Formation Kinetics of Structure I Clathrates of Methane and Ethane Using an <i>in Situ</i> Particle Size Analyzer

Abstract

Experimental data on the kinetics of structure I (sI) clathrate formation were obtained for pure methane and pure ethane in a semi-batch stirred-tank reactor that is equipped with an in situ particle size analyzer. The particle size analyzer used is a Lasentec focused beam reflectance measurement (FBRM) probe capable of measuring particle chord lengths between 0.5 and 100 μm. Experiments were conducted at temperatures ranging from 274 to 282 K and with pressures ranging from 0.99 to 7.25 MPa. A novel procedure for cleaning the FBRM probe tip, which eliminated the need to remove the probe between runs, was developed. Experimental data on the pressure, temperature, and particle size distribution were analyzed using the approach of Clarke and Bishnoi (Clarke, M. A.; Bishnoi, P. R. Determination of the intrinsic kinetics of CO2 gas hydrate formation using in situ particle size analysis. Chem. Eng. Sci. 2005, 60, 695−709), with minor modifications, and intrinsic rate constants were obtained for methane and ethane in sI.