Oxidation Catalytic Converter Research Articles

The Oxidation Catalytic Converter Reduces the Inhibitory Activity of Soluble Organic Fractions of Diesel Particles on Intercellular Communication

The genotoxicity of diesel particles has been widely documented, and their tumor promoting effect has been reported recently using the gap junction intercellular communication (GJIC) assay. In our study, the ability of soluble organic fractions (SOF) of diesel particles emitted from cars equipped (WC) or not (WoutC) with the oxidation catalytic converter (OCC) and of particle SOF from an outdoor high polluted place (OHPP) to inhibit GJIC has been evaluated with two cell lines: a rat liver epithelial cell line (REL cells) and a rat pulmonary alveolar type II cell line (3T cells). With both cell lines, our results demonstrate that GJIC is strongly inhibited by WoutC, whereas it is much less reduced by WC ones: for REL cells, the activity of WC particles is 1/4 of the one of WoutC. Also, we show that the inhibition induced by WoutC is associated with a change in the GJ protein localization. Our results clearly show the effectiveness of the OCC technology in reducing both the tumor promoting activity and the genotoxicity of diesel particle SOF.

Effects of an Oxidation Catalytic Converter and a Biodiesel Fuel on the Chemical, Mutagenic, and Particle Size Characteristics of Emissions from a Diesel Engine

This study was conducted to obtain additional information on exhaust emissions with potential health importance from an indirect injection diesel engine, typical of those in use in underground mines, when operated using a soy-derived, fatty-acid mono-ester (or biodiesel) fuel and an oxidation catalytic converter (OCC). Compared to emis sions with the diesel fuel without the OCC, use of the diesel (D2) and biodiesel fuel with the OCC had similar reductions (50−80%) in total particulate matter (TPM). The solid portion of the TPM was lowered with the biodiesel fuel. Particle-associated polynuclear aromatic hydrocarbon and 1-nitropyrene emissions were lower with use of the biodiesel fuel as compared to the D2 fuel, with or without the OCC. Vapor-phase PAH emissions were reduced (up to 90%) when the OCC was used with either fuel. Use of the OCC resulted in over 50% reductions in both particle and vapor-phase-associated mutagenic activity with both fuels. No vapor-phase-associated mutagenic activity was detecte...

Underground Metal Mine Air Quality Measurements to Determine the Control Efficiencies of Combined Catalyzed Diesel Particulate Filter and Oxidation Catalytic Converter Systems

Abstract In-mine studies were conducted as part of a collaborative study with the U.S. Bureau of Mines to assess the effects of diesel emission after-treatment control devices on mine air quality. An oxidation catalytic converter (OCC) was replaced with a combined catalyzed diesel particulate filter (CDPF) and OCC unit in one mine, designated mine Q. In a second mine, designated mine T, the OCC was replaced with a CDPF. In each mine, emissions from one diesel-powered mine vehicle were monitored with the two control configurations. In mine Q, the vehicle studied was an Elphinstone R1500 load-haul-dump vehicle equipped with a Caterpillar 3306 PCTA diesel engine used to move ore from a drawpoint to an ore pass. In mine T the vehicle studied was a Tamrock model 2S-TR1 diesel-hydraulic, roof-bolting jumbo powered by a 61-kW (82-hp) Deutz F6L912W diesel engine, which used diesel power to install roof bolts. Control efficiencies for diesel particulate matter (DPM) concentrations in the vicinity of the mine vehicle operator, calculated as the percentage reduction in concentration in the condition with the CDPF installed, were 61 percent for mine Q and 82 percent for mine T. Control efficiencies for tailpipe DPM were 95 percent for mine Q and 74 percent for mine T. Control efficiencies as determined from calculated air quality index (AQI) values were 32 percent for mine Q and 63 percent for mine T; exhaust quality index (EQI) control efficiencies were 85 percent for mine Q and 30 percent for mine T. The AQI and EQI values provide measures of the health effects of combined concentrations of DPM and gaseous emissions in the mine ambient air. Control efficiencies for DPM and DPM-associated organics (including polynuclear aromatic hydrocarbons) collected with high-volume samplers were about 70 percent or greater in both mines. Mutagenic activity decreased by an amount approximately equal to the decrease in DPM in mine T, but increased by over 100 percent in mine Q. These findings indicate that replacement of an OCC with a CDPF or with a combined CDPF and OCC had overall positive effects on the mine air quality, but the increased mutagenicity in the DPM from mine Q suggests that further study is needed.