Abstract: In response to the challenges associated with the treatment and reuse of wastewater from deep catalytic cracking (DCC) unit in refining enterprises, an innovative integrated process for advanced purification of DCC wastewater and the reuse of turbid steam has been developed, taking into account the quality requirements of steam injection in DCC processes.The industrial test demonstrated that the deep purification process can effectively remove the impurities such as oil and polymer in the DCC wastewater, and reduce the concentrations of oil and suspended solids in the wastewater to less than 10 mg/L and 5.0 mg/L, respectively.The turbid steam generated by the purified water can be directly used for the DCC reaction and the steam injection of the fractionation system without affecting the performance of the catalyst and the product distribution.Fresh steam was replaced by turbid steam in a 3.2 Mt/a DCC unit, resulting in a reduction of 12.2% in total fresh steam consumption and 79.3%in discharged DCC wastewater.The development and application of this integrated process not only solves the problem of DCC wastewater reuse, but also greatly improves the waste heat utilization rate of DCC units, and the synergistic effectof pollution reduction and carbon reduction is remarkable, which can meet the requirements of green development under the current "dual-carbon"strategy.

Key words: DCC wastewater, purification technology, phenols, steam quality, combined process