초록 |
CO2 is a representative greenhouse gas causing global warming effects, and its emission is continuously increasing due to the use of fossil fuels. Therefore, it is necessary to separate CO2 from the gas mixtures emitted from the plant. Several technologies including absorption, adsorption, and membrane separation can be applied to CO2 separation, but these methods are economically inefficient as they require a pretty large amount of energy to operate, and the separation efficiency is not high enough. Gas hydrate is a crystalline compound in which gas molecules are captured in a lattice structure of water molecules connected by hydrogen bonds. The well-known crystal structures are sI, sII, and sH. Thermodynamic conditions required to form hydrates change with the gas species/compositions, and thus CO2 can be selectively separated from the gas mixtures. For such a process, chemical additives are often used to lower the pressure required to form hydrates and accelerate their formation. In this study, several amino acids including L-methionine, L-leucine, and L-isoleucine were used to promote CO2 hydrate formation. The optimal selection and use of additives will be discussed. |