Recycling of Polymer and Nonmetallic Feaction (NmF) of E-Waste

Kaya M.

in: Horizons in Earth Science Research Vol. 22, Benjamin Veress,Jozsi Szigethy, Editor, NOVA Science Publishers Inc. , New York, pp.185-236, 2021

  • Publication Type: Book Chapter / Chapter Research Book
  • Publication Date: 2021
  • Publisher: NOVA Science Publishers Inc.
  • City: New York
  • Page Numbers: pp.185-236
  • Editors: Benjamin Veress,Jozsi Szigethy, Editor
  • Eskisehir Osmangazi University Affiliated: Yes


ABSTRACT The recovery trend of low-value and complex structured nonmetal fractions (NmF) from electronic waste (e-waste) or waste printed circuit boards (PCBs) is developing from stabilization to value-added recovery and gaining tremendous importance. Consequently, the recovery of NmF deserves more attention and new R&D studies. Cheap NmF (i.e. glass fiber (GF), epoxy resin (ER), and ceramics) accounts for seventy percent of waste PCBs. Polymeric NmF includes most of the hazardous brominated flame retardants (BFRs). In this chapter, the recent trends, developments, and future perspectives of NmF direct and chemical recycling techniques, including combustion (in smelter or incinerator), pyrolysis, depolymerization processes with supercritical fluids, plasma treatment, gasification process, hydrothermal methods, hydrogenolysis degradation, and chemical leaching are reviewed and discussed. The thermal e-waste treatment eliminates plastic or ER components. Hydrothermal depolymerization and pyrolysis of waste PCBs with different solvents are presented here in detail. This chapter also focuses on and compares the clean production, recycling efficiency, and cost of various recycling methods. The key to promoting the development of the NmF recovery is to eliminate toxic elements during the recycling process. Current industrial processes and alternative processing perspectives are also presented. Keywords: Chemical recycling; nonmetal fraction; pyrolysis; depolymerization; solvents; leaching; subcritical fluids.