Vol.:(0123456789) 1 3 Waste and Biomass Valorization https://doi.org/10.1007/s12649-019-00582-4 ORIGINAL PAPER A Simplifed Biorefnery Concept for the Valorization of Sugar Beet Pulp: Ecofriendly Isolation of Pectin as a Step Preceding Torrefaction Giuseppina Adiletta 1  · Paola Brachi 2  · Evelina Riianova 3  · Alessio Crescitelli 4  · Michele Miccio 1  · Natalia Kostryukova 3 Received: 7 March 2018 / Accepted: 3 January 2019 © Springer Nature B.V. 2019 Abstract The valorization of sugar beet pulp (SBP) from sugar industry as a source of valuable substances has been taken in consid- eration in this work. In particular, the eco-friendly extraction of pectins with citric acid has been adopted as a preliminary step in a simplifed biorefnery concept where the pectin-free solid is subsequently subjected to a torrefaction treatment for its upgrading into a commodity solid biofuel. An extensive physicochemical characterization of the raw feedstock and the isolated pectins has also been performed, which may be useful to identify suitable application routes. Results show that the extraction conditions [1.5 pH, 90 °C, 4 h contact time and SBP-to-solvent ratio of 1:30 (g/mL)] selected in this work allow obtaining a relatively high yield (25% wt, db) of high methoxyl pectins (with some impurities), which exhibit the same colorimetric characteristics of commercial citrus pectins and are not conducive to microbial growth. A further purifcation step of isolated pectins is required to improve the emulsifying properties. Graphical Abstract Keywords Sugar beet pulp · Agro-industrial residues · Bio-chemicals · Bio-fuels · Citric acid extraction · Pectin Abbreviations SBP Sugar beet pulp PE-SBP Pectin-extracted sugar beet pulp HHV Higher heating value LHV Lower heating value TA Titratable acidity * Paola Brachi p.brachi@irc.cnr.it Extended author information available on the last page of the article