Method for removing heavy metals from high temperature flue gas by using active boron nitride

Abstract

The invention discloses a method for removing heavy metals from high temperature flue gas by using active boron nitride, and belongs to the field of heavy metal adsorption. The method comprises the following steps: preparing a high temperature flue gas adsorbent S-BN adsorbent or a P-BN adsorbent, grinding the prepared high temperature flue gas adsorbent, injecting the ground high temperature flue gas into a flue gas channel, collecting the high temperature flue gas adsorbent in the flue gas channel, repeatedly cleaning the collected high temperature flue gas adsorbent, and filtering and drying the high temperature flue gas adsorbent after the heavy metals in the high temperature flue gas adsorbent are completely washed away in order to realize recycling. The addition of S and P to the active boron nitride increases the chemical adsorption effect based on original physical adsorption, so the adsorption process is effective, the adsorption of the flue gas at a high temperature of 800 DEG C or above is realized, the regeneration performance is strong, and 80% or above of the original adsorption capacity is still kept after cycle use in a laboratory 50 times.

Description

technical field [0001] The invention relates to a method for removing heavy metals in high-temperature flue gas, in particular to a method for removing heavy metals in high-temperature flue gas by using active boron nitride. Background technique [0002] At present, the existing methods for synergistically removing heavy metals in high-temperature flue gas are roughly divided into the following methods: 1. Traditional adsorbents such as activated carbon, bentonite, zeolite, etc. utilize their high specific surface area to flue gas For example, CN105056885A, through the improvement of the preparation method of activated carbon, the proportion of pores in the activated carbon is increased, which is used to remove the heavy metal mercury in the flue gas. Although the activated carbon developed by this method can be effective in the low temperature section However, activated carbon adsorbents can only maintain high-efficiency adsorption capacity in a narrow temperature range of ...

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Problems solved by technology

2. Use electrostatic precipitators to efficiently capture particulate matter and particulate heavy metal mercury, arsenic, etc. in the flue gas, such as CN104740983A, a method and device for combined removal of boiler flue gas particulate matter and heavy metals. This method first removes the flue gas Pass through the electrostatic precipitator area, then pass through the fixed bed of mercury catalytic oxidant, then enter the adsorbent injection system, and finally enter the bag filter. Although this method can efficiently remove fine particles and heavy metals in the flue gas, the removal process is complicated and increases the operation time. cost

3. Wet purification method can remove particles, acid gases, dioxins and heavy metals in the flue gas, such as CN101822942A. After the high-temperature flue gas from the solid waste incinerator cools down, the flue gas first passes through the first-stage bubbling reactor, Then through the second-stage reactor, the flue gas is finally dehumidified and then discharged into the atmosphere after being purified by the activated carbon adsorption tower. The hazards of the waste water are transferred to the waste water, and the waste water needs to be further treated, which increases the difficulty of treatment.