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Pressure effect on pyrolysis and soot inception

Objective

When fossil fuel burns, the heavier fractions can aggregate and form soot particles which contribute to atmospheric pollution. To control these emissions, one must first understand how they are formed during the combustion process.

The objective of this project is to contribute to the understanding of soot formation . The project will provide reliable quantitative data about fuel hydrocarbon pyrolysis and soot formation under conditions arising in modern power stations using gas, liquid hydrocarbons, coal dust or slurries in high power combustion chambers and in piston engines. (The operating pressures are about one order of magnitude or more above atmospheric pressure).


Shock tubes and flow reactor studies will be performed in an integrated way for the investigation of the pyrolysis and soot formation from hydrocarbons in high pressure conditions.

In order to quantify the pyrolysis and the growth of particles it will be necessary to perform shock tube experiments for carbon densities from 8 1016 to 2- 1019 C atoms per cm3. In these experiments absorption measurements in the wavelength range from 2000 Å into the infrared, and light scattering measurements will be used. These measurements will be supplemented by chemical analysis of the reaction products. For the investigation of pyrolysis in fuel sprays injected in a flow reactor analogous measurement techniques will be exploited.
They will be extended by using two-dimensional imaging of the spray and of the soot particles in the pyrolytic regions.

The research programme is divided in three parallel parts:
a) Shock tube experiment up to 50 bar (Istituto Motori, CNR) : Mixtures of vaporized and gaseous aliphatic and aromatic hydrocarbons will be introduced, at different C/O ratios, for studying soot and precursor formation up to 50 bar.

b) Shock tube experiment up to 200 bar (University of Göttingen) : The pyrolysis experiments in homogeneous mixtures will be performed in shock waves-incident and reflected. For the measurements of temperature and pressure the initial shock conditions and accurate shock velocity measurements will be used.

c) High pressure flow reactor (University of Naples) :
The determination of the chemical and physical parameters controlling soot and paralytic products formation will be performed in different spatial and temporal regions of a spray injected in the high pressure flow reactor. The part of the process controlled by chemical kinetics will be analyzed changing the chemical composition of the fuel, keeping constant the physical fuel characteristics.

In complement, Prof. Nemeth (Hungarian Acad. Sci.) will contribute in compiling possible mechanisms, find reducing methods to establish a Sequence Network and evaluate the results by computer simulation.

Call for proposal

Data not available

Coordinator

Università degli Studi di Napoli 'Federico II'
Address
Piazzale V.tecchio
80125 Napoli
Italy
 

Participants (2)

Max-Planck-Gesellschaft zur Förderung der Wissenschaften eV
Germany
Address
Bunsenstraße 10
37073 Göttingen
 
NATIONAL RESEARCH COUNCIL OF ITALY
Italy
Address
Via Guglielmo Marconi 8
80125 Napoli