钙基脱氯剂的制备及其性能研究
发布时间：2018-09-07 10:21
【摘要】：随着我国催化重整工艺的不断发展、重整装置加工能力的不断提高,在此工段中所产生的氯化氢也逐渐增多,对正常的生产和周边环境产生了显著的影响。本文通过共沉淀法制备干法钙基脱氯剂对原料气中的氯化氢进行脱除。采用正交试验、单因素实验及温度处理实验对双组份Al-Ca基脱氯剂的制备工艺条件进行探索及优化,采用自制的管式固定床反应系统对制备的样品进行脱氯性能评价,确定最优双组份脱氯剂制备工艺。并在此基础上加入三种新的金属Zn、Cu、Fe,采用控制变量法探究不同金属及不同金属添加量对Al-Ca基脱氯剂氯容的影响。采用热重分析、比表面积及孔径分析、X射线衍射分析、扫描电子显微镜分析等对制备的样品进行表征,研究各个工艺条件及添加因素对样品的影响,最后对脱氯过程及扩散模型进行了简要的阐述。(1)对于双组份Al-Ca基脱氯剂,通过正交实验及单因素实验得出在制备反应温度45℃,铝钙摩尔比1:0.7,铝钙与沉淀剂摩尔比1:0.8,沉淀剂NH4HCO3的条件下制备的样品具有最优的脱氯效果,氯容可达23.22%。表征分析表明温度因素导致样品孔结构变化明显,于45℃达到最大平均孔径,85℃孔径急剧减小。(2)对双组份样品进行加热及焙烧处理,氯容评价结果表明80℃真空条件下处理的样品氯容可提升至26.00%。表征分析表明80℃真空处理的样品有较高的平均孔径,950℃处理的样品孔径大量塌陷,随着温度升高样品逐渐经历脱水、分解、晶化的过程。(3)对三组分样品进行氯容评价,结果表明添加第三组分均有利于提高脱氯性能,其中Zn元素的添加对提高氯容影响最显著,最高氯容可达38.15%,脱氯效果优于市面上流行的ET系列脱氯剂。表征分析表明,Zn元素的添加提高了样品的比表面积及平均孔径,添加量较高时生成了锌铝复合碱式碳酸盐,并且出现了部分层状结构,Cu的添加会略微减小样品比表面积及平均孔径,添加Fe样品的平均孔径会随着添加量的增加逐渐减小。最后对氯化氢在脱氯剂内部的扩散行为进行了研究,结果表明氯化氢气体在脱氯剂固体中的内扩散符合努森(Knudsen)扩散模型,扩散系数与平均孔径呈正相关。
[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，
本文编号：2227983
[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，
本文编号：2227983
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