Effects of waxes on hydrate behaviors in water-in-oil emulsions containing asphaltenes. (23rd November 2021)

• Record Type: Journal Article
• Authors: Zhang, Dongxu; Huang, Qiyu; Li, Rongbin; Wang, Wei; Zhu, Xiangrui; Li, Huiyuan; Wang, Yijie
• Is Part Of: Chemical engineering science. Volume 244(2021)
• Publication Date: 2021-11-23
• Subjects: Hydrate formation -- Hydrate dissociation -- Water-in-oil emulsion -- Asphaltenes -- Waxes; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2021.116831
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: Effect of waxes on hydrate behaviors in asphaltene containing emulsions. Waxes delayed hydrate nucleation and decreased the formed amount of hydrates. Waxes inhibited the hydrate dissociation process in the system with asphaltenes. Wax crystal was adsorbed on water–oil interface under the synergistic effect with asphaltenes. Abstract: In this study, the effects of waxes on carbon dioxide hydrate formation and dissociation in asphaltene-containing emulsions were systematically investigated using a high-pressure stirred autoclave equipped with an on-line viscometer. The results showed that the presence of waxes strengthened the inhibiting effect of asphaltenes on hydrate formation. Specifically, the induction time increased and the amount of formed hydrates decreased with increasing wax content in water-in-oil emulsion containing asphaltenes. The results indicated that waxes increased the viscosity of emulsions. It was observed that wax crystals dispersed in the bulk phase and got adsorbed at water–oil interface through the synergistic effect with asphaltenes. Furthermore, waxes inhibited the dissociation of hydrates in these emulsions. Both the gas emission rate and the average rate of hydrate dissociation decreased with an increase in wax content. The possible mechanisms were proposed to illustrate the effects of waxes on hydrate formation and dissociation in asphaltene-containing water-in-oil emulsions.