Coal flue gas mercury adsorbing removal process capable of recovering adsorbent and device utilizing same

Abstract

The invention relates to a coal flue gas mercury adsorbing removal process capable of recovering adsorbent and a device utilizing the same. The coal flue gas mercury adsorbing removal process includes steps of firstly, delivering powdered activated carbon which serves as adsorbent into a flue gas pipeline between a flue gas dust collector and an inlet of a desulfurizing tower, and spraying the powdered activated carbon by a spray gun so that the powered activated carbon is dispersed in flue gas sufficiently and capable of adsorbing mercury in the flue gas; secondarily, filling the flue gas mixed with the activated carbon into a cloth bag type filter so as to realize gas and solid separation; and thirdly, delivering and recovering the activated carbon after the activated carbon is regenerated. When gas and solid separation is realized in the second step, flue gas without mercury enters the next desulfurizing process through the cloth bag type filter, the activated carbon retained by the cloth bag type filter is captured, desorbed and regenerated at the temperature ranging from 130 DEG C to 800 DEG C under protection of nitrogen gas, and mercury gas is released and then sent to a recovery system. The coal flue gas mercury adsorbing removal process capable of recovering the adsorbent and the device utilizing the same have the advantages that mercury removal efficiency is high, usage of the adsorbent is low, and the adsorbent can be recovered so that cost is reduced; further, since the adsorbent is separated from fly ash, the subsequent use value of fly ash is ensured, while recovery of mercury source is realized.

Description

technical field [0001] The invention relates to a coal-burning flue gas adsorption and demercuration method and a device thereof, in particular to a coal-fired flue gas adsorption and mercury removal method and a device with recyclable adsorbents, belonging to the field of flue gas purification. Background technique [0002] Boiler flue gas contains a variety of harmful substances, in addition to high content of smoke, SO 2 In addition to , NOx, mercury in coal is emitted into the atmosphere through flue gas during coal combustion, and the harm to the environment and human health cannot be ignored. 2 After , NOx, it is necessary to strictly control the discharged pollutants. The United States and the European Union have formulated and clarified specific requirements and timetables for limiting mercury emissions from coal-fired power plants. The United Nations Environmental Protection Agency plans to form a global binding mercury control law in 2013. With the increasingly s...

AI Technical Summary

Problems solved by technology

The disadvantage is that activated carbon not only adsorbs mercury, but also adsorbs smoke and dust, which increases the amount of adsorbent; activated carbon mixed into fly ash cannot be recycled and reused, which not only increases the cost of mercury removal, but also comprehensively utilizes the subsequent fly ash Adverse effects; for example, when using fly ash mixed with activated carbon to make bricks or prepare cement, the activated carbon in it will be burned out in the kiln, which will reduce the quality of the finished brick or cement, and at the same time, the secondary release of mercury will cause pollution.

Images