Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RS
Autor(a) principal: | |
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Data de Publicação: | 1998 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Journal of the Brazilian Chemical Society (Online) |
Texto Completo: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531998000200004 |
Resumo: | Captive air experiments have been carried out at a downtown location in Porto Alegre, RS, where both methyl-tert-butyl ether (MTBE) and ethanol are being used as oxygenated fuels. In a captive air experiment, ambient air is introduced in a Teflon chamber and exposed to sunlight for several hours, thus allowing photochemical reactions to take place under "real-world" conditions. Parameters measured in six experiments, the first of their kind to be carried out in Brazil, included oxides of nitrogen (NO and NO2), carbon monoxide, carbon dioxide, methane, ca. 75 non-methane hydrocarbons, formaldehyde, acetaldehyde, ethanol, MTBE, and the photochemical oxidants ozone and peroxyacetyl nitrate (PAN). Photochemical conversion of NO to NO2 and photochemical production of ozone (maximum concentrations 156-348 ppb) and PAN (maximum 13.3-29.5 ppb) were observed in all experiments, together with net (formation minus removal) photochemical production of formaldehyde and acetaldehyde. For each experiment, the contributions of each pollutant to reaction with the hydroxyl radical (OH) and to the production of ozone have been calculated. The results indicate that on the average the following 10 compounds are the most important with respect to the production of ozone (listed in order of decreasing importance): ethylene, carbon monoxide, acetaldehyde, (m + p)-xylene, formaldehyde, propene, 1,2,4-trimethylbenzene, toluene, ethanol and trans-2-pentene. MTBE makes only a small contribution to reaction with OH (ranked #27) and to the production of ozone (ranked #30), and plays only a minor photochemical role in the atmosphere of Porto Alegre. |
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Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RSurban air pollutionoxygenated fuelsozone formationcaptive air studieshydrocarbon reactivity rankingethanolmethyl-tert-butyl etherCaptive air experiments have been carried out at a downtown location in Porto Alegre, RS, where both methyl-tert-butyl ether (MTBE) and ethanol are being used as oxygenated fuels. In a captive air experiment, ambient air is introduced in a Teflon chamber and exposed to sunlight for several hours, thus allowing photochemical reactions to take place under "real-world" conditions. Parameters measured in six experiments, the first of their kind to be carried out in Brazil, included oxides of nitrogen (NO and NO2), carbon monoxide, carbon dioxide, methane, ca. 75 non-methane hydrocarbons, formaldehyde, acetaldehyde, ethanol, MTBE, and the photochemical oxidants ozone and peroxyacetyl nitrate (PAN). Photochemical conversion of NO to NO2 and photochemical production of ozone (maximum concentrations 156-348 ppb) and PAN (maximum 13.3-29.5 ppb) were observed in all experiments, together with net (formation minus removal) photochemical production of formaldehyde and acetaldehyde. For each experiment, the contributions of each pollutant to reaction with the hydroxyl radical (OH) and to the production of ozone have been calculated. The results indicate that on the average the following 10 compounds are the most important with respect to the production of ozone (listed in order of decreasing importance): ethylene, carbon monoxide, acetaldehyde, (m + p)-xylene, formaldehyde, propene, 1,2,4-trimethylbenzene, toluene, ethanol and trans-2-pentene. MTBE makes only a small contribution to reaction with OH (ranked #27) and to the production of ozone (ranked #30), and plays only a minor photochemical role in the atmosphere of Porto Alegre.Sociedade Brasileira de Química1998-04-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersiontext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531998000200004Journal of the Brazilian Chemical Society v.9 n.2 1998reponame:Journal of the Brazilian Chemical Society (Online)instname:Sociedade Brasileira de Química (SBQ)instacron:SBQ10.1590/S0103-50531998000200004info:eu-repo/semantics/openAccessGrosjean,EricGrosjean,Danieleng2005-12-12T00:00:00Zoai:scielo:S0103-50531998000200004Revistahttp://jbcs.sbq.org.brONGhttps://old.scielo.br/oai/scielo-oai.php||office@jbcs.sbq.org.br1678-47900103-5053opendoar:2005-12-12T00:00Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ)false |
