發(fā)布時間：2018-12-15 19:19

【摘要】：燃煤煙氣中的SO_2、NO等污染物的大量排放造成了光化學(xué)煙霧、酸雨等與人類健康息息相關(guān)的諸多問題,是造成大氣污染的主要原因。因此對煙氣污染物排放的控制和治理刻不容緩,而如何經(jīng)濟、高效的進行脫硫脫硝是我國環(huán)保工作的難題。干法脫硝脫硫技術(shù)由于其催化劑可回收循環(huán)利用、無二次污染、凈化效率高、占地面積小等優(yōu)點從眾多煙氣脫硫脫硝技術(shù)中脫穎而出,成為未來煙氣潔凈技術(shù)發(fā)展的趨勢。活性炭是煙氣干法脫硫脫硝的主要催化劑載體,具有協(xié)同脫除煙氣污染物、占地面積小、使用溫度低等優(yōu)勢,但較高的投資及凈化費用限制了其發(fā)展。我國半焦資源豐富,是煤粉爐熱解多聯(lián)產(chǎn)系統(tǒng)中的主要產(chǎn)物之一,其清潔及高效利用亟需解決,半焦用于脫硫脫硝等污染物處理領(lǐng)域,為其合理利用開辟了一條新的道路。相比于活性炭,活性半焦具有原料資源豐富、價格便宜、綜合強度高等特點,是非常有潛力的碳材料。因此,本文針對半焦的活化及應(yīng)用開展了研究,主要工作如下:半焦活化的實驗研究。研究了昭通褐煤半焦經(jīng)過如水熱加壓、氫氧化鉀、硝酸、高溫等單步活化法后孔隙結(jié)構(gòu)的變化規(guī)律,并對比分析了水熱加壓及氫氧化鉀協(xié)同活化和分步活化對半焦孔隙結(jié)構(gòu)的影響。最終懫用單步和協(xié)同活化組合活化半焦,先進行硝酸活化(濃度40%),然后進行氫氧化鉀(濃度10%)和水熱加壓(溫度325℃)協(xié)同活化,最終得到比表面積為502.739m2/g的活性半焦,較原料半焦提高103%。活性半焦脫硫脫硝的實驗研究。進行了活性半焦脫硫、活性半焦脫硝、活性半焦同時脫硫脫硝的實驗研究。首先通過浸漬法對活性半焦進行了金屬氧化物如氧化銅、氧化鐵的負載,考察其對活性半焦脫硫脫硝性能的影響。進而考察不同實驗條件如空速、溫度、氧氣含量、入口 SO_2、NO的濃度對負載金屬氧化物活性半焦脫硫脫硝性能的影響。半焦的表征。利用比表面積BET、掃描電子顯微鏡SEM、傅立葉變換紅外光譜FT-IR等分析手段對昭通半焦活化前后、負載金屬氧化物前后、脫硫脫硝前后進行表征,觀察分析半焦微觀層面的變化。
[Abstract]:The emission of SO_2,NO and other pollutants from coal-fired flue gas has caused many problems closely related to human health, such as photochemical smog and acid rain, which are the main causes of air pollution. Therefore, it is urgent to control and control the emission of flue gas pollutants, and how to carry out desulphurization and denitrification economically and efficiently is a difficult problem in environmental protection in our country. The dry denitrification and desulphurization technology has the advantages of recycling catalyst, no secondary pollution, high purification efficiency, small area and so on. It has become the development trend of flue gas clean technology in the future because of its advantages such as numerous flue gas desulphurization and denitrification technology. Activated carbon is the main catalyst carrier for flue gas dry desulfurization and denitrification, which has the advantages of synergistic removal of flue gas pollutants, small occupation area and low use temperature, but its development is limited by high investment and purification cost. The semi-coke in China is rich in resources and is one of the main products in the multi-cogeneration system of coal pulverized coal furnace pyrolysis. Its clean and efficient utilization needs to be solved. The use of semi-coke in the treatment of pollutants such as desulphurization and denitrification has opened a new way for its rational utilization. Compared with activated carbon, active semi-coke is a potential carbon material because of its rich raw material, cheap price and high comprehensive strength. Therefore, the activation and application of semi-coke are studied in this paper. The main work is as follows: experimental study on activation of semi-coke. The changes of pore structure of Zhaotong lignite semi-coke after single-step activation such as hydrothermal pressure, potassium hydroxide, nitric acid and high temperature were studied. The effects of hydrothermal pressure, co-activation of potassium hydroxide and stepwise activation on pore structure of semi-coke were compared and analyzed. Finally, the semi-coke was activated by one-step and co-activation combination, which was first activated by nitric acid (40%), then by potassium hydroxide (10%) and hydrothermal pressure (325 鈩，

本文編號：2381159