Zeolites are microporous aluminosilicate materials commercially used as both catalysts and adsorbents for separations. Key uses for zeolites in LNG production include gas dehydration (all scales), acid gas sweetening (small scale), removal of mercury (all scales) and other contaminants such as nitrogen (small scale). However, these zeolites often represent a significant operational cost either because of the requirement for frequent replacement (mercury capture) or because of their proprietary nature (nitrogen rejection). In this project, low cost zeolites with equivalent functionality will be synthesised from waste fly ash produced in coal-fired power plants. The PhD student will develop and test synthesis methods and characterise the separation performance of the resulting fly-ash zeolite. Billions of tonnes of waste fly ash are produced annually by countries like Australia and particularly China that rely on coal combustion for power, representing an immense environmental hazard. Methods of recycling fly ash for construction materials have been investigated but insufficient progress has been made on the scale required. However, the siliceous and aluminous nature of fly ash makes it a suitable source for the synthesis of zeolites. This project will provide a better, cheaper and greener method of recycling fly ash by producing functional low cost zeolites for natural gas separations. Such outcomes will help reduce emissions from both the LNG and coal industries.
Synthesising Low Cost Zeolites from Fly Ash
