纤维素组分对氨基酸热解的影响

Effect of cellulose composition on amino acids pyrolysis

本研究旨在揭示生物质热解过程中纤维素组分对含氮组分热解过程的影响,采用快速热解-气相色谱/质谱联用与密度泛函理论计算相结合分析生物质主要含氮组分(苯丙氨酸和谷氨酸)、纤维素单元葡萄糖和混合物热解过程中产物析出特性以及分布规律,揭示葡萄糖对氨基酸热解作用机理。研究发现葡萄糖与苯丙氨酸主要发生聚合反应;还会起到供氢的作用,促进苯丙氨酸/苯乙胺发生脱氨反应生成苯乙烯;而和谷氨酸主要发生聚合反应,会促进谷氨酸发生脱羧反应形成2-吡咯烷酮。计算结果表明,葡萄糖C1位羟基为苯乙胺C2连接的氨基提供氢,可以降低苯乙胺脱氨的反应能垒;链式葡萄糖醛基与谷氨酸氨基结合,可以降低脱羧的反应能垒,促进2-吡咯烷酮的生成。

The study aims to uncover the influence of cellulose components on the N-contained components pyrolysis during biomass pyrolysis process. The separation characteristics and distribution rules of pyrolysis from the main N-contained components(phenylalanine and glutamic acid), glucose unit of cellulose and mixture were analyzed by rapid pyrolysis-gas chromatography/mass spectrometry and density functional theory calculation to reveal the effect of glucose on amino acids pyrolysis. The result showed that glucose and phenylalanine mainly polymerized, and it supplied hydrogen, which promoted the deamination of phenylalanine/phenylethylamine to styrene. Glucose and glutamic acid mainly polymerized which promoted the decarboxylation and dehydration of glutamic acid to form 2-pyrrolidone. The calculation results show that the hydroxyl group at C1 of glucose provided hydrogen for the amino group connected with phenylethylamine C2, which can reduce the reaction energy barrier of phenylethylamine deamination. Combining the chain glucosyl group with glutamic acid amino group can reduce the reaction energy barrier of decarboxylation and promote the production of 2-pyrrolidone.