Study On The Blockage Of Fractionating Column Tray Of RFCC Unit

As Sudan for oil drilling,Sudan crude oil composition has changed.Increasing gradually Salt content and heavy metal content in crude oil brought serious test to heavy oil catalytic cracking unit.Fractionating column tower abnormal operation occurred in December 2004,and the problem appeared again and again until 2012.How to solve the problem of fractionating column an important topics.Something should be done to find out the cause of the fractionator problem.Finally salt deposition in fractionating column top,poor washing effect in desuperheating zone of fractionator bottom.Gas carrying catalyst into the fractionator upper and low-temperature condensation reaction inside of catalyst cause the fractionating column tray plug,resulting in fractionator flushing phenomenon.For the cause of fractionating column jam we took a lot of measures including improving fractionating column top temperature,increasing the top circulating oil return temperature,adding the washing process,washing online using diesel oil,reducing desuperheating section temperature,increasing slurry flow to fractionating column,increasing recycle oil flow to fractionating column,adding slurry hot oil lines to slurry line,injecting multi-function dispersant to fractionator top,strengthen electric desalting device to crude oil.These measures make fractionating column run smoothly up to now.The result show that the salt content in the feed oil increasing has a great influence on the fractionating column blockage,lowtemperature condensation reaction is easy to produce coking,adding the hot oil line process can strengthen the desuperheating section washing effect.Increasing fractionating column top temperature helps to reduce the salt content and the fractionating column tray blockage,the online water washing and diesel oil flushing can make solve the problem,but diesel oil flushing affects the quality of product,multi-function dispersant agent F-20 is advantageous to the fractionating column smoothly running.The implementation of these measures create a good economic benefit.