Formation and dissociation of carbon dioxide hydrate in presence of (NH4)2SO4: experimental characterization of the inhibition produced on the process.

Abstract

Gas hydrates are mainly known as potentially alternative energy source and the research is mainly focused in making this source accessible, competitive and carbon neutral, by accompanying the recovery of methane with the permanent disposal of carbon dioxide. However, hydrates formation and dissociation can be advantageously applied in several key processes, such as gas mixture separation, gas storage and transportation, cold energy storage, desalination and waste water treatment. This study deals with these wo latter processes. Carbon dioxide hydrates were formed and dissociated in a pure water mixed with (NH4)2SO4. Two different scopes were pursued: the thermodynamic characterization of the inhibiting action due to the presence of electrolytes diffused in the aqueous phase and the possibility of considering hydrates formation as a potential strategy for NH4 + removal from water, since the formation of clathrate structures rarely involves ions and other particles diffused in water. A lab – scale apparatus was used for the production of hydrates.