Prediction of the Upper Flammability Limits of Organic Compounds from Molecular Structures

Abstract

A quantitative structure−property relationship (QSPR) study is performed to develop mathematical models for prediction of the upper flammability limits (UFL) of organic compounds from their molecular structures. The structural features of the compounds are numerically represented by various kinds of calculated molecular descriptors such as topological, charge, and geometric descriptors. The genetic algorithm combined with multiple linear regression (GA-MLR) is used to select an optimal subset of descriptors that have significant contribution to the overall UFL property from the large pool of calculated descriptors. The best resulted model is a four-variable multilinear model with a defined applicability range. The average absolute error and root-mean-square error obtained for the external test set are 1.75 vol % and 2.77, respectively. The proposed model can be used to predict the UFL of organic compounds with only four preselected theoretical descriptors which can be directly calculated from molecular structure alone.

Determination of upper flammability limits of C H O compounds in air at reference temperature and atmospheric pressure

“…The methods by Seaton [8], Kondo et al [10], Pan et al [13] and Frutiger et al [15] presented R 2 values of 0.8862, 0.4197, 0.7540 and 0.91, respectively. The developed method presents better accuracy than the aforementioned methods, although, only slightly better in the case of the work by Frutiger et al [15].…”

“…In Table 3 the method is compared with other available methods. The methods by Albahri [11], Frutiger et al [15], Gharagheizi [12], High and Danner [7], Kondo et al [10], Lazzús [9], Pan et al [13] and Seaton [8] require the identification of molecular groups, or quantitative molecular properties, and, in some cases use the software developed by the respective authors. In the case of the present work, the developed method only needs the number of moles of C, H and O ðx C ; x H ; x O Þ, the molecular weight ðMÞ, and, the formation enthalpy h 0 f ;F .…”

“…Pan et al [13] obtained a correlation for the prediction of the UFL. The correlation uses 4 quantitative molecular properties.…”

“…Most of these data have been included in the aforementioned references and also in works by Glassman and Yetter [21] and by Carson and Mumford [37]. Also, Lazzús [9] and Pan et al [13] present experimental data on the Supplementary Material of their respective works. These sources [3,9,13,21,33] are provided as an alternative to the interested reader.…”

Method for determination of flammability limits of gaseous compounds diluted with N2 and CO2 in air

“…Several methods to calculate the FL of combustible-air mixtures at reference conditions have been developed and validated [13][14][15][16][17][18][19]. Although there are some approximations to the determination of the FL of combustible-diluent-air mixtures, there is still room for improvement.…”