Journal of Thermal Analysis and Calorimetry

, Volume 96, Issue 3, pp 741–749

Fire and explosion properties examinations of toluene–methanol mixtures approached to the minimum oxygen concentration


DOI: 10.1007/s10973-009-0027-2

Cite this article as:
Chang, YM., Lee, JC., Chen, CC. et al. J Therm Anal Calorim (2009) 96: 741. doi:10.1007/s10973-009-0027-2


The minimum oxygen concentration (MOC) is an important safety parameter of safety for fire/explosion prevention of practical processes with fuel-air-inert mixtures. In this study, the critical fire and explosion properties stand for the explosion sensitivity (lower explosion limit (LEL), upper explosion limit (UEL)), explosion maximum indices (maximum explosion pressure (Pmax), maximum rate of explosion pressure rise (dP dt−1)max) and explosion damage degree (gas or vapor deflagration index (Kg)/St Class). These imperative parameters of various toluene/methanol mixing solvents (100/0, 75/25, 50/50, 25/75 and 0/100 vol.%) were experimentally determined within a closed spherical vessel of 20 L (20-L-Apparatus) at 101 kPa and 150 °C. Particularly, we discussed the variations both on the above characteristics and implied flammability hazard degree within different initial oxygen circumstances; the specific effects on toluene/methanol mixing solvents were to be clarified accompanied with reducing loading oxygen concentrations, gradually approaching up to the MOC in this present work. Finally, a triangle flammability diagram with the five toluene/methanol components in our testing arrangements and conditions was established for graphically indicating the dangerous fire/explosion hazard region. It has been confirmed that this study would be very useful in relevant industrial processes for a proactive loss prevention program. The experimentally derived outcomes are recommended for the inherently safer design (ISD) for forestalling any accidents from fires and explosions.


Fire and explosion propertiesInherently safer design (ISD)20-L-ApparatusMinimum oxygen concentration (MOC)Toluene/methanol mixing solvents

List of symbols


Boiling point, °C

(dP dt−1)max

Maximum rate of explosion pressure rise, bar s−1


Flash point, °C


Ignition energy, J


Gas or vapor explosion constant, m bar s−1


Lower explosion limit, vol.%


Minimum oxygen concentration, vol.%


Initial pressure, kPa


Corrected explosion overpressure, bar


Maximum explosion pressure, bar


Explosion overpressure, bar


Explosion class, dimensionless


Upper explosion limit, vol.%

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2009

Authors and Affiliations

  • Y.-M. Chang
    • 1
  • J.-C. Lee
    • 1
  • C.-C. Chen
    • 2
  • C.-M. Shu
    • 1
    • 3
  1. 1.Doctoral Program, Graduate School of Engineering Science and TechnologyNational Yunlin University of Science and Technology (NYUST)Douliou, YunlinROC
  2. 2.Department of Occupational Safety and HealthChina Medical UniversityTaichungROC
  3. 3.Process Safety and Disaster Prevention LaboratoryDepartment of Safety, Health, and Environmental Engineering, NYUSTDouliou, YunlinROC