高通量金属套管式微通道反应器内脱硝过程研究

发布时间：2018-05-21 11:17

  本文选题：金属套管式微通道反应器 + 乙二胺四乙酸亚铁络合物　； 参考：《北京化工大学》2015年硕士论文

【摘要】：一氧化氮(NO)的过量排放会导致地面臭氧层(对流层)浓度升高、烟霾、全球变暖等问题,对人类健康和环境的危害巨大。目前,许多方法已被用于NO的脱除,其中,湿法脱硝受到了研究者的广泛关注。过渡金属络合物作为吸收剂用于NO脱除,此过程具有反应速率高,且再生性好的特点。但是,在传统反应器中,其吸收速率通常受传质过程控制。本论文采用自主设计和研发的金属套管式微通道为气液传质强化反应器,以乙二胺四乙酸亚铁络合物(Fe(II)EDTA)和六氨合钴(Co(NH3)6Cl2)为吸收剂,开展了NO的脱除过程研究。全文的主要研究内容如下：1.在金属套管式微通道反应器内,采用Fe(Ⅱ)EDTA为吸收剂,考察了吸收液pH、浓度、气液流量比、气液流速以及微通道结构尺寸等参数对NO脱除率的影响,得到了较优脱除工艺条件。研究发现,NO脱除率随着Fe(Ⅱ)EDTA溶液的pH逐渐升高,呈现先升高再降低的趋势,pH为7时脱除率最高；NO脱除率随温度的升高而降低;固定气液流量比,同时增加气体和液体流量,NO脱除率先增高后降低;随着微孔孔径和套管环隙尺寸的增大,NO脱除率明显降低。当Fe(Ⅱ)EDTA浓度为0.04mol/L,套管内气液流量比为32,反应温度为293 K,套管微孔孔径为10μm,套管环隙尺寸为250μm时,NO脱除率可达到95%。2.进一步采用Co(NH3)6Cl2为吸收剂,研究了各个反应参数条件对NO脱除率的影响规律。研究结果表明,六氨合钴脱除NO的规律与Fe(Ⅱ)EDTA为吸收剂时基本相同,但其脱除效果略差于Fe(Ⅱ)EDTA,在较优脱除条件下,Co(NH3)6Cl2的NO脱除率为85%。3.基于Fe(Ⅱ)EDTA脱除NO过程,采用双膜理论,研究了套管式微通道反应器内气液传质过程,推导并计算了套管式微通道反应器内吸收NO的体积传质系数(KLa)。重点考察了各个反应条件参数,包括套管内气液流速、气液流量比、反应温度、套管结构尺寸等对KLa的影响。套管式微通道反应器内气体和液体流量的增加会强化传质。随着套管微孔孔径及套管环隙尺寸的增加,KLa逐渐降低。KLa会随着反应温度的降低、吸收液浓度的升高而升高。此外,套管内气液流量比的增加会促进传质,使得KLa升高。
[Abstract]:The excessive emission of nitric oxide (no) will lead to the increase of ground ozone layer (troposphere) concentration, haze, global warming and so on, which will cause great harm to human health and the environment. At present, many methods have been used to remove no. Among them, wet denitrification has been widely concerned by researchers. The transition metal complex is used as absorbent for no removal. This process is characterized by high reaction rate and good regeneration. However, in conventional reactors, the absorption rate is usually controlled by mass transfer processes. In this paper, the removal process of no was studied by using the metal-tube microchannel designed and developed by ourselves as gas-liquid mass transfer enhanced reactor, using EDTAA and CoNH3Cl2 as absorbent. The main contents of this paper are as follows: 1. In a metal tube microchannel reactor, the effects of pH, concentration, gas-liquid flow ratio, gas-liquid flow rate and structure size of microchannel on the removal rate of no were investigated by using Fe (鈪，

本文编号：1918981