Effects of Lignite Fly Ash on the Degradative Pathways of Aqueous Amine Solvents
The investigation of the catalysis of the side reactions that affect alkanolamine solvents used in post-combustion carbon capture has been focused on dissolved metals present alongside them. These metals enter the process by way of suspended fly ash present in flue gas from coal-fired power stations. Once present in the solution, they dissolve to produce soluble metal species, which interact with alkanolamine present. The fly ash is composed of aluminosilicate with metals interspersed throughout. The influence of the presence of fly ash in model solutions was investigated. It was found increase the degradation rate significantly, and products unique to this study were identified. The fly ash was characterized post-trial by spectroscopic and physical methods. A large increase in the adsorption capacity of pyridine in the post-reactor sample was attributed to an increase in the availability of Lewis acid sites on the particle surface. Furthermore, this study found that the aluminosilicate structure of fly ash remains intact, with significant portions of transition metals retained following exposure to post-combustion carbon capture model solution conditions.
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Faculty of Graduate Studies and Research, University of Regina