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Butanol is a superior biofuel to ethanol as it packs more energy than ethanol and can be blended in gasoline in any proportion. During World Wars I and II, butanol fermentation was commercial; however, it ceased operation after World War II due to development of the petrochemical industry. In the 1980s, research on production of butanol from renewable agricultural biomass returned due to the 1973s oil embargo. Prior to the 1990s, the maximum concentration of butanol, and total solvents (acetone–butanol–ethanol; ABE) in the fermentation broth did not exceed 15 g/L and 25 g/L, respectively. This limitation was due to butanol toxicity to the culture or microbial strain. As a result of solvent toxicity, other problems such as low reactor productivity existed. To improve these parameters, numerous laboratories around the globe initiated their research programs. Currently, using a novel strain of Clostridium tyrobutyricum , butanol concentration in excess of 26 g/L and butanol + ethanol (BE) in excess of 38 g/L can be produced. Also, simultaneous product removal techniques have been developed and ABE in excess of 460–698 g/L reactor volume can be produced. Reactor productivities of 15.8–16.2 g/L · h have been achieved as compared to 0.10–0.50 g/L · h in old batch fermentations. Use of solventogenic strains such as C. tyrobutyricum in combination with simultaneous product recovery could be a solution to the future's biofuel problem. With these challenges met, it is viewed that butanol production from renewable biomass could be commercial in the future.