ESTIMATION OF FLAMMABILITY LIMITS AND FLASH POINT

Abstract

Flammability limit is a significant safety issue for industrial processes. A certain amount of flammability limit data for pure hydrocarbons are available in the literature, but for induStrial applications, there are conditions including different combinations of fuels at standard and non-standard conditions, in which the flammability limit data are scarce and sometimes unavailable. In this dissertation work a new method of estimating the lower flammability limit (LFL) of general organic compounds is presented using "C". The LFL is predicted at 298K for gases and liquids from structural contributions and the ideal gas heat of formation of the fuel. In this work an equation is proposed for the accurate and user friendly estimation of the lower flammability limit (LFL) & upper flammability limit (UFL) of C/H, C/H/N, C/1-1/0, C/H/O/N organic pure compounds in air at atmospheric pressure & room temperature (25°C). The equation derived in this study used 28 organic chemicals LFLs/UFLs for the derivation and validation. Comparisons between experimental data and estimated data show that the average absolute deviation is small enough and it can be ignored. Lower flammability limits estimation based on adiabatic temperature of the combustion reaction taking place and specific heat capacity, standard heat of formation, heat of reaction etc. For easier calculation of lower flammability limit, a program is written in "C" which makes simpler the estimation procedure of lower flammability limit. Further this method can be extended to estimate the lower flammability for chemicals containing C, H, N, 0, S, Cl. The flash point is an important indicator of the flammability of liquids and solids. Many methods of estimating the flash point of pure chemicals have been published. This work presents a method of estimating the flashpoint of general organic compounds based entirely on structural contributions and lower flammability limit using "C".