Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, China.
Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, China.
J Environ Sci (China). 2019 Jun;80:35-44. doi: 10.1016/j.jes.2018.07.013. Epub 2018 Aug 5.
Coal-fired power plants are considered a major source of fine particle emissions in China. Aimed to improve the removal efficiency of fine particles during the limestone-gypsum wet flue gas desulfurization (WFGD) process, a novel technology using chemical agglomeration to abate the emission of fine particles is presented herein. The relationship between fine particle emission and the proportion of fine particles in the desulfurization slurry was studied. Additionally, the influence of chemical agglomeration on fine particle size distribution, both in the flue gas and slurry was experimentally investigated. When chemical agglomeration agents were added to the desulfurization slurry, the fine particle removal performance as well as the effects of the operation parameters was also explored via the simulated experimental facility. The results revealed that the fine particles in both the desulfurization slurry and flue gas were significantly enlarged after the addition of the agglomeration agents. This was more marked in the submicron particles. Thus, the proportion of fine particles (< 10 μm) in the slurry decreased from 31.1% to 22.6%. An increase in the desulfurization slurry temperature and liquid-to-gas ratio aided the reduction in fine particle emission. Moreover, the addition of an agglomeration agent in the slurry did not affect the desulfurization efficiency of the desulfurization tower and even promoted the WFGD process. Thus, the proposed chemical agglomeration technique reduced the fine particle emission of the WFGD system by ~30%, while a desulfurization efficiency >90% was maintained.
燃煤电厂被认为是中国细颗粒物排放的主要来源。为了提高石灰石-石膏湿法烟气脱硫（WFGD）过程中细颗粒物的去除效率，本文提出了一种利用化学团聚来减少细颗粒物排放的新技术。研究了细颗粒物排放与脱硫浆液中细颗粒物比例之间的关系。此外，还通过模拟实验装置实验研究了化学团聚对烟气和浆液中细颗粒物粒径分布的影响。当在脱硫浆液中添加化学团聚剂时，还通过模拟实验装置探讨了添加团聚剂对细颗粒去除性能和操作参数的影响。结果表明，添加团聚剂后，脱硫浆液和烟气中的细颗粒明显增大，亚微米颗粒更为显著。因此，浆液中细颗粒（<10μm）的比例从 31.1%降至 22.6%。脱硫浆液温度和液气比的升高有助于减少细颗粒排放。此外，浆液中添加团聚剂不会影响脱硫塔的脱硫效率，甚至会促进 WFGD 过程。因此，所提出的化学团聚技术可将 WFGD 系统的细颗粒物排放减少约 30%，同时保持脱硫效率>90%。
