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• What is source of organic chlorides in crudes? why some crudes report organic chlorides while others not?

  Oct-2022

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Answers

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• Peter Marsh, XBP Refining Consultants Ltd., peter.marsh@xbprefining.co.uk

  In addition to some naturally-occurring organic chlorides present in crude oils, organic chloride contamination of crude oil can occur via intermittent injection of chloride-containing chemicals into crude oil. Examples include 1) chlorinated solvents which are sometimes used by oil producers to remove deposits from production well risers and to degrease drilling equipment during maintenance activities, 2) cold flow improver treatment chemicals.

  Check retention samples of crude oil for organic chloride concentration as intermittent chemical treatment is unlikely to be declared by the supplier, especially if they do not understand the consequence of its presence on downstream refinery process safety and reliability performance. Also, be sure to sample NHT Product Separator sour water regularly to check for evidence of accelerated corrosion.

   

  Jan-2023

• Doug Morgan, Searles Valley Minerals, morgan@svminerals.com

  I echo Ted Raab's comments.  Microbe respiration involves some surptising oxidation/reduction reactions. ClO4−(perchlorate) ⟶ ClO3− (chlorate)⟶ ClO2−  (chlorite) ⟶ Cl−(chloride) + O2 is actually quite popular with microbes that grow in highly saline environments.  I know biologists who are convinced that the high concentrations of perchlorate detected in Martian soil suggest life on Mars thrives in cold, yet still liquid, Perchlorate-saturated brines.  One should check to make sure he is not doing something to encourage microbes to do something undesirable on the surface.  Storing crude in carbon steel tanks on top of a layer of saltwater can lead to plugging of crude unit heat exchanger trains with iron oxide respirated from the tanks by microbes, for example.

   

  Nov-2022

• Ted K. Raab, Carnegie Inst for Science, tkraab@stanford.edu

  Though the spectrum of compounds in current reservoirs is very different from the original source materials, it's worth noting that org-Cl is common in peats, lignites, and other energy materials. Many living organisms (fungi, plants, insects) synthesize them, and we must presume that they did in the past, as well. Bacteria can also respire (I.e. derive energy from) org-Cl. Reservoirs associated with salty horizons support microbial activity for long periods.

   

  Nov-2022