How do you minimize slurry concentration in the MF bottom/slurry circuit system? What operational parameters can be checked/adjusted?
GAURAV KUMAR TYAGI, MANGALORE REFINERY AND PETROCHEMICALS LTD, firstname.lastname@example.org
Slurry concentration in MF bottom can be indicated by BS&W analysis. If it is continuous basis on higher side then a few checks can be done:
1) Catalyst PSD analysis for checking fines in circulating catalyst.
2) If fines are more than reduce regenerator level and made up with available e-cat with correct PSD.
3) Operate regenerator at lower temperature within acceptable limit to avoid catalyst attrition and optimize air to regenerator. Take off line DFAH if it is in line.
4) Reduce LCO draw flow rate and drop it to bottom to dilute slurry.
5) Start bleed towards IFO or DCU from slurry circuit 5-10 m3/hr.
6) if still no improvement then go for PSD analysis of slurry sample. Most probable cause will be damage if reactor hardware like cyclones, splash plate etc.
7) Recommended to have frequent thickness survey in slurry loop mainly PA pump discharge section.
Victor Scalco, General Atomics Electromagnetic Systems (GA-EMS), Vic.Scalco@ga.com
There are several causes for increased slurry in the Bottom Circuit, however I would start with the efficiency of the regenerator cyclones. If operation here is within normal operation a catalyst review and PSD of the ash or catalyst fines would give you a quick understanding of your catalyst matrix. This is helpful to determine if you are losing fresh catalyst into the bottoms as well. To reduce concentration and increase the values of your MCB, I would look into the Gulftronic Electrostatic Separator for reducing the catalyst content in the system and being able to reduce valve and heat exchanger erosion as well.