Sustainable biofuels production: goals, strategies and perspectives

The transition from an unsustainable economy based on fossil resources to a more sustainable economy based on renewable biomass is the biggest challenge faced by the chemical industry in the 21^st century. The integral utilization of biomass for the production of energy, chemicals and materials, within the concept of biorefinery, is considered crucial to ensure a sustainable low-carbon economy for the future with potential benefits for the environment, economy, and society. The production of sustainable biofuels, in particular, has been strongly encouraged due to the increased concern to reduce the emission of greenhouse gases (GHG) into the atmosphere. The production of second generation ethanol (from lignocellulosic feedstocks) at commercial scale is already a reality in some countries, although improvements are still needed in order to have a more economically competitive technology. Currently, the entire sector of transports is committed to reducing the GHG emissions. The aviation sector, for example, aims to achieve CO₂-neutral from 2020 onwards and expects that by 2050 its net carbon dioxide emissions will drop by 50% compared to 2005, being the use of renewable fuels an essential element to accomplish those promises. A new European initiative is also being launched with the aim of promoting the use of biofuels as a sustainable, reliable, and low emissions alternative for the marine sector.  In the economic perspective, the development of biorefinery strategies is fundamental to achieve efficient and cost-competitive processes.