NOVELTY - Separating alcohol from fermented feed and concentrating thin stillage (274) into syrup (276), comprises: separating at least portion of feed in beer column (220) maintained at below atmospheric pressure to make alcohol-rich vapor and -poor beer bottoms (thin stillage); evaporating water from stillage to make first-mid stillage and -effect steam; evaporating water from first mid stillage to make second-mid stillage and -effect steam; evaporating water from second mid stillage to make syrup; and using at least portion of last effect steam to supply heat to distill feed in column.    USE - The method is useful for separating an alcohol from a fermented feed and concentrating thin stillage into syrup (claimed), where the alcohol is butanol, which is useful as a fuel additive, blend component to diesel fuel, feedstock chemical in the plastics industry, and food grade extractant in the food and flavor industry.    ADVANTAGE - The method: recovers an alcohol from a fermented feed using distillation, and concentrates thin stillage byproducts into syrup using additional evaporators (three train, triple effect evaporators) in alternative configurations than those found in conventional ethanol plants at similar size; recovers butanol from an extractant that efficiently utilizes waste heat generated from the concentration of the stillage by-products; separates at least a portion of a fermented feed in a beer column maintained at a pressure below atmospheric pressure to produce an alcohol-rich vapor and an alcohol-poor beer bottoms including thin stillage; is a more energy efficient process than the conventional ethanol production process, even when an evaporation train is taken off-line during concentration of the stillage by-products; and has improved energy efficiency and flexibility, hence provides commercial production of alcohol fuel from renewable resources, along with the production of livestock feed from the stillage by-products, in an economical, environmentally friendly and flexible way.    DETAILED DESCRIPTION - Method for separating an alcohol from a fermented feed and concentrating thin stillage (274) into syrup (276), comprises: separating at least a portion of a fermented feed in a beer column (220) maintained at a pressure below atmospheric pressure to produce an alcohol-rich vapor and an alcohol-poor beer bottoms including thin stillage; evaporating water from the thin stillage to produce a first mid stillage and a first effect steam using at least two first effect evaporators arranged in series; evaporating water from the first mid stillage produced with heat from the first effect steam to produce a second mid stillage and a second effect steam using at least two second effect evaporators arranged in series; evaporating water from the second mid stillage produced with heat from the second effect steam to produce a syrup using at least one third effect evaporator; and using at least a portion of a last effect steam produced by a last effect evaporator to supply heat for distilling the fermented feed in the beer column. INDEPENDENT CLAIMS are also included for:    (1) a system for separating alcohol from a fermented feed and concentrating thin stillage into syrup; and    (2) a multi-effect evaporation system for concentrating the thin stillage into syrup.    DESCRIPTION OF DRAWING(S) - The figure illustrates a system useful for practicing a method for separating an alcohol from a fermented feed and concentrating thin stillage into syrup.    Beer column (220)    Solvent column (230)    Separator (270)    Thin stillage (274)    Syrup (276)