Abstract: Unsmooth catalyst transportation in the operation of the standpipe of the catalyst regenerator in 0.8Mt/a FCC unit of PetroChina Karamay Petrochemical Complex was found. The driving pressure in the standpipe and the pressure drop of the slide valve were both lower than the designed requirement, resulting in fluctuation of reaction temperature in the riser. Compared the axial pressure distribution in standpipe with the original design data, the results showed that no fluidized column was formed in the standpipe, and the pressure storage capacity is seriously insufficient due to the aeration orifices blockage and air rate insufficient, leading the catalyst bridging in the standpipe. By dredging the aeration orifices and adjusting the aeration rate, the conveying catalyst capacity of the standpipe can be improved to a certain extent.

Key words: FCC, standpipe of regenerator, transportation, fault, analysis