Effect of Eco-Friendly Cyclodextrin on the Kinetics of Mixed Methane–Tetrahydrofuran Hydrate Formation

Abstract

Use of environmentally friendly additives to promote methane hydrate formation is an active area of research for gas storage via solidified natural gas (SNG) technology. The key advantages of SNG technology include a high degree of safety and a compact mode of natural gas storage in comparison to conventional methods of NG storage. In this paper, we evaluate the effect of β-cyclodextrin as a kinetic promoter for mixed methane−tetrahydrofuran hydrate formation. β-Cyclodextrin is an eco-friendly cyclic oligosaccharide containing seven glucose monomers that form a ring structure. The concentration of β-cyclodextrin was varied under different hydrate forming conditions (temperature and pressure), and the formation kinetics along with the morphology of mixed hydrate formation were observed. It is found that β-cyclodextrin served as an effective kinetic promoter for mixed methane–tetrahydrofuran hydrate formation at moderate pressure and temperatures in a simple unstirred reactor configuration. Further, no foam formation was observed during the hydrate dissociation that envisages an enhanced gas recovery and suitability of SNG technology for methane storage.

Alleviation of Foam Formation in a Surfactant Driven Gas Hydrate System: Insights via a Detailed Morphological Study

“…It has been documented in literature that ecofriendly amino acids when employed as kinetic promoters did not result in foam formation unlike the conventional SDS surfactant. − Further, Veluswamy et al. , provide morphology evidence of the absence of foam formation in the presence of amino acids. Lin et al report β-cyclodextrin’s ability to prevent foam formation during the mixed methane/THF hydrate formation. Though the listed compounds possess the inherent ability to prevent foam during hydrate formation, in selected applications, it might be necessary to add antifoaming agents along with surfactants in order to avoid compromise in the intended kinetic performance.…”

Defective Ultrathin ZnIn2S4 for Photoreductive Deuteration of Carbonyls Using D2O as the Deuterium Source

“…The hexagonal Moiré pattern resulting from interference between the crystalline lattices of the stacked nanosheets in D‐ZIS could also be observed (inset of Figure 1C), which further confirmed its 2D ultrathin structure. [ 25 ] In fact, the thickness of D‐ZIS was estimated to be ≈1.3 nm (Figure 1D) based on the atomic force microscopy (AFM) analysis. Such a thin thickness was consistent with the size of a half unit cell of ZnIn 2 S 4 along the [001] axis (model of Figure 1A).…”

Kinetics of Methane Hydrate Formation in the Presence of 1-Dodecyl-2-pyrrolidinone and Tetrahydrofuran in Pure Water

“…Their results showed that the methane uptake improvement was about 11.6 times higher with the presence of THF as a promoter. Similar to the experimental conditions of this study, Lin et al investigated the effect of 5.6 mol % THF at 283.2 K and 5 MPa in the presence of biofriendly cyclic oligosaccharide beta-cyclodextrin. They reported a higher methane uptake and faster rate of hydrate formation in the presence of 5.6 mol % of THF.…”