Chemical Cleaning of Crude Oil Fouling Deposits; Applying the Coke Spectrum

Abstract

Fouling of heat exchangers and refining equipment by crude oil deposits is a chronic operating problem. In general, many such deposits are narrowly defined as coke fouling, for which the prescribed cleaning has traditionally been high-pressure water blasting. The results for this type of cleaning are mixed at best. Heat exchangers are often returned to service at conditions less than 85% clean performance, driving the need for more efficient cleaning regimens. A detailed characterization of 62 field-based crude oil fouling deposits from hydrocarbon process units was presented by the authors in 2019. This paper demonstrated that such deposits are exceptionally complex, resulting in the introduction of the Coke Spectrum. Here, these deposits are revisited, and chemical cleaning methods are applied. Chemical cleaning encompasses a variety of applications. Circulation, ultrasonic immersion, and clean-in-place techniques were reviewed on laboratory-scale samples to determine what chemical cleaning agents are most effective toward the various categories of foulant making up the Coke Spectrum. Combination techniques which employ both chemical and mechanical applications simultaneously or in sequence are considered in depth. The correlation between chemical composition and the effectiveness of the cleaning method is explored with considerations for scaling from laboratory to industrial application.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Roxanne Angela Shank

Roxanne Angela Shank is the Vice-President of the National Product Line for Ultrasonics and Offsite Cleaning for Clean Harbors and HPC Industrial Groups across North America. Coming from a chemical and technical background, she is a Professional Chemist with the Association for the Chemical Profession of Alberta (ACPA) and holds an HNC in Process Engineering from Teesside University and an M.Sc. in Biochemistry from the University of Lethbridge where she specialized in Nuclear Magnetic Resonance and thermodynamics modeling. In 2018, she shifted her focus from the chemical aspects of Ultrasonic Chemical Cleaning, toward the adoption and implementation of Ultrasonic Operations within the North American Industrial Market.

Thomas McCartney

Thomas McCartney is the Technical Services Manager for the Specialty Chemical Department for Clean Harbors Energy & Industrial Services out of Calgary, Alberta, Canada. As a Professional Chemist with the ACPA he has been working with the group toward creating national recognition for chemists in Canada in high level positions. He has over 40 years of experience in Industrial Chemistry and Chemical Cleaning and leads a team of talented young individuals who continue to redefine the industry.