【摘要】：硝化反應在有機化合物的合成反應中占有重要地位,但是該反應卻存在很多問題,如安全生產(chǎn)問題,區(qū)域選擇性問題等,為此本文將微通道反應器引入到硝化反應中,旨在利用微反應器的獨特優(yōu)勢達到硝化反應的安全生產(chǎn),同時提高目標產(chǎn)物的選擇性。本文研究了脂肪醇和簡單芳烴的硝化,主要以異辛醇和鄰二甲苯為硝化對象,將微通道反應器應用到硝酸酯和硝基芳烴化合物的合成反應中。(1)以硝硫混酸作硝化劑,通過考察反應溫度、硝硫混酸的配比、硝酸濃度、異辛醇流速、硝酸與異辛醇的摩爾比以及惰性溶劑的使用對異辛醇硝化反應的影響,得到硝酸異辛酯在微通道反應器內(nèi)合成的最佳條件。實驗結(jié)果表明,在常溫下,以n(HNO3):n(H2SO4)=1:2.5,硝酸濃度為55%,硝酸與異辛醇的摩爾比為1.4：1,此時硝酸異辛酯的純度高達99.6%,收率也達到了99.5%。論述了微通道反應器內(nèi)硝硫混酸硝化合成硝酸酯的反應機理。(2)對比HNO3、HNO3-H2SO4以及N205對鄰二甲苯的硝化,我們最終選擇使用綠色硝化劑五氧化二氮。以鄰二甲苯為研究對象,系統(tǒng)研究了微通道反應器內(nèi)反應溫度、反應停留時間、五氧化二氮的用量以及不同溶劑的選擇等因素對反應的影響,從鄰二甲苯轉(zhuǎn)化率、4-硝基鄰二甲苯選擇性兩個方面出發(fā),得到最佳反應條件。實驗結(jié)果表明,選擇乙腈作溶劑,在30℃下反應29.6s,當五氧化二氮摩爾量是鄰二甲苯的1.1倍時,反應轉(zhuǎn)化率達到87.6%,4-硝基鄰二甲苯的選擇性高達57.3%。(3)將微通道反應器應用到其他脂肪醇和簡單芳烴的硝化反應中,與常規(guī)反應器相比,發(fā)現(xiàn)無論是轉(zhuǎn)化率,還是選擇性,都得到了明顯的提高。
[Abstract]:Nitrification plays an important role in the synthesis of organic compounds, but there are many problems in the reaction, such as safety in production, regional selectivity and so on. The aim is to make use of the unique advantages of microreactors to achieve the safety of nitrification and to improve the selectivity of the target products. The nitration of fatty alcohol and simple aromatics was studied in this paper. The nitration of iso-octanol and o-xylene was studied. The microchannel reactor was applied to the synthesis of nitrates and nitroaromatic compounds. The effects of reaction temperature, the ratio of nitrate-sulfur mixed acid, the concentration of nitric acid, the flow rate of isooctanol, the molar ratio of nitric acid to isooctanol and the use of inert solvent on the nitration of isooctanol were investigated. The optimum conditions for synthesis of isooctyl nitrate in microchannel reactor were obtained. The experimental results show that at normal temperature, n (HNO3): n (H2SO4) = 1: 2.5, the concentration of nitric acid is 55 and the molar ratio of nitric acid to isooctanol is 1.4: 1. The purity of isooctyl nitrate is 99.6%. The yield was 99.5%. The reaction mechanism of nitration of nitrate-sulfuric acid to nitrate ester in microchannel reactor was discussed. (2) compared with the nitration of HNO3,HNO3-H2SO4 and N205 for o-xylene, we finally chose to use green nitrifying agent nitrogen pentoxide. The effects of reaction temperature, residence time, amount of nitrogen pentoxide and different solvents on the reaction of o-xylene in microchannel reactor were systematically studied. The optimum reaction conditions were obtained from the selectivity of 4-nitro-o-xylene. The experimental results show that when acetonitrile is used as solvent and reaction temperature is 30 鈩，

本文編號：2368497