Catalytic hydrodeoxygenation of bio-oil obtained from microwave co-pyrolysis of food waste and low-density polyethylene

Abstract

Food waste can be a useful carbon resource when chemically recycled. While co-pyrolysis of realistic food waste (FW) has been studied, its complex upgrading is yet to be investigated. The catalytic hydrodeoxygenation (HDO) was employed for studying the pyrolysis oil generated from microwave co-pyrolysis of FW and low-density polyethylene (LDPE). More particularly, the effects of reaction temperature and time on stream were assessed in a continuous flow reactor. The combination of 48 h on stream at 200 ?C exhibited optimal performance in terms of nitro-oxygenated compounds reduction (N1�2, O1N1, O1N2 and O2N1 classes) and large oxygenated compounds classes (O7-O9) conversion into smaller ones (O1-O4). Stability analysis of pyrolysis oil showed that HDO significantly improved the properties of HDO oil (density, pH, TAN and HHV) and stabilized its properties for longer storability (60 days), i.e., after HDO at 48 h/200 ?C the oil quality had improved in terms of lower density (18 %), moisture content (88 %) and TAN (74 %) along with a higher pH and HHV (28 % and 51 %, respectively). This brings the HDO oil quality close to generic bio-oil and bio-diesel standard requirements. � 2022 The Institution of Chemical Engineers