• I am in Hydrotreater, I want to know how much stripping steam is required in stripper, during startup we use excess steam in stripper to achieve diesel doctor test negative, is it beneficial or adversely affect steam stripping?



  • Nasir Hussain, PARCO OIl refinery Pakistan, nasir.mughal3010@gmail.com

    During start-up stripping steam should be nearly at the design rate as the unit is normally at the turndown rate. Steam is injected in stripper at temperature above the saturation temperature of steam. Focus on improving the stripper conditions and like inlet and top temperature, stripper pressure. As the conditions are met at the operating, then Doc. test will become normal.   

    High stripping steam might not benefit but the operating conditions achievement will be better.


  • Jake Gotham, InSite Technical Services, jake.gotham@insitetechnical.com

    Stripping steam is usually around 5-15 lb steam per bbl of bottom product (15-45 kg/m³).  During start-up, while the stripper tower might not be at normal operating temperature, high stripping steam flow can compensate to some extent, but there are diminishing returns at very high steam rates.  Too much steam, particularly if the tower isn’t up to normal temperature, can cause condensation of water within the tower leading to unstable operation, fouling and corrosion.