Disclosed is an improved SMB process incorporating novel regeneration steps for the separation of ethanol associated oxygenates such as butanediol from a dilute mixture of ethanol and associated oxygenates in water in the presence of organic compounds derived from a biofermentation process. Applicant discovered that increasing the number of raffinate streams alone or in combination with a hot regeneration zone within the SMB cycle can significantly reduce the capital and operating costs associated with the incorporation of the SMB process in a complex for the production of ethanol and butanediol from biofermentation effluent. The process is useful for removing water from dilute aqueous mixtures of organic compounds comprising ethanol in dilute concentration in water and produced by fermentation, biomass extraction, biocatalytic and enzymatic processes which are not economically recoverable by conventional distillation methods.