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Opacity issues

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This topic contains 1 reply, has 2 voices, and was last updated by  Anonymous 13 years, 4 months ago.

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  • #3110


    Any guru’s have some thoughts of reducing opacity on a partial burn cat?    Alreadly have electro precips and TSS (Jeff Polland, FSS not possible and have seen all your other advertising).   Basically my baby is well over due for T/A but it keeps getting pushed because of CD delays.

    Somone mentioned raising the regen pressure but when we start to bump the air, the opacity seems gets worse…    Basically its to the point where someone has discovered adding dip to the walnut shells helps knock S%!* off the expander…   Or interesting daily to say the least.

    Thank you all in advance for the considerations about the situation,

  • #5981


    Questions for you….. is the opactiy catalyst?
    what color is the opacity? and how long does it take
    to dissipate?
    Some other thoughts alternate ideas:

    If the opacity is “Blue/Bluish tint” and it does not dissipate
    quickly it could be SO3. The addition of a SOx reduction
    additive could help with that.

    If it white flakes or snow (but not catalyst) it could be
    ammonium sulphate. If you are adding NH3 to the ESP to
    enhance the performance of the ESP, there may be too
    much NH3 and it is reacting with the sulphur emissions to
    form this salt. This is ESPECIALLY true if the ESP is
    operating too cold (less than 500 deg F).
    This phenomena has been observed in several West Coast refineries.
    We have also seen the ammonium salts cover the plates & wires of the ESP
    reducing the overall effeciency / effectivness of the ESP.
    Check the effectiveness and frequency of “rappers” and “Vibrators” of the ESP.

    Check the ESP for Arcs & Sparks (is it tuned effectively/efficiently?).

    Check the temperature of the ESP. Catalyst undergoes a historisys. The
    amount of charge a catalyst particle can accept decrease as the temperature
    of the particle decreases impacting its’ capturability. (Old saying– a HOT ESP
    is a HAPPY ESP!).

    If it is catalyst check the bed level knowing that a change in catalyst
    type or manufacturer can have an impact on the catalyst density
    which changes the level readings if the level readings are not compensated
    for using actual unit measurements.

    Also, check to see the Patricle Size Distribution (PSD) of the freshly delivered
    fresh catalyst. IF the unit cyclones are only holding onto 10 wt% 0-40 um and
    the refinery is receiving a fine grade (over 16 wt% 0-40 um) many of the light
    particles are leaving and ending up as opacity.

    Check for sources of attrition.

    Ken Peccatiello

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