Flammability Characteristics of Combustible Vapor Mixtures from Bio Oil

Study of fire and explosion is very important mainly in industrial activities 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 bio oil sample. In this study,
bio oil liquid sample containing mixtures of hydrocarbon products were produced by
fast pyrolysis process using palm oil kernel shell as the main biomass source. The bio
oil-liquid phase was analysed using Gas Chromatography Mass Spectrometry (GCMS)
and Gas Chromatography Flame Ionization Detector (GC-FID) to examine the
compositions of the sample Mole fractions of components in the liquid phase were
obtained from the GC-FID 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. LFL and UFL values for mixture (LFLmix and UFLmix) were
calculated according to Le Chatelier equation. The LFLmix and UFLmix values were
used to construct the flannnability diagram and subsequently used to determine the
flannnability of the mixture. In this study, the LFLmix for the mixture is calculated at
3.89vol% and 12.4vol% for UFLmix Meanwhile, the Limiting Oxygen Concentration
(LOC) for the mixture is 1 0.69vol%. The findings of this study can be used to
propose suitable inherent safer methods to prevent the flammable mixture from
occurring and to minimizing the loss of properties, business and life due to fire
accidents in bio oil production. The findings of this study also may assist in
minimizing fire hazards associated with presence of hydrocarbon vapours derived
from bio oil storage system.