Novel nanomaterial surface treatments within subsea processing

Abstract

Sustainability is of great importance to maintain humanities quality of life as well as preserving natural resources for future generations. The strive towards sustainability promotes innovation, causing industries and their equipment to become more effective than ever before. Aker Solutions, a company within the energy sector, have several projects focusing on sustainability and increasing efficiency, one of which is improving upon the subsea cooling systems. In this project a novelty surface treatment was investigated and proven to challenge conventional materials, otherwise used in subsea cooling and processing. The surface treatment is based on Yttrium nanoparticles which affects the surface morphology of the metal utilizing the reactive element effect, ultimately increasing the surface’s corrosion resistance and fouling mitigation properties. Three different variations of the surface treatment on five different Iron, or Nickel based alloys were evaluated along with the bare alloys and other commonly used materials. Counting up to 19 material systems in total. Since the surface free energy has been found to affect fouling and microbial growth, contact angle measurements and calculations in line with the OWRK method generated each material system’s total surface free energy and its polar and dispersive contribution. It was from these measurements proven that the polar contribution of the surface free energy is eliminated post surface treatment, however it was the fouling test which determined the superiority of a specific surface treatment variation, from both its resistance to corrosion and fouling mitigation properties. This particular version of the surface treatment was thermally treated for relatively longer period at a lower temperature, causing the protective oxide formed to become thicker or denser, thus less oxygen permeable. Due to the minimal amount of Yttrium added to the surface of the otherwise common material the CAPEX is relatively low. Additionally, the surface treatment has potential of superior operational lifetime as well as being a more environmentally conscious choice.