烧结烟气低温SCR脱硝催化剂半工业化试验

低温SCR是烧结烟气脱硝技术发展的主要方向,而催化剂是其中的关键因素。针对烧结烟气的特点,研发出低温平板式抗碱脱硝催化剂。为了明确该催化剂的低温脱硝活性、运行稳定性、积灰特性和抗碱金属中毒能力,在太钢450 m2烧结机活性炭脱硫脱硝装置后进行了低温SCR脱硝催化剂半工业化试验。结果表明,在150 ℃的烟气温度下,催化剂脱硝效率平均达85%,NO_x排放浓度小于50 mg/m3,氨逃逸不超过1.0 μL/L,完全满足烧结烟气超低排放的要求;催化剂层积灰主要是钾盐和活性炭粉,经过60天的连续运行,因积灰导致的反应器进出口压差增加值仅90 Pa;催化剂抗碱金属中毒能力优异,催化剂表面累积的钾含量达到新鲜催化剂的5.5~7.0倍时,脱硝活性没有明显降低。

Semi-industrial test on low temperature SCR denitrification catalyst for sintering flue gas

Low temperature SCR is the main development direction of sintering flue gas denitrification technology, and catalyst is the key factor. According to the characteristics of sintering flue gas, a low temperature-plate type-anti alkali metal poisoning denitrification catalyst was developed. In order to clarify the denitrification activity, operation stability, ash deposition and alkali metal poisoning resistance of the catalyst, the semi-industrial test on low temperature SCR denitrification catalyst was carried out after the activated carbon desulfurization and denitrification device of 450 m2 sintering machine of Tisco. The results showed that the average denitrification efficiency was 85% at 150 ℃, NO_x emission was below 50 mg/m3, and ammonia slip was less than 1.0 μL/L, which fully met the requirements of ultra-low emission of sintering flue gas. The ash in catalyst layer was mainly potassium salt and activated carbon powder. Through 60 days running test, the increase of pressure difference caused by ash deposition was only 90 Pa. The alkali metal poisoning resistance of the catalyst was outstanding, and the denitrification activity did not change significantly when the content of potassium accumulated on the surface of catalyst was 5.5-7.0 times that of fresh catalyst.