COLD ENERGY STORAGE USING HYDRATES

Abstract

The energy demand for space cooling has more than three times in the last three decades, resulting in very large annual CO2 emissions (about 1Gt). The continuous increasing energy demand for space cooling has raised a difficult dilemma on how to improve cooling process energy efficiency. As a result, there is a pressing need to find a PCM that can effectively utilize the cold energy emitted from the industrial sectors for storage and transportation to the required sectors. In the present work, semi-clathrate hydrate is studied as a PCM for cold energy storage for cooling processes. Semi-clathrate hydrates with an appropriate phase change temp. (5-27⁰C) and high dissociation heat (190-220 kJ/kg) stand out as a good candidate for (a) storing and transporting cold energy and (b) improving the energy efficiency of cooling operations synergistically among all PCMs. Semi-clathrate hydrates resemble gas hydrates, which are made up of water and tiny gases like methane, carbon dioxide, and hydrogen. The ionic compounds are firmly embedded in the cage-like network, and they also form hydrogen bonds with the cage water molecules. It offers better heat transfer properties as compared to ice and eutectic salts. Due to good thermal conductivity, heat storage capacity, and other properties, they are suitable for cooling medium, and they provide numerous advantages over other PCM in terms of cost and environmental aspects. It was found that semi clathrate of TBA, TBP, THF, and some others are more stable than low-pressure applications. It motivates us to find the best semi-clathrate hydrate among several hydrates as PCM for the cooling processes. Present work includes different SCHs properties and providing the best hydrates for cooling applications.