Evolution of the Biorefinery Concept and Tools for Its Evaluation Toward a Circular Bioeconomy

In its simplest definition, biorefinery was coined as a processing facility that receives biomass for its transformation into products and energy. This work summarizes the evolution of biorefinery processing in the past twenty years from three perspectives. From the feedstock point of view, biorefineries first processed dedicated crops, but now they include a great variety of non-conventional biomasses. From the process point of view, pioneer schemes considered well-established technologies such as enzymatic saccharifications, yeast fermentation, and purifications. Currently, schemes incorporate novel intensified strategies for converting biomass with higher yields at lower costs. From the product point of view, biorefineries are well known to be coproduction facilities, from commodities such as cooking oil, sugar, or ethanol to high-value-added chemical specialties. Climate change has recently stressed the importance of assessing the sustainability of the biorefining processes. Developing sustainability evaluation methods (technical, environmental, and social) has received great attention in the past fifteen years to understand the real impacts of these biorefining processes. Finally, biorefineries represent a real opportunity for countries from all regions and levels of economic development to adopt the Circular Economy in the coming decades.