Kinetic Effects of Ionic Liquids on Methane Hydrate

• Published in: Energy & Fuels
• Main Authors: Shen, Xiao-dong, Zhou, Xue-bing, Liang, De-qing
• Format: Report
• Language: English
• Published: AMER CHEMICAL SOC 2019
• Subjects: DUAL FUNCTION INHIBITORS; PHASE-EQUILIBRIA; CO2 HYDRATE; DISSOCIATION CONDITIONS; INDUCTION TIME; AMINO-ACIDS; WATER; SOLVENTS; RISK; CHLORIDE; Energy & Fuels; Engineering; Chemical; Methane hydrate
• Online Access: http://ir.giec.ac.cn/handle/344007/24636; https://doi.org/10.1021/acs.energyfuels.8b03108

The kinetic effects of several kinds of ionic liquids (ILs) on the formation of methane hydrate were experimentally investigated on both the macroscale and microscale levels. These ILs were 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIm]-BF4), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm]-BF4), 1-butyl-3-methylimidazolium iodide ([BMIm]-I), and N-butyl-N-methylpyrrolidinium tetrafluoroborate ([Py14]-BF4). Formation temperature, max subcooling, induction time, and growth rate of methane gas hydrates were used to evaluate the kinetic effects of ionic liquids in a high-pressure cell and flow loop. As evaluated from the indicator of the formation temperature in the high-pressure cell, the sequence of inhibition performance of ILs was as follows: pure water < 1 wt % [EMIm]-BF4 < 1 wt % PVP < 1 wt % [BMIm]-I < 1 wt % [BMIm]-BF4 < 1 wt % [Py14]-BF4. ILs could not slow the growth rates of methane hydrate effectively and even promote the gas consumption rates irrespective of in a high-pressure cell or flow loop. RXRD spectra showed that ILs could not change the structure of methane hydrate. Cryo-scanning electron microscopy images showed that there was a porous texture of methane hydrate containing ILs. Raman spectra showed that ILs interact with the cages of methane hydrate.