PVC Waste to Fuel: Pyrolysis Oil Upgrading through Catalytic Hydrodechlorination.

Area of Science:

• Catalysis
• Chemical Engineering
• Materials Science

Background:

• Polyvinyl chloride (PVC) pyrolysis oil contains organochlorides, causing operational issues in fuel applications.
• Effective dechlorination is crucial for utilizing PVC pyrolysis oil as a cleaner fuel source.

Purpose of the Study:

• To investigate the hydrodechlorination (HDC) of PVC pyrolysis oil using palladium-based catalysts.
• To evaluate the performance of commercial Pd/C and homemade Pd/ZrO2 catalysts for chlorine removal.
• To optimize HDC conditions for efficient chlorine reduction in PVC pyrolysis oil.

Main Methods:

• Two-stage thermal pyrolysis of virgin PVC to produce pyrolysis oil.
• Analysis of oil composition and chlorine content using GC × GC with FID and AED.
• Catalyst characterization (H2-TPD, BET, SEM/EDS, XRD, XPS) and HDC testing on chlorobenzene and PVC pyrolysis oil.

Main Results:

• Two-step pyrolysis yielded PVC oil with 316 ppm chlorine content.
• Pd/C catalysts showed higher initial HDC efficiency than Pd/ZrO2 due to better Pd dispersion.
• Optimized HDC conditions achieved 82-89% chlorine removal from PVC pyrolysis oil.

Conclusions:

• Palladium-based catalysts, particularly Pd/C and Pd/ZrO2, are effective for hydrodechlorination of PVC pyrolysis oil.
• Catalyst performance is influenced by dispersion, reaction conditions (temperature, time), and catalyst type.
• Successful chlorine reduction enables the potential use of PVC pyrolysis oil in cleaner fuel production.