Two-Stage Chemical Absorption-Biological Reduction System for NO Removal: System Start-up and Optimal Operation Mode
Two-Stage Chemical Absorption-Biological Reduction System for NO Removal: System Start-up and Optimal Operation Mode
复制标题
两级化学吸收-生物还原脱硝系统：系统启动和最佳运行模式
DOI：
10.1021/acs.energyfuels.8b00756
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发表时间：
2018
期刊：
影响因子：
5.3
通讯作者：
Wei Li
中科院分区：
文献类型：
--
作者：
Chunyan Zhang;Jingkai Zhao;Cheng Sun;Sujing Li;Dongxiao Zhang;Tianjiao Guo;Wei Li
以Fe（II）EDTA为强化吸收剂的化学吸收-生物还原（CABR）工艺是一种新型的氮氧化物去除技术。本研究开发了一种新的两级CABR系统，该系统由筛板塔和生物还原塔组成，将吸收和还原过程分离，采用了铁还原菌和反硝化菌混合培养的模式。两级系统的启动周期缩短至19天，而一级CABR系统的启动周期为46天。此外，两级CABR系统具有更好的抗氧能力和更高的NO去除负荷。为优化系统运行，比较了不同的系统运行方式，发现连续投加葡萄糖优于间歇投加;当FeEDTA浓度大于4 mmol/L时，NO去除率可保持在90%以上;降低Fe 3+铁络合物的初始浓度可抑制Na 2 EDTA的损失率。最佳操作条件为：初始Fe（III）EDTA浓度为4 mmol/L，Na 2 EDTA浓度为0.6 mg/min，葡萄糖浓度为5 mg/min，气体流量为2 L/min，NO浓度为400 ppm，NO去除率大于90%;以葡萄糖计的相应操作成本为8.4g葡萄糖/这项工作的目的是提供初步的数据，以支持未来的工业应用NOx去除，以及对两段CABR系统的工艺配置和反应器操作的充分技术见解。
A novel chemical absorption–biological reduction (CABR) integrated process, employing Fe(II)EDTA as an enhanced absorbent, is a promising technology for nitrogen oxides removal. In this work, we developed a new two-stage CABR system applying a mixed cultivation model of denitrifying bacteria and iron-reducing bacteria, which consists of a sieve-plate tower and a bioreduction tower to separate the absorption and reduction processes. The start-up period of the two-stage system was shortened to 19 days, while that of the one-stage CABR system was 46 days. In addition, the two-stage CABR system featured a better oxygen-resistance ability and a higher NO removal loading. In effort to optimize system operation, we compared different modes of system operation and found that (1) continuous addition of glucose was better than the batch-type addition and that (2) the NO removal efficiency could be maintained at >90% while the FeEDTA concentration was higher than 4 mmol/L; however, reducing the initial concentration of ferric iron complex could inhibit the loss rate of Na2EDTA. Furthermore, the optimized operating mode parameters were 4 mmol/L initial Fe(III)EDTA, 0.6 mg/min Na2EDTA, and 5 mg/min glucose with a 2 L/min gas flow rate under a 400 ppm of NO condition, while the NO removal efficiency was kept >90%; the corresponding operating cost in terms of glucose was 8.4 g of glucose/g of NO. The purpose of this work was to provide preliminary data to support future industrial application for NOxremoval, as well as sufficient technological insights on the process configuration and reactor operation of the two-stage CABR system.