dc.title.none.fl_str_mv |
Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RS |
title |
Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RS |
spellingShingle |
Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RS Grosjean,Eric urban air pollution oxygenated fuels ozone formation captive air studies hydrocarbon reactivity ranking ethanol methyl-tert-butyl ether |
title_short |
Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RS |
title_full |
Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RS |
title_fullStr |
Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RS |
title_full_unstemmed |
Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RS |
title_sort |
Formation of Ozone in Urban Air by Photochemical Oxidation of Hydrocarbons: Captive Air Experiments in Porto Alegre, RS |
author |
Grosjean,Eric |
author_facet |
Grosjean,Eric Grosjean,Daniel |
author_role |
author |
author2 |
Grosjean,Daniel |
author2_role |
author |
dc.contributor.author.fl_str_mv |
Grosjean,Eric Grosjean,Daniel |
dc.subject.por.fl_str_mv |
urban air pollution oxygenated fuels ozone formation captive air studies hydrocarbon reactivity ranking ethanol methyl-tert-butyl ether |
topic |
urban air pollution oxygenated fuels ozone formation captive air studies hydrocarbon reactivity ranking ethanol methyl-tert-butyl ether |
description |
Captive air experiments have been carried out at a downtown location in Porto Alegre, RS, where both methyl-tert-butyl ether (MTBE) and ethanol are being used as oxygenated fuels. In a captive air experiment, ambient air is introduced in a Teflon chamber and exposed to sunlight for several hours, thus allowing photochemical reactions to take place under "real-world" conditions. Parameters measured in six experiments, the first of their kind to be carried out in Brazil, included oxides of nitrogen (NO and NO2), carbon monoxide, carbon dioxide, methane, ca. 75 non-methane hydrocarbons, formaldehyde, acetaldehyde, ethanol, MTBE, and the photochemical oxidants ozone and peroxyacetyl nitrate (PAN). Photochemical conversion of NO to NO2 and photochemical production of ozone (maximum concentrations 156-348 ppb) and PAN (maximum 13.3-29.5 ppb) were observed in all experiments, together with net (formation minus removal) photochemical production of formaldehyde and acetaldehyde. For each experiment, the contributions of each pollutant to reaction with the hydroxyl radical (OH) and to the production of ozone have been calculated. The results indicate that on the average the following 10 compounds are the most important with respect to the production of ozone (listed in order of decreasing importance): ethylene, carbon monoxide, acetaldehyde, (m + p)-xylene, formaldehyde, propene, 1,2,4-trimethylbenzene, toluene, ethanol and trans-2-pentene. MTBE makes only a small contribution to reaction with OH (ranked #27) and to the production of ozone (ranked #30), and plays only a minor photochemical role in the atmosphere of Porto Alegre. |
publishDate |
1998 |
dc.date.none.fl_str_mv |
1998-04-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531998000200004 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50531998000200004 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
10.1590/S0103-50531998000200004 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
text/html |
dc.publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
publisher.none.fl_str_mv |
Sociedade Brasileira de Química |
dc.source.none.fl_str_mv |
Journal of the Brazilian Chemical Society v.9 n.2 1998 reponame:Journal of the Brazilian Chemical Society (Online) instname:Sociedade Brasileira de Química (SBQ) instacron:SBQ |
instname_str |
Sociedade Brasileira de Química (SBQ) |
instacron_str |
SBQ |
institution |
SBQ |
reponame_str |
Journal of the Brazilian Chemical Society (Online) |
collection |
Journal of the Brazilian Chemical Society (Online) |
repository.name.fl_str_mv |
Journal of the Brazilian Chemical Society (Online) - Sociedade Brasileira de Química (SBQ) |
repository.mail.fl_str_mv |
||office@jbcs.sbq.org.br |
_version_ |
1750318163378044928 |