Asphaltene Adsorption from Toluene onto Silica through Thin Water Layers

Journal Article · Wed Dec 12 00:00:00 EST 2018 · Langmuir

DOI:https://doi.org/10.1021/acs.langmuir.8b03835· OSTI ID:1571132

Hu, Xiaozhen ^[1]; Yutkin, Maxim P. ^[2]; Hassan, Saleh ^[2]; Wu, Jiangtao ^[3]; Prausnitz, J. M. ^[4]; Radke, C. J. ^[5]

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1. Univ. of California, Berkeley, CA (United States); Xi’an Jiaotong Univ. (China)
2. King Abdullah Univ. of Science and Technology (KAUST), Thuwal (Saudi Arabia)
3. Xi’an Jiaotong Univ. (China)
4. Univ. of California, Berkeley, CA (United States)
5. Univ. of California, Berkeley, CA (United States); King Abdullah Univ. of Science and Technology (KAUST), Thuwal (Saudi Arabia)

Asphaltenes in crude oil play a crucial role in reservoir oil production because they control rock-surface wettability. Upon crude-oil invasion into a brine-filled reservoir trap, rock adherence of sticky asphaltene agglomerates formed at the crude oil/brine interface can change the initially water-wet porous medium into mixed-oil wetting. If thick, stable water films coat the rock surfaces, yet, asphaltenic-oil adhesion is thought to be prevented. We explore whether water films influence the uptake of asphaltenes in crude oil onto silica surfaces. Water films of known thickness are formed at a silica surface in a quartz crystal microbalance with dissipation (QCMD) and contacted by toluene-solubilized asphaltene. We confirm that thick water films prevent asphaltene molecular contact with the silica surface blocking asphaltene adhesion. The thicker the water film, the smaller is the amount of asphaltene deposited. Film thickness necessary for complete blockage onto silica is greater than about 500 nm, well beyond the range of molecular-chain contact. Water films of thickness less than about 500 nm, sandwiched among toluene and solid silica, apparently rupture into thick water pockets and interposed molecularly thin water layers that permit asphaltene adherence.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: China Scholarship Council (CSC); National Natural Science Foundation of China (NNSFC); USDOE Office of Science (SC)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1571132
• Journal Information: Langmuir, Journal Name: Langmuir Journal Issue: 2 Vol. 35; ISSN 0743-7463
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY