Inherently Safer Design for Hazardous Waste Contaminated in Industrial drains

Study of fire and explosion is very important mainly in refineries and industries due
to several accidents which have been reported in the past and present. This study
investigates the possibility of the occurrence of fire accident occasioned by the
vaporization of hydrocarbon components derived from refinery wastewater drainage
systems. In this study, liquid sample containing mixtures of hydrocarbon products
and water were collected from a refinery’s drainage systems and subjected to a
distillation process to separate the oil and water contents. The oil-liquid phase was
analysed using Gas Chromatography Mass Spectrometry (GC-MS) to examine the
compositions of the sample. A total of 77 hydrocarbon compounds ranging from C9
to C22 were detected. Mole fractions of components in the liquid phase were
obtained from the GC analysis while the mole fractions of the components in gas
phase were calculated via modified Raoult’s law. In this study, the gas mixture is
considered as a real solution. The activity coefficients were calculated using
UNIversal Functional Activity Coefficient (UNIFAC) method; while the fugacity
coefficients were obtained by using Peng-Robinson method, which is implemented
in ThermoSolver Software. Lower Flammability Limits (LFLs) and Upper
Flammability Limits (UFLs) for individual components were calculated using
stoichiometric concentration method while the LFL and UFL values for mixture
(LFLmix and UFLmix) were calculated in using Le Chatelier equation. The LFLmix and
UFLmix values were used to construct the flammability diagram and subsequently
used to determine the flammability of the mixture. In this study, the LFLmix for the
mixture is calculated at 0.74vol% and 4.71vol% for UFLmix. Meanwhile, the Limiting
Oxygen Concentration (LOC) for the mixture is 11.43vol%.