Enhanced formation kinetics of hydrates using 1,3-dioxolane, l-leucine, and β-cyclodextrin

Abstract

As the cleanest fossil fuel, natural gas (NG) plays an important role in energy supply systems and the carbon cycle worldwide. However, given the rapid increase in NG demand, there exists a compelling need for more efficient NG storage and transportation technology. Recently, solidified natural gas (SNG) technology has received increasing attention because of its safety, low cost, and flexibility. In this work, tetrahydrofuran (THF) and 1,3-dioxolane (DIOX), two dual-effect promoters (kinetic and thermodynamic), were investigated for use in SNG technology. The promotion effect of environmentally friendly l-leucine and β-cyclodextrin as co-promoters was also examined. This is the first study to our knowledge of the synergistic effects of DIOX, l-leucine, and β-cyclodextrin on the kinetics of hydrate formation at a near ambient temperature. The results showed that the methane uptake in DIOX solution was 46.28% higher than that in THF solution under the same conditions, and DIOX is less harmful to the environment and the human body. This indicates that DIOX is more valuable for application than THF. l-leucine and β-cyclodextrin were both useful in enhancing hydrate formation kinetics, but l-leucine was more effective. T90 was reduced by l-leucine and β-cyclodextrin by a maximum of 42.08% and 28.67%, respectively. Rapid hydrate formation kinetics demanded a higher driving force, according to controlled experiments at a near ambient temperature with varied driving forces. Additionally, varied NaCl concentrations promoted hydrate nucleation while reducing the gas storage capacity. This work contributes to a safer, more stable, and environmentally friendly SNG technology at a close ambient temperature.