Doctoral theses

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Identifier	000324887
Title	Αριθμητικές προσομοιώσεις της επίδρασης διαλυτών στην τροποσφαιρική χημεία
Alternative Title	Numerical simulations of the impact of solvents on tropospheric chemistry
Author	Περάκης, Λάζαρος Γ
Thesis advisor	Κανακίδου, Μαρία
Abstract	Anthropogenic emissions of volatile organic compounds (VOC) in the troposphere and their consecutive degradation in presence of nitrogen oxides, result in the production of secondary products like ozone, nitric oxide and peroxyacetylnitrate (PAN). These pollutants seriously affect the environment and human health. In addition, certain VOCs contribute to the production of secondary organic aerosols (SOA), which also affect human health, act as substrates for heterogeneous chemical reactions, affect tropospheric chemistry and scatter solar radiation modifying atmospheric radiative forcing. A considerable percentage of these emissions, are due to the use of organic compounds as solvents i.e. compounds able to dissolve, suspend or extract other materials, without any chemical reactions to occur. This percentage in Europe is about 25% of total anthropogenic emissions of non methane VOC. The understanding of the environmental changes due to the anthropogenic activities is facilitated by the study of the impact of solvent use emissions on tropospheric chemistry, both on local and global scales. In addition, because volatile compounds present different ability to produce pollutants, it is of particular interest to investigate if possible replacements of solvents in use with other new compounds, could lead in reduction of pollutant concentrations. Such global estimates are prohibited by the large number of species used as solvents today and hence, by the even greater number of chemical species that are involved in their atmospheric chemical degradation. To overpass these limitations for global models, a small number of compounds must be selected to represent in the model all solvents in use today. In addition a reduced degradation scheme has to be used, to maintain a limited number of chemical species suitable for consideration into a global model. The aim of the present study is the estimate of the impact of solvents in use and of their possible replacement with selected oxygenated compounds, on the oxidizing power of the atmosphere and particularly on ozone, nitric oxide, PAN and SOA levels. The study is performed on local scale using box models and on global scale using a global 3-dimensional chemistry-transport model of the troposphere. The eleven VOCs selected to represent all solvents in use in the present study are: decane, acetone, methyl ethyl ketone, methyl isobutyl ketone, benzene, toluene, xylene, methanol, ethanol, ethyl acetate and 2-butoxy ethanol. As replacement solvents, the following twenty oxygenated VOCs are studied: allyl alcohol (AA), 1-buten-3-ole (BA), crotyl alcohol (CA), 2,4 pentadione (PDIONE), 2,5 hexadione (HDIONE), butyl vinyl ether (BVE), ethyl vinyl ether (EVE), isobutyl vinyl ether (IBVE), methyl vinyl ether (MVE), ethylene glycol vinyl ether (MVE1), diethyleneglycol monovinyl ether (MVE2), propylene vinyl ether (PVE), terbutyl vinyl ether (TBVE), dipropylene glycol monoethylether (DPM), dodecyl vinyl ether (DDVE), octadecyl vinyl ether (ODVE), cyclohexane dimethanol divinyl ether (CHDVE), ethylene glycol divinyl ether (DVE1), diethyleneglycol divinyl ether (DVE2) and triethyleneglycol divinyl ether (DVE3). This study shows that total solvent abolishment reduces ozone and PAN concentrations by up to 5 and 15% respectively and increases nitric oxide concentrations by less than 5%. No more than 3% of the global and of the European ozone and nitric oxide tropospheric chemical production, are due to solvent use emissions. Changes in pollutants concentrations, as a result of solvent replacements, are generally low and often, instead of reductions, increases of pollutants concentrations are calculated. This is not the case for anthropogenic SOA production, where the impact of the solvents, as well as their replacements, is considerable. In particular, we have calculated that about 25% and 30% of anthropogenic SOA production on global and European scale respectively, are due to solvent use emissions. Solvent replacement could decrease global and European tropospheric production of anthropogenic SOA up to 21,9% and 24,2% respectively.
Language	Greek
Issue date	2008-02-29
Collection	School/Department--School of Sciences and Engineering--Department of Chemistry--Doctoral theses
	Type of Work--Doctoral theses
Permanent Link	https://elocus.lib.uoc.gr//dlib/d/2/7/metadata-dlib-f8c6311e51b66072f79522aa687907c8_1237196389.tkl
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