本文選題：丙烷氧化脫氫 + β分子篩�。� 參考：《北京服裝學院》2017年碩士論文

【摘要】：丙烯是石油化工基礎原料之一,主要用于生產丙烯酸、丙烯醛、醇、酸、酐及腈等。隨著需求量的快速增長,傳統(tǒng)技術生產的丙烯難以滿足實際需求。雖然丙烷直接脫氫制丙烯已經實現(xiàn)工業(yè)化,但此反應是吸熱反應,生產工藝需要高溫,耗費大量能量,而丙烷氧化脫氫反應是在較低溫度下的放熱反應,可以大大降低能耗。所以,開發(fā)高選擇性、高活性的丙烷氧化脫氫催化劑具有重要意義。本文利用浸漬法制備了V/β和V/γ-Al2O3催化劑,為了尋求更高選擇性的丙烷氧化脫氫制丙烯的催化劑,對上述催化活性較好的催化劑進行改性,制備了不同鎂含量的V-Mg/β和V-Mg/γ-Al2O3催化劑。利用XRD、BET、H2-TPR、NH3-TPD、UV-Vis DRS和FT-IR等手段對催化劑進行分析,并考察它們在丙烷氧化脫氫制丙烯反應中的催化性能。借助原位紅外光譜儀研究丙烷和丙烯在催化劑上的吸附以及在程序升溫過程中的變化,最后借用化學模擬軟件模擬丙烷和丙烯在分子篩上的吸附過程。實驗結果表明:1.反應溫度500℃下,V負載量為8wt%的8V/β和8wt%的8V/γ-Al2O3的催化劑的活性較好。2.Mg的含量為4wt%的8V4Mg/β催化劑的活性較好,反應溫度500℃下,丙烯選擇性為71.2%,丙烷轉化率為17.2%。3.利用原位紅外光譜儀研究在50、500℃下,丙烷分別在β分子篩、8V/β和8V4Mg/β催劑上吸附的過程,同時研究丙烷和丙烯分別在8V/β、8V/γ-Al2O3、8V4Mg/β和8V4Mg/γ-Al2O3催化劑的程序升溫過程。原位紅外光譜表明,活性組分釩的加入,有利于催化劑對丙烷的吸附,堿金屬Mg有利于丙烯的選擇性。4.分子篩的大孔更有利丙烷和丙烯的吸附,丙烯的吸附量比丙烷大,丙烷自擴散系數(shù)均隨著吸附量的增加而減少,V2O5與丙烷、丙烷+氧氣反應時,出現(xiàn)不同反應過程,但都有丙烯的生成。
[Abstract]:Propylene is one of the basic petrochemical raw materials, mainly used in the production of acrylic acid, acrolein, alcohol, acid, anhydride and nitrile. With the rapid growth of demand, propene produced by traditional technology is difficult to meet the actual demand. Although the direct dehydrogenation of propane to propylene has been industrialized, the reaction is an endothermic reaction, which requires high temperature and consumes a lot of energy. However, the oxidative dehydrogenation of propane is an exothermic reaction at a lower temperature, which can greatly reduce the energy consumption. Therefore, it is of great significance to develop highly selective and highly active catalysts for oxidative dehydrogenation of propane. In this paper, V / 尾 and V / 緯 -Al _ 2O _ 3 catalysts were prepared by impregnation method. In order to find more selective catalysts for oxidative dehydrogenation of propane to propylene, the catalysts with better catalytic activity were modified, and V-Mg/ 尾 and V-Mg/ 緯 -Al _ 2O _ 3 catalysts with different magnesium contents were prepared. The catalysts were analyzed by means of DRS and FT-IR, and their catalytic properties in the oxidative dehydrogenation of propane to propylene were investigated. The adsorption of propane and propylene on the catalyst and the changes in temperature programmed process were studied by in situ infrared spectrometer. Finally, the adsorption process of propane and propylene on molecular sieve was simulated by chemical simulation software. The result of the experiment shows that 1: 1. At 500 鈩，

本文編號：1869688