OS5A-4:KINETICS OF METHANE HYDRATE FORMATION IN A GAS-INDUCING AGITATED REACTOR WITH LOW CONCENTRATION SODIUM DODECYL SULFATE

Jianwei DU and Liguang WANG
School of Chemical Engineering, The University of Queensland, AUSTRALIA

    The slow kinetics of methane hydrate formation remains an impediment to advancing the hydrate-based gas transport technologies. Surfactants such as sodium dodecyl sulfate (SDS) are known to speed up hydrate formation in unstirred static reactor, but the required surfactant dosage was prohibitively high for natural gas transport. In this study, isochoric formation kinetics of methane hydrate was investigated in a 362.5 ml gas-inducing agitated reactor loaded with 75 ml aqueous solutions of SDS. The incipient experimental condition was 274.2 K and 10 MPa. Compared to the static tests with 1×10-2 M SDS solutions, gas-inducing agitation at 600 rpm with 5×10-4 - 1×10-3 M SDS solutions gave higher hydrate formation rate, higher probability of forming hydrate within a given time period (e.g., 4 hours), and almost the same gas storage capacity (84% – 87% of theoretical capacity). The enhanced methane hydrate formation kinetics can be attributed to the significant increase in gas-liquid contact area, with the coalescence of induced gas bubbles being inhibited by SDS at concentrations well below the critical micelle concentration.