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• Currently, the refinery is processing crude oil with a high H2S content. How can this affect the distillation unit? Would it affect the cap and transfer lines? What do you recommend I apply?

  Nov-2024

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Answers

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• Marcio Wagner da Silva, Petrobras, marciows@petrobras.com.br

  Processing high H2S crude oils (sour crudes) are always a high risk with two point of view: Personnel risks - H2S is highly toxic even under low concentrations can cause health issues varying from headache and eye irritation to death. Asset management risks - The presence of high concentration of H2S can cause severe corrosion in process equipment and lines which can lead to hydrocarbon contention loss and severe process safety accidents. The corrosion process can be directly associated with H2S or due to salt deposition like ammonium bisulfide (NH4HS), especially in crudes with high nitrogen content. A good way to deal with the sour crudes in distillation units is to use H2S scavengers like triazine. This will increase the operating costs but is well developed strategy to deal with H2S. Another strategy is to make a blend with the high H2S crude with sweet crude oils in order to reduce the H2S content in the feed to the crude oil distillation unit or use a synergy of both strategies. In parallel, the asset integrity refinery team should define a monitoring strategy to follow the corrosion rate in critical systems like the top section of the fractionating columns during the processing of sour crudes until some mitigation alternative is applied. A very good reference about the use of H2S scavengers in the Oil & Gas industry is the article published by Mr. Marc Schulz in the Gas Supplement of PTQ Magazine in 2018, which you can READ HERE

   

  Nov-2024