Distillation enhanced

Enhanced distillation designates special techniques for separating nonideal azeotropic mixtures, or zeotropic mixtures with very low relative volatility, based on the use of a dedicated mass-separation agent that has to be recycled. Sometimes, a component already present in the mixture can play this role. 

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Jeffrey J SiirolO/ Ph D / Research Fellow, Eastman Chemical Company Member, National Academy of Engineering Fellow, Ametican Institute of Chemical Engineers, American Chemical Society, Amet ican Association for Artificial Intelligence, Amet ican Society for Engineering Education. (Enhanced Distillation)... 

Suppressed retrogression of primary coal dissolution products resulting in enhanced distillate yield and residuum product quality... 

Chemically enhanced distillation is similar to extractive distillation, but this time the solvent is an ionic salt or a complex organic molecule. As an example, acetone separates easier from a solution with methanol in the presence of a concentrated solution of calcium chloride. More modern solvents are based on ionic liquids. 

To overcome these problems, the plant was modified in late 1976 to increase residence time in the reactor and to recycle some of the ash-containing bottoms. These modifications resulted in greatly enhanced distillate production and changed the objective of the process from producing a solid fuel (SCR-I) to producing a liquid product (SCR-II). The plant was shut down in 1981 and later dismantled. 

Several enhanced distillation-based separation techniques have been developed for close-boiling or low-relative-volatility systems, and for systems exhibiting azeotropic behavior. All these special techniques are ultimately based on the same differences in the vapor and liquid compositions as ordinary distillation but, in addition, they rely on some additional mechanism to further modify the vapor-liquid behavior of the key components. These enhanced techniques can be classified according to their effect on the relationship between the vapor and liquid compositions ... 

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