Due to Low octane number of the final product of catalytic reforming unit, a decision was made to regenerate the catalyst. However, because of the high sulphur content in our Naphtha feed, we decided to carry out sulphur removal from the catalyst befor coke bure (we have not carried out sulphur removal process before and our catalyst vendor advised against it because the sulphur level in the catalyst was just 400ppm and they only recommended sulphur removal at sulphur level of 1000ppm and above). However the suphur removal process was successful.
The problem is that when we switched to coke burn, the results have been erratic, very low temp. difference and oscilating between + and -. We have four reactors in series. sometimes, we have CO2 formation in 3rd reactor while the first and second reactor is showing CO2 even with visible delta T. Please find attched some of the results log sheet.
What could be responsible for all these??
Please advise??
Thank you.