Pyrolytic valorization of E-waste Plastics: State-of-the-art, technical roadblocks, and opportunities

Abstract

• Advanced pyrolysis methods including vacuum, catalytic, microwave, co-pyrolysis, and plasma demonstrate higher efficiency in converting e-waste plastics into valuable fuels and chemicals. • These techniques achieve yields of up to 84 wt% high-energy liquid fuels with a calorific value of 49 MJ/kg from e-waste plastics. • Catalyst optimization with HZSM-5 and NiMo/AZM significantly enhances aromatic hydrocarbon yields, achieving up to 69.45% in co-pyrolysis. • Pyrolysis reduces hazardous emissions while enabling up to 99% carbon conversion into hydrogen, syngas, and other strategic resources such as olefins and indium. • The use of corrosion-resistant materials and machine learning approaches enhances the scalability of pyrolysis for industrial e-waste recycling. The escalating generation of electronic waste (e-waste) has rendered conventional disposal methods such as landfilling and incineration increasingly inadequate due to their associated environmental hazards, energy demands, economic inefficiencies, and poor material recovery rates. These traditional practices fall short in addressing the dual imperatives of resource efficiency and sustainable development. As an alternative, pyrolysis has emerged as a promising strategy for managing electronic plastic waste, offering notable advantages in terms of resource recovery and environmental protection. This review provides a comprehensive examination of five advanced pyrolysis techniques: vacuum pyrolysis, catalytic pyrolysis, co-pyrolysis, microwave-assisted pyrolysis, and plasma pyrolysis. It delves into their underlying reaction mechanisms, current development trends, and the technical challenges faced in practical applications. By analyzing experimental results and real-world implementations, the strengths and limitations of each method are critically assessed. While pyrolysis presents a viable route for the valorization of electronic polymers, its commercial deployment is hindered by challenges such as material degradation, catalyst performance, and energy optimization. To bridge the gap between research and industrial application, future efforts must prioritize the development of robust catalytic systems, integration of hybrid technologies, intelligent process control, comprehensive life-cycle assessments, and pilot-scale validation. Advancing these fronts will be essential for transitioning pyrolysis from experimental setups to scalable, environmentally responsible industrial operations. Future opportunities include microwave-assisted thermal storage for energy efficiency, multi-stage catalytic systems for contaminant removal, and hybrid plasma–catalytic approaches to improve cracking. Integrating digital tools such as machine learning and digital twin modeling can enable real-time optimization, accelerate scale-up, and strengthen the role of pyrolysis in advancing circular economy goals.