Thermochemical conversion of biomass to second generation biofuels through integrated process design—A review

The need for clean and environmental friendly fuels is leading the world to the production of biofuels and replacing conventional fuels by them. Second generation biofuels derived from lignocellulosic feedstocks tackle the drawbacks posed by the so-called first generation ones regarding feedstock availability and competition with the food industries. Thermochemical conversion of biomass to biofuels is a promising alternative route relying on well-established technologies including gasification and the Fischer–Tropsch synthesis. The conjunction of these processes creates a pathway through which the production of biofuels is sustainable. However, the multiple interactions between the processing steps greatly increase the difficulty in the accurate design of such processes. Detailed process modelling and optimization studies combined with process integration methods are necessary to demonstrate an effective way for the exploitation of these interactions. The aim of this work is to present and analyze the thermochemical conversion of biomass to second generation liquid biofuels as well as to indicate the emerging challenges and opportunities of the application of process integration on such processes towards innovative and sustainable solutions concerning climate concerns and energy security.