Pauperization of fossil resources is favoring the development of biorefinery platforms, where goods derive from biomass processing. Exploitation of organic residues present in agroindustrial, forestry, zootechnical, fishery, and municipal leftovers would enhance biorefinery competitiveness. This approach is referred to as “2nd generation biorefinery” and is still in its infancy, the large majority of studies being conducted at laboratory scale and very few at pilot scale.

A very recent trend is represented by the development of multipurpose and integrated biorefining processes. Each of these processes is addressed to extensively exploit selected organic fractions of the feedstock, thus preventing competition for carbon and energy source between single steps of the whole biorefinery, through a noncompetitive scheme. This approach is aimed at achieving several marketable targets from a single feedstock and appears as the most promising to reach economic sustainability. However, the large majority of the investigations to date is focused on single-target or stand-alone processes, with little or no consideration on the exploitability of the effluents that are generated in their process, in a biorefinery perspective. This is a major limitation for the development of pilot scale studies, as the leftover treatment is not considered with a cradle-to-grave approach.

This research topic is intended to invite papers which discuss the application of multiple, noncompetitive processes aimed at gaining the maximum in terms of efficiency and/or productivity from leftovers biorefining. Application of two or more refining processes (that is, generation of two or more marketable bioproducts) should be described while using real leftovers. The overall benefit of the 2nd generation biorefinery approach as a whole should be thoroughly described. Further, the impact of the main effluents generated by the described processes should be addressed. Detailed physicochemical characterization of actual site leftovers is strongly encouraged, with the perspective of improving the link between waste organic fractions and dedicated valorization processes.

Potential topics include, but are not limited to:

• Separation, fractionation, purification, extraction, and recovery technologies
• Fermentation and microbial bioconversion technologies (aerobic and anaerobic)
• Nutrient recovery technologies
• Technoeconomical and LCA analyses