MILD Combustion and Biofuels: A Minireview

Even in presence of the formidable growth of renewable energy sources advanced combustion processes have and will continue to have an irreplaceable role as a driving force for energy market. This is indeed motivated by the same huge amount of energy that can be conveniently stored in the form of energy carriers, made available from the renewable sources. The coupling of the appropriate combustion conversion technology with locally available biofuels certainly is among the most effective solutions, now on the table, for facing the decarbonization challenge. In this framework MILD Combustion is among the best candidates to support the transition toward the net zero emission target. Indeed, due to its inherent features it is highly fuel flexible and efficient. It is also characterized by an inherent low or absent pollutant emission. In this mini-review, the main features of MILD Combustion are summarized with particular regards to their relevance in the conversion of fuels, both gaseous and liquids, produced by the processing of biomasses, wastes and industrial by-products. It is here demonstrated how MILD Combustion is highly fuel-flexible, due to its peculiar reaction physical and chemical features. It is also put in evidence how this process is stable, clean and performing in a wide range of reactants composition. Remarkably these benefits are almost independent from the fuel properties, like HHV or other reactivity indicators, and are only relatively dependent on the physical and thermodynamical properties of the fuels.