Corresponding States Method for Estimation of Upper Flammability Limit Temperature of Chemical Compounds
The accuracy and predictability of predictive methods to determine the flammability characteristics of chemical compounds are of drastic significance in the chemical industry. This work aims at continuing application of the gene expression programming (GEP) mathematical strategy to modify the existing thermophysical properties correlations available in the literature to pursue the following objectives: optimization of the number of independent parameters, amplification of the generality, and improvement of the accuracy and predictability. This work deals with presenting a simple corresponding states model to predict the upper flammability limit temperature of 1462 organic compounds from 76 chemical families. The parameters of the correlation include the critical temperature and the acentric factor of the compounds. The obtained statistical parameters including average absolute relative deviation of the results from DIPPR 801 database values (1.7, 1.8, 1.7% for training, optimization, and prediction sets, ...
A method for measuring upper flash point
Abstract An easy, practical method for the measurement of the upper flash point is reported. The two small observing windows of a Seta-flash closed-cup apparatus were closed to air. A sample was introduced into the cup, left for 5 min, then ignited. The upper flash point could be measured under the vapour–liquid equilibrium state by this modified procedure. The upper flash points of 33 chemicals and three petroleum products were determined. An empirically obtained equation (Tf = Ts + 6.42) was used to calculate the upper flammable-limit temperature, Tf, with 5.25°C precision, using the observed upper flash point Ts. The temperature ranges of the cool flame zone could also be measured using sensitive fine thermocouples.
The partial solubility parameters: An equation-of-state approach
The division of the well-known solubility parameter into its dispersion, polar, and hydrogen-bonding components has significantly upgraded its capacity and usefulness in the screening and selection of the appropriate solvents in Industry and in Laboratory. This work presents a new statistical thermodynamic approach for the estimation of these partial components over a broad range of temperature and pressure. Key to this approach is the development of explicit expressions for the contribution of dispersion, dipolar, and hydrogen-bonding interactions to the potential energy of the fluid. The approach is applicable to ordinary solvents, to supercritical fluids, as well as to high polymers. Information on various thermodynamic properties of fluids is used in order to estimate the three solubility parameter components. Extensive tables with the key parameters are presented. On the other hand, available information on these separate components is exploited in order to extract information for the thermodynamic behaviour of the fluids over an extended range of external conditions.