Method for dedusting and desulfurizing catalytic-cracking oil refining regenerated flue gas

Abstract

The invention relates to a method for dedusting and desulfurizing catalytic-cracking oil refining regenerated flue gas. The method which utilizes a sodium alkali and magnesia combined sodium-magnesium method comprises the following steps: magnesium hydroxide slurry is prepared from magnesia firstly and is mixed with a sodium alkali solution according to a certain ratio so as to prepare a desulfurization solution, and the desulfurization solution is conveyed to each spraying layer from the bottom of a tower by a desulfurization circulating pump; the flue gas is subjected to spraying, humidifying and cooling at an entrance of a desulfurization tower, then rises from the bottom of the desulfurization tower and is subjected to enhanced dedusting, desulfurizing and acid mist trapping by a combination unit, and the flue gas flowing out of the combination unit is then subjected to deep desulfurizing and dedusting by an upper spraying zone; sulfur dioxide in the flue gas is converted into magnesium sulfite and sodium sulfite; desulfurizing waste liquid is subjected to adequate aeration and oxidation, and then, produced magnesium sulfate and waste residues are discharged by a residue slurry pump and enter a subsequent filtration and dewatering system; and slurry concentrated by a cyclone is subjected to dewatering by a filtering machine so as to obtain disposable solid wastes. Compared with the prior art, the method has the advantages that the cost of the desulfurizing liquid can be remarkably reduced, the wastewater output is reduced, and meanwhile, the dedusting and desulfurization of FCC (Fluidized catalytic cracking) regenerated flue gas can be realized efficiently.

Description

technical field [0001] The invention relates to a high-efficiency desulfurization and dust removal method, in particular to a method for dust removal and desulfurization of regenerated flue gas from catalytic cracking refinery (FCC). Background technique [0002] Fluid Catalytic Cracking (FCC) process is an essential process for deep processing of poor quality heavy oil. In the FCC regenerator, about 90% of the sulfur on the coke is converted to sulfur dioxide, and the rest exists in the form of sulfur trioxide. If no sulfur transfer agent is added to the cracking catalyst, almost all the sulfur oxides in the regeneration process will enter the flue gas and be discharged with the flue gas. It is reported that before 2001, the content of SOx in the FCC regeneration flue gas of some refineries in my country was around 800ppm. With the increase of raw material sulfur content, SOx content in FCC regeneration flue gas continues to increase. At present, it is conservatively est...

AI Technical Summary

Problems solved by technology

However, there are some outstanding problems in the operation of the EDV wet scrubbing system, such as the high resistance of the flue gas, resulting in a large energy loss

In addition, the one-time investment of the system (mainly import costs) is high, and the operating cost is also high, mainly in the aspects of high power consumption, desulfurization agent and water consumption.

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