关键词: 甲烷, 叔丁胺, 混合水合物, 储气

Abstract: The formation of hydrate in a methane-tBuNH2 (tert-butylamine)-water system without stirring was studied at 6℃ at different pressures (2.50, 3.50 and 4.50 MPa) and at different initialization reaction quantities (30.0 and 100.0 g). The results showed that the hydrate in this system was pasty, and the reaction rate with CH4 increased when the reaction pressure increased. There is no clear relationship between the reaction pressure and the final CH4 storage capacity (the ratio of volume of CH4 in hydrate to that of initialization reactant at standard condition, mL/mL) while 30.0 g sample was loaded in the reactor, and the final CH4 storage capacity decreased when the reaction pressure increased while 100.0 g sample was loaded in the reactor (5.4 mL/mL at 2.50 MPa, 0.9 mL/mL at 4.50 MPa). Two hydrate structures, Structure VI and Structure II, may form simultaneously in the reaction, and the ratio of the amount of tBuNH2 Structure VI hydrate to that of CH4/tBuNH2 Structure II hydrate may increase in the end of the reaction time, and the methane-tBuNH2-water system at xtBuNH2=9.3% is not suitable to store the CH4 by formation of the hydrate as the maximal CH4 storage capacity is only 5.4 mL/mL. It is considered that hydrate formation mechanism may undergo three steps: contacting and gathering of reactants molecules, forming of hydrate framework, and growing of hydrate.

Key words: methane, tert-butylamine, double hydrate, gas storage