Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser Theoretical and unused potential for residual biomasses in the Emilia Romagna Region (Italy) through a revised and portable framework for their categorization Nicolas Greggio a,∗ , Enrico Balugani b , Carlotta Carlini b , Andrea Contin b,c , Nicola Labartino d , Roberto Porcelli c , Marta Quaranta b , Serena Righi c , Luciano Vogli b , Diego Marazza c a University of Bologna, CIRI FRAME - Interdepartmental Centre for Industrial Research on Renewable Sources, Environment, Sea and Energy, Via Sant'Alberto 163, 48123, Ravenna, Italy b University of Bologna, CIRSA - Interdepartmental Research Centre for Environmental Sciences, Via Sant'Alberto 163, 48123, Ravenna, Italy c University of Bologna, Department of Physics and Astronomy, Via Irnerio, 46, 40126, Bologna, Italy d Centro Ricerche Produzioni Animali, C.R.P.A. S.p.A, Viale Timavo, 43/2, 42121, Reggio Emilia, Italy ARTICLE INFO Keywords: Residual biomasses Biomass categorization Theoretical residual biomass potential Unused residual biomass potential Seasonal availability ABSTRACT Global energy demand is lowering its growth, but it is still expected to increase by 30% between now and 2040. To decrease greenhouse gas emissions a shift to more sustainable renewable energy sources is fundamental. Among the renewable energy sources, biomasses already have the largest share in Europe and their future demand for biorefnery plants will increase at global level. This study provides a comprehensive and exportable categorization of the residual biomasses (RB) from diferent supply sectors. Thanks to the individual descriptive and quantitative parameters introduced in the paper, an estimate of the theoretical and techno-economic potential is presented for a well-industrialized, agricultural-oriented and environmentally advanced European Region. Results are presented as recoverable biogas or biomethane, considering also the seasonal availability. In a relatively small region like Emilia Romagna (Italy), 106 diferent types of residual biomasses belonging to 6 main groups have been characterized. Over half of the total residues come from the agro-industrial and food businesses (58) followed by the agricultural sector (33). The estimate reveals a theoretical potential of 3544 ± 291 Gg/year of total solids for thermochemical valorisation and 3460 ± 639 Gg/year of total solids suitable for biological treatment. In terms of unused potential, the quantities decrease respectively to 2120 ± 298 and 915 ± 167 Gg/year. The estimates indicate stable results over the years from 2014 to 2016. The seasonal availability shows two evident peaks from August to October, while a signifcant shortage is present from April to June for the residues suitable for thermochemical valorisation. The theoretical potential that can be obtained from the Region's re- sidues corresponds to about 1.8–2.3 million TOE/year, corresponding to 13–17% of the total regional con- sumption. Unused residues contribute to 0.9–1.2 million TOE/year. 1. Introduction In the last years, global energy needs are rising more slowly than in the past but are still expected to increase by 30% between now and 2040 [1]. Improving energy efciency and reducing energy demand are widely considered as the most promising, fastest, cheapest and safest ways to mitigate climate change [2], but a simultaneous shift to more sustainable renewable energy sources (RES) is needed to signifcantly decrease greenhouse gas (GHG) emissions. The European Union (EU) has set the targets for climate and energy in 2030 at: 40% reduction in GHG emissions; 27% renewable energy installed capacity for the entire EU energy supply; and 27% improve- ment in the energy efciency [3,4]. The Paris Climate Agreement has defned RES as one of the most important segments for both realization of energy self-sufciency and for lowering GHG emissions [5]. At 63% (124 million of Tonne of Oil Equivalent, MTOE), biomasses have the largest share among the RES used in Europe, followed by hydro energy with a 16% share (32 MTOE) and wind energy with a 11% https://doi.org/10.1016/j.rser.2019.06.019 Received 24 October 2018; Received in revised form 8 April 2019; Accepted 10 June 2019 ∗ Corresponding author. E-mail address: nicolas.greggio2@unibo.it (N. Greggio). Renewable and Sustainable Energy Reviews 112 (2019) 590–606 Available online 14 June 2019 1364-0321/ © 2019 Elsevier Ltd. All rights reserved. T