School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
J Hazard Mater. 2021 Apr 5;407:124380. doi: 10.1016/j.jhazmat.2020.124380. Epub 2020 Oct 27.
Conventional flue gas nitrogen oxides (NO) abatement technologies commonly convert NO into harmless compounds, while less effort has been made to recycle NO as a profitable chemical in many industries. Towards this end, adsorption is a promising technology for which an advanced technique for NO desorption and efficient sorbent regeneration provides the key step for success in practical applications. This work reports a novel cyclic adsorption process for NO removal with recycling of NO from iron-ore sintering flue gas of a steel plant. This process using self-prepared and validated pelletized Na-ZSM-5 zeolites as low-cost sorbents involves NO catalytic adsorption and reversible desorption using multiple hot gas circulations (GC) within the enclosed fixed bed followed by scavenging and purge at mild conditions. In comparison to conventional cyclic processes, greater amount of recyclable NO was obtained, rendering the NO recovery of >92% and the mean NO concentration of >2% significantly enriched from original 20 ppm in feed gas. A robust adsorption-desorption performance with appreciable NO working capacity was achieved for up to 16 cycles. The key role of the segmentation of GC in boosting NO regenerability was addressed, providing an economical three-tower strategy for continuous NO production for practical use.
传统的烟气氮氧化物（NO）减排技术通常将 NO 转化为无害化合物，而在许多工业中，将 NO 回收再利用为有利可图的化学品的努力较少。为此，吸附是一种很有前途的技术，对于这种技术，NO 的解吸和高效吸附剂再生的先进技术为实际应用中的成功提供了关键步骤。本工作报道了一种从钢厂铁矿烧结烟气中回收 NO 的新型循环吸附法，用于去除 NO。该过程使用自制并经过验证的粒状 Na-ZSM-5 沸石作为低成本吸附剂，涉及使用封闭固定床内的多次热气体循环（GC）进行 NO 催化吸附和可逆解吸，然后在温和条件下进行清除和吹扫。与传统的循环工艺相比，可回收的 NO 量更多，使 NO 回收率>92%，进料气中原始 20 ppm 的平均 NO 浓度显著富集到>2%。在多达 16 个循环中实现了具有可观的 NO 工作能力的稳健吸附-解吸性能。还解决了 GC 分段在提高 NO 可再生性方面的关键作用，为实际应用中连续生产 NO 提供了经济的三塔策略。
