Abstract: The S Zorb unit of SINOPEC Zhenhai Refining & Chemical Company is a 0.90 Mt/a FCC gasoline desulfurization unit. After the start-up in June 2018, it was found that the desulfurization activity was insufficient, the fine powder content of the adsorbent was greatly increased, and the zinc silicate content in the system was abnormal, even up to 15%. The pressure difference of the regenerative flue gas filter increased rapidly, close to the interlocking value of 65 kPa, which seriously affects the normal operation of the unit. The analysis and verification indicated that the main reason for the deactivation was the quality of the adsorbent decreased due to more hydrocarbons on the adsorbent. On the other hand, the fluidization state in the reactor was not good. By measures of replacing adsorbent, reducing the amount of hydrocarbons in the adsorbent, improving the fluidization state of the reactor, adjusting the circulation rate and regeneration temperature, the desulfurization activity, amount of fine powder, zinc silicate content and regenerative flue gas filter pressure difference were gradually improved.

Key words: S Zorb, adsorbent, zinc silicate, gasoline, desulfurization