Chemoinformatic design of amphiphilic molecules for methane hydrate inhibition (original) (raw)

ARTICLE Molecular dynamics screening for new kinetic inhibitors of methane hydrate

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. Résumé : La mise au point d'additifs chimiques polymériques et oligomériques permettant de maîtrise la nucléation et la croissance des hydrates de gaz demeure un sujet de recherche suscitant un grand intérêt, et dont les retombées auront une incidence importante sur la sécurité énergétique et l'environnement. Dans le présent article, nous présentons une étude de dynamique moléculaire portant sur huit composés oligomériques différents qui sont proposés en tant qu'éventuels inhibiteurs cinétiques de la formation de l'hydrate de méthane. Les résultats indiquent que l'on peut observer des variations quant a ` la formation de l'hydrate, significatives sur le plan statistique et induites par l'additif chimique, dans une série relativement restreinte de simulations de dynamique moléculaire. Ces résultats ouvrent ainsi la voie au criblage in silico d'additifs possédant les propriétés optimales pour maîtriser la formation des hydrates. Un oligomère d'acide aminé, a ` base d'asparagine, s'est révélé plus actif que plusieurs inhibiteurs synthétiques, dont le PVCap. [Traduit par la Rédaction] Mots-clés : hydrate de méthane, hydrates de gaz, clathrates, dynamique moléculaire, inhibiteurs cinétiques, nucléation.

Molecular dynamics screening for new kinetic inhibitors of methane hydrate

Canadian Journal of Chemistry, 2015

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.

Evidence of Structure-Performance Relation for Surfactants used as Anti-Agglomerants for Hydrates Management

Langmuir : the ACS journal of surfaces and colloids, 2017

Molecular dynamics simulations were employed to study the structure of molecular-thin films of anti-agglomerants adsorbed at the interface between sII methane hydrates and a liquid hydrocarbon. The liquid hydrocarbon was composed of dissolved methane and higher molecular weight alkane such as n-hexane, n-octane, or n-dodecane. The anti-agglomerants considered were surface-active compounds with three hydrophobic tails and a complex hydrophilic head that contains both amide and tertiary ammonium cation groups. The length of the hydrophobic tails and the surface density of the compounds were changed systematically. The results were analyzed in terms of the preferential orientation of the anti-agglomerants, density distributions of various molecular compounds, and other molecular-level properties. At low surface densities the hydrophobic tails do not show preferred orientation, irrespectively of the tail length. At sufficiently high surface densities, our simulations show pronounced dif...

Molecular simulations as a tool for selection of kinetic hydrate inhibitors

Molecular Simulation, 2005

The possible effects of tour different functional groups that operate in kinetic hydrate inhibitors have been examined by molecular dynamics simulations, with focus on their possible effects at the hydrate surface. New simulations for models of PVCAP (Poly(N-vinylprolactam)) and another functional group that takes part in the inhibitor VC-713 are presented and discussed in relation to previously published results for PVP (Poly(N-vinylpyrrolidine)). A modified version of the PVCAP polymer is also suggested. In addition a monomer of the polymer chitosan is also simulated. Simulated results are discussed in relation to observations from experiments on real systems. For the model systems in this study we find that PVPCAP has more favourable interaction properties with hydrate water than PVP and should, according to the simulations presented in this paper, have better properties as a kinetic hydrate inhibitor than PVP. A modified version of the PVP monomer, where a hydroxyl group is added to the ring, increases the attachment to the hydrate surface further. In VC-713 a third group is alternating with PVP monomers and PVCAP monomers as the functional groups attached to the paraffinic backbone. The simulations of this particular group indicate favourable interactions between hydrate water and for the limited monomer simulated in this study, practically all coloumbic interaction between this group and water is devoted to connections with the hydrate crystal. A monomer of chitosan is also simulated and although this monomer has strong attachment energy to the hydrate surface it also has very favourable interactions with liquid water. It is, therefore, somewhat unclear whether this polymer would have a sufficient attachment to a hydrate in the competition with a liquid water environment.

Design of Methane Hydrate Inhibitor Molecule Using Density Functional Theory

Journal of Cluster Science, 2014

A strategy for designing methane hydrate inhibitor molecule has been established depending upon geometrical parameters, interaction energy, highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) structures and energies, natural bond orbital (NBO) analysis, potential energy curve, Mullikan charge, IR intensity and red shift. One methane hydrate inhibitor molecule namely 2, 2'-oxydipropane-1, 3-diol has been designed based on the established design strategy. Theoretical study of effectiveness of the designed inhibitor molecule has been performed for methane hydrate pentagonal dodecahedron cage (1CH 4 @5 12) using WB97XD/6-31++G(d,p). Calculated geometrical parameters, interaction energies and HOMO LUMO study indicate that reduction of the strength of hydrogen bonded network of 1CH 4 @5 12 cage is more by designed inhibitor 2,2'oxydipropane-1,3-diol compared to conventional thermodynamic inhibitor (methanol) and consequently 2,2'-oxydipropane-1,3-diol can be more effective methane hydrate inhibitor than methanol.