Upcycling waste polyethylene into graphitizable char

table showing ratio of NaCl to PE and CuCl<sub>2</sub> to PE, as well as char yield

CMI researchers at Oak Ridge National Laboratory conducted the research for this highlight

Innovation
A new processing method uses CuCl2 salt as a reactive surface area enhancer that increases cross-linking of polyethylene (PE) melts to increase the yield of graphitizable char.

Achievement 
The yield of graphitizable PE char was increased three-fold to 60% by weight by using CuCl2 salts to increase the effective surface area of PE melts during crosslinking and promote additional cross-linking that cannot be achieved when chemically inert salts (e.g., NaCl) are used.

Significance and Impact
Recent technoeconomic assessments by CMI indicate that improving PE char yields is a critical step for improving the energy efficiency and costs of chemical polarization induced graphitization (CPIG) of PE over conventional Acheson-based graphitization of pet coke feedstocks.

Hub Target Addressed 
Scalable materials processing for persistent challenges in graphite materials.
 

SEM Image of PE char produced using the CuCl2 stabilization method.
SEM Image of PE char produced using the CuCl2 stabilization method.