Start Date
December 2021

Background
Fouling in crude tower overheads and pump around circuits can be linked to multiple sources and chemistries. Project will focus on common issues between refiners and methods to identify the fouling mechanism(s) and source materials.

Milestones as of February 2024

• Initial project meeting held in December 2021.
  
• Three samples were received from three different refineries. The deposit characterizations were presented at the June 2022 project meeting.
  
• At the September 2022 meeting, a review of the previous sample analysis included a discussion on the origin of the elemental sulfur found in all three deposits.
  
• Results of the characterization of two new deposits were presented at the September 2022 meeting. One tower overhead and one LVGO reflux cooler. Both refiner and the CCQTA characterizations of the deposits were presented. Elemental sulfur was also identified in the overhead deposit.
  
• Analysis of 8-12 deposits from the another refinery were presented.
  
• After the September 2022 meeting information was provided indicating the decontamination process prior to opening the units to collect the samples was the likely source of elemental sulfur. More details were provided at the December 2022 project meeting.
  
• Characterization data from additional deposit samples were received was presented at the December 2022 project meeting.
  

• Seeking additional tower top deposit samples.
  
• At the December 2023 meeting a summary was provided on the findings to date including:
  — Crude tower top fouling
  — Crude overhead emulsion
  — Crude overhead water pump strainer fouling
  — Crude tower fouling
  — Discussion on the carbon allotrope (graphite) found in recent deposits and possible origins.
  
• See the December 2023 meeting minutes for details.