Study on the Promotion of Gas Hydrate Generation by Three Different Electric Field Waveform Signals in Synergy with Surfactants

The rapid development of the natural gas hydrate industry has put forward higher requirements for hydrate promotion technology. The exploration of methods that can simultaneously enhance both the hydrate formation rate and the final gas and water conversion efficiency has become a critical research focus. This study systematically investigated the synergistic effects of electric field (EF) signals, including three distinct waveforms (square, sine, ramp wave) at six different voltage levels, combined with four concentration gradients of the cationic surfactant called hexadecyl trimethylammonium bromide (CTAB) on the CH4 hydrate formation process. Experimental results demonstrated that the application of external EF significantly enhanced the gas storage capacity of hydrate, with different waveforms exhibiting varying degrees of promotional effects. Notably, square wave and ramp wave, which allow for instantaneous changes in the EF direction, exhibited superior performance in improving hydrate formation rates and gas and water conversion efficiency and enhancing hydrate fluidity. Furthermore, a kinetic model for hydrate formation was developed, which showed excellent agreement with the observed results. These findings not only advance the theoretical framework of EF-assisted hydrate formation but also provide valuable insights and practical guidance for the development of natural gas hydrate technologies.