本文選題：MoO_3 + 木質(zhì)素　； 參考：《中國(guó)科學(xué)技術(shù)大學(xué)》2017年碩士論文

【摘要】：為克服化石能源短缺及大量化石燃料消費(fèi)引起的環(huán)境污染問(wèn)題,人們正努力開(kāi)發(fā)可替代化石能源的可再生能源與新能源。生物質(zhì)是新能源中唯一可轉(zhuǎn)化為碳?xì)湟后w燃料的可再生碳資源,已成為科技工作者的研究熱點(diǎn)。木質(zhì)素是由苯丙烷結(jié)構(gòu)單體組成的天然高分子聚合物,在自然界中的含量?jī)H次于纖維素,具有較高的能量密度。然而,木質(zhì)素解聚得到的液體產(chǎn)物含氧量較高,較高的氧含量引起液體燃料具有熱值低、化學(xué)性質(zhì)不穩(wěn)定、粘度大等缺點(diǎn)。因此必須對(duì)這類解聚液體產(chǎn)品進(jìn)行加氫脫氧(hydrodeoxygenation,HDO)處理�；诖�,本論文以MoO3為催化劑的主要構(gòu)成組分,以芳烴為目標(biāo)產(chǎn)物開(kāi)展木質(zhì)素解聚的酚類化合物的催化加氫脫氧反應(yīng)特性研究。首先,以(NH4)6Mo7O24.4H2O為前驅(qū)體通過(guò)簡(jiǎn)單的焙燒方法制備了非負(fù)載型MoO3催化劑。以低溫N2吸附、XRD、XPS和H2-TPR等技術(shù)對(duì)催化劑特性進(jìn)行了表征,以苯酚等酚類物質(zhì)的加氫脫氧反應(yīng)對(duì)催化劑的催化活性進(jìn)行了評(píng)價(jià)。重點(diǎn)考察了反應(yīng)溫度、反應(yīng)時(shí)間、反應(yīng)氣組成等參數(shù)對(duì)苯酚轉(zhuǎn)化率、目標(biāo)產(chǎn)物苯選擇性的影響,并就氧化鉬催化加氫脫氧反應(yīng)機(jī)制及催化劑的可重復(fù)使用性能進(jìn)行了考察。實(shí)驗(yàn)結(jié)果表明,在340 ℃、0.5 MPa H2與3 MPa N2混合氣氛的優(yōu)化工況下,苯酚的轉(zhuǎn)化率達(dá)到98.1%,產(chǎn)物苯的選擇性達(dá)到99.5%。MoO3催化材料中的氧缺陷位是催化苯酚分子中CAR-OH鍵直接氫解生成芳烴苯的主要活性位。此外,MoO3重復(fù)使用三次后催化活性仍無(wú)明顯下降。其次,以浸漬法、分步沉淀法與共沉淀法分別制備了 MoO3/SiO2催化劑。研究了不同方法制備的MoO3/SiO2催化劑作用下酚類模型化合物加氫脫氧反應(yīng)特性,考察了負(fù)載量、反應(yīng)溫度等參數(shù)對(duì)反應(yīng)物轉(zhuǎn)化率、產(chǎn)物芳烴選擇性的影響。反應(yīng)溫度為=340℃時(shí),分步沉淀法制得的MoO3含量為80%時(shí)的MoO3/SiO2催化劑上愈創(chuàng)木酚加氫脫氧反應(yīng)其轉(zhuǎn)化率為98.5%,總的芳烴收率達(dá)到82.4%。分布沉淀法制得的催化劑催化活性高的本質(zhì)原因在于該催化劑中Mo5+含量最高,這是酚類化合物加氫脫氧反應(yīng)的關(guān)鍵活性位。反應(yīng)后的催化劑上積炭量極少,表明具有的優(yōu)異的抗積碳性能。最后,在酚類模型化合物研究的基礎(chǔ)上,選取未負(fù)載的MoO3和分步沉淀法制得的MoO3/SiO2為催化劑開(kāi)展了熱解木質(zhì)素(生物油重質(zhì)組分)的加氫脫氧反應(yīng),實(shí)驗(yàn)結(jié)果表明MoO3/SiO2具有較好的催化活性,產(chǎn)物中芳烴類產(chǎn)物含量更高。
[Abstract]:In order to overcome the problem of environmental pollution caused by the shortage of fossil energy and the consumption of a large amount of fossil fuels, people are trying to develop renewable energy and new energy which can replace fossil energy. Biomass is the only renewable carbon resource that can be converted into hydrocarbon liquid fuel in new energy, which has become the research hotspot of science and technology workers. Lignin is a natural polymer composed of phenylpropane monomers, and its content in nature is second only to cellulose, which has a high energy density. However, the liquid products obtained by lignin depolymerization have higher oxygen content, and the higher oxygen content leads to the low calorific value, unstable chemical properties and high viscosity of liquid fuel. Therefore, hydrodeoxygenation (HDOO) must be carried out for these depolymerized liquid products. Based on this, the catalytic hydrogenation deoxidation of lignin depolymerized phenols was studied using MoO3 as the main component and aromatic hydrocarbons as the target product. Firstly, the unsupported MoO3 catalyst was prepared by a simple roasting method with NH _ 4N _ 6Mo _ 7O _ 24.4H _ 2O as the precursor. The characteristics of the catalyst were characterized by low temperature N2 adsorption XRDX XPS and H2-TPR, and the catalytic activity of the catalyst was evaluated by hydrodeoxidation of phenol and other phenols. The effects of reaction temperature, reaction time and composition of reaction gas on the conversion of phenol and benzene selectivity of the target product were investigated. The mechanism of molybdenum oxide catalytic hydrogenation deoxidation reaction and the reusability of the catalyst were also investigated. The experimental results show that under the optimum condition of 340C 0.5 MPa H2 and 3 MPa N2 mixed atmosphere, The conversion of phenol reaches 98.1, and the selectivity of benzene to oxygen defect in 99.5%.MoO3 catalyst is the main active site of direct hydrogenation of CAR-OH bond to aromatics benzene in phenol molecule. In addition, the catalytic activity of MoO3 was not significantly decreased after three times of repeated use. Secondly, MoO3/SiO2 catalysts were prepared by impregnation method, step precipitation method and co-precipitation method respectively. The hydrodeoxidation reaction characteristics of phenolic model compounds under the action of MoO3/SiO2 catalyst prepared by different methods were studied. The effects of loading amount and reaction temperature on the conversion of reactants and the selectivity of aromatic hydrocarbons were investigated. The conversion of guaiacol hydrodeoxidized over MoO3/SiO2 catalyst was 98.5 and the total yield of aromatics was 82.4% when the reaction temperature was 340C and the content of MoO3 prepared by step precipitation method was 80%. The essential reason for the high catalytic activity of the catalyst prepared by the distributed precipitation method is that the Mo5 content in the catalyst is the highest, which is the key active site for the hydrodeoxidation of phenolic compounds. The amount of carbon deposited on the catalyst after the reaction is very small, which indicates that the catalyst has excellent resistance to carbon deposition. Finally, based on the study of phenolic model compounds, the hydrogenation deoxidation of lignin (bio-oil heavy component) was carried out on the basis of unsupported MoO3 and MoO3/SiO2 prepared by step precipitation method. The experimental results show that MoO3/SiO2 has better catalytic activity and the aromatics in the product is higher.
【學(xué)位授予單位】：中國(guó)科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：O643.36;O625.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前9條

