【正文】 sorption peaks of xylan, which suggests that the main position of hemicellulose is xylose and its main structure is pyran ring. The weak absorption peak at 1161 cm1reflects that there are Arab carbohydrate side chains there. We obtained the simplified molecular structure of hemicellulose dimmer model by bining infrared spectrum experiment result with the fruits of other researchers. The experimental results and the existing theoretical model also shows that the model structure is analysis is used to research the pyrolysis characteristics of xylan pyrolysis reaction process is divided into four stages according to the TG and DTG curves. And the pyrolysis experiment result tells hat 30 ℃ / min heating rate is the best reaction circumstance. It is found that 500K and 700K respectively corresponding to the second stage of pyrolysis experiment and the third stage by analyzed the molecular simulation results. Pyrolysis reaction of hemicellulose is severe when the temperature is low, mainly corresponding the rupture of hemicellulose branched chain. The main chain of the hemicellulose deposed to generate a variety of products with the increase of experimental results and molecular simulation results can fit well.Key Words：Hemicellulose；Molecular model；Pyrolysis；Microscopic reaction mechan 目 錄第一章 緒論.....................................................................................................1 引言..................................................................................................................1 生物質(zhì)熱解技術(shù)的研究現(xiàn)狀......................................................................... 1 ........................................................................1 ................................................................... 2 半纖維素的研究概述......................................................................................4 .................................................................... 4 .................................................................................5 分子模擬生物質(zhì)熱解綜述...............................................................................6 分子模擬方法........................................................................................6 分子模擬生物質(zhì)熱解的研究............................................................... 7 本文主要的研究內(nèi)容……………...................................................................7第二章 半纖維素分子結(jié)構(gòu)的研究..........................................................9 引言....................................................................................................................9 半纖維素的化學(xué)結(jié)構(gòu)模型................................................................................9 半纖維素結(jié)構(gòu)的紅外光譜研究.......................................................................10 .........................................................................................10 ..........................................................11 半纖維素模型物分子結(jié)構(gòu)的建立....................................................................13 本章小結(jié)............................................................................................................15第三章 半纖維素模型物的熱解反應(yīng)機(jī)理研究...............................16 引言....................................................................................................................16 計(jì)算方法............................................................................................................16 4O甲基D葡萄糖醛酸D木糖二聚體的量子化學(xué)計(jì)算..............................17 第一階段 4O甲基D葡萄糖醛酸D木糖的解聚........................................17 .......................................................................................17 ...............................................................................................18 第二階段兩單體分別反應(yīng)生成 2糠醛............................................................22 .........................................................................................24 .................................................................................................28 本章小結(jié).............................................................................................................33第四章 半纖維素?zé)峤馓匦缘膶?shí)驗(yàn)研究..............................................34 引言.....................................................................................................................34 半纖維素?zé)峤鈱?shí)驗(yàn).............................................................................................34 ...................................................................................................34 ...........................................................................................34 實(shí)驗(yàn)結(jié)果解析.....................................................................................................34 ...........................................................................34 ...............................................................................38 與分子模擬計(jì)算結(jié)果的驗(yàn)證.............................................................................40 本章小結(jié).........................................……………………………....................…40結(jié)論與展望.............................................................................................................421 結(jié)論......................................................................................................................422 展望......................................................................................................................42參考文獻(xiàn)..................................................................................................................44致謝............................................................................................................................48第一章 緒論能源對(duì)于發(fā)展社會(huì)經(jīng)濟(jì)，維持人類生活和物質(zhì)文明有著重要意義，人們的日常生活和各種生產(chǎn)都離不開能源[12]。隨著溫度的升高，半纖維素主鏈發(fā)生分解生成各種產(chǎn)物。由分子模擬計(jì)算結(jié)果，500K 和 700K 分別對(duì)應(yīng)熱解實(shí)驗(yàn)的第二階段和第三階段。通過 TG 和 DTG