Investigation of Methane Hydrate Formation in a Recirculating Flow Loop: Modeling of the Kinetics and Tests of Efficiency of Chemical Additives on Hydrate Inhibition

Summary Offshore natural-gas production from methane-hydrate (MH) reservoirs has received considerable attention. In this study, the offshore production method is briefly described, followed by the flow loop experiments performed to investigate the formation processes of MH in methane-in-water bubbly flows. Transient processes of phase transformation are characterized by phase paths, flow morphologies, pump heads, and in-situ particle-size measurements. It is realized that an MH slurry is generated by MH shells covering unconverted bubbles, whereas it can be transformed into a colloidal flow with fine crystalline particles under an intense turbulent shear. This study suggests that, in practice, the flow pattern under MH formation would be determined by the phase path and the flow velocity in the pipeline, which is one of the important factors considered in the evaluation of flow-assurance risks.

Download Full-text

Combination of Silica Gel and Surfactin Promoting Methane Hydrate Formation

Journal of Energy Resources Technology ◽

10.1115/1.4049318 ◽

2020 ◽

pp. 1-31

Author(s):

Amit Arora ◽

Swaranjit Singh cameotra ◽

Chandrajit Balomajumder ◽

Rajnish Kumar ◽

Anil Kumar Singh ◽

...

Keyword(s):

Silica Gel ◽

Gas Hydrate ◽

Methane Hydrate ◽

Fixed Bed ◽

Hydrate Formation ◽

Subtilis Strain ◽

Chemical Additives ◽

Gas Hydrate Formation ◽

Novel Applications

Abstract Recently gas hydrates based technologies have been exploited for few novel applications such as Storage and transpiration of natural gas, gas mixtures separation, CO2 capture ,seawater desalination etc. Most of these applications are currently facing a challenge of low rate of gas hydrate formation. Chemical additives like surfactants can play a role of a good kinetic promoter for gas hydrate formation. The present study reports application of biosurfactant for enhancing gas hydrate formation. Biosurfactant was produced by Bacillus subtilis strain A21. These types of microbes show their presence in the real gas hydrate sites also. The surfactin was characterized using many sophisticated technique conforming the formation of surfactin. It was used in presence of fixed bed media of silica gel and it was observed that surfactin in the presence of silica gel has increased the consumption of moles of methane as well as reduced the induction time also as well as the conversion was also increase up to 27.9 % for 390 minutes for 1000 ppm surfactin hence indicating it to be a clean and novel promoter of methane hydrate formation in combination with silica gel which can replace its synthetic counter parts which are having environmental concerns.

Download Full-text

Molecular dynamics screening for new kinetic inhibitors of methane hydrate

Canadian Journal of Chemistry ◽

10.1139/cjc-2015-0003 ◽

2015 ◽

Vol 93 (9) ◽

pp. 1043-1049 ◽

Cited By ~ 11

Author(s):

Paul A. Oluwunmi ◽

Aaron R. Finney ◽

P. Mark Rodger

Keyword(s):

Molecular Dynamics ◽

Methane Hydrate ◽

Hydrate Formation ◽

Nucleation And Growth ◽

Major Research ◽

Chemical Additives ◽

Chemical Additive ◽

Computational Screening ◽

Dynamics Simulations ◽

Oligomeric Compounds

The development of polymeric and oligomeric chemical additives that can control the nucleation and growth of gas hydrates remains a topic of major research interest, with important implications for energy security and the environment. In this paper we present a molecular dynamics study of eight different oligomeric compounds that have been proposed as potential kinetic inhibitors for methane hydrate. The results show that statistically significant variations in hydrate formation, induced by the chemical additive, can be observed within a relatively modest series of molecular dynamics simulations, thus opening the way for computational screening for optimal additives to control hydrate formation. One amino acid oligomer, asparagine, was found to be more active than a number of synthetic inhibitors, including PVCap.

Download Full-text