Polystyrene (PS) is one of the most important polymers in the plastic sector due to its
inexpensive cost as well as many preferred properties. Its international market is
expected to achieve $28.2 billion by 2019. Although PS has a high calorific value of 87 GJ
tonne-1, there is no a practical method to manage its waste but landfill. As a result, the
PS debris in the oceans has reached 70% of the total plastic debris. This issue is
considered as the main economical and environmental drivers of converting polystyrene
waste into renewable chemical feedstocks.
The aim of this work is to develop a catalyst for converting PS into renewable chemicals
under mild conditions. We introduce FeCu/Alumina with excellent catalytic activity to
fully degrade polystyrene with 66% liquid yield at 250 °C. The GC/MS confirmed that the
primary products are in the gasoline range. Next, we present the bimetallic
FeCo/Alumina and successfully we have obtained 100% PS conversion and 90% liquid
yield with maintaining the products selectivity. Later, the tri-metallic FeCuCo/Alumina
was synthesized and showed 100% PS conversion and 91% liquid yield. Surprisingly,
ethylbenzene was the major product in which 80 wt. % was achieved with excellent
reproducibility. Furthermore, the real waste Styrofoam was thermally and catalytically
degraded at 250 °C. Interestingly, a high styrene content of 78 wt. % was recovered
after 30 minutes of the reaction under mild conditions. Keeping in mind that a good
balance between acidity and basicity is required to convert PS into aromatic under mild
reaction conditions catalytically. Finally, the performance of the catalysts was compared
to literature reports and showed novel liquid yields. In conclusion, we have synthesized
cheap, easy to scale up, and efficient catalysts to fully degrade PS into high liquid yields
of aromatics with excellent selectivity.
Date of Award | Aug 2017 |
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Original language | English (US) |
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Awarding Institution | - Physical Sciences and Engineering
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Supervisor | Kuo-Wei Huang (Supervisor) |
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- Polystyrene
- Ethylbenzene selectivity
- Low-temperature
- Catalytic degradation
- Styrene selectivity
- Renewable-aromatics