【摘要】：隨著我國催化重整工藝的不斷發(fā)展、重整裝置加工能力的不斷提高,在此工段中所產(chǎn)生的氯化氫也逐漸增多,對正常的生產(chǎn)和周邊環(huán)境產(chǎn)生了顯著的影響。本文通過共沉淀法制備干法鈣基脫氯劑對原料氣中的氯化氫進行脫除。采用正交試驗、單因素實驗及溫度處理實驗對雙組份Al-Ca基脫氯劑的制備工藝條件進行探索及優(yōu)化,采用自制的管式固定床反應系統(tǒng)對制備的樣品進行脫氯性能評價,確定最優(yōu)雙組份脫氯劑制備工藝。并在此基礎上加入三種新的金屬Zn、Cu、Fe,采用控制變量法探究不同金屬及不同金屬添加量對Al-Ca基脫氯劑氯容的影響。采用熱重分析、比表面積及孔徑分析、X射線衍射分析、掃描電子顯微鏡分析等對制備的樣品進行表征,研究各個工藝條件及添加因素對樣品的影響,最后對脫氯過程及擴散模型進行了簡要的闡述。(1)對于雙組份Al-Ca基脫氯劑,通過正交實驗及單因素實驗得出在制備反應溫度45℃,鋁鈣摩爾比1:0.7,鋁鈣與沉淀劑摩爾比1:0.8,沉淀劑NH4HCO3的條件下制備的樣品具有最優(yōu)的脫氯效果,氯容可達23.22%。表征分析表明溫度因素導致樣品孔結構變化明顯,于45℃達到最大平均孔徑,85℃孔徑急劇減小。(2)對雙組份樣品進行加熱及焙燒處理,氯容評價結果表明80℃真空條件下處理的樣品氯容可提升至26.00%。表征分析表明80℃真空處理的樣品有較高的平均孔徑,950℃處理的樣品孔徑大量塌陷,隨著溫度升高樣品逐漸經(jīng)歷脫水、分解、晶化的過程。(3)對三組分樣品進行氯容評價,結果表明添加第三組分均有利于提高脫氯性能,其中Zn元素的添加對提高氯容影響最顯著,最高氯容可達38.15%,脫氯效果優(yōu)于市面上流行的ET系列脫氯劑。表征分析表明,Zn元素的添加提高了樣品的比表面積及平均孔徑,添加量較高時生成了鋅鋁復合堿式碳酸鹽,并且出現(xiàn)了部分層狀結構,Cu的添加會略微減小樣品比表面積及平均孔徑,添加Fe樣品的平均孔徑會隨著添加量的增加逐漸減小。最后對氯化氫在脫氯劑內(nèi)部的擴散行為進行了研究,結果表明氯化氫氣體在脫氯劑固體中的內(nèi)擴散符合努森(Knudsen)擴散模型,擴散系數(shù)與平均孔徑呈正相關。
[Abstract]:With the continuous development of catalytic reforming process in China and the continuous improvement of the processing capacity of the reforming unit, the hydrogen chloride produced in this section is also gradually increasing, which has a significant impact on the normal production and the surrounding environment. In this paper, dry calcium-based dechlorination agent was prepared by co-precipitation to remove hydrogen chloride from raw gas. The preparation conditions of two-component Al-Ca based dechlorination agent were investigated and optimized by orthogonal test, single-factor experiment and temperature treatment experiment. The dechlorination performance of the prepared samples was evaluated by a self-made tubular fixed-bed reaction system. The optimum preparation process of two-component dechlorination agent was determined. On this basis, three new metals, Zn,Cu,Fe, were added to study the effect of different metals and different metal contents on the chlorine capacity of Al-Ca based dechlorination agent by controlling variable method. The samples were characterized by thermogravimetric analysis, specific surface area and pore size analysis, X-ray diffraction and scanning electron microscopy. In the end, the dechlorination process and diffusion model are briefly described. (1) for two-component Al-Ca based dechlorination, the reaction temperature is 45 鈩，

本文編號：2227983