醇类抑制剂对甲烷水合物形成的影响

在本工作中,甲烷水合物的生长动力学是通过甲醇、乙醇、乙二醇三种不同醇类抑制剂存在下的分子动力学模拟研究的.模拟结果发现,三种醇类都可作为甲烷水合物的抑制剂,醇类分子中的亲水性羟基极大地破坏了水合物笼的结构,并且羟基可以与局部的液态水分子形成氢键,从而增加了形成水合物笼型结构的难度,导致甲烷水合物的生长速率降低.对于甲醇分子,甲醇分子的亲水性羟基与水分子形成氢键从而破坏了水分子结构,而亲油性甲基对周围的水分子具有簇效应,两者都会降低水合物生长速率;对于乙二醇和乙醇分子,它们只含有羟基,特别是乙二醇分子含有两个羟基,其对H₂O分子有很强的吸附作用,导致水合物生长速率降低.在抑制效果方面,甲醇分子最优,乙二醇稍微优于乙醇.

Effects of alcohol inhibitors on the formation of methane hydrate

In this work, the growth kinetics of methane hydrate is studied by molecular dynamics simulations in presence of three different alcohols inhibitors such as methanol, ethanol, and ethylene glycol. The simulation results show that the three alcohols can be used as inhibitors of methane hydrate. The hydrophilic hydroxyl groups in the alcohol molecules greatly destroy the structure of the hydrate cage, and the hydroxyl groups can form hydrogen with local liquid water molecules. The bond thereby increases the difficulty of forming a hydrate cage structure, resulting in the decrease in the growth rate of methane hydrate. For the methanol molecule, hydrophilic hydroxyl groups of methanol molecules form hydrogen bonds with water molecules to destroy the structure of water molecules, and the lipophilic methyl group has a cluster effect on the surrounding water molecules, both of which will reduce the growth rate of the hydrate; for the ethylene glycol and ethanol, they only contain hydroxyl groups, especially ethylene glycol molecules contain two hydroxyl groups, which has a strong adsorption effect on H2O molecules, resulting in a decrease in the growth rate of hydrates. In terms of inhibitory effect, methanol molecule is the best, and ethylene glycol is slightly better than ethanol.