Jeong HC  Kim AR  Lim JH  Won YS

Vol. 22,  No. 3, pp. 154-160, Sep.  2016
10.7464/ksct.2016.22.3.154

Gas hydrate R-134a (HFC-134a) Edible surfactants Density functional theory (DFT) Kinetics

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For any conceivable desalination process using the gas hydrate formation, the kinetics has to be one of the most important parameters from the economic point of view. We thus were to improve the kinetics of the R-134a (also known as HFC-134a) gas hydrate formation by using promoters and three different kinds of edible surfactants were selected for the desalination process targeted to produce potable water; κ-carrageenan, lecithin, and polysorbate 80 among anionic, amphoteric, and nonionic surfactants, respectively. Then, the kinetics change of the R-134a hydrate formation was monitored by varying the surfactant concentration. Experimental results demonstrated that the rate of R-134a hydrate formation increases with the addition of edible surfactants in general and the effect as a promotor has an order of polysorbate 80 > κ-carrageenan > lecithin. As a supportive measure, the atomic charges of each surfactant were calculated by using a DFT (density functional theory)-based molecular modeling and the results showed a positive relationship between the promotor effect of each surfactant and the number of oxygens available for hydrogen bonding and the negativity of their atomic charge values.