高氨氮有机废液用于烟气脱硝的实现途径及耦合机制

Aiming at the problems of highly cost and easily bringing about second pollution for the traditional disposal method of high ammonia nitrogen organic waste, high temperature coupling SNCR denitrification technology for wastewater is studied ,which can reduce the consumption of reducing agent in the denitration system, as well as realize treatment of wastes with processes of wastes against one another by controlling the ammonia escape with SNCR/SCR mixing technology. The research focuses on the ways of realizing the denitrification and the coupling mechanism, the reduction mechanism of NOx and the mechanism of coupling with SNCR/SCR system in the high temperature of waste liquid are studied through the establishment of dual furnace micro reactor, fourier transform infrared spectroscopy, mass spectrometry and gas chromatography are used to detect the gas components on-line.Based on the characteristics of high temperature pyrolysis of waste liquid, the removal efficiency of the main components and the transformation of the products are studied. The influence of the second pollution on the denitration system and the elimination of side effects are explored by optimizing the ratio of reducing agent and adding rate, so as to provide parameters for practical application and expand the technology application scope.

针对高氨氮有机废液传统处置方式成本高、易造成二次污染等问题，开发废液高温耦合SNCR脱硝技术，一方面减少脱硝体系还原剂消耗，另一方面结合SNCR/SCR混合技术有效控制氨逃逸，实现以废治废。重点围绕废液用于脱硝的实现途径及耦合机制进行研究，通过建立双炉体微型反应装置，采用傅里叶变换红外、质谱、气相色谱等对气体组分进行在线检测，开展废液主导成分高温下对NOx的还原机制和与SNCR/SCR体系的耦合脱硝机制研究；基于废液的高温热解特性，对废液主导成分脱硝效率及生成产物迁移转化进行研究，优化还原剂配比、添加速率等，为实际应用提供参数依据，探索废液二次污染物对脱硝体系的影响及副作用消除方法，拓展技术的应用范围。

中文摘要：为解决氨氮有机废液处置成本高、易造成二次污染等问题，以垃圾渗滤液为代表完成了废液高温热解特性、有机废液高温还原NOx机理、SNCR/SCR 体系耦合脱硝机制、二次污染物对脱硝体系的影响和脱除研究。通过研究得到以下结果：.（1）垃圾渗滤液的主导有机成分的燃烧温度均低于热解温度，有机物在高温下产生的还原性·OH，·CHi和·O自由基可参与SNCR反应，并降低了SNCR反应的活化能。有机物单组分耦合脱硝率最高为51.2%。多组分协同脱硝率可达90%以上，并且有机物的加入可扩宽SNCR反应的温度窗口。当反应温度高于800℃时，有机组分之间的相互作用加剧导致参与SNCR反应的实际自由基减少，导致脱硝率降低。.（2）SNCR技术后水泥窑尾烟气的氨逃逸测试结果表明氨逃逸平均值为35.29 mg/Nm3，应采取SNCR/SCR联用技术有效措施来减少NH3的排放。从实验室结果来看SNCR/SCR耦合脱硝的总脱硝率随着反应总氨氮比的升高而升高，但在氨氮比超过1后脱硝率仅提高了3.0%，耦合脱硝的最佳氨氮比为1，且NH3分配比为20%和80%时，耦合脱硝率高达96.9%。.（3）渗滤液协同后酸性气体如SO2对SCR有明显的毒化作用，SCR催化剂上钨的负载可以提升常规钒钛基催化剂的抗硫性能，钨的负载可以提高SCR催化剂的抗硫性能，改性后的催化剂在连续评价22 h后脱硝率仍有84.1%。SCR脱硝催化剂在负载CaO后脱硝率最大降低了72%，CaO与V2O5的结合是造成催化剂反应活性降低的主要原因。铈的负载可以提高催化剂的耐碱性，氧化铈对0.1VWT有显著的促进作用，在反应温度为250℃时可实现脱硝率从12.9%升高到97.7%。针对垃圾渗滤液有机有害气体脱除研究，采用活性炭吸附催化法对有害气体如氯酚能够有效脱除，金属负载的AC-O催化性能比化学改性的AC-O催化性能更好。经过化学改性的催化剂的最大氯酚降解效率仅为82.2%，而在经过金属负载后的催化剂的氯酚降解效率可达93.2%。 .