高炉炉顶煤气中HCl气体脱除的研究

The chlorine ion concentration is about 100mg/m3 in the process of blast furnace gas dry-type cleaning system, which affect seriously the good operation of bag filter and TRT unit, and decreas significantly the life of cowper stove. The corrosion phenomena of blast furnace gas pipes and equipments caused by condensation and liquification of HCl acid gas were appeared in blast furnace gas dry-type cleaning system of many iron & steel companies, such as Tangsteel, Baosteel, Jisteel, Taisteel and Shousteel. Therefore, the removal of HCl from blast furnace gas is a effective measure of solving gas pipes and equipments corrosion problems caused by condensation and liquification of HCl acid gas. The thermodynamics and kinetics of HCl removed from blast furnace gas will be studied with some methods in the fields of integrated gasification combined cycle power generation(IGCC), integrated gasification fuel cell (MCFC), petrochemical industry and waste incineration. Moreover, several dechlorinating agents and feasible dechlorinating methods for removing HCl from blast furnace gas will be developed. The effect of dust content on HCl removing process from blast furnace gas will be evaluated and the proper installation place of HCl removing equipments will be determined.

高炉干法除尘工艺在运行过程中净煤气中的氯离子浓度达到了100mg/m3左右，严重影响布袋除尘器和TRT的正常运行，降低热风炉寿命。唐钢、宝钢、济钢、太钢、首钢等许多钢铁企业的高炉干法煤气系统都存在HCl等酸性气体因冷凝析出而带来的煤气管道及设备腐蚀问题，脱除高炉炉顶煤气中的HCl气体是解决HCl等酸性气体因冷凝析出而带来的煤气管道及设备腐蚀问题最有效的途径。利用在煤气化联合循环发电（IGCC）、煤气化燃料电池（MCFC）、石油化工和垃圾焚烧等领域比较成熟的研究方法，研究高炉炉顶煤气中HCl气体脱除的热力学和动力学过程，开发出高炉炉顶煤气中HCl气体脱除适宜的脱氯剂并确定适宜的脱氯方式，找出炉尘含量对高炉炉顶煤气中HCl气体脱除过程的影响规律，确定高炉炉顶煤气中HCl气体脱除工艺适宜的实施地点。

高炉炉顶煤气中HCl的生成与高炉内存在NaCl、P2O5、SO2、NO2和水蒸气等物质有关，高炉中上部300℃至800℃温度范围内是HCl在高炉内主要生成的位置。石灰石、轻烧石灰石和Na2CO¬3可以作为高炉炉顶煤气脱氯剂的主体活性组分，NaHCO3和 KOH只能作为高炉炉顶煤气脱氯剂中的辅助活性组分，应该选择蒙脱石含量比较适宜的膨润土作为粘结剂，选择聚乙二醇作为造孔剂。稀土金属氧化物可以改善高炉炉顶煤气中HCl气体脱除过程，少量的转炉钢渣可以改善高炉炉顶煤气中HCl气体脱除过程。固定床反应器脱氯工艺过程得到的尾气HCl浓度比较低，脱氯剂消耗量比较小，高炉炉顶煤气中HCl气体脱除采用脱氯反应器置于高炉炉顶煤气出口处实行固定床反应器脱氯工艺是比较适宜的。重力灰的存在严重恶化了高炉炉顶煤气中HCl气体脱除过程；少量的布袋灰可以改善高炉炉顶煤气中HCl气体脱除过程，高炉炉顶煤气中HCl气体脱除工艺适宜的实施地点应该选择在布袋除尘器后。煤气空速提高会恶化高炉炉顶煤气中HCl气体脱除的效果，煤气温度提高有利于改善高炉炉顶煤气中HCl气体脱除过程。高炉炉顶煤气中的水蒸气和CO2都会恶化高炉炉顶煤气中HCl气体脱除过程，应该采取有效的技术措施适当控制高炉炉顶煤气中的水蒸汽和CO2含量。