HCFC-141b hydrate formation with amino acid surfactants: Insights into hydrate formation promotion mechanism

Surfactants are good promoters for hydrate nucleation and growth. The hydrate promoting mechanism study by surfactants is very important for hydrate application technology. Amino acid surfactants (AAS) are environmentally friendly and easily degradable surfactants. Five AAS are used to investigate the influence on hydrate nucleation and growth. HCFC-141b is effectively dispersed in water by AAS. AAS with head group glutamic acid and longer aliphatic acyl chain can effectively promote hydrate for-mation. Sodium cocoyl glutamate and sodium stearoyl glutamate improve and stabilize hydrate nucle-ation. The hydrate conversion rate and hydrate cooling storage capacity by adding the optimal mass fraction of sodium cocoyl glutamate or sodium stearoyl glutamate is similar. Hydrate nucleation and growth are studied using microscopic imaging techniques. Hydrate nucleus first appear at the surface of HCFC-141b droplets. Hydrophobic HCFC-141b droplets formed under the help of AAS is the key to improve hydrate nucleation and growth.(c) 2023 Elsevier Ltd. All rights reserved.

Automated summary

Surfactants play a significant role in promoting the nucleation and growth of hydrates. Understanding the promoting mechanism of hydrates by surfactants is crucial for hydrate application technology. Amino acid surfactants are environmentally friendly and easily degradable, and they have been used to investigate their effects on hydrate formation. Specific amino acid surfactants with glutamic acid as the head group and longer aliphatic acyl chains prove to be effective in promoting hydrate formation. Sodium cocoyl glutamate and sodium stearoyl glutamate enhance and stabilize hydrate nucleation. Microscopic imaging techniques reveal that hydrate nucleation first occurs at the surface of HCFC-141b droplets, and the formation of hydrophobic HCFC-141b droplets with the help of amino acid surfactants is the key to improving nucleation and growth.