石灰石-石膏法烟气脱硫过程中细颗粒物形成特性

Formation of fine particles in flue gas desulphurization process using limestone-gypsum

利用石灰石-石膏湿法烟气脱硫模拟试验装置分析探讨脱硫净烟气中细颗粒物物性与脱硫浆液中晶体粒度分布、浓度、形貌及元素组成间的关系,并试验考察了烟气组分及脱硫工艺条件对脱硫净烟气中细颗粒物排放的影响。结果发现:石灰石-石膏湿法烟气脱硫过程中可生成大量亚微米级细颗粒,生成的细颗粒物性与脱硫浆液中晶体物性存在密切关系,脱硫操作参数如空塔气速、液气比等对脱硫浆液液滴夹带量存在显著影响;脱硫浆液蒸发夹带是石灰石-石膏法脱硫过程中生成细颗粒物的主要来源,通过抑制细小石膏晶粒的形成及优化脱硫工艺参数可减少石灰石-石膏湿法脱硫过程中细颗粒的形成。

Usingsimulated experimental setup for flue gas desulphurization with limestone-gypsum, it was studied and analyzed that the relationship existed between properties of fine particles in flue gas formed in desulphurization process and particle size distribution, concentration, morphology, and elements composition of the limestone-gypsum slurry. The effects of flue gas component and desulphurization operation parameters on the fine particle emission were also experimentally investigated. The results show that large numbers of submicron particles are formed during the desulphurization process and their properties are close related to crystal properties of limestone-gypsum in desulphurization slurry. The desulphurization operation parameters such as empty column gas velocity and liquid-gas ratio have great influence on the quantity of slurry drops carried by flue gas out of the scrubber. The evaporation and entrainment of desulphurization slurry is the main source of fine particles formed during desulphurization and their formation can be reduced by the prevention of fine crystal formation in desulphurization slurry and operation parameter optimization.