本文選題：褐煤 + 熱解機(jī)理　； 參考：《華北理工大學(xué)》2017年碩士論文

【摘要】：煤無(wú)定型的非均相結(jié)構(gòu)導(dǎo)致其熱解過(guò)程十分復(fù)雜。它不但包含眾多基元反應(yīng),而且產(chǎn)生的中間體壽命極短,無(wú)法用實(shí)驗(yàn)方法逐一探測(cè)。采用基于活性反應(yīng)力場(chǎng)下的(Reax FF force field,Reax FF)分子動(dòng)力學(xué)模擬方法是實(shí)驗(yàn)方法的有效補(bǔ)充,模擬褐煤不同環(huán)境下的熱反應(yīng)過(guò)程,對(duì)含氮自由基的變化進(jìn)行監(jiān)測(cè)或捕獲。通過(guò)對(duì)其中發(fā)生的含氮基元反應(yīng)統(tǒng)計(jì)和歸類,探討褐煤的氮轉(zhuǎn)化機(jī)理。以Wolfrum褐煤分子模型作為褐煤體系的結(jié)構(gòu)單元,分別構(gòu)建了三個(gè)熱解體系:加氧熱解體系(氣化過(guò)程)、加氫熱解體系(液化過(guò)程)和熱解體系(熱解過(guò)程)。用LAMMPS程序進(jìn)行Reax FF模擬計(jì)算,并編寫相應(yīng)的了C++程序?qū)δM計(jì)算后的結(jié)果進(jìn)行處理,統(tǒng)計(jì)常見(jiàn)的含氮?dú)怏w產(chǎn)物的分布和模擬過(guò)程中發(fā)生的含氮基元反應(yīng)。模擬結(jié)果與實(shí)驗(yàn)結(jié)果基本一致,例如褐煤熱解體系和加氫體系中氮氧化物很少,含氮產(chǎn)物以HCN、NH3和腈類物質(zhì)為主;加氧熱解體系中有大量氮氧化物生成,氮氧化物主要為NO。結(jié)果表明,熱解過(guò)程中會(huì)生成CH2NH分子、NH自由基、CON自由基和CN自由基等中間體,在加氫熱解體系中與氫相互作用可生成HCN、NH3,在加氧熱解體系中與氧化劑相互作用可生成NO。該研究為褐煤氣化和液化過(guò)程中氮轉(zhuǎn)化機(jī)理研究提供了可靠的理論依據(jù)。
[Abstract]:The process of pyrolysis is very complicated due to the amorphous heterogeneous structure of coal. It not only contains many elementary reactions, but also produces intermediates with very short lifetime, which can not be detected one by experimental method. The molecular dynamics simulation method based on the reactive force field is an effective supplement to the experimental method, which simulates the thermal reaction process of lignite in different environments and monitors or captures the changes of nitrogen-containing free radicals. The nitrogen conversion mechanism of lignite was discussed by statistics and classification of nitrogen-containing elementary reactions. Using Wolfrum lignite molecular model as the structural unit of lignite system, three pyrolysis systems were constructed: oxygen-added pyrolysis system (gasification process), hydropyrolysis system (liquefaction process) and pyrolysis system (pyrolysis process). The Reax FF was simulated by LAMMPS program, and the corresponding C program was written to deal with the results of the simulation. The distribution of products containing nitrogen gas and the nitrogen element reactions occurred in the simulation process were analyzed. The simulation results are in good agreement with the experimental results, for example, there are few nitrogen oxides in lignite pyrolysis system and hydrogenation system, and the nitrogen products are mainly HCN-NH _ 3 and nitrile compounds, and a large number of nitrogen oxides are formed in oxygen-added pyrolysis system, the nitrogen oxides are mainly no _ 2. The results show that the intermediates of CH2NH molecule, such as NH radical, Con radical and CN radical, can be formed during pyrolysis. In the hydropyrolysis system, the hydrogen can interact with the hydrogen to form HCNN NH 3, and in the oxygen-added pyrolysis system, no can be formed by the interaction with oxidant. This study provides a reliable theoretical basis for the study of nitrogen conversion mechanism in the process of gasification and liquefaction of brown coal.
【學(xué)位授予單位】：華北理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TQ530.2;TD849.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 劉健;李曉霞;郭力;鄭默;韓君易;袁小龍;聶峰光;劉曉龍;;反應(yīng)分子動(dòng)力學(xué)(ReaxFF MD)模擬結(jié)果分析工具VARxMD[J];計(jì)算機(jī)與應(yīng)用化學(xué);2014年06期

2 袁銀梅,鄭明東,李朝祥;煤結(jié)構(gòu)研究及其在新材料制備中應(yīng)用[J];煤化工;2004年01期

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本文編號(hào)：1916773