Abstract:

The emission characteristics and co-removal through air pollution control devices of sulfurous pollutant were conducted at three 410 t·h^-1 circulating fluidized bed boilers equipped with in-situ desulfurization + electrostatic precipitator (ESP)/fabric filter (FF) + wet flue gas desulfurization (WFGD). The US EPA Method 8 was used for the sampling of various forms of sulfurous pollutant in flue gas. Concurrent with flue gas sampling, the feed fuel, limestone, bottom ash, fly ash, gypsum and wastewater were sampled. The results showed that particulate-bound sulfur and SO₂ are the dominant species in the flue gas at the outlet of boilers, accounting for 48.94%-55.05% and 44.14%-49.07%, respectively. The removal efficiency of particulate-bound sulfur by ESP or FF is more than 95%. About 62.66%-67.82% of SO₃/sulfuric acid mist and 53.06%-60.89% of particulate-bound sulfur in flue gas was removed by WFGD, respectively. The majority of sulfur in fuel was migrated into fly ash + bottom ash and gypsum + wastewater, accounting for 56.79%-70.12% and 29.25%-41.70%, respectively. Only 0.63%-1.51% of total output sulfur was emitted into atmosphere.

Key words: sulfurous pollutant, circulating fluidized bed, petroleum coke, distribution, emission characteristics

摘要：

在3台配备了炉内脱硫+静电除尘器（ESP）/布袋除尘器（FF）+湿法脱硫装置（WFGD）的410 t·h^-1循环流化床（CFB）锅炉进行了硫污染物排放特性研究。在3个测点采用US EPA Method 8对烟气中不同形态硫污染物进行了平行取样，并同时采集了相应工况下入炉燃料、石灰石、底渣、飞灰、石膏和废水等，考察了污染物控制装置对硫污染物的影响以及硫在电厂的迁移和分布特性。结果表明，锅炉出口烟气中硫主要以颗粒态硫和SO₂的形式存在，占比分别为48.94%～55.05%和44.14%～49.07%。ESP和FF能高效脱除颗粒态硫，脱除效率均达95%以上；WFGD对SO₃/硫酸雾、颗粒态硫的脱除效率分别达62.66%～67.82%和53.06%～60.89%。燃料中硫经过燃烧和污染物控制装置脱除之后绝大部分迁移至灰渣（底渣+飞灰）和湿法脱硫产物（石膏+废水）中，分别占硫总输出的56.79%～70.12%和29.25%～41.70%，只有0.63%～1.51%的硫排放到大气环境中。

关键词: 硫污染物, 循环流化床, 石油焦, 分布, 排放特性