction of soot formation (as opposed to increased soot oxidation). DOC oxidation behavior differs depending on the combustion characteristics, which change exhaust species and temperature.

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