A MULTI-STEP DISSOCIATION METHOD FOR CH₄ STABILITY STUDY IN NABR, KBR SOLUTIONS

An experimental setup has been built to study the stability conditions of gas hydrate. The stability conditions of methane hydrate in solutions with different salt concentration are preliminarily investigated using multi-step dissociation method. In this paper, P-T conditions of methane hydrate have been measured in four kinds of solutions containing various concentrations of NaBr and/or KBr. The results show that the influence of Na⁺ ion under certain P-T conditions is stronger than K⁺ ion under same concentration. In the NaBr and KBr solutions with concentrations of 0.2mol/L and 0.3mol/L, the equilibrium points of methane hydrate were (0.5±0.1) K and (0.2±0.1) K, and (1.0±0.1) K and (0.5±0.1) K respectively, lower than those in a pure water system.