Converting Plastic Wastes to Naphtha for Closing the Plastic Loop
Lin Li, Hu Luo, Zilong Shao, Haozhi Zhou, Junwen Lu, Junjun Chen, Chaojie Huang, Shunan Zhang, Xiaofang Liu, Lin Xia, Jiong Li, Hui Wang, Yuhan Sun
Abstract
To solve the serious environmental problem and huge resource waste of plastic pollution, we report a tandem catalytic conversion of low-density polyethylene (LDPE) into naphtha, the key feedstock for renewable plastic production. Using β zeolite and silicalite-1-encapsulated Pt nanoparticles (Pt@S-1), a naphtha yield of 89.5% is obtained with 96.8% selectivity of C 5 –C 9 hydrocarbons at 250 °C. The acid sites crack long-chain LDPE into olefin intermediates, which diffuse within the channels of Pt@S-1 to encounter Pt nanoparticles. The hydrogenation over confined metal matches cracking steps by selectively shipping the olefins with right size, and the rapid diffusion boosts the formation of narrow-distributed alkanes. A conceptual upgrading indicates it is suitable for closing the plastic loop, with a significant energy saving of 15% and 30% reduced greenhouse gas emissions.