Method for reducing discharge of fine particulates and metals during combustion process

Abstract

The invention discloses a method for reducing discharge of fine particulates (PM2.5) and metals during the combustion process. An adsorbent with kaolin as the main component is sprayed into the high-temperature (800 to 1,100 DEG C) tail flue gas of a combustion device in a quantity of 1 to 20 g / Nm<3>. The adsorbent is solid powder with the particle diameter being 5 to 73 Mum. Metals such as Na, K, Pb and Cd and PM2.5 in the flue gas are absorbed by the absorbent through chemical reaction and physical adsorption and converted to solid particulates with aerodynamic size being larger than 2.5 Mum at the high temperature, so as to be easily removed by a dust removing device, thereby remarkably reducing the discharge amount of metals such as Na, K, Pb and Cd and PM2.5 to the ambient atmosphere. Gaseous and aerosol-state toxic and harmful substances are converted to solid water-insoluble large particulates, so as to be favorable for entrapment and harmless and resource utilization. The discharge amounts of Na and K, Pb and Cd, and PM2.5 are reduced by 80%, 50% and 50%, respectively.

Description

technical field [0001] The invention belongs to combustion pollutant emission control technology, in particular to a method for reducing fine particulate matter (PM) in the combustion process 2.5 ) and metal Na, K, Pb, Cd pollutant discharge methods. Background technique [0002] Coal combustion and municipal waste incineration are one of the main causes of environmental pollution. During the combustion process, the heavy metals (Pb, Cd, etc.) present in coal or garbage will evaporate as the temperature rises, and will be enriched in fine particles during the cooling process of the tail flue. Due to the limit of the performance of the dust collector, the fine particles generated during the combustion process will inevitably partly penetrate the dust collector and diffuse into the atmosphere. These fine particles will directly enter the human respiratory system and cause various diseases. In addition, some heavy metals can become or be enriched in organic substances through...

AI Technical Summary

Problems solved by technology

The above various methods of removing heavy metals before combustion have achieved good results in reducing the total amount of heavy metals in certain coal types. The particle capture efficiency is very low, so the concentration of heavy metals, alkali metals and fine particles in the flue gas at the outlet of the air pollution device does not decrease in a corresponding proportion, and in some cases even changes little

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