Butadiene vapor-liquid equilibria

A vapor-liquid equilibrium calculation shows that a good separation is obtained, but the required product purity of butadiene <0.5 wt% and sulphur... 

A vapor-liquid equilibrium calculation shows that a good separation is obtained but the required product purity of butadiene <0.5 wt% and sulfur dioxide <0.3 wt% is not obtained. Further separation of the liquid is needed. Distillation of the liquid is difficult because of the narrow temperature limits between which the distillation must operate. However, the liquid can be stripped using nitrogen (Figure 14.21c). 

Solubilities of 1,3-butadiene and many other organic compounds in water have been extensively studied to gauge the impact of discharge of these materials into aquatic systems. Estimates have been advanced by using the UNIFAC derived method (19,20). Similarly, a mathematical model has been developed to calculate the vapor—liquid equilibrium (VLE) for 1,3-butadiene in the presence of steam (21). 

VER chart, 372 Vapor-liquid equilibrium data acetone/methanol, 416 acetone/water, 416,423 butadiene, 420... 

Fifty-six isothermal data sets for vapor-liquid equilibria (VLB) have been used for 15 polymer-HSolvent binaries, 11 copolymer-nsolvent binaries and for 30 polymer-polymer-solvent ternaries to study compatibility of polymer blends. The equilibrium solubility of a penetrant in a polymer depends on their mutual compatibility. Equations based on theories of polymer solution tend to be more successful when there is some kind of similarity between the penetrant and the monomer repeat unit in the polymer, e.g., for nonpolar penetrants in polymers which do not contain appreciable polar groups. Expected nonideal behavior has been observed for systems containing hydrocarbons and poly(acrylonitrile-co-butadiene). The role of intramolecular interaction in vapor-liquid equilibria of copolymer-nsolvent systems is well documented for poly(aciylonitrile-co-butadiene) that have higher affinity for acetonitrile than do polyaciylonitrile or polybutadiene. 

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