烟气脱硝除尘一体催化滤布的开发过程
文献类型:学位论文
作者 | ABDULLAHI ABUBAKAR |
答辩日期 | 2020-07-01 |
授予单位 | 中国科学院大学 |
导师 | 余剑 |
关键词 | 催化滤芯,催化布袋,脱硝,除尘 |
学位名称 | 硕士 |
学位专业 | 化学工程 |
英文摘要 | 当前烟气脱硝除尘净化技术主要分别在脱硝单元和除尘单元完成:脱硝过程主要包括基于V-W-Ti催化体系的选择性催化还原(SCR)以及选择性非催化还原技术(SNCR);除尘过程则包括湿法除尘、电除尘、过滤除尘等多种工艺技术。脱硝与除尘单元的独立运行不仅增加占地空间,还显著提升设备投资和运行成本。因此,如何将烟气脱硝除尘一体化,缩短工艺流程,降低工艺成本,是当前烟气脱硝除尘净化领域发展的一个重要方向。当前的研究主要集中于脱硝除尘工艺耦合与优化以降低工程和操作成本,但是由于当前脱硝与除尘工艺的相对独立性,如何在同一单元实现燃烧烟气脱硝除尘净化依然是该领域面临的重大挑战。催化滤芯或催化滤袋,可实现脱硝与除尘单元在同一操作单元内完成,可显著降低烟气脱硝除尘的工艺和运行成本,并成为当前烟气净化领域的一个新兴热点方向。针对中高温烟气净化,本文首先研发了可同时去除NOx和灰尘的V- W-Mo-Ti催化滤芯,并在实验室和中试现场进行测试。研究了催化剂浆料,催化剂负载量和空速,以进一步优化催化滤芯以获得更好的SCR活性和工业实用性。 此外,在实验室条件下研究了粉尘对催化活性和压降的影响,作为中试应用的数据支持。 2700只优化后的催化滤芯在100,000 Nm3/h的玻璃窑炉烟气中进行了同时脱硫,脱硝和除尘的中试试验同。在入口烟气NOx浓度2600 mg/Nm3,SOx浓度3000 mg/Nm3,玻璃灰浓度500 mg/Nm3, 温度为350 °C条件下稳定运行90天,其压降低于1.4 KPa, NOx转化率和SOx转化率均为95%,除尘效率高达99%。对于200-250°C的中低温烟气净化,开发了具有良好脱硝活性,除尘效率和高附着强度的同时脱硝、除尘催化滤袋。对涂层用催化剂粉末的研究表明,催化剂中V和Mo含量的增加可以提高低温活性,所选的涂层用V10Mo10配方在180°C时表现出最佳100%的NO转化活性。对催化滤袋的进一步研究发现,低比例的PTFE,高催化剂负载量和较长的停留时间(例如,较低的过滤速度或双层过滤器)将有助于实现高的脱硝效率。在催化剂负载量为500 g/m2、使用10%PTFE和0.5 m/min线速度且存在SO2/H2O的条件下,双层催化滤布在200-250°C仍可获得超过80%的NO转化率和99.9%的除尘效率,证明了其工业应用的巨大可行性。在高粉尘浓度的中小型锅炉烟气净化领域,本文的研究结果表明,催化滤芯或催化布袋具有很强的可行性和工业应用的可行性。 ;The current flue gas denitration and dust removal purification technology is mainly completed in the denitration unit and the dust removal unit: the denitration process mainly includes selective catalytic reduction (SCR) and selective non-catalytic reduction technology (SNCR) based on the VW-Ti catalytic system; the dust removal process includes Wet process dust removal, electric dust removal, filter dust removal and other process technologies. The independent operation of the denitration and dust removal unit not only increases the flow space, but also significantly increases equipment investment and operating costs. Therefore, how to integrate flue gas denitrification and dust removal, shorten the process flow, and reduce process costs is an important development direction of the current flue gas denitration and dust removal purification field. Current research mainly focuses on coupling and optimization of denitrification and dust removal processes to reduce engineering and operating costs, but due to the relative independence of current denitrification and dust removal processes, how to achieve combustion flue gas denitrification and dust removal in the same unit is still a major challenge in this field. The catalytic filter element or the catalytic filter bag can realize the denitration and the dust removal unit in the same operation unit, which can significantly reduce the process and operating costs of flue gas denitration and dust removal, and has become an emerging hot spot in the field of flue gas purification. For the purification of medium and high temperature flue gas, this article first develops a vanadium-based catalytic filter material. The V-W-Mo-Ti catalytic filter for the industrial application was developed to remove NOx and dust simultaneously in the lab and pilot test. The catalytic slurry, catalyst loading, and space velocity were investigated to further optimize the catalytic filter for a better SCR activity and industrial applicability. Moreover, the effect of dust on catalytic activity and pressure drop was studied in the lab as a data support for the pilot application. The pilot test of 2700 catalytic filters over the flue gas from glass kiln exhibited excellent performance with above 95% NOx/SOx conversion and 99% dust removal efficiency at a stable pressure drop (1.4KPa) during the 90-day test under the conditions of 2600 mg/Nm3 inlet NOx concentration, 3000 mg/Nm3 inlet SOx, 500 mg/Nm3 inlet dust concentration and 350 °C. V2O5 – MoO3/TiO2 based catalytic bag filters were developed for the simultaneous removal of particulates and NO in the temperature range of 200 - 250 °C, which exhibited good denitrification activity, dedust efficiency as well as high adhesion strength in the temperature range of 200 - 250 °C. The study of catalyst powder for coating revealed that the increased V and Mo content in catalyst can elevate the low-temperature activity, and the chosen V10Mo10 sample for coating showed the best activity with 100% NO conversion at just 180 °C. The further research on catalytic bag filter found the low ratio of PTFE, high loading and long residence time (e.g., low filtration velocity or double layer filter) may help to achieve high DeNOx efficiency. The best performance was obtained with above 80% NO conversion at 200 - 250 °C even in the presence of SO2/H2O and 99.9% dust collection efficiency on the condition of 500 g/m2 loading, 10% PTFE, 0.5 m/min filtration velocity and double layers of filter, which demonstrated great feasibility for industrial application. In the field of small-medium boiler flue gas purification with high concentration of dust, the findings published here indicate that catalytic filter has great viability and great feasibility for industrial application. |
语种 | 中文 |
源URL | [http://ir.ipe.ac.cn/handle/122111/49652] ![]() |
专题 | 中国科学院过程工程研究所 |
推荐引用方式 GB/T 7714 | ABDULLAHI ABUBAKAR. 烟气脱硝除尘一体催化滤布的开发过程[D]. 中国科学院大学. 2020. |
入库方式: OAI收割
来源:过程工程研究所
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