Kinetics of methane hydrate formation in saline droplets/copper foam composite system
Improving seawater hydration storage rate and storage density is crucial for the large-scale application of hydrate technology.A certain concentration of NaCl solution was dispersed with hydrophobic fumed nano-silica by high-speed stirring into micrometer-sized saline droplets.Under the conditions of 8.0 MPa and 274.15 K,methane hydrate storage experiments were conducted by using saline droplets with different silicon contents to study the kinetic characteristics of methane hydrate formation.With a gas storage capacity of 141.01 cm3·cm-3 and a gas storage rate of 7.37 cm3·cm-3·min-1,saline droplets with a silicon content of 2.5%(mass)demonstrated the best dispersibility and gas storage performance,according to the data.The silicon-containing brine droplets are further filled into the open-pore copper foam to construct a saline droplet/copper foam composite hydration gas storage system.It is discovered that the three-dimensional nested metal framework of copper foam can significantly accelerate the transfer of hydration reaction heat and improve the gas storage performance of saline droplets hydration.At 5.0-8.0 MPa,compared to the saline droplets single system,the hydration gas storage capacity of the composite system is increased by 4.72%-21.70%,and the maximum gas storage rate is increased by 38.25%-110.58%.