Abstract:

Gas hydrate technology has broad application prospects in the seawater desalination, hydrate cold storage, carbon dioxide storage, etc. The hydrate formation speed is one of the key issues restricting the application of hydrate technology. The CO₂ hydrate formation with rhamnolipid enhancement were studied using a self-built CO₂ hydrate generation visualization experimental device, and the effects of rhamnolipids on gas consumption, induction time and morphological images during the formation of CO₂ hydrate were analyzed. The results showed that in the rhamnolipid solution, the gas consumption was increased by 4.47mmol/mol, but the induction time was shortened by 260min, comparing with pure water. It is found that the induction time of hydrate formation in 0.2% rhamnolipid solution was the shortest, and then the continuous increase of concentration inhibited the growth of hydrate from the study of the CO₂ hydrate formation characteristics in different concentrations of rhamnolipid solution. In addition, there was a linear relationship between the induction time and the initial temperature change in the system because the CO₂ hydrate gas consumption decreased with the increase of initial temperature which led to decrease in the degree of supercooling. The increase of initial pressure resulted in shortening induction time and reducing the amount of hydrate formation. There were great differences in the morphological images of CO₂ hydrate formation in rhamnolipid solution under different generation conditions.

Key words: carbon dioxide hydrate, rhamnolipids, mass transfer, heat transfer, morphology

摘要：

气体水合物技术在海水淡化、水合物蓄冷、CO₂封存等领域有着广阔的应用前景，水合物生成速度缓慢是制约水合物技术应用的关键问题之一。本文利用自主搭建的CO₂水合物可视化生成实验装置进行鼠李糖脂强化CO₂水合物生成的实验研究，分析鼠李糖脂对CO₂水合物生成过程中耗气量、诱导时间及形态学图像的影响。结果表明，与纯水相比，鼠李糖脂溶液中气体消耗量增加了4.47mmol/mol，且诱导时间缩短了260min。对不同质量分数的鼠李糖脂溶液中CO₂水合物生成特性进行研究发现，0.2%的鼠李糖脂溶液中水合物生成的诱导时间最短，质量分数持续增大会抑制水合物的生成。初始温度升高导致过冷度降低，CO₂水合物耗气量随之减少，认为体系内的诱导时间与初始温度变化存在一定的线性关系。初始压力的增大，缩短了诱导时间但降低了水合物生成量。不同生成条件下的鼠李糖脂溶液中CO₂水合物生成过程中形态学图像存在差异。

关键词: CO₂水合物, 鼠李糖脂, 传质, 传热, 形态学