本文關(guān)鍵詞： 零價汞 集中控制 吸附劑再生 Fe-Ti-Mn尖晶石 磁黃鐵礦 鐵閃鋅礦　出處：《南京理工大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：我國的汞污染排放狀況已經(jīng)引起了全球范圍的高度關(guān)注。燃煤電廠排放的零價汞是我國大氣汞的主要來源。國際上用于控制燃煤電廠零價汞排放的技術(shù)為活性炭吸附法和SCR協(xié)同氧化法,但這兩種技術(shù)的脫汞效率較依賴于原煤氯含量,且會將汞引入燃煤副產(chǎn)物中造成二次污染,限制了這兩種技術(shù)在我國的推廣應(yīng)用。本文中創(chuàng)新性地提出了以磁性Fe-Ti-Mn尖晶石和磁黃鐵礦為吸附劑,分別協(xié)同靜電除塵器(ESP)+布袋除塵器(FF)和濕式電除塵器(WESP)集中控制煙氣汞污染的技術(shù)工藝,并開發(fā)了用于儲存高濃度氣態(tài)零價汞的吸附材料鐵閃鋅礦。主要研究成果如下:(1)Fe-Ti-Mn尖晶石噴入ESP后FF前的煙氣中吸附零價汞。在150 ℃含有400 ppm SO2和10%H2O的模擬煙氣條件下,Fe-Ti-Mn尖晶石的零價汞吸附容量為0.8 mg g-1。由于Fe-Ti-Mn尖晶石的超順磁性,可通過磁分離將其從FF捕集的細粒子飛灰中分離出來。吸附在Fe-Ti-Mn尖晶石上的HgO在450℃熱處理時再次分解,產(chǎn)生高濃度的氣態(tài)零價汞,從而實現(xiàn)吸附劑的再生和汞的集中控制。此外,研究通過水洗改善了 Fe-Ti-Mn 尖晶石在循環(huán)吸附中因 S02 導(dǎo)致的硫化失活現(xiàn)象。(2)磁黃鐵礦噴入WESP前的煙氣中吸附零價汞。在60 ℃的模擬煙氣中磁黃鐵礦的零價汞吸附速率為0.28ugg-1 min-1,其吸附活性不受煙氣中SO2的影響。磁黃鐵礦可通過磁分離從WESP捕集的混合物中回收,經(jīng)熱再生后再次投入煙氣中吸附零價汞。在5次吸附再生循環(huán)中,磁黃鐵礦始終保持著優(yōu)秀的零價汞去除效率和強磁性。同時,煙氣中低濃度的零價汞在再生過程中被富集成高濃度的汞蒸氣,便于汞的集中控制。(3)由水熱法合成的鐵閃鋅礦(Fe0.1Zn0.9S)在室溫下的零價汞吸附速率達4.82ug g-1 min-1,吸附容量高于8.65 mg g-1可用于儲存由吸附劑再生過程釋放的高濃度零價汞。零價汞以HgS的形式吸附在鐵閃鋅礦上,室溫下穩(wěn)定存在,在溶液中不存在浸出毒性。鐵閃鋅礦還可作為液態(tài)汞泄漏后的處置材料,8 g鐵閃鋅礦能夠完全遏制0.3 g液態(tài)汞向環(huán)境中釋放氣態(tài)零價汞�？傊�,運用Fe-Ti-Mn尖晶石、磁黃鐵礦和鐵閃鋅礦能夠?qū)崿F(xiàn)燃煤煙氣中零價汞污染的集中控制并使之資源化利用,具有廣闊的應(yīng)用前景。
[Abstract]:Mercury pollution situation in China has attracted worldwide attention. Zero valent mercury emissions from coal-fired plants is a major source of atmospheric mercury in China. International is used to control the zero valent mercury emission from coal-fired power plant technology method for CO oxidation of activated carbon adsorption and SCR, but these two kinds of technology for mercury removal the efficiency is dependent on coal chlorine content, and will introduce a by-product of coal-fired mercury cause two pollution limits, these two kinds of technology application in China. This paper put forward the innovation of the magnetic Fe-Ti-Mn spinel and pyrrhotite as adsorbent were synergistic electrostatic precipitator (ESP) + bag dust collector (FF) and wet electrostatic precipitator (WESP) concentration of mercury pollution control technology of flue gas, and the development of the adsorption material used for marmatite storage of high concentrations of gaseous elemental mercury. The main research results are as follows: (1) Fe-Ti-Mn spinel after ESP before FF injection The adsorption of zero valent mercury in flue gas. The condition of simulating flue gas containing 400 ppm SO2 and 10%H2O at 150 DEG C, Hg0 adsorption capacity of Fe-Ti-Mn spinel is 0.8 mg g-1. due to superparamagnetic Fe-Ti-Mn spinel, by magnetic separation of fine particles from the FF will capture fly ash. The adsorption separation in Fe-Ti-Mn HgO on the decomposition of spinel at 450 DEG C during the heat treatment, produce high concentrations of gaseous mercury, so as to realize the centralized control of regeneration and mercury sorbent. In addition, the research by washing improved Fe-Ti-Mn spinel in cyclic adsorption due to sulfide S02 leads to deactivation phenomenon. (2) injected into pyrrhotite the adsorption of zero valent mercury in flue gas before WESP. In simulated flue gas of 60 DEG C in Hg0 adsorption rate of pyrrhotite is 0.28ugg-1 min-1, its activity is not affected by the adsorption of SO2 in flue gas. The mixture of pyrrhotite from WESP capture by magnetic separation In the heat recovery, regeneration after adsorption again into zero valent mercury in flue gas. In 5 adsorption regeneration cycle, pyrrhotite has always maintained a good Hg0 removal efficiency and strong magnetism. At the same time, zero valent mercury in low concentration of flue gas in the regeneration process by enrichment and high concentrations of mercury vapor, centralized control for mercury. (3) by hydrothermal synthesis of marmatite (Fe0.1Zn0.9S) zero valent mercury adsorption rate at room temperature up to 4.82ug g-1 min-1, the adsorption capacity is higher than 8.65 mg g-1 can be used for storage of high concentration of Hg0 released during regeneration of the adsorbent. By zero valent mercury adsorbed on iron in the form of HgS sphalerite, stable at room temperature, the leaching toxicity does not exist in solution. Marmatite can be used as a liquid mercury leak after the disposal of materials, 8 g christophite able to fully contain 0.3 g liquid mercury release into the environment of gaseous elemental mercury. In short, the use of Fe-Ti-Mn spinel Stone, pyrrhotite and sphalerite can realize centralized control and utilization of zero valent mercury pollution in coal-fired flue gas, and have a broad application prospect.

【學(xué)位授予單位】：南京理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：X701

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本文編號：1517992