Methane concentrations from gas hydrate dissolution laboratory experiments

This dataset reports methane concentrations from nine hydrate dissolution laboratory experiments. Experiments were conducted in a 600 mL stainless steel, bench top, cylindrical pressure chamber over 20 days. To form hydrate quickly, we utilized the surfactant sodium dioctyl sulfosuccinate (SDS). The chamber was filled with ~ 350 mL SDS- water and temperature was brought down to between 0 and 2˚C in the fridge. Hydrocarbon gases, either propane or methane, were introduced to the chamber using a needle valve. Using the source gas, the chamber was brought up to between 3 and 6 MPa pressure and the hydrate formed at the gas-water interface. Once hydrate was formed, it was flushed with a solution of 380 ppm SDS in distilled water, the headspace was flushed with nitrogen, and water samples were collected to determine the dissolution rate. Water samples were collected through a port interfaced to the bottom of the chamber with a needle valve. The needle valve was opened to a 6-port sampling valve with a 1 mL sample loop that opened to 20 mL gas tight syringe. Typically 1 mL of water and several milliliters of gas were collected. Samples were diluted to 20 mL total value with helium, and methane was extracted from the water by headspace equilibrium. Headspace methane concentrations were measured using a Gas Chromatograph– Flame Ionization Detector (GC-FID). This data can be used to calculate dissolution rates over time.