The purpose of this study is to investigate the characteristics of soot particles in C2H4/CO2/O2/N2 com- bustion at equivalence ratio of 3.0-5.0. As the oxidant is switched from conventional air to CO2/O2/N2 mixture, ...The purpose of this study is to investigate the characteristics of soot particles in C2H4/CO2/O2/N2 com- bustion at equivalence ratio of 3.0-5.0. As the oxidant is switched from conventional air to CO2/O2/N2 mixture, the key species C2H2, C3H3 responsible for formation of first aromatic ring, the apical aromatics and 4zring aromatics total production rate all decrease greatly. In addition, with CO2 mole fraction from 0.2 to 0.5 in the mixture, the soot particle number density, volume fraction, surface area density, which are three most important parameters to soot oarticle orooertv, are suooressed obviously. Furthermore, the increasing content of C02 in the oxidizer influences mostly H, OH radical concentrations by two reactins CO ＋ OH == CO2＋ H and H ＋ O2===O＋ OH, and the procluction rate ofvo reactions declined, which revealed that C02 in mixture has an inhibiting ef- fect on soot particle generation.展开更多
The objectives of this work are to study the primary chemical structure of soot aerosol derived from lump-coal combustion in different experimental conditions in fixed bed. A laboratory-scale movable fixed bed, water-...The objectives of this work are to study the primary chemical structure of soot aerosol derived from lump-coal combustion in different experimental conditions in fixed bed. A laboratory-scale movable fixed bed, water-cooled soot aerosol collection system, and electric reactor have been designed and used in the process. Three kinds of coals, sized at 3-5 ram, have been heated in the experiments. Fourier Transform Infrared Spectroscopy （FTlR） has been employed to test functional groups of soot aerosol samples. Infrared spectra from 400 to 4000 cm^ -1 and semiquantitative analysis have been employed. The results of experiments show that contents of hydrogen-bonded are increased, contents of unsaturated hydrocarbons are increased, and contents of aromatic hydrocarbons are decreased with temperature increase; contents of hydrogen-bonded and unsaturated hydrocarbons are increased first and decreased late, and contents of aromatic hydrocarbons are decreased with gases residence time extension; the contents of hydrogen bonded and unsaturated hydrocarbons derived from soot aerosol samples are higher than those from original coal samples in lower-volatile coals, and the contents of aromatic hydrocarbons derived from soot aerosol samples are lower than those from original coals; and contents of hydrogen-bonded are decreased, contents of unsaturated hydrocarbons are increased, and contents of aromatic hydrocarbons are decreased with a increase.展开更多
基金＊ Supported by the National Natural Science Foundation of China （51176181）, the National Basle Research of China （2012CB719704）, and the National Key Technology Research and Development Program Of China （2011BAK07B01）.
文摘The purpose of this study is to investigate the characteristics of soot particles in C2H4/CO2/O2/N2 com- bustion at equivalence ratio of 3.0-5.0. As the oxidant is switched from conventional air to CO2/O2/N2 mixture, the key species C2H2, C3H3 responsible for formation of first aromatic ring, the apical aromatics and 4zring aromatics total production rate all decrease greatly. In addition, with CO2 mole fraction from 0.2 to 0.5 in the mixture, the soot particle number density, volume fraction, surface area density, which are three most important parameters to soot oarticle orooertv, are suooressed obviously. Furthermore, the increasing content of C02 in the oxidizer influences mostly H, OH radical concentrations by two reactins CO ＋ OH == CO2＋ H and H ＋ O2===O＋ OH, and the procluction rate ofvo reactions declined, which revealed that C02 in mixture has an inhibiting ef- fect on soot particle generation.
文摘The objectives of this work are to study the primary chemical structure of soot aerosol derived from lump-coal combustion in different experimental conditions in fixed bed. A laboratory-scale movable fixed bed, water-cooled soot aerosol collection system, and electric reactor have been designed and used in the process. Three kinds of coals, sized at 3-5 ram, have been heated in the experiments. Fourier Transform Infrared Spectroscopy （FTlR） has been employed to test functional groups of soot aerosol samples. Infrared spectra from 400 to 4000 cm^ -1 and semiquantitative analysis have been employed. The results of experiments show that contents of hydrogen-bonded are increased, contents of unsaturated hydrocarbons are increased, and contents of aromatic hydrocarbons are decreased with temperature increase; contents of hydrogen-bonded and unsaturated hydrocarbons are increased first and decreased late, and contents of aromatic hydrocarbons are decreased with gases residence time extension; the contents of hydrogen bonded and unsaturated hydrocarbons derived from soot aerosol samples are higher than those from original coal samples in lower-volatile coals, and the contents of aromatic hydrocarbons derived from soot aerosol samples are lower than those from original coals; and contents of hydrogen-bonded are decreased, contents of unsaturated hydrocarbons are increased, and contents of aromatic hydrocarbons are decreased with a increase.
