NOVELTY - Preparation (p1) of at least one butene involves a) obtaining a fermentation broth comprising 1-butanol; b) separating dry 1-butanol from the fermentation broth to produce separated dry 1-butanol; (c) contacting the separated dry 1-butanol of step b), optionally in the presence of a solvent, with at least one acid catalyst at 50-450degrees C and a pressure of 0.1-20.7 MPa to produce a reaction product comprising the butene; and d) recovering the butene from the reaction product to obtain at least one recovered butene.    USE - For preparation of butene useful for preparing alkyl substituted aromatic compounds and butyl alkyl ethers (claimed).    ADVANTAGE - The method improves air quality and increasing energy production from renewable resources have resulted in renewed interest in alternative fuels, such as ethanol and butanol, that might replace gasoline and diesel fuel.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) preparation (p2) of a reaction product comprising at least one isoalkane, involving: steps a)-d); and e) contacting the at least one recovered butene with 3-5C alkane in the presence of at least one acid catalyst, to produce the reaction product comprising at least one isoalkane;    (2) preparation (p3) of a reaction product comprising at least one 10-13C substituted aromatic compound involving steps a)-d); and e) contacting the at least one recovered butene with benzene, and/or 1-3Calkyl-substituted benzene in the presence of at least one acid catalyst or at least one basic catalyst at 100-450degrees C, and at a pressure of 0.1-10 MPa to produce the reaction product comprising at least one 10-13C substituted aromatic compound;    (3) preparation (p4) of a reaction product comprising at least one butyl alkyl ether involving steps a)-d); and e) contacting the at least one recovered butene with methanol, ethanol, and/or 3-15C alcohol in the presence of at least one acid catalyst at 50-200degrees C, and at a pressure of 0.1 MPa to 20.7 MPa to produce the reaction product comprising at least one butyl alkyl ether;    (4) preparation of (p5) a reaction product comprising at least one isooctene involving: steps a)-d); and e) contacting the at least one recovered butene with at least one acid catalyst to produce the reaction product comprising at least one isooctene;    (5) preparation of (p6) a reaction product comprising at least one isooctane involving: steps a)-d); e) contacting the at least one recovered butene with at least one acid catalyst to produce a second reaction product comprising at least one isooctene; f) isolating the at least one isooctene from the second reaction product to produce at least one recovered isooctene; g) contacting the at least one recovered isooctene with hydrogen in the presence of at least one hydrogenation catalyst to produce the reaction product comprising at least one isooctane; and h) optionally recovering the at least one isooctane from the reaction product to obtain at least one recovered isooctane;    (6) preparation (p7) of a reaction product comprising at least one isooctanol involving: steps a)-d); e) contacting the at least one recovered butene with at least one acid catalyst to produce a second reaction product comprising at least one isooctene; f) isolating the at least one isooctene from the second reaction product to produce at least one recovered isooctene; g) contacting the at least one recovered isooctene with water and at least one acid catalyst to produce the reaction product comprising at least one isooctanol; and h) optionally recovering the at least one isooctanol from the reaction product to obtain at least one recovered isooctanol; and    (7) preparation (p8) of a reaction product comprising at least one isooctyl alkyl ether involving: steps a)-d); e) contacting the at least one recovered butene with at least one acid catalyst to produce a second reaction product comprising at least one isooctene; f) isolating the at least one isooctene from the second reaction product to produce at least one recovered isooctene; g) contacting the at least one recovered isooctene with at least one optionally branched 1-5C alcohol and at least one acid catalyst to produce the reaction product comprising at least one isooctyl alkyl ether; and h) optionally recovering the at least one isooctyl alkyl ether from the reaction product to obtain at least one recovered isooctyl alkyl ether.