Objectif A.- EXPERIMENTAL PROGRAMME :COMBUSTION OF AROMATIC/UNSATURATED HYDROCARBONS AND CRITICAL EVALUATION OF KINETIC DATA FOR CHEMICAL MODELLING OF COMBUSTION. IN ORDER TO IMPROVE THE PERFORMANCE OF COMBUSTION I E ENERGY CONSERVATION AND MINIMIZATION OF POLLUTANT FORMATION, IMPROVED MODELLING SCHEMES ARE REQUIRED. BETTER EXPERIMENTAL DATA OF RATES OF KEY REACTIONS ARE REQUIRED AS WELL AS BETTER CRITICAL DATA COMPILATIONS. THIS SUBPROJECT CONCENTRATES: A) ON EXPERIMENTAL STUDIES OF COMBUSTION OF AROMATIC HYDROCARBONS AND B) ON CRITICAL DATA EVALUATION OF COMBUSTION REACTIONS. B.- SOOT FORMATION: THE GROWTH OF SOOT MASS WILL BE DETERMINED QUANTITATIVELY IN PREMIXED COMBUSTION SYSTEMS. PARTICLE GROWTH, THE CHANGE OF PARTICLE NUMBER DENSITY AND THE GROWTH OF SOOT MASS WILL BE FOLLOWED BY LASER OPTICAL METHODS, THE CHEMICAL ANALYSIS OF THE SURROUNDING GAS WILL BE THE ZONE BETWEEN OXIDATION AND THE APPEARANCE OF PARTICLES UP TO 50 ANGSTROEM DIAMETER. C.- OXIDATION OF ALKYL RADICALS: RATES AND MECHANISMS OF THE CHAIN BRANCHING REACTION BETWEEN CH3 AND O2 WILL BE STUDIED BETWEEN 300 AND 1100 K. EMPHASIS WILL BE PLACED ON QUANTIFYING THE " 1000 K RATE MINIMUM " WHICH CHARACTERIZES THE TRANSITION FROM A LOW T PEROXI MECHANISM (CH3 + O2 + M -> CH3O2 + M; CH3O2 + RH -> CH3OOH + R; CH3OOH -> CH3O + OH) TO A HIGH T " DIRECT " MECHANISM (CH3 + O2 -> CH3O + O; CH3O + M -> CH2O + M; CH3O + O2 -> CH2O + H2O). RATE CONSTANTS FOR THE INDIVIDUAL REACTIONS WILL BE DETERMINED. PART A: A) PYROLYSIS AND OXIDATION OF AROMATIC HYDROCARBONS. THE ELEMENTARY STEPS OF THE THERMAL DECOMPOSITION AND OXIDATION OF AROMATIC HYDROCARBONS SUCH AS TOLUENE, XYLENE ETHYL AND PROPYLBENZENE ARE STUDIED WITH EXISTING SHOCK WAVE EQUIPMENT. EXPERIMENTS SHOULD START FIRST FOR SIMPLER AROMATIC COMPOUNDS LIKE TOLUENE AND VARIOUS SOURCE OF AROMATIC RADICAL SHOULD BE STUDIED. B) TASK GROUPS FOR THE CRITICAL EVALUATION OF COMBUSTION RATE DATA AND PREPARATION OF DATA SHEET FOR INDIVIDUAL REACTIONS SHOULD MEET REGULARLY. PART B: - SOOT. USING A STABILIZED PREMIXED LAMINAR FLAME PRODUCED BY FLAT POROUS PLATE OR CAPILLARY BURNERS THE PARTICULE GROWTH, THE DENSITY VARIATION AND THE GROWTH OF THE SOOT MASS WILL BE FOLLOWED BY LASER OPTICAL METHODS TAKING INTO ACCOUNT THE NATURE OF THE FUEL, MIXTURE COMPOSITION, TEMPERATURE PRESSURE AND FLOW VELOCITY. PART C: OXIDATION OF ALKYL RADICAL. THE EXPERIMENTS TO BE CONDUCTED UNDER THIS RESEARCH TOPIC WILL BE CARRIED OUT IN AN ALL QUARTZ REACTOR AT TEMPERATURES UP TO 1100 K. THE REAGENT MIXTURE, COMPRISING O2, CH3 PRECURSOR AND DILUENT GAS, WILL BE SLOWLY FLOWN THROUGH THE REACTION CELL. HOWEVER, THE KINETICS WILL BE FOLLOWED UNDER PSEUDOSTATIC CONDITIONS ON A MS TIME SCALE. CH3 RADICALS WILL BE GENERATED BY UV-LASER PHOTOLYSIS FROM (CH3)2N2 (LAMBDA = 351,210 NM) OR FROM CL2/CH4 MIXTURES (LAMBDA = 308 NM). IN THE LATTER CASE CH3 RESULTS FROM THE SEQUENCE CL2 + HV - 2CL; CL + CH4 - CH3 + HCL. LONG WAVELENGTH PHOTOLYSIS IS CHOSEN HERE TO AVOID PHOTODISSOCIATION OF O2 AND HENCE THE FORMATION OF O ATOMS. THESE GENERATION METHODS OF CH3 RADICALS HAVE BEEN TESTED IN OUR LABORATORY AT TEMPERATURES UP TO 700 K. FOR TIME RESOLVED DETECTION OF CH3O2 A LONG PATH UV LASER ABSORPTION TECHNIQUE AT LAMBDA = 257 NM Champ scientifique natural scienceschemical scienceselectrochemistryelectrolysisnatural scienceschemical sciencesorganic chemistryhydrocarbonsnatural scienceschemical sciencesorganic chemistryaromatic compoundsengineering and technologyenvironmental engineeringenergy and fuelsnatural sciencesphysical sciencesopticslaser physics Programme(s) FP1-ENNONUC 3C - Research and development programme (EEC) in the field of Non-Nuclear Energy, 1985-1988 Thème(s) Data not available Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur GEORG-AUGUST-UNIVERSITY GOETTINGEN Contribution de l’UE Aucune donnée Adresse Grisebachstrasse 6 37077 GOETTINGEN Allemagne Voir sur la carte Coût total Aucune donnée Participants (1) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire United Kingdom Atomic Energy Authority (UKAEA) Royaume-Uni Contribution de l’UE Aucune donnée Adresse Harwell Laboratory OX11 0RA Didcot Voir sur la carte Coût total Aucune donnée
