Abstract: Causes for flooding in the desulphurization tower of 2.4 Mt/a delayed coking unit of Ningbo Daxie/Zhoushan Petrochemical Co., Ltd. was analyzed, and the countmeasures were proposed. The liquefied gas from delayed coking unit contains a large amount of coke powder, which continuously deposited in the LPG desulfurization tower, and cause the blockage of packing or tray in desulfurization tower, resulting in the liquid flooding. In order to ensure normal production, the desulfurization tower must be frequently cut out and cleaned, leading to disqualified LPG product. Therefore two static mixers were added to the desulfurization process. This simple modification of desulfurization process can guarantee the quality of the liquefied petroleum gas during the cutting out of the desulfurization tower, thus can markedly reduce the economic loss.

Key words: liquefied petroleum gas, desulfur tower, blockage, treatment