Enzymatic catalysis as a tool in biofuels production in Brazil: Current status and perspectives

Growing fossil raw material demand, especially for producing fuels, has caused serious damage to the environment, mainly in the form of greenhouse gas (GHG) emissions. To minimize non-renewable fuel use and impacts, biomasses can be used as substitutes to achieve a sustainable circular economy, especially in Brazil, which is one of the largest biomass producers in the world. Ethanol, biodiesel, and biogas/biomethane have been extensively studied as alternatives to fossil fuels, the two first being already produced at industrial scales and used as vehicle fuels in Brazil. Additionally, different biomasses have been used as raw materials to produce biofuels, and enzymatic catalysis have shown promising potential to achieve feasible and sustainable processes. Some main enzymes are amylases, which are used extensively in corn starch hydrolysis to produce first generation (1G) ethanol using a well-established process, while cellulases and xylanases are promising in hydrolyzing lignocellulosic materials for producing second generation (2G) ethanol. Lipases, on the other hand, are interesting catalysts for effectively converting triacylglycerols (TAGs), and free fatty acids (FFAs) from several vegetable oils or animal fats into biodiesel. This review comprehensively address biofuels production in Brazil, with a focus on the current status of industrial enzymes, exploring their characteristics, advantages, and discussing current technical challenges for their industrial application.