本文選題：醋酸甲酯　切入點：丙烯酸甲酯　出處：《中國地質(zhì)大學(北京)》2017年博士論文

【摘要】：丙烯酸甲酯是一種重要的精細化工原料,廣泛應用于粘合劑、絮凝劑、涂料、紡織、制革、制藥、造紙和高吸水性樹脂等領域。醋酸甲酯和甲醛經(jīng)過羥醛縮合反應一步法合成丙烯酸甲酯是一種環(huán)境友好型的綠色合成工藝。此外,隨著現(xiàn)代煤化工的快速發(fā)展,甲醇和醋酸產(chǎn)能出現(xiàn)嚴重過剩,開發(fā)新的下游產(chǎn)品和拉長化工產(chǎn)業(yè)鏈是解決產(chǎn)能過剩的有效途徑。因此對該工藝的研究具有重要的學術價值和現(xiàn)實意義。研究和開發(fā)高活性,高選擇性的催化劑是實現(xiàn)該工藝工業(yè)化的關鍵課題,本論文針對酸堿雙功能催化劑的設計與制備及反應過程的關鍵科學問題進行系統(tǒng)的基礎研究;主要研究工作如下:(1)采用等體積浸漬法制備了Cs-P/γ-Al2O3酸堿雙功能催化劑。通過XRD、XPS、SEM、TEM、FT-IR和N2吸脫附等對催化劑的微觀形貌、結(jié)構(gòu)及表面活性中心分布狀態(tài)進行分析,表征結(jié)果顯示Cs-P/γ-Al2O3酸堿雙功能催化劑是一種介孔材料;Cs、P活性組分在載體表面形成磷酸鹽、偏磷酸鹽和焦磷酸鹽等多種磷酸鹽結(jié)構(gòu)。催化劑表面的酸堿特性決定催化劑的活性,通過CO2/NH3-TPD對催化劑的酸堿性進行表征,發(fā)現(xiàn)P可有效調(diào)控催化劑表面的酸堿特性,隨著P負載量的增加催化劑的酸堿強度降低。采用固定床反應裝置對Cs-P/γ-Al2O3催化劑的催化活性進行評價,考察負載量、載體和焙燒溫度對催化性能的影響規(guī)律,結(jié)果顯示10%Cs-5%P/γ-Al2O3催化劑在550℃焙燒后表現(xiàn)較好的催化活性,丙烯酸甲酯的收率和選擇性分別達到44.3%和94%。(2)利用響應面法(RSM)對催化反應工藝參數(shù)進行合理優(yōu)化。構(gòu)建丙烯酸甲酯收率與反應溫度、酯醛比和反應時間之間響應關系的二次多項式模型,并用于分析各因素及其交互關系對響應值的影響規(guī)律。該模型具有很高的可靠性和精密度,可用于對反應參數(shù)進行合理的優(yōu)化和預測。(3)通過摻雜過渡金屬氧化物對Cs-P/γ-Al2O3催化劑改性,評價結(jié)果顯示Cs-P-W/γ-Al2O3催化劑表現(xiàn)出較好的催化活性。表征結(jié)果表明Cs-P-W/γ-Al2O3催化劑表面形成的CsW2O6結(jié)構(gòu)促進了醋酸甲酯與甲醛反應,同時CsW2O6結(jié)構(gòu)具有較好的熱穩(wěn)定性。Cs-P-W/γ-Al2O3催化劑經(jīng)過長周期的壽命評價,累計反應1600h,再生催化劑的活性沒有明顯的降低,表現(xiàn)出較好的循環(huán)使用性。(4)對優(yōu)化后的催化劑進行公斤級放大制備,并在120L/d移動床反應裝置上進行放大實驗,為中試放大實驗做準備。
[Abstract]:Methyl acrylate is an important fine chemical raw material, widely used in adhesives, flocculants, coatings, textiles, tanning, pharmaceutical, The synthesis of methyl acrylate from methyl acetate and formaldehyde through hydroxaldehyde condensation is an environmentally friendly green synthesis process. In addition, with the rapid development of modern coal chemical industry, There is serious excess capacity in methanol and acetic acid, so developing new downstream products and elongating chemical industry chain is an effective way to solve overcapacity. Therefore, the research on this process has important academic value and practical significance, and research and development of high activity. High selectivity catalyst is the key to realize the industrialization of the process. In this paper, the design and preparation of acid-base bifunctional catalysts and the key scientific problems in the reaction process are systematically studied. The main work is as follows: (1) Cs-P/ 緯 -Al _ 2O _ 3 acid-base bifunctional catalysts were prepared by iso-volume impregnation method. The microstructure, structure and distribution of surface active sites of the catalysts were analyzed by XRDX, XRDX, XPS, SEMX, TEMT-IR and N2 adsorption and desorption. The characterization results show that the Cs-P/ 緯 -Al 2O 3 acid-base bifunctional catalyst is a mesoporous material, the active component of CSP forms phosphate, metaphosphate, pyrophosphate and other phosphate structures on the surface of the support. The acid-base properties of the catalyst surface determine the activity of the catalyst. The acidity and alkalinity of the catalyst were characterized by CO2/NH3-TPD. It was found that P could effectively regulate the acid-base properties of the catalyst surface. The activity of Cs-P/ 緯 -Al 2O 3 catalyst was evaluated by a fixed bed reactor, and the influence of loading amount, carrier and calcination temperature on the catalytic activity was investigated. The results showed that 10%Cs-5%P/ 緯 -Al 2O 3 catalyst exhibited good catalytic activity after calcination at 550 鈩，

本文編號：1664999