發(fā)布時間：2018-04-12 19:27

  本文選題：木質(zhì)素 + 氫轉(zhuǎn)移反應(yīng)�。� 參考：《中國科學(xué)技術(shù)大學(xué)》2017年碩士論文

【摘要】：在最近的一個世紀,由于鋼鐵,汽車等行業(yè)的飛速發(fā)展,隨著化石能源的不斷消耗,一些尖銳的問題已經(jīng)漸漸的成為了全世界所關(guān)注的焦點。其中包括由于化石能源的不可再生導(dǎo)致的能源問題,以及由于大量廢氣排放而導(dǎo)致的大氣污染問題以及溫室效應(yīng)。為了解決這些問題,生物質(zhì)能源逐漸成為了人們所關(guān)注的焦點。世界各國解決能源危機的一個重要途徑就是利用生物質(zhì)能源來制造人們所需要的燃燒或高附加值化學(xué)品。而在生物質(zhì)資源當(dāng)中,最受人們所關(guān)注的就是木質(zhì)纖維素了。由于木質(zhì)纖維素產(chǎn)量巨大而利用率較低,導(dǎo)致每年都有大量的木質(zhì)纖維素?zé)o法得到有效利用,被白白的燃燒而浪費,造成了巨大的損失。因此,如何有效地催化降解木質(zhì)素得到可以利用的產(chǎn)物是一個十分重要的課題。而在催化降解木質(zhì)素的過程中,使用氫轉(zhuǎn)移反應(yīng)來進行降解由于其條件溫和、綠色、清潔、環(huán)境友好等特點已經(jīng)越來越受到人們的關(guān)注�；�于以上背景,本論文主要分為以下幾個方面:第一章,詳細介紹了各類木質(zhì)素的結(jié)構(gòu)以及性質(zhì),氫轉(zhuǎn)移反應(yīng)的背景以及研究進展。以及氫轉(zhuǎn)移反應(yīng)催化劑以及氫供體的種類及其作用,包括貴金屬催化劑以及金屬負載型催化劑。第二章,介紹了一種基于氫轉(zhuǎn)移反應(yīng)使用兩步法將木質(zhì)素轉(zhuǎn)化為有價值的低分子量化合物。在這部分實驗中,首先對于兩種不同類型的木質(zhì)素進行分析,然后對不同的氫轉(zhuǎn)移反應(yīng)催化劑對木質(zhì)素的催化效果進行分析。最終得出最優(yōu)反應(yīng)條件:首先使用Raney Ni催化劑在氫轉(zhuǎn)移反應(yīng)下對木質(zhì)素進行催化,最優(yōu)反應(yīng)條件為在180℃下反應(yīng)18h,將木質(zhì)素液化為分子量較大的初級產(chǎn)物,轉(zhuǎn)化率達到90%以上。然后使用鈀碳催化劑在氫轉(zhuǎn)移反應(yīng)下對木質(zhì)素的液化產(chǎn)物進行降解。最優(yōu)反應(yīng)條件為80℃下反應(yīng)12h,最終得到高轉(zhuǎn)化率高選擇性的產(chǎn)物。各產(chǎn)物通過氣相色譜-質(zhì)譜聯(lián)用法進行標(biāo)定,主要產(chǎn)物收率總計達到30%以上。第三章,介紹了一種金屬負載于石墨烯的氫轉(zhuǎn)移反應(yīng)催化劑對木質(zhì)素及其模型化合物進行催化的方法。通過使用這種催化劑對木質(zhì)素模型化合物進行催化降解,發(fā)現(xiàn)其可以很好的使木質(zhì)素中的β-O-4鍵斷裂。將這種氫轉(zhuǎn)移反應(yīng)催化劑應(yīng)用于木質(zhì)素的催化,可以檢測出兩種單體形成,并對這兩種單體的產(chǎn)率以及反應(yīng)的轉(zhuǎn)化率進行分析。
[Abstract]:In the last century, due to the rapid development of steel, automobile and other industries, with the constant consumption of fossil energy, some sharp problems have gradually become the focus of attention all over the world.These include energy problems caused by non-renewable fossil fuels, air pollution caused by massive emissions and Greenhouse Effect.In order to solve these problems, biomass energy has gradually become the focus of attention.One of the most important ways to solve the energy crisis in the world is to use biomass energy to produce the burning or high added value chemicals that people need.Among biomass resources, lignocellulosic is the most concerned by people.Because of the huge yield and low utilization rate of lignocellulose, a large number of lignocellulose can not be used effectively every year, which is wasted by burning and causing huge losses.Therefore, how to effectively catalyze the degradation of lignin to obtain the available products is a very important issue.In the process of catalytic degradation of lignin, hydrogen transfer reaction has attracted more and more attention because of its mild conditions, green, clean and environmentally friendly.Based on the above background, this paper is divided into the following aspects: chapter 1, the structure and properties of lignin, the background of hydrogen transfer reaction and the research progress are introduced in detail.And the types and functions of hydrogen transfer reaction catalysts and hydrogen donors, including noble metal catalysts and metal supported catalysts.In chapter 2, a two-step method for converting lignin into valuable low molecular weight compounds based on hydrogen transfer reaction is introduced.In this part of the experiment, two different types of lignin were analyzed firstly, and then the catalytic effect of different hydrogen transfer reaction catalysts on lignin was analyzed.Finally, the optimal reaction conditions were obtained: firstly, Raney Ni catalyst was used to catalyze lignin under hydrogen transfer reaction. The optimum reaction conditions were as follows: the lignin was liquefied into the primary product with high molecular weight at 180 鈩，

本文編號：1741099