Fouling in centrifugal compressors can cause significant headaches in petrochemical processing. The fouling process is often complicated and depends on numerous variables. The causes may even be a moving target in some cases, as feedstocks change over time. Options to control fouling are limited. Typical options are either chemical injection to control temperatures and/or to aid in cleaning the flow surfaces, or coatings with anti-stick properties that prevent the foulant from building up in the first place. Some operators use both. Neither of these options are ideal, and there are trade-offs associated with each.
As a compressor manufacturer, Elliott Group has an interest in providing the best solution possible to operators. Like most original equipment manufacturers (OEMs), Elliott offers chemical injection systems, but most advances in this area correlate to the chemical injected. Given the implications of adding chemicals to the process gas, this option is best left to the user. For this reason, the company’s primary focus is the development of improved coating options.
Industry standard coating systems
Several years ago during a technical conference centred on centrifugal compressor operation, Elliott Group asked participants about the use of coatings to deal with fouling issues. The responses were surprisingly polarised. In one group were those who use coatings regularly, with and without wash systems, believing that the cost is easily offset by extended run times. In the other group were those who prefer wash systems alone to deal with fouling because they do not believe coatings work. A subset of the second group included respondents who had a bad experience with coatings. To address these negative views on coatings, it makes sense to review the current state of industry standard coatings and how they are used…
Written by Scot J. Laney, Elliott Group, USA.
This article was originally published in the July 2020 issue of Hydrocarbon Engineering. To read the full article, and other great technical articles in this issue, view the full issue here. You can also register to receive a free regular copy of the magazine here.
Read the article online at: https://www.hydrocarbonengineering.com/special-reports/22072020/hitting-a-moving-target/