scispace - formally typeset
Search or ask a question
Author

Irvin Glassman

Bio: Irvin Glassman is an academic researcher from Princeton University. The author has contributed to research in topics: Combustion & Soot. The author has an hindex of 34, co-authored 129 publications receiving 4604 citations.


Papers
More filters
Journal ArticleDOI
01 Jan 1989
TL;DR: In this article, the relative tendency of various fuels to soot when consumed in pre-mixed and diffusion flames has been determined by the qualitative measurements of critical sooting equivalence ratios and smoke heights at various temperatures and quantitatively confirmed by measurements of chemical species, soot number density and volume fraction.
Abstract: Sooting tendencies of fuels are analyzed with respect to the type of experimental configuration used—per-mixed flames, normal and inverse co-annular, Wolfhard-Parker and counter-flowing diffusion flames, or shock tubes. The important effect of temperature in each type of experiment is examined. The relative tendency of various fuels to soot when consumed in pre-mixed and diffusion flames has been determined by the qualitative measurements of critical sooting equivalence ratios and smoke heights at various temperatures and quantitatively confirmed by measurements of chemical species, soot number density and volume fraction. Fuel structure has a significant effect on the sooting tendency of diffusion flames, but little influence in premixed flames. Irrespective of the fuel in diffusion flames soot inception occurs around 1400 K and is dependent somewhat on H atom diffusion. Particle burnout ceases at about 1300 K and is responsible for the smoke height. Incipient particle formation determines the volume fraction of soot and is controlled by the rate of formation of the first aromatic species containing one to two rings. The particle growth process is found to be the same regardless of flame type. A generalized chemical mechanism of soot formation irrespective of flame type or process is presented. The various routes in this mechanism support the relative sooting tendency of fuels found in both flame and shock tube experiments. The effect of oxygen added to various fuel in diffusion controlled experiments is analyzed.

513 citations

Journal ArticleDOI
TL;DR: In this article, an improved kinetic model for the high-temperature oxidation of toluene has been developed using previously established reaction mechanisms for benzene, and a linear sensitivity analysis indicated that the reaction mechanism was most sensitive to the rate constant of C{sub 6}H{sub 5}CH{sub 3} + O{sub 2} {r_arrow}
Abstract: An improved kinetic model for the high-temperature oxidation of toluene has been developed using previously established reaction mechanisms for benzene and toluene. The model is compared to benzene and toluene flow reactor experiments near 1100 and 1200 K, respectively. Fuel decay rates and many intermediate species profiles are reproduced successfully for both lean and rich equivalence ratios. A linear sensitivity analysis indicated that the reaction mechanism was most sensitive to the rate constant of C{sub 6}H{sub 5}CH{sub 3} + O{sub 2} {r_arrow} C{sub 6}H{sub 5}CH{sub 2} + HO{sub 2} (71). A value of k{sub 71} = 3.0 x 10{sup 14} exp(-20700/T) cm/mol/s was found to fit the experimental data best. The model revealed that the presence of resonantly stable radical such as benzyl and phenoxy can inhibit the reaction rate of the fuel by removing H atoms from the system. Specific shortcomings of the model are also discussed. 70 refs., 10 figs., 4 tabs.

311 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented a simplified, overall kinetic scheme which could accurately predict the major species formed and the temperature-time history (rate of heat release) of the system.
Abstract: —Extensive experimental results were obtained on the oxidation of many aliphatic hydrocarbons in a high temperature, turbulent flow reactor developed for kinetic studies. These results indicated the viability of presenting this complex kinetic situation in the format of a simplified, overall kinetic scheme which could accurately predict the major species formed and the temperature-time history (rate of heat release) of the system. The proposed overall mechanism follows the general form:

267 citations

Journal ArticleDOI
TL;DR: The sooting behavior of laminar diffusion flames were altered by addition of diluents to the fuel flow as discussed by the authors, and the effect of water vapor, carbon dioxide and sulphur dioxide in reducing the tendency to soot was purely thermal with no observable chemical interaction.
Abstract: The sooting behavior of laminar diffusion flames were altered by addition of diluents to the fuel flow. Fuel additives which decrease the sooting tendency had an effectiveness in order of their molar specific heat capacity; helium exhibited some exaggerated trends, probably due to its high thermal diffusivity. The effect of water vapor, carbon dioxide and sulphur dioxide in reducing the tendency to soot was purely thermal with no observable chemical interaction. Trace amounts of oxidizers and halogenated compounds increased the sooting tendency substantially. Results from tests with blended fuels and fuel-hydrogen nitrogen mixtures in which the C/H ratio and temperature were controlled revealed that C/H ratio was not a dominant parameter in the sooting tendency. These results and temperature measurements provided evidence that the sooting behavior of a diffusion flame is controlled by the initial fuel pyrolysis which is dominated by the flame temperature and the field it causes. Since accurate ca...

