Hydrate formation and adhesion on low surface energy materials

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 43-44).Clathrate hydrates are ice-like solid substances that often form inside oil and gas pipelines and are responsible for flow blockages, sometimes leading to catastrophic disasters. Minimizing hydrate adhesion and accumulation of solids on pipelines can effectively address this problem. In this thesis, we reduce the adhesion of cyclopentane hydrates by promoting the formation of a cyclopentane barrier film between the hydrate and the solid surface. The presence of this liquid film depends on the spreading coefficient of cyclopentane on the solid in the presence of water. Through a systematic modification of the surface chemistry of the solid surface using two different silanes, we correlate the wettability of water and cyclopentane to the adhesion of cyclopentane hydrates. We demonstrate negligible hydrate formation and adhesion on octadecyltrichlorosilane-coated surfaces via macroscopic visualization, surface tilt and adhesion measurements. The use of the spreading coefficient as a design parameter could further advance the development of effective, passive, hydrate-repelling surfaces.by Taylor A. Farnham.S.M