东南大学学报(英文版)
東南大學學報(英文版)
동남대학학보(영문판)
JOURNAL OF SOUTHEAST UNIVERSITY
2013年
3期
282-288
,共7页
吴石亮%沈德魁%高山韵%查晓%肖睿
吳石亮%瀋德魁%高山韻%查曉%肖睿
오석량%침덕괴%고산운%사효%초예
左旋葡聚糖%甘油醛%B3 LYP%量子模拟%生物质
左鏇葡聚糖%甘油醛%B3 LYP%量子模擬%生物質
좌선포취당%감유철%B3 LYP%양자모의%생물질
levoglucosan%glyceraldehyde%B3LYP%quantum simulation%biomass
为了更好地理解纤维素热解过程,对纤维素热解中重要中间产物---左旋葡聚糖和甘油醛的反应过程进行了量子化学模拟.对左旋葡聚糖的4条可能反应路径进行了热力学分析,并且对甘油醛的反应能垒进行了计算,给出了其反应过程中的过渡态和活化能.计算结果表明,文献提出的左旋葡聚糖的3条反应路径在500~1000 K下均能自发进行,但左旋葡聚糖生成四碳糖的反应不能自发进行,因为该路径的自由能ΔG总是大于0.通过过渡态理论对甘油醛热解过程的分析表明,脱羰反应和脱水反应是主要的反应路径.采用量子化学模拟甘油醛和左旋葡聚糖的分解路径为寻找纤维素及其他生物质大分子的热解反应路径提供了理念和方法上指导.
為瞭更好地理解纖維素熱解過程,對纖維素熱解中重要中間產物---左鏇葡聚糖和甘油醛的反應過程進行瞭量子化學模擬.對左鏇葡聚糖的4條可能反應路徑進行瞭熱力學分析,併且對甘油醛的反應能壘進行瞭計算,給齣瞭其反應過程中的過渡態和活化能.計算結果錶明,文獻提齣的左鏇葡聚糖的3條反應路徑在500~1000 K下均能自髮進行,但左鏇葡聚糖生成四碳糖的反應不能自髮進行,因為該路徑的自由能ΔG總是大于0.通過過渡態理論對甘油醛熱解過程的分析錶明,脫羰反應和脫水反應是主要的反應路徑.採用量子化學模擬甘油醛和左鏇葡聚糖的分解路徑為尋找纖維素及其他生物質大分子的熱解反應路徑提供瞭理唸和方法上指導.
위료경호지리해섬유소열해과정,대섬유소열해중중요중간산물---좌선포취당화감유철적반응과정진행료양자화학모의.대좌선포취당적4조가능반응로경진행료열역학분석,병차대감유철적반응능루진행료계산,급출료기반응과정중적과도태화활화능.계산결과표명,문헌제출적좌선포취당적3조반응로경재500~1000 K하균능자발진행,단좌선포취당생성사탄당적반응불능자발진행,인위해로경적자유능ΔG총시대우0.통과과도태이론대감유철열해과정적분석표명,탈탄반응화탈수반응시주요적반응로경.채용양자화학모의감유철화좌선포취당적분해로경위심조섬유소급기타생물질대분자적열해반응로경제공료이념화방법상지도.
In order to better understand the pyrolysis process of cellulose, the decomposition of levoglucosan and glyceraldehyde, which are important intermediate products of cellulose, are simulated by quantum simulation. Thermodynamic analysis of four possible reaction pathways for levoglucosan is conducted by quantum chemistry.The reaction process of glyceraldehyde is checked, and the intermediates and the activation energies of the process are given. The simulation results indicate that the three well-established chemical pathways for levoglucosan in literature can spontaneously occur within the pyrolysis temperature range from 500 to 1 000 K. However, the reaction pathway involving the formation of erythrose cannot be accepted since the free energy ΔG is estimated to be above zero during the pyrolysis process. Through the analysis of glyceraldehyde decomposition by the transition state theory, decarbonylation and dehydration may be the dominant pathways for glyceraldehyde decomposition. The quantum simulation for determining the chemical pathway of glyceraldehyde and levoglucosan can give a conceptual and methodological guide for searching possible chemical pathways of cellulose pyrolysis or other macromolecules in biomass.