2,2,4-Trimethyl-pentane calculation

Figure 4-23. Calculated and experimental selectivities and distribution coefficients for the type-I ternaries in the 2,2,4-trimethyl pentane-cyclohexane-furfural-benzene system.

Three pounds of 2,2-dimethyIbutane and 2 lb of 2,2,4-trimethyl-pentane are mixed in a sealed container. The temperature and pressure are adjusted to 5 psia and 100°F. Calculate the compositions and weights of the gas and liquid at equilibrium. Assume that the mixture acts like an ideal solution. 

In a bond additivity scheme, a property is related to contributions from each of the bonds in the molecule. For example, the heat of formation of isooctane (2,2,4-trimethyl-pentane), whose structure is shown in Figure 1, would be calculated from its bond units as... 

We know by experience that the kij value has a huge influence on fluid-phase equiUbiium calculation. To illustrate this point, it was decided to plot - using the PR EoS - the isothermal phase diagram for the system 2,2,4 trimethyl pentane (1) + toluene (2) at T = 333.15 K giving to fci2 different values (see Figure 1). The obtained curves speak for themselves ... 

For this calculation, gasoline is assumed to be 2,2,4-trimethyl pentane (CH3C(CH3)2CH2CH(CH3)CH3) (also known as isooctane). The table summarizes several of the properties of these two compounds, calculated using the EPlSuite software. 

Figure 2. Comparison of Calculated Diffusional barriers for 2,4,4-trimethyl-3-pentane (TMP) in Various Zeolites and Molecular Sieves... 

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