A comparison of kinetics and thermodynamics of methane hydrate formation & dissociation in surfactant and solid dispersed emulsion

Abstract

In the process of pipeline transportation, due to the internal high pressure and low temperature environment, hydrate particles tend to agglomerate and lead to blockage. The interfacial structure of Pickering emulsion can inhibit the combination of particles. Therefore, the formation and dissociation of hydrate in emulsion dispersed by surfactant and solid were studied. In addition, the pressure temperature equilibrium behavior of the reaction process has been studied extensively. Furthermore, the mechanism of interfacial interaction between the two in emulsion was also studied. The concentrations of Tween 20 and Cellulose Nanocrystals(CNCs) are 0.1░wt%, 0.3░wt% and 1░wt%. Compared with Tween 20, the presence of CNCs prolonged the induction time of hydrate formation and increased the final residual pressure in the formation stage. At the same time, the results show that the amount of methane needed for hydrate formation in CNCs is higher. After studying the decomposition enthalpy, it was found that as the concentration increases, T20░system moves towards low pressure and high temperature. However, due to the high viscosity of CNC system, the heat absorbed by hydrate is difficult to overflow, which shows that it moves towards high pressure and low temperature. Further the formation mechanism of hydrate and the molar consumption of methane gas were studied.