TECHNOLOGY FOCUS - BIOTECHNOLOGY - Preferred Process: The reactant is obtained from a fermentation broth, where the reactant is obtained by subjecting the fermentation broth to a refining process that comprises at least one step selected from evaporation, gas-stripping, adsorption, liquid-liquid extraction, and distillation. The distillation produces a vapor phase having a water concentration of at least 42% (by weight relative to the weight of water plus 1-butanol), and where the vapor phase is used as the reactant, where the at least one acid catalyst is a heterogeneous catalyst, and the temperature and the pressure are chosen so as to maintain the reactant and the reaction product in the vapor phase. The distillation produces a vapor phase, where the vapor phase is condensed to produce a butanol-rich liquid phase having a water concentration of at least 18% (by weight relative to the weight of the water plus 1-butanol) and a water-rich liquid phase, where the butanol-rich liquid phase is separated from the water-rich phase, and where the butanol-rich liquid phase is used as the reactant. Making a reaction product comprising at least one isooctane comprises contacting a reactant comprising 1-butanol and at least 5% water (by weight relative to the weight of the water plus 1-butanol) with at least one acid catalyst at 50-450degrees C and a pressure of 0.1-20.7 MPa to produce a first reaction product comprising at least one isooctene, recovering the at least one isooctene from the first reaction product to obtain at least one recovered isooctene, and 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 optionally recovering at least one isooctane from the reaction product to obtain at least one recovered isooctane. Making a reaction product comprising at least one isooctanol comprises contacting a reactant comprising 1-butanol and at least 5% water (by weight relative to the weight of the water plus 1-butanol) with at least one acid catalyst at 50-450degrees C and a pressure of 0.1-20.7 MPa to produce a first reaction product comprising at least one isooctene, recovering the at least one isooctene from the first reaction product to obtain at least one recovered isooctene, and 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 optionally recovering at least one isooctanol from the reaction product to obtain at least one recovered isooctanol. Making a reaction product comprising at least one isooctyl alkyl ether comprises contacting a reactant comprising 1-butanol and at least 5% water (by weight relative to the weight of the water plus 1-butanol) with at least one acid catalyst at 50-450degrees C and a pressure of 0.1-20.7 MPa to produce a first reaction product comprising at least one isooctene, recovering the at least one isooctene from the first reaction product to obtain at least one recovered isooctene, and contacting the at least one recovered isooctene with at least one straight-chain or branched C1 to C5 alcohol and at least one acid catalyst to produce the reaction product comprising at least one isooctyl alkyl ether; and optionally recovering at least one isooctyl alkyl ether from the reaction product to obtain at least one recovered isooctyl alkyl ether. Making at least one isooctane comprises:(A) contacting a reactant comprising l-butanol and at least 5% water (by weight relative to the weight of the water plus 1-butanol) with at least one acid catalyst at 50-450degrees C and a pressure of 0.1-20.7 MPa to produce a first reaction product comprising at least one isooctene;(B) contacting the first reaction product with hydrogen in the presence of at least one hydrogenation catalyst to produce a second reaction product comprising at least one isooctane; and(C) recovering the at least one isooctane from the second reaction product to produce a recovered isooctane. EXAMPLE - No suitable example given.