Complex absorption cycle semi-dry desulfurization and denitrification integral process and device

Abstract

The invention discloses a complex absorption cycle semi-dry desulfurization and denitrification integral process and a device; the process sequentially comprises the following steps: flue gas pre-conditioning, alkaline complexing agent absorption, semi-dry absorption, dust precipitation by a dust precipitator and circulating dust conditioning. The device comprises a U-shaped reactor, the dust precipitator and a conditioner; the U-shaped reactor comprises a flue gas conditioning part, a circulating semi-dry reaction absorption device, a drainage device arranged between the flue gas conditioning part and the circulating semi-dry reaction absorption device, and a deflector arranged between the circulating semi-dry reaction absorption device and the dust precipitator; the conditioner is provided with a bunker, a lye inlet and a dust inlet connected with the dust precipitator; the output of the conditioner is connected with the circulating semi-dry reaction absorption device; and a processwater spray device and an alkaline complexing agent spray device are arranged in the flue gas conditioning part. The complex absorption cycle semi-dry desulfurization and denitrification integral process and device realizes the integration of desulfurization and denitrification, reduces the investment and operation cost, improves the desulfurization and denitrification efficiency, and is particularly applicable to medium- and small-sized boiler flue gas treatment projects.

Description

【Technical field】 [0001] The invention relates to the technical field of environmental protection, in particular to an integrated process and device for complexation absorption cycle semi-dry desulfurization and denitrification. 【Background technique】 [0002] A large number of sulfur oxides and nitrogen oxides produced during the combustion of fossil fuels have caused increasingly serious air pollution in my country. At present, domestic flue gas desulfurization and denitrification projects mostly use imported technologies. [0003] Desulfurization technology can be roughly divided into three categories: dry method, semi-dry method and wet method. Among them, wet method such as limestone-gypsum flue gas desulfurization technology is mostly used in large-scale coal-fired boiler flue gas desulfurization projects such as thermal power plants, and 90% of domestic The above thermal power plant flue gas desulfurization adopts this method, while the dry method and semi-dry method ...

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Problems solved by technology

The former is to control NO through combustion technology X The general denitrification efficiency of this technology is 30% to 50%, but it is easy to cause the combustion stability in the furnace to decrease, and the burner area is easy to form a local reducing atmosphere, resulting in a decrease in ash melting point and causing stickiness of the water wall. The phenomenon of fouling and slagging affects the normal and safe operation of the boiler. With the NO X Strict emission standards, it is difficult for this technology to meet environmental protection requirements

For the latter flue gas denitrification technology, developed countries such as Europe, America, Germany and Japan mostly use selective catalytic reduction technology (SCR), which has high denitrification efficiency and stable operation, and is currently the most widely used, mature and effective in the world. A flue gas denitrification technology, the problem is that the catalyst is deactivated, and the reducing agent such as ammonia water is easy to leak to cause secondary pollution. The high temperature and high dust arrangement of the SCR is easy to cause problems such as catalyst wear and blockage, and the operating cost is very expensive.

However, the device of this method is bulky, occupies a large area, is expensive to invest, has a long construction period, is difficult to operate and manage, and is expensive. It is barely acceptable for the flue gas treatment of large boilers such as thermal power plants, but it is not suitable for small and medium boilers in industrial enterprises. Smoke control, the law is basically impossible to implement

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