基于LIBS技术的SCR催化剂成分检测

Composition Detection of SCR Catalyst Based on LIBS Technology

【目的】火电厂SCR催化剂运行一段时间后,由于烟气冲蚀、氯与钒发生反应等,催化剂中的活性成分V_(2)O_(5)流失和载体TiO_(2)、结构助剂WO_(3)含量改变,催化剂活性下降。因此,催化剂成分含量的检测对于SCR脱硝系统的安全经济运行具有重要意义。【方法】通过实验室配制7个催化剂定标样品,采用激光诱导击穿光谱技术装置进行检测,通过多元线性回归得到V_(2)O_(5)、WO_(3)、TiO_(2)质量百分含量和各自特征谱线强度之间的定标曲线方程。再对8号样品(现场取样的新鲜催化剂)进行测量,验证测量的准确度。【结果】结果表明,8号样品中V_(2)O_(5)、WO_(3)、TiO_(2)测量值与实际值的相对误差r分别为:2.7%、1.5%、1.6%,相对误差值均小于5%,测量精度较高。【结论】为SCR催化剂成分的测量提供了一种新的、有效的检测方法,可为催化剂的更换、再生管理及火电厂脱硝系统的安全经济运行提供重要保障。

[Purposes]After running for a period of time,the SCR catalyst in thermal power plants loses the active ingredient V_(2)O_(5) and changes the content of the carrier TiO_(2) and structural aid WO_(3) due to factors such as flue gas erosion and reaction between chlorine and vanadium,which directly leads to a decrease in catalyst activity.Therefore,the detection of catalyst component content is of great significance for the safe and economic operation of SCR denitrification systems.[Methods]This article prepared 7 catalyst calibration samples in the laboratory,and for the first time,laser induced breakdown spectroscopy technology was used for detection.V_(2)O_(5) was obtained through multiple linear regression.The calibration curve equation between the mass percentage of V_(2)O_(5),WO_(3),TiO_(2) and the intensity of their characteristic spectral lines was obtained by multiple linear regression.Then the sample No.8(fresh catalyst sampled on site)was measured to verify the accuracy of the measurement.[Findings]The results indicate that the relative errors between the measured values and the actual values of V_(2)O_(5),WO_(3) and TiO_(2) in sample 8 are 2.7%,1.5%and 1.6%,respectively.The relative error values are all less than 5%,indicating high measurement accuracy.[Conclusions]This provides a new and effective detection method for measuring the composition of SCR catalysts,and also provides important guarantees for catalyst replacement,regeneration management,and safe and economic operation of denitrification systems in thermal power plants.