From laboratory scale to pilot plant: Evaluation of the catalytic co-pyrolysis of grape seeds and polystyrene wastes with CaO

5 figures, 5 tables.-- Supplementary information available.-- © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The catalytic co-pyrolysis of grape seeds and polystyrene was successfully scaled-up from thermogravimetric analysis to an auger reactor pilot plant. Agricultural residues were co-pyrolyzed with waste polystyrene plastics (up to 20 wt%) using calcium oxide as the catalyst. Particularly, an upgraded organic fraction was produced where synergetic positive effects were observed due to both the presence of plastics and of the CaO catalyst. These effects were mainly reflected in the production of a more deoxygenated and practically dehydrated organic fraction, rich in aromatic compounds and with a remarkable heating value. The synergetic positive effect of these materials is mainly attached to the promotion of the H2 transfer reactions resulting from the scission of polystyrene radicals, and from the decarboxylation and dehydration effects associated with CaO. Moreover, a non-condensable H2-rich gas stream with remarkably low CO2 concentration, proved potentially valuable not only for use in further energetic applications but also as a potential source of synthetic fuels. The great potential of this process in the production of bio-products was, thus, demonstrated in a representative scale.The authors would like to thank MINECO and FEDER for their financial support (Project ENE2015-68320-R). O.S.P acknowledges the FPI fellowship (BES-2016-077750) funded by MINECO. The authors would also like to thank the Regional Government of Aragon (DGA) for the support provided under the research groups support programme.Peer reviewe