Method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust

Mathematical modeling of ambient air photochemistry requires comprehensive speciation of hydrocarbons from mobile source emission. The objective of this study is to develop a simple and reliable method for analyzing tailpipe emission focusing on benzene, toluene, ethylbenzene and xylenes (BTEX)....

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Main Author:	Zakaria, Norasalwa
Format:	Thesis
Language:	English English
Published:	2001
Subjects:	Photochemistry Motor vehicles - Pollution control devices
Online Access:	http://psasir.upm.edu.my/id/eprint/9213/1/FSAS_2001_10_A.pdf
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spelling	my-upm-ir.92132014-10-28T01:42:23Z Method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust 2001-12 Zakaria, Norasalwa Mathematical modeling of ambient air photochemistry requires comprehensive speciation of hydrocarbons from mobile source emission. The objective of this study is to develop a simple and reliable method for analyzing tailpipe emission focusing on benzene, toluene, ethylbenzene and xylenes (BTEX). The method consists of sampling, qualitative analysis and quantitative analysis. The samples were collected in Tedlar bags at cold start and hot start conditions and were injected manually using a gas-tight syringe into Gas Chromatograph-Mass Spectrometer (GC-MS) operated on Electron Impact Ionization (EI) mode. The method developed has demonstrated ability to produce rapid and reliable separations of exhaust hydrocarbons. An approximate of 50 hydrocarbon compounds were identified in the exhaust ranging from C₄ to C₁₂. It was found difficult to analyze C₁ to some of the C₄ hydrocarbons without the required accessories for volatile organic gases analysis. The emission rate of BTEX was emphasized because of its potential carcinogenicity and toxicity. High concentration of BTEX was observed during cold start and hot start. The mean concentrations of BTEX at cold start were as follows: benzene (55.4 ppm), toluene (184.7 ppm), ethylbenzene (50.2 ppm), m-xylene (143.9 ppm), p-xylene (59.0 ppm) and o-xylene (65.4 ppm). The mean concentrations ofBTEX at hot start were as follows: benzene (82.4 ppm), toluene (198.3 ppm), ethylbenzene (40.0 ppm), m-xylene (184.0 ppm), p-xylene (62.1 ppm) and o-xylene (50.3 ppm). The concentrations of BTEX in weighted percentages for all cars were fairly constant. The weighted percentages concentration was used to estimate the photochemical ozone reactivity by applying the Maximum Incremental Reactivity (MIR) factors to the concentrations. The ozone forming potential as a result ofBTEX emission from vehicle exhaust were estimated as follows: 3.07 g O₃/g benzene, 74.64 g O₃/g toluene, 13.0 g 0₃/ g ethylbenzene, 145.8 g O₃/g m- and p-xylene, and 50.97 g O₃/g 0- xylene. The results suggested that BTEX emitted from the vehicle exhaust increases the formation of photochemical ozone in the atmosphere significantly. Photochemistry Motor vehicles - Pollution control devices 2001-12 Thesis http://psasir.upm.edu.my/id/eprint/9213/ http://psasir.upm.edu.my/id/eprint/9213/1/FSAS_2001_10_A.pdf application/pdf en public masters Universiti Putra Malaysia Photochemistry Motor vehicles - Pollution control devices Faculty of Science and Environmental Studies English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
topic	Photochemistry Motor vehicles - Pollution control devices
spellingShingle	Photochemistry Motor vehicles - Pollution control devices Zakaria, Norasalwa Method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust
description	Mathematical modeling of ambient air photochemistry requires comprehensive speciation of hydrocarbons from mobile source emission. The objective of this study is to develop a simple and reliable method for analyzing tailpipe emission focusing on benzene, toluene, ethylbenzene and xylenes (BTEX). The method consists of sampling, qualitative analysis and quantitative analysis. The samples were collected in Tedlar bags at cold start and hot start conditions and were injected manually using a gas-tight syringe into Gas Chromatograph-Mass Spectrometer (GC-MS) operated on Electron Impact Ionization (EI) mode. The method developed has demonstrated ability to produce rapid and reliable separations of exhaust hydrocarbons. An approximate of 50 hydrocarbon compounds were identified in the exhaust ranging from C₄ to C₁₂. It was found difficult to analyze C₁ to some of the C₄ hydrocarbons without the required accessories for volatile organic gases analysis. The emission rate of BTEX was emphasized because of its potential carcinogenicity and toxicity. High concentration of BTEX was observed during cold start and hot start. The mean concentrations of BTEX at cold start were as follows: benzene (55.4 ppm), toluene (184.7 ppm), ethylbenzene (50.2 ppm), m-xylene (143.9 ppm), p-xylene (59.0 ppm) and o-xylene (65.4 ppm). The mean concentrations ofBTEX at hot start were as follows: benzene (82.4 ppm), toluene (198.3 ppm), ethylbenzene (40.0 ppm), m-xylene (184.0 ppm), p-xylene (62.1 ppm) and o-xylene (50.3 ppm). The concentrations of BTEX in weighted percentages for all cars were fairly constant. The weighted percentages concentration was used to estimate the photochemical ozone reactivity by applying the Maximum Incremental Reactivity (MIR) factors to the concentrations. The ozone forming potential as a result ofBTEX emission from vehicle exhaust were estimated as follows: 3.07 g O₃/g benzene, 74.64 g O₃/g toluene, 13.0 g 0₃/ g ethylbenzene, 145.8 g O₃/g m- and p-xylene, and 50.97 g O₃/g 0- xylene. The results suggested that BTEX emitted from the vehicle exhaust increases the formation of photochemical ozone in the atmosphere significantly.
format	Thesis
qualification_level	Master's degree
author	Zakaria, Norasalwa
author_facet	Zakaria, Norasalwa
author_sort	Zakaria, Norasalwa
title	Method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust
title_short	Method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust
title_full	Method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust
title_fullStr	Method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust
title_full_unstemmed	Method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust
title_sort	method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust
granting_institution	Universiti Putra Malaysia
granting_department	Faculty of Science and Environmental Studies
publishDate	2001
url	http://psasir.upm.edu.my/id/eprint/9213/1/FSAS_2001_10_A.pdf
_version_	1747810914574270464

Method development, speciated measurements and culculated reactivities of benzine, toluene, ethylbenzene and xylenes from vehicle exhaust

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