Recovery system and method for desulfurizing agent in desulfurized gas of catalytic-cracking regeneration waste gas

Abstract

The invention relates to a recovery system and method for a desulfurizing agent in a desulfurized gas of a catalytic-cracking regeneration waste gas. The recovery system comprises a desulfurizing tower, a condensing heat exchanger, a mechanical separation purifier, a heating heat exchanger and a filter, wherein a gas outlet of the desulfurizing tower is communicated with a gas inlet of the mechanical separation purifier through a first pipeline; the condensing heat exchanger is mounted in the first pipeline; the heating heat exchanger is mounted in a gas exhaust pipeline of the mechanical separation purifier; the condensing heat exchanger and the mechanical separation purifier are communicated with the filter respectively through second pipelines. The recovery system can be used for effectively decreasing the dew point of an outlet gas from the desulfurizing tower, is used for decreasing water vapor content and the particle concentrations of entrained desulfurizing agent and catalyst in the outlet gas, can be used for recovering most of the desulfurizing agent, and is used for decreasing the discharge loss of the desulfurizing agent, decreasing a running cost and meanwhile reducingenvironment pollution; through arranging the heating heat exchanger, an exhausted gas can be prevented from entering an environment of which temperature is lower than the temperature of the gas so that a liquid drop can be still immediately condensed and the formation of a rime fog is prevented.

Description

technical field [0001] The invention relates to the technical field of environmental protection technology, in particular to a system and method for recovering a desulfurizer in gas after desulfurization of catalytic cracking regenerated waste gas. Background technique [0002] Catalytic cracking is an important process in oil refining production. Catalysts for catalytic cracking need to be periodically regenerated, and the waste gas generated during the regeneration process contains pollutants such as sulfur dioxide, which need to be purified by a desulfurization process before being discharged. Desulfurization generally adopts a wet desulfurization process. The desulfurization agent is lye, and the desulfurization agent contacts with the gas and reacts with sulfur dioxide to remove the sulfur dioxide in the gas. The lye can be lime, sodium hydroxide or sodium carbonate, ammonia, etc., and the corresponding desulfurization processes are called calcium desulfurization, sodi...

AI Technical Summary

Problems solved by technology

However, due to the fact that the solid dust carried in the hot flue gas is easy to deposit in the regenerator, this technology causes blockage and operation problems; and heating the gas at the outlet of the desulfurization tower cannot effectively reduce the dew point of the gas. On the one hand, the water vapor entrained in the gas and the desulfurization The agent will still be lost in a large amount, causing pollution after entering the atmosphere. On the other hand, the probability of condensation of the gas in a lower temperature environment is still high, and it is easy to corrode and deposit to block pipes and equipment.

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