Obiettivo To understand the contribution of biogenic emissions (e.g. isoprene, monoterpenes) to various aspects of tropospheric chemistry (e.g. ozone and aerosolLaboratory studies have been performed on the importance of ozone reactions with biogenic volotile organic compounds (VOC), the atmospheric oxidation of halogenated organic compounds used as fuel additives and the atmospheric oxidation of halogenated compounds af anthropogenic and biogenic origin.Reactions of ozone with biogenic compoundsKinetics and project studies of reactions of ozone with a variety of biogenic compounds. Emphasis has been placed on ozone with alkenes, since experimental evidence that these reactions lead to the formation of OH radicals. The reactions with a series of alkenes have been investigated and the OH radical yoeld rationalized in terms of the molecular stucture of the alkenes.Atmospheric oxidation of oxygenated VOCsThe rate constants of the reaction of OH radicals with a series of alcohols, esters and ethers have been measured. studies have focused on difunctional cmpounds such as CH3O(CH2)nOCH3 which have potential applications as fuel additives and water based solvents in industry, Structure reactivity relationships are being developed to facilitate prediction of the kinetics of atmosperic oxygen and hence tropospheric lifetimes.Atmospheric oxidation of halogenated organic compoundsRate constants have been determined fro the reaction of hydroxyl radicals with a number of fluorinated ethers and chlorinated alkanes and alkenes. The results give estimates of the atmospheric lifetimes of these compounds and provide structure reactivity information on the reactions. A detailed knowledge of the elementary reactions taking place in the gas phase degradation of biogenic compounds is required. The number and complexity of the emissions, and more importantly the reactive intermediates (substituted peroxy and oxy radicals), mean that it is impossible to investigate all of these reactions in isolated laboratory studies. Structure-Activity Relationships (SAR) provide an alternative approach. By studying a series of carefully chosen generic compounds it is possible to determine the effects of substituent groups at various positions (or combinations of groups), and hence calculate site specific rate constants. At present such information is unavailable for biogenic emissions and the development of SARs for reactions relevant to biogenic VOC degradation is the primary aim of this project. The degradation of biogenic hydrocarbons can be divided into three components: 1) initiation and peroxy radical formation, 2) peroxy radical reactions, 3) oxy radical reactions and the structure of the proposal follows similar lines. Very little experimental data are available for these classes of reaction, especially for the reactions of the peroxy and oxy radical intermediates. For each class of reaction a variety of complementary laboratory techniques (many of them novel) will be used to determine rate coefficients and branching ratios for a number of model compounds. In many cases the laboratory studies will be backed up by theoretical calculations. A subcoordinator is then responsible for drawing together the laboratory studies and organizing the construction of SAR for that class of reaction. The major deliverable item from this research will be a set of data which can be used to calculate rate coefficients for the reactions relevant to biogenic emissions. The information will be used to construct degradation mechanisms for common complex examples, such as the monoterpenes. Atmospheric models will be run using these mechanisms to evaluate the effects of these compounds. Sensitivity analysis and mechanism reduction will be used to determine the crucial steps in the degradations, indicating the areas for further or more detailed experimental studies. The project has strong links with other EU projects: BIOVOC (coordinator J. Hjorth, smog chamber studies of biogenic decomposition schemes) and AEROBIC (coordinator B. Bonsang, field of monoterpene emissions and aerosol formation). Both of these projects will require chemical models to validate their observations and the kinetic and SAR data generated from SARBVOC will be used to construct these models. Campo scientifico natural scienceschemical sciencesorganic chemistryvolatile organic compoundsnatural scienceschemical scienceselectrochemistryelectrolysisnatural scienceschemical sciencesorganic chemistryhydrocarbonsnatural scienceschemical sciencesorganic chemistryalcoholsnatural sciencesmathematicsapplied mathematicsmathematical model Programma(i) FP4-ENV 2C - Specific programme of research and technological development in the field of environment and climate, 1994-1998 Argomento(i) 01020102 - Tropospheric physics and chemistry Invito a presentare proposte Data not available Meccanismo di finanziamento CSC - Cost-sharing contracts Coordinatore UNIVERSITY OF LEEDS Contributo UE Nessun dato Indirizzo Woodhouse Lane LS2 9JT LEEDS Regno Unito Mostra sulla mappa Costo totale Nessun dato Partecipanti (6) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto Centre National de la Recherche Scientifique (CNRS) Francia Contributo UE Nessun dato Indirizzo Université des Sciences et Technologie 59655 Villeneuve-d'Ascq Mostra sulla mappa Costo totale Nessun dato KATHOLIEKE UNIVERSITEIT LEUVEN Belgio Contributo UE Nessun dato Indirizzo 200 F,Celestijnenlaan 200 F 3001 HEVERLEE Mostra sulla mappa Costo totale Nessun dato UNIVERSITY COLLEGE DUBLIN Irlanda Contributo UE Nessun dato Indirizzo Stillorgan Road Belfield 4 Dublin Mostra sulla mappa Costo totale Nessun dato UNIVERSITY OF ESSEN Germania Contributo UE Nessun dato Indirizzo Universitatsstrasse 5-7 45117 ESSEN Mostra sulla mappa Costo totale Nessun dato United Kingdom Atomic Energy Authority (UKAEA) Regno Unito Contributo UE Nessun dato Indirizzo Culham Laboratory OX14 3DB Abingdon Mostra sulla mappa Costo totale Nessun dato Université de Bordeaux I Francia Contributo UE Nessun dato Indirizzo 351 cours de la Libération 33405 Talence Mostra sulla mappa Costo totale Nessun dato
