NOVELTY - Production (M1) of at least one butene involves: (a) obtaining a fermentation broth comprising isobutanol; (b) separating dry isobutanol from the fermentation broth to form separated dry isobutanol; (c) contacting the separated dry isobutanol of step (b), optionally in the presence of a solvent, with at least one acid catalyst at 50-450degreesC, and pressure of 0.1-20.7 MPa to produce a reaction product comprising at least one butene; and (d) recovering butene from the reaction product.    USE - For producing butenes from dry isobutanol derived from fermentation broth; and for the preparation of isoalkanes, 10-13C substituted aromatic compounds, butyl alkyl ethers, isooctene, isooctane, isooctyl alkyl ethers, and isooctane, using butene as intermediate (claimed), the products are useful as fuel additives in transportation fuels, butenes are also useful for the preparation of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE).    ADVANTAGE - The process effectively utilizes the isobutanol streams produced by fermentative microorganisms, for the production of butenes.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) producing a reaction product comprising at least one isoalkane involving: steps (a)-(d) of the process (M1); and (e) contacting the at least one recovered butene with a straight-chain, branched or cyclic 3-5C alkane in the presence of at least one acid catalyst to produce a reaction product comprising at least one isoalkane;    (2) producing a reaction product comprising at least one 10-13C substituted aromatic compound involving: steps (a)-(d) of the process (M1); and (e) contacting the at least one recovered butene with benzene (optionally substituted by 1-3C alkyl) in the presence of at least one acid catalyst or basic catalyst at 100-450degreesC, and at a pressure of 0.1-10 MPa to produce a reaction product comprising at least one 10-13C substituted aromatic compound;    (3) producing a reaction product comprising at least one butyl alkyl ether involving: steps (a)-(d) of the process (M1); and (e) contacting the at least one recovered butene with methanol, ethanol, and/or 3-15C straight-chain, branched or cyclic alcohol in the presence of at least one acid catalyst at 50-200degreesC, and a pressure of 0.1-20.7 MPa to produce the reaction product comprising at least one butyl alkyl ether;    (4) producing (M2) a reaction product comprising at least one isooctene involving: steps (a)-(d) of the process (M1); and (e) contacting the recovered butene with at least one acid catalyst to produce the reaction product comprising at least one isooctene;    (5) producing a reaction product comprising at least one isooctane involving: steps (a)-(d) of the process (M1); (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; and (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) producing a reaction product comprising at least one isooctanol involving: steps (a)-(e) of the process (M2) for producing 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 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 isooctanol from the reaction product to obtain at least one recovered isooctanol;    (7) producing a reaction product comprising at least one isooctyl alkyl ether involving: steps (a)-(e) of the process (M2) to produce the second reaction product comprising at least one isooctene; (f) isolating the isooctene from the second reaction product to produce at least one recovered isooctene; (g) contacting the recovered isooctene with at least one straight-chain or branched 1-5C alcohol and at least one acid catalyst to produce a 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; and    (8) producing a reaction product comprising at least one isooctane involving: steps (a)-(d) of the process (M1) to obtain at least one recovered butene; (e) contacting the recovered butene with at least one acid catalyst to produce a second reaction product comprising at least one isooctene; (f) contacting the second reaction product with hydrogen in the presence of at least one hydrogenation catalyst to produce reaction product comprising at least one isooctane; and (g) optionally recovering the at least one isooctane from the reaction product to obtain at least one recovered isooctane.