Improving plastic pyrolysis oil quality via an electrochemical process for polymer recycling: a review

Abstract

Electrochemical hydrogenation (ECH) is a novel route for the upgradation of pyrolysis oil from both biomass and plastic feedstocks. Compared with conventional routes, including thermal cracking, ECH can be performed under mild conditions (<80 °C and 1 atm) and without the requirement of additional H₂ supply. The successful demonstration of this application can be a critical step to enabling a circular plastic economy and low-carbon fuel production. In this review we provide a critical overview of the recent advancements in understanding the variables that influence the ECH process. In addition, we debate how this technology could be optimized and applied to plastic waste pyrolysis oil, assessing concerns such as the selection of cathode material, which needs to be resilient enough to address the complex nature of bio-oil. In addition, we present ideas on how to circumvent the challenge where the commonly used water-based electrolytes are unlikely to be suitable for pyrolysis oil treatment. Finally, we discuss the possible utilization of this product and scalability of this process.