• We have a problem in the specifications of the feed of the Reforming Unit (Heavy Naphtha: Sulfur content = 2.6 must be <1; Dr. test = Slightly H2S must be negative )

    Knowing that the operating conditions of the Hydrodesulfurization unit are normal.

    Any solutions welcome.



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

    Considering your information that the Hydrodesulfurisation is OK, we need to check the characteristics of the feed. Some relevant questions need to be answered like if your catalytic reforming is operating with only straight run naphtha, in some refineries it's common to apply hydrotreated coker naphtha as feed for catalytic reforming units.

    I will consider that your processing unit is operating wit only straight run naphtha, in this case, it's necessary to check the sulphur content of the straight run naphtha to check that this is respecting the maximum hydrodesulfurisation capacity of the hydroprocessing unit. Maybe the change of processed crude to heavier or sourer crudes can be affected the sulphur content of the straight run naphtha.

    Another point to check is the fractionating quality int he atmospheric column of the crude distillation unit, in some cases the salt formation in the tower internals can led to the poor fractionating quality in some sections and kerosene can be dragged to the naphtha, raising the sulphur content of this stream. My suggestion is to carry out a characterisation of the naphtha fed to hydrodesulfurisation with analysis of total sulphur and boiling range to identify possible contamination with heavy hydrocarbons.