1 張興華;陳倫剛;張琦;龍金星;王鐵軍;馬隆龍;;木質(zhì)素基酚類化合物加氫脫氧制取碳?xì)淙剂蟍J];化學(xué)進(jìn)展;2014年12期

2 周明松;周莉莉;伍思龍;楊東杰;潘兵;邱學(xué)青;;氧化堿木質(zhì)素制備高效水泥助磨劑[J];精細(xì)化工;2011年10期

3 包建國(guó);楊運(yùn)泉;王威燕;蔣新民;李婭;;CoMo/ZrO_2-Al_2O_3催化劑的制備及其加氫脫氧性能[J];燃料化學(xué)學(xué)報(bào);2011年01期

4 孔德金;楊為民;;芳烴生產(chǎn)技術(shù)進(jìn)展[J];化工進(jìn)展;2011年01期

5 李增文;;煤焦油加氫工藝技術(shù)[J];化學(xué)工程師;2009年10期

6 柳善建;易維明;柏雪源;王麗紅;殷哲;吳娟;;流化床生物質(zhì)快速熱裂解試驗(yàn)及生物油分析[J];農(nóng)業(yè)工程學(xué)報(bào);2009年01期

7 楊運(yùn)泉;羅和安;童剛生;Kevin J.Smith;TYE Ching Thian;;不同結(jié)構(gòu)硫化鉬催化劑上酚類模型化合物的加氫脫氧(英文)[J];Chinese Journal of Chemical Engineering;2008年05期

8 ;造紙黑液的資源化處理——噴霧干燥法[J];福建紙業(yè)信息;2007年10期

9 姜洪濤;李會(huì)泉;張懿;;生物質(zhì)高壓液化制生物原油研究進(jìn)展[J];化工進(jìn)展;2006年01期

相關(guān)碩士學(xué)位論文 前1條

1 湯文武;木質(zhì)素降解單環(huán)酚類產(chǎn)物加氫脫氧特性研究[D];中國(guó)科學(xué)技術(shù)大學(xué);2016年

，

本文編號(hào)：1836526