Biomass boiler flue gas desulfurization device and process

Abstract

The invention relates to a biomass boiler flue gas desulfurization device and process. A large amount of sulfur dioxide is removed by spraying and washing biomass boiler flue gas in an absorbing tower slurry tank through lime milk slurry, and generated desulfurization products through reaction is forcedly oxidized to generate calcium sulfate by air to be connected and crystallizes to generate raw gypsum in the slurry tank. Amount of the lime milk slurry entering the absorbing tower is adjusted through a flow meter, pH value of the absorbing tower slurry tank is maintained between 5.6 and 5.8, slurry in an absorbing tower is controlled to be discharged out with a concentration ranging from 8% to 10%, and discharged slurry is pumped in a boiler deslagging system. The biomass boiler flue gas desulfurization device and the process need no gypsum dehydration system, is free of discharge of waste water, waste residues and by-products, and solves secondary pollution problems of power station gypsum. A multiple systemic function of gypsum discharge, accident discharge, slurry return and the like can be achieved through submerged pumps arranged in a pit of the absorbing tower, and one submerged pump is in operation and one submerged pump is reserved, and the biomass boiler flue gas desulfurization device and the process greatly reduces equipment investment of regular wet process desulfurization.

Description

technical field [0001] The invention relates to a device and process for removing sulfur dioxide, in particular to a device and process for removing sulfur dioxide applied to biomass boiler flue gas. Background technique [0002] With the gradual increase of domestic projects using biomass fuel to generate electricity, the control of flue gas emissions from biomass power plants (boiler capacity is usually less than 150t / h) is also included in the scope of regional environmental control. For biomass boilers located near central cities, SO in flue gas 2 Although the concentration is low about 200mg / Nm 3 , but still can not meet the regional control requirements, such as Beijing's "Boiler Air Pollutant Emission Standard" (DB11 / 139-2007) the sulfur dioxide emission concentration requirement does not exceed 20mg / Nm 3 . There is a demand for the construction of flue gas desulfurization equipment. [0003] Most of the existing desulfurization technologies and process systems in...

AI Technical Summary

Problems solved by technology

The limestone-gypsum wet desulfurization process system is complicated, and it is applied to small units with poor economy and high failure rate; the circulating fluidized bed semi-dry desulfurization process requires high-concentration circulating materials, which is not suitable for biomass boilers; ammonia desulfurization uses ammonia water as Desulfurization agent, which will cause a large amount of escaped ammonia in the application of small boilers; the double-alkali desulfurization process uses soda ash as the desulfurization agent, which has high operating costs and poor reliability

[0004] Up to now, domestic biomass boiler flue gas desulfurization technology is still blank, unable to meet the environmental protection needs of biomass boilers

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