580results about "Extractive distillation" patented technology

An energy-efficient extractive distillation process for producing anhydrous ethanol from aqueous / ethanol feeds containing any range of ethanol employs an extractive distillation column (EDC) that operates under no or greatly reduced liquid reflux conditions. The EDC can be incorporated into an integrated process for producing anhydrous ethanol used for gasoline blending from fermentation broth. By using a high-boiling extractive distillation solvent, no solvent is entrained by the vapor phase to the EDC overhead stream, even under no liquid reflux conditions. The energy requirement and severity of the EDC can be further improved by limiting ethanol recovery in the EDC. In this partial ethanol recovery design, ethanol which remains in the aqueous stream from the EDC is recovered in a post-distillation column or the aqueous stream is recycled to a front-end pre-distillation column where the ethanol is readily recovered since the VLE curve for ethanol / water is extremely favorable for distillation.

The invention relates to methods for separating mixture components such as reactor effluent components. In particular, the invention relates to the use of an extractive agent such as a hydrocarbon in an extractive distillation process to separate monomers such as a C4-C7 isoolefins such as isobutylene from mixtures such as reactor effluents including one or more hydrofluorocarbon(s) (HFC).

Systems and methods for separating an alcohol, and in particular butanol, from a fermented feed and concentrating thin stillage into syrup includes operation of one or more alcohol recovery distillation columns using the heat supplied by steam generated from concentration of the thin stillage in a multi-train, multi-effect evaporation system.

Disclosed is a method for recovering diluted waste sulfuric acid containing impurities from nitration processes, a highly concentrated nitric acid required in the nitration process being produced in association with the nitration process by means of extractive rectification with concentrated sulfuric acid which is re-concentrated in order to be reutilized. According to the inventive method, the waste sulfuric acid from the nitration process is fed to the top of a first, indirectly heated stripping column, optionally together with another waste sulfuric acid in the form of a DNT washing acid, and is divided into an overhead product containing nitric acid and nitro-organic compounds as well as a prepurified sulfuric acid in the bottom product. The prepurified sulfuric acid withdrawn from the bottom of the first stripping column is fed to the top of a second, serially connected additional indirectly heated stripping column, into the bottom zone of which another waste sulfuric acid is fed in the form of a diluted sulfuric acid recovered from the nitric acid concentration system such that the prepurified sulfuric acid from the first stripping column is further purified in the second stripping column and is preconcentrated along with the diluted sulfuric acid recovered from the extractive rectification of nitric acid.