A Study on Effect of Temperatures on the Flammability of Biodiesel Vapour Mixtures for Accident Prevention

• Main Author: Muhamad Nazori, Qurratuaini
• Format: Final Year Project
• Language: English
• Published: Universiti Teknologi PETRONAS 2012
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/9627/1/2012%20-%20A%20Study%20on%20Effect%20of%20Teperatures%20on%20the%20Flammability%20of%20Biodiesel%20Vapour%20Mixture%20for%20Accid.pdf; http://utpedia.utp.edu.my/9627/

Biodiesels are widely used as an alternative fuel resulting from higher global energy demands as they are environmental friendly. Study on fire and explosion is very important mainly in industrial activities due to previous cases that have been reported involving biodiesel. In general biodiesel is considered to be much safer than fossil fuels as it is much less flammable due to its high flash point. However, biodiesel will combust if it is heated up to over 150°C. Therefore, this study is conducted to investigate the flammability of biodiesel vapor mixtures at different range of temperature varying from 50°C-200°C. Biodiesel produced by chemically reacting lipids with an alcohol via transesterification process was analyzed using Gas Chromatography Mass Spectrometry (GC-MS) to examine the composition of the sample. Total components vaporized from biodiesel sample differ at different temperatures. The results from GC-MS indicated that there are three components vaporized from biodieselliquid sample at 150°C and six components at 200°C. Mole fractions of components in the vapor phase were calculated using modified Raoult' s law. The fugacity coefficients were predicted using ThermoSolver software based on Peng-Robinson method, while the activity coefficients were calculated using COSMO software. Lower Flammability Limit (LFL) and Upper Flammability Limit (UFL) for individual components were calculated using the flammability limit dependence on temperature equation (Zabetakis, S.Lambiris, & Scott, 1959). While LFL and UFL values for the mixture (LFLmix and UFLmix) were determined using Le Chatelier equation (Chatelier, 1891). Limiting Oxygen Concentrations (LOCs) were determined using equation proposed by Hansen and Crowl (Hansen & Crowl, (June 2010)). The LFLmix, UFLmix, and LOCmix values were used to construct the flammability diagram and to determine the flammability of biodiesel vapor mixture at 50°C, 100°C, 150°C and 200°C. From the flammability diagram, it shown that biodiesel vapor mixture is not flammable at lower temperature; 50°C and 1 00°C but as the temperatures increase; 150°C and 200°C the biodiesel became flammable. The findings of this study may assist in minimizing frre hazards associated with presence of organic compound vapors derived from biodiesel.