Flue gas desulfurization method and system

Abstract

The invention discloses a flue gas desulfurization method and a flue gas desulfurization system; the flue gas desulfurization method comprises the steps that: flue gas including SO2 is in countercurrent contact with barren liquor of absorption liquid to form rich liquor, after temperature of the rich liquor raises, the rich liquor is in countercurrent contact with secondary steam in a desorber to complete desorbing and regeneration, the steam including the SO2 exhausted from the top of the tower forms a regenerative primary steam under the injection effect of fresh primary steam to serve as a hot source of a reboiler for heating the barren liquor in the desorber, and then secondary steam is generated for continuously steam stripping SO2. The flue gas desulfurization comprises an absorption tower, a rich liquor pre-heater, a rich-barren liquor heat exchanger and a desorber, wherein the desorber is connected to a steam coupling regeneration device and a condenser respectively, and the steam coupling regeneration device is connected to a reboiler that is also connected to the desorber. The flue gas desulfurization method and system provided by the invention has the advantages of being capable of improving temperature of rich liquor of absorption liquid entering the desorber, achieving circular steam balance, saving steam consumption and reducing thermal load of condenser.

Description

technical field [0001] The invention belongs to the technical field of flue gas desulfurization, and in particular relates to a flue gas desulfurization method and system which require steam to participate in the cycle regeneration of absorption liquid. Background technique [0002] With the development of industry, the emission of sulfur dioxide is increasing year by year, and the massive emission of sulfur dioxide has seriously damaged the ecological environment of our country. According to data, my country's annual sulfur dioxide emissions have exceeded 30 million tons, making it one of the countries with the most serious sulfur dioxide pollution in the world. Therefore, it is imminent to control sulfur dioxide flue gas pollution. [0003] There are many kinds of flue gas desulfurization technologies. Since the 1950s, many countries in the world have begun to study desulfurization technologies. Up to now, there have been hundreds of desulfurization technologies. Traditio...

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Problems solved by technology

However, this method has the following two problems: (1) The compressor is used to compress the regeneration gas to do work. When the obtained high-temperature and high-pressure superheated steam heats the bottom liquid of the regeneration tower, the amount of secondary steam generated is less than that of the primary steam entering the reboiler The amount of steam cannot solve the mass balance problem of circulating steam; (2) The vapor compression system (MVR evaporator) relies on electric energy / mechanical energy to compress the regeneration gas, the equipment structure is complex, expensive, and requires high maintenance. In addition, the steam at the top of the tower is corroded Strong resistance, and contains a large amount of sulfur dioxide non-condensable gas, which is not conducive to the stable operation of equipment

[0007] The Chinese patent document with the publication number CN102049176A discloses a high-gravity solvent circulation absorption flue gas desulfurization technology, which uses nitrogen, air, etc. as the regenerative stripping gas. This method can save energy to a certain extent, but there are Problems such as incomplete liquid desorption and difficult recovery of sulfur resources

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