chloride and iron content were within the desired limits due to the low chloride, sulphur, and nitrogen content of the PPO selected for processing in the FCC unit. Main fractionator boot water corrosion parameters, which are monitored before and during the PPO trial, are given in Figure 6 . Achieving circularity in processing PPO in the FCC unit
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Before PPO trial During PPO trial
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Dry gas
LPG
CRN
LCO
Resid
Coke
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Figure 5 Product yields before and during the PPO trial at the Mumbai refinery FCC unit
PPO was processed in an FCC unit, where it was transformed into fuels and propylene (present in the LPG fraction). If propylene is recovered from the LPG fraction, it can be converted again to plastics such as polypropylene and polyacrylonitrile, which closes the plastic loop and enhances circularity and sustainability. This process not only reduces dependence on virgin fossil resources but also helps mitigate plastic waste accumulation. By integrating PPO into refining operations, industries can contribute to a more resource-efficient and environmentally responsible economy. Summary Plastic pyrolysis oil processing in the FCC unit was successfully done without negatively impacting FCC product yields, and no major operational issues were faced in terms of unit corrosion and gum formation. The co-processing of plastic pyrolysis oil increased conversion, dry gas, LPG, and cracked naphtha, and reduced LCO, resid, and coke yield.
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Before PPO trial During PPO trial
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to avoid ammonium chloride corrosion in the top trays of the main fractionator. Due to the low sulphur and nitrogen content of the PPO used in the trial, no ammonium sulphide corrosion was anticipated. The main fractionator top temperature and respective ammonium sublimation temperature before and during the PPO trial are given in Figure 4 . The co-processing of PPO increased conversion, dry gas, LPG, and cracked naphtha, and reduced LCO, resid and coke yield. Product yields obtained during the trial are given in Figure 5 . Impact of co-processing of PPO on corrosion parameters Processing PPO is suspected to cause corrosion in the main fractionator top trays and overhead condensers due to high chloride and sulphur content. However, corrosion parameters such as ammonium chloride sublimation temperature, overhead condenser boot water pH, and Figure 6 Main fractionator boot water corrosion parameters before and during the PPO trial
Pramod Kumar pramodkumar@hpcl.in Somanath Kukade somanathrkukade@hpcl.in Hemant Mishra Hemant.Mishra@hpcl.in Sanju Kumari Sanju.Kumari@hpcl.in
Refining India
14
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