Promoted disappearance of CO2 hydrate self-preservation effect by surfactant SDS

Abstract

Capture, storage and utilization of CO2 gas through the hydrate technology is deemed as a promising approach to solve the problem on global warming. After efficient transportation of CO2 gas with the self-preservation effect of hydrate, the dissociations of hydrate are required in some practical scenarios. In order to investigate the initial dissociation properties of hydrates while the self-preservation effect was removed, CO2 hydrates were formed in different experimental conditions and media and then frozen. After that, the self-preservation effect of hydrates was slowly removed through a uniform heating method. The measurement results exhibit that comparing with the pure water (PW), the initial dissociation temperatures (IDT) are significantly lowered by the silica gel powder (SG) and sodium dodecyl sulphate (SDS) solution (SS). Similarly, the initial dissociation rates (IDR) of hydrates are also reduced. These patterns are opposite to the traditional elucidating mechanism of the self-preservation effect of hydrate. Hence, the theory of ice shell was supplemented furthermore. In addition, it is found that the final duration time of the entire dissociation process of hydrate after losing the preservation effect presents obvious dependence on the initial dissociation rate (IDR). These findings are expected to provide some references for the future transportation of CO2 gas with the self-preservation effect of hydrate.