E-waste derived silica-alumina for eco-friendly and inexpensive Mg-Al-Ti photocatalyst towards glycerol carbonate (electrolyte) synthesis: Process optimization and LCA

Waste Manag. 2022 Mar 1:140:213-224. doi: 10.1016/j.wasman.2021.11.022. Epub 2021 Nov 24.

Abstract

Valorization ofe-waste, i.e. waste printed circuit board (WPCB) through mechano-chemical activation to obtain silica as the catalyst support and alumina as the catalyst precursor for eco-friendly synthesis of inexpensive highly proficient photocatalyst has been explored. The WPCB derived silica-supported layered double oxide photocatalyst (MATLSW) and its counterpart (MATLSC) involving commercial silica and alumina precursors were synthesized through the wet-impregnation method under energy-efficient solar simulated quartz halogen lamp (SSQHL) irradiations to improve its photocatalytic properties compared to conventional methods. The prepared MATLSWpossessed a significantly low band-gap-energy (1.58 eV) that rendered efficient photocatalysis in the green-synthesis of glycerol carbonate (GC) (an effective electrolyte). The catalytic performance of the optimal MATLSWresulted in a superior yield of GC (98.68%) compared to that rendered by MATLSCcatalyst (GC yield: 96.56%) at optimal process conditions. Detailed life cycle assessment (LCA) of the entire process (deploying Ecoinvent 3.5 database) dictated conducive environmental impacts concerning 1 kg GC synthesis alongside a scale-up study for 1 MT GC synthesis encompassing silica-alumina extraction from WPCB, MATLSW preparation, and employment of SSQHL-radiated batch reactor (SSQHLBR) (56.64% less energy consumption than conventional). The overall process deploying the novel MATLSWin conjunction with the effectual reactor demonstrated superiority over the conventional GC synthesis process through appreciable reductions of environmental impact parameters, namely GWP, FDP, and HTP by 5.78%, 3.60%, and 5.72% respectively. The developed green process for e-waste utilization can procreate an effective waste management protocol towards a cleaner world.

Keywords: E-waste Valorization; Glycerol carbonate; LCA; LDO photocatalyst; PCB derived silica-alumina; Solar simulated quartz halogen radiation.

MeSH terms

  • Aluminum Oxide
  • Carbonates
  • Electrolytes
  • Electronic Waste*
  • Glycerol*
  • Silicon Dioxide
  • Titanium

Substances

  • Carbonates
  • Electrolytes
  • Silicon Dioxide
  • Titanium
  • Aluminum Oxide
  • Glycerol