Insightfully understanding the process of volatiles from plastic depolymerization entering from the exterior into internal structure of catalyst favors to rationalize the catalyst design in scale-up principles. Herein, catalytic degradation of plastic wastes with fluid catalytic cracking catalyst (FCC) was investigated in-depth. The yield and composition of liquid and gas products over various FCCs were studied quantitatively. The structural evolution of catalyst on overall scope, including the topology of heterogeneous pore systems and spatial distribution of zeolite was probed by X-ray nano-CT. The results showed that FCC enhanced the transformation of C16-C30 chains to C9-centered monocyclic aromatics. The nano-CT analysis of FCCs illustrated remarkable loss of exterior porosity after reaction, particularly at the depth of ~16.5 μm from the outmost layer. While the interior pores were marginally affected, indicating large hydrocarbons incapable of engaging with active sites to full advantage, which preferably occupied large-size pores (>385 nm) of external surface. © 2022, The Authors. All rights reserved.
Bibliographical noteThe authors are grateful for financial supports provided by the Royal Society of Chemistry Enablement Grant (E21-5819318767) and Royal Society of Chemistry Mobility Grant (M19- 2899), National Natural Science Foundation of China (No. 51906110), the Natural Science Foundation of Jiangsu province, China (No. BK20190465). The authors gratefully acknowledge financial support from China Scholarship Council.
- Plastic wastes
- catalytic degradation
- zeolite catalyst
- structural evolution