In-situ sulfur fixation using aluminum-based sorbents during the pyrolysis of sulfur-containing waste polymers.
- 2026-04
- Journal of environmental management 405
- PubMed: 42025093
- DOI: 10.1016/j.jenvman.2026.129764
Study Design
- Methods
- Aluminum-based sorbents (M-Al-O, where M = Ca, Zn, Cu, Fe) were evaluated for in-situ sulfur capture performance during pyrolysis of sulfur-containing plastics (PPS).
Hazardous sulfur species (H2S, thiophenes, etc.) are released during pyrolysis of sulfur-containing plastics (PPS, etc.), challenging their recycling. Aluminum-based sorbents (M-Al-O, where M = Ca, Zn, Cu, Fe) were evaluated for in-situ sulfur capture performance. Results showed that all sorbents increased sulfur in char to 71.09-79.67%, compared to 48.56% without sorbent. The overall sulfur regulation performance followed the order: Cu-Al-O > Fe-Al-O > Ca-Al-O > Zn-Al-O. Ca-Al-O minimized sulfur in tar (6.71%) by inhibiting oligomer/thiophene formation. Zn-Al-O promoted PPS depolymerization but showed limited cracking activity, raising tar sulfur (8.19%). Cu-Al-O and Fe-Al-O achieved high H2S fixation (>92.40%). Cu-Al-O facilitated decomposition of dimers and trimers while promoting polycyclic thiophenes. Fe-Al-O exhibited limited tar sulfur suppression (7.45%) due to ineffective oligomer cracking. Based on these complementary mechanisms, a synergistic Ca-Cu-Al-O composite sorbent was designed. Sulfur fixation efficiency increased with sorbent loading (74.18-93.67%). At a 1:1 ratio, sulfur fixation efficiency reached 86.24%, and the tar sulfur concentration was reduced to 44,480 ppm, below the calculated additive value of 48,458 ppm. In this system, CuAl2O4 promoted the cracking of oligomers, reducing trimer content by 61.51-94.66%, while Ca3Al2O6 suppressed thiophene formation, decreasing benzodibenzothiophene intensity by 2.33-52.3%. Sulfur was fixed as CaS, which mitigated poisoning of copper active sites and preserved their catalytic activity for oligomer cracking. This work elucidates the role of aluminum-based sorbents in regulating sulfur transformation and provides a viable strategy for clean recycling of sulfur-containing plastics.
Research Insights
| Supplement | Dose | Health Outcome | Effect Type | Effect Size | Source |
|---|