半干半湿法烟气脱硫技术的原理及应用研究

半干半湿法烟气脱硫技术利用蒸气激活粉煤灰中的碱性物质,以及水蒸气与石灰反应生成的强碱性的消石灰,降低了石灰的使用量.脱硫灰在蒸气输送过程中,CaSO3被携带的空气氧化生成CaSO4.由于采用高盐锅炉废水进行增湿,提高了SO2与脱硫剂的反应速度与效率.本文通过对脱硫机理的讨论,研究了该技术的工艺特点.在CaO和SO2的物质的量比值小于1的条件下,SO2去除率达80%以上.这项技术不但适用于锅炉烟气脱硫处理,还可用于垃圾焚烧炉的烟气脱酸净化.

MECHANISM AND INDUSTRIAL APPLICATION OF SEMI-DRY FLUE GAS DESULPHURIZATION

The present paper aims to introduce the author's research on the desulphurization mechanism and the features of its technical applications. A series of experiments has been conducted in Laixi Heating & Power Plant, Shandong, with the capacity of 61 750 Nm~3/h. The experimental results show that when CaO/SO_2 molar ratio rate is less than 1.0, the desulphurization efficiency of over 80% can be obtained, with SO_2 removal efficiency being as high as 88.3% when CaO/SO_2 molar ratio rate is 1.2. The mass recirculation dust is 3 to 5 times over mass lime as SO_2 sorbent. The process developed by the author is not only suitable for SO_2 removal, but also for hydrochloric removal application. Therefore, it can be used for flue gas disposal from municipal solid waste incineration. Since semi-dry flue gas desulphurization is a novel technology for the flue gas cleaning from industrial coal fired boiler, lime is used as SO_2 sorbent, and recirculated dust collected from the cyclone cleaner as addictive desulphurization agent, which is mainly of fly ash and used lime. By employing alkaline composition activated from fly ash by steam, and Ca(OH)_2 reacted from lime and steam, SO_2 removal efficiency can thus be improved. By means of boiler wastewater for hydration, reaction velocity between desulphurization agents and SO_2 is improved, and the SO_2 removal efficiency is thus increased. Due to the process of steam conveyance, most CaSO_3 containing in byproduct can be oxidized into CaSO_4, and the dust collected can also be used for cement and other building materials. Which helps to rank the technology to be one of the most advanced technologies in China.