265 citations

Journal ArticleDOI
01 Jan 1981
TL;DR: In this article, the velocity of flame propagation over the surface of thick PMMA and thin paper sheets has been measured as a function of the velocity and oxygen concentration of a forced gas flow opposing the direction of the flame propagation.
Abstract: The velocity of flame propagation over the surface of thick PMMA and thin paper sheets has been measured as a function of the velocity and oxygen concentration of a forced gas flow opposing the direction of flame propagation. It is shown that although for thin fuels the flame spread rate always decreases as the opposed flow velocity increases, for thick fuels the dependence of the spread rate on the gas velocity is also a function of the ambient oxygen concentration. For low oxygen concentrations the flame spread rate decreases as the velocity of the gas flow increases. For high oxygen concentrations, however, the spread rate increases with the flow velocity, reaches a maximum and then decreases as the gas velocity increases. The velocity of the opposed flow at which the maximum occurs is a function of the oxygen concentration, decreasing as the concentration decreases. Following phenomenological considerations and simplified descriptions of the primary mechanisms occurring during the flame spread process, the experimental results are correlated by two non-dimensional parameters, one describing the gas phase kinetic effects and the other describing the process of heat transfer from the flame to the fuel. Such a correlation provides a powerful means of predicting the flame spread prcess as well as physical insight into the mechanisms controlling the propagation of the flame.

173 citations


Cited by
More filters
Journal ArticleDOI
TL;DR: This article presented a bottom-up estimate of uncertainties in source strength by combining uncertainties in particulate matter emission factors, emission characterization, and fuel use, with uncertainty ranges of 4.3-22 Tg/yr for BC and 17-77 Tg /yr for OC.
Abstract: [1] We present a global tabulation of black carbon (BC) and primary organic carbon (OC) particles emitted from combustion. We include emissions from fossil fuels, biofuels, open biomass burning, and burning of urban waste. Previous ‘‘bottom-up’’ inventories of black and organic carbon have assigned emission factors on the basis of fuel type and economic sector alone. Because emission rates are highly dependent on combustion practice, we consider combinations of fuel, combustion type, and emission controls and their prevalence on a regional basis. Central estimates of global annual emissions are 8.0 Tg for black carbon and 33.9 Tg for organic carbon. These estimates are lower than previously published estimates by 25–35%. The present inventory is based on 1996 fuel-use data, updating previous estimates that have relied on consumption data from 1984. An offset between decreased emission factors and increased energy use since the base year of the previous inventory prevents the difference between this work and previous inventories from being greater. The contributions of fossil fuel, biofuel, and open burning are estimated as 38%, 20%, and 42%, respectively, for BC, and 7%, 19%, and 74%, respectively, for OC. We present a bottom-up estimate of uncertainties in source strength by combining uncertainties in particulate matter emission factors, emission characterization, and fuel use. The total uncertainties are about a factor of 2, with uncertainty ranges of 4.3–22 Tg/yr for BC and 17–77 Tg/yr for OC. Low-technology combustion contributes greatly to both the emissions and the uncertainties. Advances in emission characterization for small residential, industrial, and mobile sources and topdown analysis combining field measurements and transport modeling with iterative inventory development will be required to reduce the uncertainties further. INDEX TERMS: 0305 Atmospheric Composition and Structure: Aerosols and particles (0345, 4801); 0322 Atmospheric Composition and Structure: Constituent sources and sinks; 0345 Atmospheric Composition and Structure: Pollution—urban and regional (0305); 0360 Atmospheric Composition and Structure: Transmission and scattering of radiation; 0365 Atmospheric Composition and Structure: Troposphere—composition and chemistry; KEYWORDS: emission, black carbon, organic carbon, fossil fuel, biofuel, biomass burning

2,180 citations

Journal ArticleDOI
TL;DR: In this paper, a general scheme of polycyclic aromatic hydrocarbons (PAH) formation and sequential growth of PAH by reactions with stable and radical species, including single-ring aromatics, other PAH and acetylene, is discussed.

1,620 citations

Journal ArticleDOI
TL;DR: In this paper, a comprehensive model of high temperature hydrocarbon oxidation in combustion is presented, with emphasis on the hierarchical structure of reaction mechanisms for complex fuels, including both inhibition and promotion of combustion.

1,435 citations

Journal ArticleDOI
TL;DR: In this article, the authors review and discuss the literature concerning the measurement of smoke particle size, chemistry, thermodynamic properties, and emission factors, and show that very large differences in measured particle properties have appeared in the literature, in particular with regards to particle carbon budgets.
Abstract: . The last decade has seen tremendous advances in atmospheric aerosol particle research that is often performed in the context of climate and global change science. Biomass burning, one of the largest sources of accumulation mode particles globally, has been closely studied for its radiative, geochemical, and dynamic impacts. These studies have taken many forms including laboratory burns, in situ experiments, remote sensing, and modeling. While the differing perspectives of these studies have ultimately improved our qualitative understanding of biomass-burning issues, the varied nature of the work make inter-comparisons and resolutions of some specific issues difficult. In short, the literature base has become a milieu of small pieces of the biomass-burning puzzle. This manuscript, the second part of four, examines the properties of biomass-burning particle emissions. Here we review and discuss the literature concerning the measurement of smoke particle size, chemistry, thermodynamic properties, and emission factors. Where appropriate, critiques of measurement techniques are presented. We show that very large differences in measured particle properties have appeared in the literature, in particular with regards to particle carbon budgets. We investigate emissions uncertainties using scale analyses, which shows that while emission factors for grass and brush are relatively well known, very large uncertainties still exist in emission factors of boreal, temperate and some tropical forests. Based on an uncertainty analysis of the community data set of biomass burning measurements, we present simplified models for particle size and emission factors. We close this review paper with a discussion of the community experimental data, point to lapses in the data set, and prioritize future research topics.

1,344 citations

Journal ArticleDOI
TL;DR: In this article, a computational study was performed for the formation and growth of polycyclic aromatic hydrocarbons (PAHs) in laminar premixed acetylene and ethylene flames.

1,117 citations