Flammability is an important factor of safe practices for handling and storage of
liquid mixtures and for the evaluation of the precise level of risk. Flash point is a major
property used to determine the fire and explosion hazards of a liquid, and it is defined as
the minimum temperature at which the vapor present over the liquid at equilibrium
forms a flammable mixture when mixed with air.
Experimental tests for the complete composition range of a mixture are time
consuming, whereas a mixture flash point can be estimated using a computational
method and available information. The information needed for mixture flash point
predictions are flashpoints, vapor pressures, and activity coefficients as functions of
temperature for each mixture component. Generally, sufficient experimental data are
unavailable and other ways of determining the basic information are needed. A
procedure to evaluate the flash point of binary mixtures is proposed, which provides
techniques that can be used to estimate a parameter that is needed for binary mixture
flash point evaluations.
Minimum flash point behavior (MFPB) is exhibited when the flash point of the
mixture is below the flash points of the individual components of the mixture. The
identification of this behavior is critical, because a hazardous situation results from
taking the lowest component flash point value as the mixture flash point.
Flash point predictions were performed for 14 binary mixtures using various Gex
models for the activity coefficients. Quantum chemical calculations and UNIFAC, a
theoretical model that does not require experimental binary interaction parameters, are employed in the mixture flash point predictions, which are validated with experimental
data. MFPB is successfully predicted using the UNIFAC model when there are
insufficient vapor liquid data.
The identification of inherent safety principles that can be applied to the
flammability of binary liquid mixtures is also studied. The effect on the flash point
values of three binary mixtures in which octane is the solute is investigated to apply the
inherent safety concept.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/2536 |
| Date | 01 November 2005 |
| Creators | Vidal Vazquez, Migvia del C. |
| Contributors | Mannan, M. Sam |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 92673 bytes, 181249 bytes, 914470 bytes, electronic, application/vnd.ms-excel, application/vnd.ms-excel, application/pdf, born digital |
Page generated in 0.002 seconds