Effect of mechanoactivated chemical additives on the process of gas hydrate formation

Abstract

This study addresses the production of gas hydrate of methane with a high gas-hydrate-forming content in a solid phase in the isolated system at T=274 K and pressure of 5 MPa and presence of mechanically activated rocks close to the bottom of the chamber. We used mechanically activated samples of various degrees of grinding to increase an area of contact surface of heterogeneous phases. We carried out mechanochemical activation of materials in a vertical vibrating mill (VVM). In the study, we found out that formation of gas hydrates on activated aluminosilicates leads to the cryochemical synthesis of hydrocarbons, due to formation of additional reaction centers formed upon activation. This indicates a change in the mechanism of formation of GH during the process. We calculated three rate constants for the formation of GH of methane, which vary from 1.20×10-2 to 1.25×10-2 hour-1, based on semi-logarithmic anamorphosis. The study showed that formation of methane gas hydrates in presence of activated additives leads to formation of up to 5-6 % of ethane. Chromatographic method confirmed this. This indicates possibility of carrying out a low-temperature synthesis of higher hydrocarbons in the artificial production of GH, in contrast to the known mechanochemical transformations during the process of obtaining gas from gas hydrates.