Home › Forums › CatCracking › FCC Process › Opacity issues
This topic contains 1 reply, has 2 voices, and was last updated by Anonymous 13 years, 4 months ago.
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April 27, 2009 at 6:31 pm #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,
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September 30, 2009 at 9:55 pm #5981
AnonymousQuestions 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
Ken@PeccatielloEngineering.com
Ken@CatCracking.com -
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