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Our client has recently started processing heavy crude slates from Western Canada. They are having an issue with their Desalter Brine Treatment Unit (BTU, which is a pre-treatment plant for oily solids removal before being sent to the de-oiling train) with higher than design temperatures and light hydrocarbon carry over. Does anyone have experience with this issue? Is steam stripping prior to BTU an option for dealing with this issue?

Thank you for the responses so far. This has provided some insight into the issue. As a follow up, is there any experience with steam stripping of the brine. I believe some refineries in US have this unit for BTEX removal. How efficient would this be for light hydrocarbon removal? Also any insight into requirement of an equalization tank upstream and if solids removal is recommended upstream of the stripper?
13/09/2016 A: Daniel Kemp, Spectrum Water Technology, dkemp@spectrumwater.com
What kind of treatment is downstream of the desalter? Does the client have a DGF or DNF? Typically with the WCS, the issue is with elevated asphaltenes that can be removed with a special chemical program at the pretreatment unit upsteam of biological treatment.
01/06/2016 A: Krishna Rao Pulugurti, Retired/Consultant, pkrao2012@yahoo.com
It appears that the crude contains calcium. Please check. Calcium has to be removed to lower the crude going with desalter brine.
31/05/2016 A: Eric Vetters, ProCorr Consulting Services, ewvetters@yahoo.com
Oil undercarry from the desalter will foul downstream coolers leading to high temperatures. The oil undercarry is typically highly emulsified, which makes it difficult to separate in the front end of the waste water system. This problem is common when processing heavy crudes. The first step in solving the problems would normally be to modify desalter operation and/or chemistry to address the problem at the source. If the problem cannot be adequately resolved at the source, then a centrifuge is often employed to break the emulsions, allowing separation of the oil, solids, and water.
The oil undercarry will normally either look like crude oil, slop or will be mostly asphaltenes. If you are truly seeing just light hydrocarbon, then you very likely either have an extraneous source of hydrocarbon finding its way into your brine or a light slop stream is the cause.
31/05/2016 A: Morgan Rodwell, Fluor Canada Limited, morgan.rodwell@fluor.com
I don't know exactly what your BTU looks like, but the presence of light hydrocarbons in the brine from Western Canadian crudes has been documented before. The issue is that these very heavy crudes are blended with diluents that can contain a lot of C4-C6 range material. The solubility of these in the brine at high desalter temperatures can result in venting from desalter brine treatment.
You could steam or gas strip the brine to get the light hydrocarbons off. Often simply dropping the pressure to atmosphere is enough, but then you need a compressor/ejector to lift the vented gas to fuel pressure.