Ethylene-hydrocarbon binaries

The kifs for Other Hydrocarbon Binaries. Table II presents optimum kij values for heavy hydrocarbon binaries of ethylene and ethane. The two sets of fc /s are very similar, and this is shown more clearly in Figure 2, where the results of Chueh and Prausnitz (4) have been plotted also. Chueh and Prausnitz actually found that there was no significant difference in the s between ethylene and ethane—or between n-hexane and benzene. 

Figure 2. Optimum ky values for ethylene- and ethane-hydrocarbon binaries (— —), Equation 15 ...

The first ionization potential may prove useful in sorting out and ordering the data for binaries of inorganic compounds, but it is certainly of little use in the prediction of ky s for hydrocarbon-hydrocarbon binaries. For example, the I of n-pentane (10.55 eV) is very similar to that of ethylene (10.51 eV), but the kys for the n-pentane binaries are markedly lower than those for the corresponding ethylene binaries (4). On the other hand, the ethylene and ethane binaries have similar kys (Figure 2), even though the I of ethane is 1.25 eV higher than for ethylene (20). 

Many simple systems that could be expected to form ideal Hquid mixtures are reasonably predicted by extending pure-species adsorption equiUbrium data to a multicomponent equation. The potential theory has been extended to binary mixtures of several hydrocarbons on activated carbon by assuming an ideal mixture (99) and to hydrocarbons on activated carbon and carbon molecular sieves, and to O2 and N2 on 5A and lOX zeoHtes (100). Mixture isotherms predicted by lAST agree with experimental data for methane + ethane and for ethylene + CO2 on activated carbon, and for CO + O2 and for propane + propylene on siUca gel (36). A statistical thermodynamic model has been successfully appHed to equiUbrium isotherms of several nonpolar species on 5A zeoHte, to predict multicomponent sorption equiUbria from the Henry constants for the pure components (26). A set of equations that incorporate surface heterogeneity into the lAST model provides a means for predicting multicomponent equiUbria, but the agreement is only good up to 50% surface saturation (9). 

Five binary-hydrocarbon mixtures of ethane or ethylene with heavier hydrocarbons were studied (Table III). The only substrate used in these studies was water. If an RPT did not occur, ice always formed rapidly. When n-butane or n-pentane was the heavier component, RPTs were 100% reproducible over a particular composition range. This was not, however, true if the heavier component were propane. 

We have applied some of these principles to the extraction of 1-butene from a binary mixture of 1,3-butadiene/1-butene. Various mixtures of sc solvents (e.g., ethane, carbon dioxide, ethylene) are used in combination with a strongly polar solvent gas like ammonia. The physical properties of these components are shown in Table I. The experimental results were then compared with VLE predictions using a newly developed equation of state (18). The key feature of this equation is a new set of mixing rules based on statistical mechanical arguments. We have been able to demonstrate its agreement with a number of binary and ternary systems described in the literature, containing various hydrocarbon compounds, a number of selected polar compounds and a supercritical component. 

EMA (5) and EMA-salts (15) have been used in binary blends in order to increase the impact strength and tensile strength of polyamides (PA). EMA and EMA-salts have also recently been used to improve the toughness of poly(ethylene terephthalate) while maintaining low permeability to hydrocarbons and other organic solvents (16). ... 

LEE Lee, S.-H., Phase behavior of binary and ternary mixtures of poly(ethylene-co-octene)-hydrocarbons (experimental data by S.-H. Lee), J. Appl. Polym. ScL, 95, 161,2005. 

For Nuxit activated carbon, the binary equilibria of the following systems were simulated (1) methane-ethylene (293 K) (2) ethylene-propylene (293 K) (3) ethane-propane (293 and 333 K) (4) ethane thylene (293 K) (5) ethane-methane (293 K) (6) ethylene CO2 (293 K). Like the case of Ajax activated carbon, the model predictions from the MPSD model are again excellent, suggesting that the MPSD model is appropriate to study multicomponent equilibria of hydrocarbons on activated carbon. 

Abstract The miscibility of two phospholipids dipalmitoyl-phosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC) possessing both a choline head group, with per-(6-dodecanoylamino-6-deoxy) j8-cyclodextrin (CnCONH-/ -CD) and poly(ethylene oxide)-bearing lipid (PEO-lipid), respectively, has been assessed by surface pressure measurements of binary monolayers under dynamic conditions. Although the four studied amphiphiles had similar hydrophobic moieties constituted of hydrocarbon units with the number of carbons ranging from 12 to 16, PEO-lipid markedly differed from other amphiphiles due to its bulky poly(ethylene oxide) chain containing 13 ethylene oxide units totally immersed in the aqueous subphase. The additivity rule applied to these binary mixtures clearly showed that molecular areas for both systems deviated from linearity. For... 

Two areas listed in Table 1 were not discussed—hydrocarbon-water binaries and petroleum fractions. For the former systems only eight systems of experimental VLE data (ethylene, propylene, 1-butene, 1-hexene, n-hexane, cyclohexane, benzene, and n-nonane) were available. Use of solubility data and calculated VLE data added only five more systems (propane, propyne, cyclopropane, n-butane, and 1,3-butadiene). For petroleum fraction systems only three sources and seven systems have been characterized well enough to use in analytical correlations to be tested. These systems Include three naphtha-fuel oil systems, two hydrogen-hydrocrackate fractions, and two hydrogen-hydrogen sulfide-hydrocrackate fractions. No reasonable work can be done without additional data. 

Figure 5 presents the linear dependences [Eq. (54)] for binary mixtures of hydrocarbons on Nuxit-AL charcoal [191]. The experimental data have been measured by Szepesy and Hies [192]. The solid lines in Fig. 5 correspond to the mixtures with ethylene, and the dashed lines refer to the mixtures with ethane. It is clearly visible that Eq. (54) approximated the experimental points exeellently. In the case of the mixtures in question, the heterogeneity parameter m is equal to 0.9 for alkanes and 1 for alkenes. Fiuther studies have shown that Eq. (54) gives a satisfactory representation of adsorption from hydrocarbons mixtures on polystyrene, silica gel, and various activated carbons [5,190,191]. 

FIG. 5 The linear dependences [Eq. (54)] for the adsorption of binary mixtures of hydrocarbons on active carbon (Nuxit-AL) at 293 K ethylene-methane (right semiclosed circles), ethylene-propylene (top semiclosed circles), ethane-methane (bottom semiclosed circles), ethane-ethylene (open circles), and ethane-propane (closed circles). The symbol i(12) denotes the partial adsorbed amount of the ith component. [Reprinted fiom M. Jaroniec, Adsorption from multicomponent gas mixtures on sohd surfaces. Thin Solid Films, 77 273-304 (1980), with permission from Elsevier Science.]... 

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