Regeneration of alkali-free gasoline deodorization tower

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Treatment in an alkali-free deodorization tower – Commissioning of the new tower: ㈠ The installation of the activated carbon bed inside the tower should be carried out under the guidance of the manufacturer; the bed must be firmly packed, and only after technicians confirm that everything is in order can the access hatch be sealed, along with the safety valve being reinstalled. (ii) Water is introduced at the bottom of the tower, and the vent at the top is opened; water overflows from the top of the tower. Feeding water is stopped when the color of the water becomes clearer. Steam is supplied at the bottom of the tower to carry out boiling, with the temperature inside the tower maintained at 80°C for 4–8 hours. (III) Supply water until the water coming out of the top of the tower becomes clear, then drain all the water. (IV) Open the bottom drain valve of the tower and close the top vent; continue to blow steam from the top of the tower for at least 2 hours until no water is discharged from the condensate. (v) Open the vent at the top of the tower, close the drain at the bottom, and carry out cyclic impregnation with a catalyst-containing alkaline solution. After the impregnation is complete, close the vent at the top of the tower, fill it with nitrogen to remove the alkali solution, and set it aside. Catalyst impregnation: If possible, it should be carried out after nitrogen purging first. An impregnation solution was prepared using 10% NaOH and a catalyst, which was then applied to the bed layer and circulated ； The amount of catalyst used for the initial impregnation of the bed generally accounts for 0.4% of the weight of the activated carbon bed; it is first added at a concentration of 2000 ppm in the alkaline solution and then circulated, with additional amounts being added gradually as the color lightens. The alkali solution is used for cyclic impregnation for at least 7 days. In future, reduce the amount of catalyst used during bed regeneration as appropriate, with a minimum of not less than 0.0005. Note: When receiving alkali, be sure to adjust the process properly to prevent leakage and cross-contamination. Regeneration of the deodorization tower: ⑴ Water is introduced from the bottom of the tower to push the unqualified gasoline out of the tower and back into the tank for reprocessing. ⑵ After the gasoline in the unqualified tower has been processed, the vent at the top of the tower is opened; water overflows from the top of the tower. Water supply is stopped once the color of the water becomes clearer. Steam is supplied to the bottom of the tower to boil the water, with the temperature inside the tower maintained at 80°C for 12–24 hours. After that, the water is removed while steam is still being supplied. ⑶ After the water has been drained, open the discharge valve at the bottom of the tower and close the vent at the top. Steam supply should be switched to come from the top of the tower; once steam is detected at the bottom, increase the amount of steam supplied, ensuring that the pressure at the top of the tower does not exceed 0.3 Mpa, while keeping the temperature at the bottom between 145–155°C. The tower should be steamed continuously for 24 hours. Catalyst impregnation is carried out after nitrogen purging and cold cutting.