text: ABE fermentation is attracting renewed interest with a focus on butanol as a renewable biofuel.
  Sustainability is by far the topic of major concern over the last years. The energy challenge is the key point of the environmental friendly policies adopted by all the most developed and industrialized countries worldwide. For this purpose Horizon 2020, the biggest EU Research and Innovation programme, was funded by the European Union over the 2014–2020 period.
  The International Energy Agency defines renewables as the centre of the transition to a less carbon-intensive and more sustainable energy system. Biofuels are believed to represent around 30% of energy consumption in transport by 2060. Their role is particularly important in sectors which are difficult to decarbonise, such as aviation, shipping and other long-haul transport. That is why several bioprocesses have seen a renewed interest in recent years, both from a research and an industrial perspective.
  For this reason, the ABE fermentation process has been reconsidered from a different perspective. Although it was originally conceived to produce acetone, it is considered as a suitable production pathway for biobutanol that has become the product of major interest.
  Biogenic butanol is a possible substitute of bioethanol or even better and it is already employed both as fuel additive and as pure fuel instead of standard gasoline because, differently from ethanol, it can be directly and efficiently used in gasoline engines. Moreover, it has the  advantage that it can be shipped and distributed through existing pipelines and filling stations.
  Finally biobutanol is widely used as a direct solvent for paints, coatings, varnishes, resins, dyes, camphor, vegetable oils, fats, waxes, shellac, rubbers and alkaloids due to its higher energy density, lower volatility, and lower hygroscopicity. It can be produced from different kinds of cellulosic biomass and can be used for further processing of advanced biofuels such as butyl levulinate as well.
  The application of n-butanol in the production of butyl acrylate has a wide scope for its expansion, which in turn would help in increasing the consumption of n-butanol globally. Butyl acrylate was the biggest n-butanol application in 2014 and is projected to be worth US$3.9 billion by 2020.