Start Date
June 2016

Background
A member company approached the participant based Organic Chloride project group in April of 2016 with the idea of pursuing the development of test method for measuring organic chlorides in distillate/gas oil streams. Following a data review and discussion, project members suggested that the CCQTA support ongoing work previously undertaken by Marathon and XOS.

Milestones as of February 2024

• Gas oil samples were requested in June 2016.
  
• Low level (estimated at 4 - 5 wppm) contaminated distillated samples were provided by Suncor in late 2016. Samples were tested by Marathon and XOS. There were insufficient quantities of TOX in the samples to undertake further method assessment/development work. Samples with higher concentrations are required.
  
• In June of 2019, evidence was provided at the Open Forum meeting that a “false positive” for organic chlorides had recently been reported in a sample of heavy crude (>940kg/m3). Follow up work further suggested that excessive heating of the sample during the naphtha distillation step might be responsible for thermal cracking, olefin generation, salt hydrolysis and subsequent organic chloride formation. This mechanism is now being investigated by the project group.
  
• In December 2019, additional data was presented based on the continuing investigation. New observations indicate incomplete combustion, high sulfur content in the recovered naphtha as well as the orientation of the combustion furnace may also be contributing to false positive readings. Further work in in progress.
  
• It was reported at the December 2019 project meeting, that there have also been false positives observed on lighter US gulf coast crudes.
  
• Results presented in June 2020, were inconclusive for “false positives” however the work did highlight the wide variation in results that could be encountered on the same naphtha sample run at different laboratories. Please see the June 2020 meeting minutes.
  
• Project was moved to “Project Maintenance Activities” as opposed to a stand-alone project.
  
• A lengthy discussion took place at the March 2023 Open Forum meeting regarding performing ASTM D4929 on samples with low naphtha content (<5%). The discussion centered around false positives and potential revisions to the test method to avoid them.
  
• CCQTA Lunch & Learn on “Chlorides in Crude Oil” was released on Oct 31, 2023.
  

• A revision to ASTM D4929 was submitted for ballot to sub-committee D02.03 in September 2023. The revision includes two notes added to section 12.1 which refers to the distillation procedure. The first note provides guidance for low naphtha content samples with a focus on avoiding cracking. The second note clarifies that the distillation rate is not critical to the success of the subsequent analysis, but prevention of decomposition is.
  
• The September ballot received several negatives that have been addressed and the revision is in concurrent ballot closing February 19, 2024.