• Quayle, Peter
• Krogstad, Jessica A.
• Braun, Paul V.
• Daryadel, Soheil
• Shetty, Pralav P.
• Wu, Tiffany
• Tucker, Zoë R.
• Subramani, Velu
• Yeates, Stephen G.
• Haire, Barnaby T.
• Morrison, John

Abstract

Asphaltene deposition in petroleum refineries is known to be problematic as it reduces efficiency<br/>and may lead to structural failure or production downtime. Though several successful approaches<br/>have been utilized to limit deposition through the addition of dispersants and inhibitors to<br/>petroleum, these methods require constant intervention and are often expensive. In this study, we<br/>demonstrate an innovative technique to engineer the surface chemistry of pipeline alloy steels to<br/>inhibit asphaltene deposition. Pack aluminization, a standard industrial-scale chemical vapor<br/>deposition process, is employed at a low temperature of 600 oC to aluminize API 5L X65 high<br/>strength pipe steel substrates. The results showed deposit free steel surfaces after high-pressure<br/>and high-temperature fouling experiments. The improvement is attributed to the formation of an<br/>aluminide intermetallic phase of Fe2Al5, which changes the native oxide chemistry to favor<br/>alumina over hematite. The continuous passivating oxide scale, acting as a protective barrier, mitigates asphaltene deposition and sulfidic corrosion. Since this process is based on alloying the<br/>surface of the steel and is not a coating, it is not prone to delamination, and it can be reformed<br/>when damaged within the aluminized region. The combination of low-cost processing and<br/>improved anti-fouling characteristics makes surface chemistry modification of steel a promising<br/>preventative approach against asphaltene deposition.

Topics

• Deposition
• impedance spectroscopy
• surface
• corrosion
• phase
• experiment
• strength
• steel
• chemical vapor deposition
• aluminide