Design Of Heavy Oil Catalytic Cracking Reaction And Regeneration System Of2Million Tons/Year

Since the1980s, the structure of the oil refining products has undergone agreater change, that the demand for heavy oil or residue declines. As well as theraw material oils are becoming heavy and poor gradually, which has a higherdemand for heavy oil deep processing. As a major method of converting heavy oilto light oil, the technology of heavy oil catalytic cracking has been developedrapidly. The same time, the catalytic cracking reactor has also been a rapiddevelopment, its research is more and more, and made initial progress. In thispaper, the key technology of1million tons/year of a joint workshop of Yan’anRefinery FCCU reaction-regeneration system was studied and analyzed, whilethe actual operation of the device and the result of production were investigated.In order to expand the size of the company and meet the balance of the wholeplant residue, a new200tons/year of heavy oil catalytic cracking was built. In mydesign，the MIP catalytic cracking process is adopted, which will divided the riserreactor into two reaction zones. The first reaction zone has a higher intensity ofreaction, shorter reaction time and mainly based on cracking. The second reactionzone has a slightly higher temperature, longer reaction time, higher proportion ofsolvent and oil, mainly based on the hydrogen transfer and isomerization reaction,making the olefins of gasoline into the propylene and isoparaffin so that thecontent of olefin reduced. I also adopt the technology of overlapping regenerationequipment and multi-stage highly efficiency stripper. The overlappingregeneration equipment can keep the activity and stability of catalyst well. Themulti-stage highly efficiency stripper improves the mobility of the stripper andresidence time distribution of catalyst so that makes the gas-solid contact ofstripper remain the best state. Meanwhile, we also use the new technology andadvanced chemical equipment，such as the closed vortex quick separation systems(VQS), BY-type first and second-stage cyclone and BSX-type three-stage cyclone. They play an extremely important role in the catalytic cracking equipment,because they can recycle catalyst, reduce the loss of the catalyst, preventinterference and fluctuation and lower the cost. What’s more, they have theadvantages of high efficiency, low pressure drop, large capacity, wide flexibilityof operating and ensuring the long-period of running of the device.