Device for desulfurizing flue gas by seawater through membrane absorption and its process

Abstract

The invention discloses a device for desulfurizing flue gas by seawater through membrane absorption and its process, the flue gas is sent to a membrane absorber shell side by a supercharging blower fan, the pretreated seawater enters in a membrane absorber tube side through a sea water pump and is taken as absorption liquid, gas phase and liquid phase form a reaction interface at the micropore ofa hollow fiber membrane, SO2 in flue gas is reacted with seawater to generate sulfite and timely is taken away for realizing the flue gas desulphurization. Desulfurized seawater is discharged throughaeration sulfur fixation and pH value standard achieving. The device of the invention is composed of a one stage or multistage membrane absorber, the membrane absorber is composed of multi-group curtain type or column type hollow fiber film component group. The process has the characteristics of low air resistance of the device, small power consumption and high desulphurization efficiency. A design of an automatic on-line backwashing and cleaning technology is capable of controlling and mitigating membrane pollution, the device possesses small volume and light weight, and enables modularized integration; the flow velocity of the gas phase and the liquid phase can be independently controlled in a wide scope, and the problem of device corrosion caused by entrainment water vapor in flue gas in a traditional seawater method can be avoided.

Description

Technical field [0001] The invention belongs to the cross field of air pollution control technology and membrane science and technology application, and specifically relates to a system that uses seawater as an absorption liquid and adopts membrane absorption technology to remove sulfur dioxide in flue gas. Background technique [0002] The sulfur dioxide in the atmosphere mainly comes from the combustion of industrial waste gas, coal and petroleum and other fossil fuels. At present and for a long period of time in the future, the use of coal to provide heat and power resources is still the mainstream in China. In recent years, the rapid economic development in coastal areas has increased the economic burden caused by power shortages, resulting in rapid development of coastal thermal power, which currently accounts for about one-third of the total installed capacity of thermal power. SO emissions from the power industry 2 It accounts for about 50% of the country's total emission...

AI Technical Summary

Problems solved by technology

Among them, the dry and semi-dry processes need to consume a large amount of absorbent, and produce solid by-products, which cause heavy equipment wear and high operation and maintenance costs.

Mature wet processes include seawater method and limestone-gypsum method. Compared with limestone-gypsum method, seawater method can save a lot of fresh water consumed for preparing absorption liquid, but due to the use of traditional gas absorption equipment (such as packed tower, liquid column tower and still cannot get rid of the common problem of wet flue gas desulfurization: due to the direct contact between the gas-liquid two-phase during the flue gas absorption process, the process is vulnerable to hydrodynamic conditions such as liquid flooding, channeling, and mist entrainment Limitation, resulting in uneven distribution of absorption liquid and flue gas, low mass transfer efficiency, and a large amount of water vapor in the discharged flue gas, coupled with residual SO 2 , so there is equipment corrosion problem

Due to the large air resistance caused by the capillary phenomenon of the hollow fiber membrane absorber, it is necessary to provide flue gas through a gas compressor, which consumes a lot of power

Therefore, the previous research on the removal of acid gas by membrane absorption method is in the laboratory stage, and it is difficult to realize engineering application.

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