Enhanced natural gas hydrates formation in the suspension with metal particles and fibers

The relatively slow gas storage rate as well as poor storage capacity of the static hydration system are still major challenges in the large-scale practical application of hydrate technology. Sodium dodecyl sulfate (SDS) solutions containing suspended copper particles (CP) and stainless steel fibers (SSF) were used for natural gas storage in clathrate hydrates at 4.0–7.0 MPa and 274.15 K. The particles and fibers in the suspension provided a large number of metal nuclei for crystallization, especially the fibers acted as metal pathway for crystallization heat transfer. The enhanced effect of CP and SSF on gas capture in hydrates was concluded through kinetics comparison of hydrates formation in the suspension and in a simple surfactant solution. In the SDS/CP–SSF system, the time required to reach the storage capacity of 100 cm3·cm−3 was shorter not only than that in the SDS solution but also than that in the CP suspension at each pressure. The hybrid suspension exhibited higher gas storage capacities (112.6–149.2 m3·m−3) and larger storage rates (7.54–39.47 cm3·cm−3·min−1) at the applied pressures, increasing by 35.6–173.0% and 19.8–26.2%, respectively, over those of the simple surfactant solution. A “point (CP)–line (SSF) model” was proposed to illustrate the synergetic enhancement effect of the CP and SSF on hydrate nucleation and heat transfer.