机组新型无毒催化剂烟气脱硝性能试验研究 -

在SCR脱硝系统中,脱硝催化剂性能的优劣极大地影响了脱硝效率。目前广泛使用的V_2O_5-WO_3/TiO_3催化剂不仅价格高昂,且失活后催化剂中的钒氧化物会对环境造成严重污染,因此需对传统催化剂进行改进。新型无毒脱硝催化剂以稀土金属氧化物为活性组分,该组分可降低对环境的污染程度。为了研究新型无毒脱硝催化剂在实际工程中的应用效果,以电厂8号机组为例,对机组SCR脱硝系统的脱硝效率、氨逃逸率和SO_2/SO_3转化率等进行研究,选择了360、500和600 MW三个运行负荷,每个工况下分别对A、B两侧进行采样检测。测试结果表明,SCR脱硝系统在3个运行负荷下的平均脱硝效率分别为82.31%、76.81%和81.58%;单层新型无毒脱硝催化剂的脱硝效率分别为52.34%、55.34%和57.14%,均大于保证值45%;在600 MW负荷下首层催化剂,即新型无毒催化剂的SO_2/SO_3平均转化率为0.38%,小于保证值1%;3个负荷下首层催化剂的阻力分别为96、117.5和153 Pa,均小于保证值200 Pa;平均氨逃逸浓度分别为1.26×10~(-6)、1.46×10~(-6)以及0.52×10~(-6),均小于保证值2.5×10~(-6)。360 MW下脱硝系统A、B两侧出口NOx浓度分别为38、46 mg/m~3;500 MW下脱硝系统A、B两侧出口NOx浓度分别为21、28 mg/m~3;600 MW下脱硝系统A、B两侧出口NOx浓度分别为27、31 mg/m~3。所有工况下脱硝系统出口A、B两侧烟气中NO_x浓度均低于超低排放标准要求,新型无毒脱硝催化剂可满足工业应用的要求。 In the SCR system,the denitration efficiency is greatly affected by the performance of the catalyst. The V_2O_5-WO_3/TiO_3 cata-lyst which is widely used is not only expensive,but also the vanadium oxide in the catalyst after deactivation will cause serious pollution tothe environment. Therefore,traditional catalysts need to be improved. The new non-toxic catalyst uses rare earth metal oxide as the ac-tive component,which can greatly reduce the degree of environmental pollution. In order to study the application effect of the new non-tox-ic catalyst in practical engineering,and taking unit 8 of the power plant as an example,the denitration efficiency,ammonia escape rate,and SO_2/SO_3 conversion rate of the SCR denitration system of the unit were tested. Three operating loads of 360,500,and 600 MW weretested,and sampling inspection was carried out on both sides of A and B under each operating condition. The test results show that the av-erage denitration efficiency of the SCR denitration system under 3 operating loads is 82.31%,76.81%,and 81.58% respectively,and thedenitration efficiency of the single-layernon-toxic denitration catalyst is 52.34%,55.34%,and 57.14% respectively,which are all greaterthan guaranteed value of 45%.Under the test load of 600 MW,the average SO_2/SO_3 conversion rate of the newnon-toxic catalyst is 0.38%,which is less than the guaranteed value of 1%,and the resistance of the first-layer catalyst under the three loads is 96,117.5 and 153 Parespectively,which are both less than the guaranteed value of 200 Pa.The average ammonia escape concentrations are 1.26×10~(-6),1.46×10~(-6),and 0.52×10~(-6) respectively,which are less than the guaranteed value of 2.5×10~(-6). The NOxconcentrations at the sides of the denitration system A and B at 360 MW are 38 and 46 mg/m~3.The NOx concentrations at the sides of the denitration system A and B at 500 MW