【摘要】：隨著國(guó)家環(huán)保法規(guī)的日益嚴(yán)格,冶金行業(yè)NO_x的排放也將嚴(yán)格控制。目前,部分鋼鐵冶金行業(yè)燒結(jié)工序采用活性炭法同時(shí)脫除SO2、NO_x、二VA英等多種有害氣體,但活性炭脫硫脫硝成本較大。冶金行業(yè)不僅氮氧化物排放量高,產(chǎn)生的固廢量巨大,如鋼渣累積量大,但利用率低。鋼渣中仍含有一定量的未被利用的鐵氧化物,眾多學(xué)者研究表明,鐵基催化劑具有廉價(jià)易得、脫硝活性窗口寬、抗毒能力強(qiáng)等特點(diǎn),其在選擇性催化還原SCR脫硝工藝中具有良好的應(yīng)用前景。因此,若以鋼渣為原料與活性炭制備復(fù)合吸收劑,不僅為鋼渣找到一條新的利用途徑,而且可以利用鋼渣與活性炭聯(lián)合脫硝實(shí)現(xiàn)催化協(xié)同吸附的共同作用,亦可降低活性炭的脫硝成本,這對(duì)于實(shí)際工程應(yīng)用將具有重要的意義。收集寶鋼不同種類的鋼渣與煤基活性炭樣品經(jīng)過預(yù)處理制備成不同摻混比例的混合物(以下簡(jiǎn)稱“復(fù)合吸收劑”),并于電加熱石英玻璃管反應(yīng)器進(jìn)行鋼渣/活性炭復(fù)合吸收劑的最佳配比實(shí)驗(yàn)研究同時(shí)進(jìn)行了復(fù)合吸收劑脫硝性能的實(shí)驗(yàn)研究,并綜合考慮了反應(yīng)溫度、NO濃度、氧氣濃度、鋼渣種類等的影響�；陧憫�(yīng)面法優(yōu)化了實(shí)驗(yàn)運(yùn)行條件及工作參數(shù)并預(yù)測(cè)了實(shí)驗(yàn)的最佳反應(yīng)工況點(diǎn)及效率。在最佳反應(yīng)工況點(diǎn)分別對(duì)不同鐵含量鋼渣制備的復(fù)合吸收劑進(jìn)行了實(shí)驗(yàn)研究,進(jìn)行了BET、XRF、SEM表征及TG分析,并分析了復(fù)合吸收劑的脫硝過程。實(shí)驗(yàn)發(fā)現(xiàn)復(fù)合吸收劑的最佳活性摻混比例為活性炭/鋼渣=2:1�；钚蕴亢弯撛忻撓趸钚�,其中活性炭脫硝率較高可達(dá)36%,但隨著溫度的升高效率逐漸降低。鋼渣脫硝率隨著溫度升高而升高,最高為13%�；钚蕴夸撛鼡交熘苽涞膹�(fù)合吸收劑的脫硝率大于同樣反應(yīng)條件下活性炭的脫硝率,且在低溫區(qū)復(fù)合吸收劑的脫硝率大于活性炭和鋼渣的脫硝率之和,說明活性炭與鋼渣制備的復(fù)合吸收劑存在協(xié)同脫硝作用。實(shí)驗(yàn)結(jié)果表明反應(yīng)溫度與NO初始濃度對(duì)復(fù)合吸收劑脫硝率的影響為“負(fù)相關(guān)”,煙氣中氧含量對(duì)復(fù)合吸收劑脫硝率的影響為“正相關(guān)”。結(jié)合響應(yīng)面法復(fù)合吸收劑反應(yīng)條件優(yōu)化實(shí)驗(yàn)結(jié)果可知溫度、NO濃度、氧含量等三因素對(duì)吸收劑效率的影響均顯著,其中溫度與氧含量二者的交互作用明顯。優(yōu)化器預(yù)測(cè)的最佳工況點(diǎn)為反應(yīng)溫度116℃、O2含量12%、NO濃度400ppm,最大效率為72.5%,復(fù)合吸收劑最佳工況點(diǎn)的實(shí)驗(yàn)驗(yàn)證結(jié)果為71.4%。通過對(duì)活性炭、鋼渣、復(fù)合吸收劑進(jìn)行表征分析(包括TG、XRF、BET、SEM分析等),表明活性炭具有一定的熱穩(wěn)定性,單質(zhì)鐵含量是影響復(fù)合吸收劑效率的主要內(nèi)在因素,初步分析復(fù)合吸收劑脫硝過程存在活性炭吸附作用以及鋼渣催化作用。
[Abstract]:With the increasingly strict national environmental protection regulations, metallurgical industry NO_x emissions will be strictly controlled. At present, activated carbon is used to remove many kinds of harmful gases such as SO2,NO_x, and VA in some iron and steel metallurgical industry simultaneously, but the cost of desulfurization and denitrification of activated carbon is high. The metallurgical industry not only has high nitrogen oxide emissions, but also produces a large amount of solid waste, such as large accumulative amount of steel slag, but low utilization rate. Steel slag still contains a certain amount of unused iron oxides. Many scholars have shown that iron based catalysts are cheap, easy to obtain, wide denitrification active window, strong ability to resist toxicity, etc. It has a good application prospect in selective catalytic reduction of SCR denitrification process. Therefore, if the composite absorbent is prepared from steel slag and activated carbon, it can not only find a new way for the utilization of steel slag, but also make use of the combined denitrification of steel slag and activated carbon to achieve the cooperative catalytic adsorption. It can also reduce the denitrification cost of activated carbon, which will be of great significance for practical engineering application. The samples of steel slag and coal-based activated carbon of Baosteel were pretreated to produce a mixture of different blending ratios (hereinafter referred to as "composite absorbent"). The optimum ratio of steel slag / activated carbon composite absorbent was studied in an electrically heated quartz glass tube reactor. The denitrification performance of the composite absorber was also studied. The reaction temperature, NO concentration and oxygen concentration were taken into account. The influence of steel slag types, etc. Based on the response surface method, the operating conditions and operating parameters of the experiment were optimized and the optimum reaction conditions and efficiency of the experiment were predicted. At the optimum reaction condition, the composite absorbent prepared from steel slag with different iron content was experimentally studied, characterized by BET,XRF,SEM and analyzed by TG, and the denitrification process of composite absorber was analyzed. It is found that the optimum ratio of active carbon to steel slag is 2: 1. Both activated carbon and steel slag have denitrification activity. The denitrification rate of activated carbon is higher than that of steel slag, but the efficiency decreases with the increase of temperature. The denitrification rate of steel slag increases with the increase of temperature, and the highest is 13%. The denitrification rate of the composite absorber prepared by mixing the steel slag with activated carbon is higher than that of the activated carbon under the same reaction conditions, and the denitrification rate of the composite absorber at low temperature is greater than the sum of the denitrification rate of the activated carbon and the steel slag. It shows that the composite absorbent prepared by activated carbon and steel slag has synergistic denitrification effect. The experimental results show that the effect of reaction temperature and initial concentration of NO on denitrification rate of composite absorber is "negative", and the effect of oxygen content in flue gas on denitrification rate of compound absorber is "positive correlation". The experimental results show that the effects of temperature, NO concentration and oxygen content on the absorbent efficiency are significant, and the interaction between temperature and oxygen content is obvious. The optimum operating conditions predicted by the optimizer are reaction temperature 116 鈩，

本文編號(hào)：2307494