白腐真菌预处理稻秆和麦秆的超临界醇解
发布时间：2018-12-27 07:38
【摘要】：本课题研究了白腐真菌预处理的稻秆和麦秆在甲醇介质中的超临界醇解过程,并通过考察白腐真菌预处理的微晶纤维素、木聚糖和碱性木质素在甲醇中的超临界醇解给出了白腐真菌预处理可能影响秸秆醇解的机理。本研究探讨了白腐真菌的不同预处理时间对稻秆和麦秆的超临界醇解所得可溶物收率的影响,确定白腐真菌预处理的优化条件;通过傅立叶红外光谱仪(FTIR)、气相色谱/质谱联用仪(GC/MS)和傅里叶变换离子回旋共振质谱仪(ESI FTICRMS)等分析了醇解可溶物的化学组成,采用FTIR、扫描电子显微镜(SEM)、X射线光电子能谱仪(XPS)、X射线粉末衍射仪(XRD)和热重分析了白腐真菌预处理的秸秆的化学组成等性质。结果表明,白腐真菌预处理的秸秆的超临界醇解优化条件为:稻秆经过白腐真菌预处理10天后,在260oC下反应30分钟,醇解所得可溶物的收率最高;麦秆经过白腐真菌预处理5天后醇解所得可溶物的收率最高,在同样反应条件下,醇解所得可溶物的收率最高。白腐真菌预处理秸秆醇解所得可溶物组分的FTIR和GC/MS分析表明:两种秸秆超临界醇解所得可溶物的化学组分都较为复杂,主要包括酯、酮、酚、和醚类等化合物;不同预处理时间对醇解所得产物的组分分布有一定的影响,预处理时间的延长,可提高酯类化合物的产率并选择性地生成长链烷酸酯,尤其是棕榈酸甲酯,(9Z,12Z)-十八碳-9,12-二烯酸甲酯和(E)-十八碳-11-烯酸甲酯等三种长链烷酸酯;白腐真菌预处理秸秆醇解所得可溶物组分的ESI FTICRMS分析表明:预处理秸秆醇解所得产物中的含氧化合物和含氮化合物较未处理秸秆醇解所得产物差异显著,化合物种类有一定减少,同时含氧化合物和含氮化合物分别呈现向O4类化合物和N2O4类化合物的定向转化。秸秆的FTIR、SEM、XPS、XRD和热重分析表明:白腐真菌预处理可以有效地破坏秸秆的晶型结构,促进秸秆醇解。分别以微晶纤维素、木聚糖和碱性木质素为原料,进行不同预处理时间生物质组分的超临界醇解研究,考察了其可溶物组分的收率,结果表明:纤维素和木聚糖可以获得较优的醇解产物收率,木质素的醇解产物收率变化不明显。通过GC/MS分析生物质组分醇解可溶组分的化学组成,结果表明:预处理后的纤维素和木聚糖的醇解产物组成较未处理的纤维素和木聚糖的醇解产物出现显著差异,酯类化合物的含量显著增加,而木质素的醇解产物未出现明显差异。结合其本身结构和相关文献提出了白腐真菌预处理可能影响秸秆超临界醇解的机理。
[Abstract]:The supercritical alcoholysis of rice stalk and wheat stalk pretreated by white rot fungi in methanol medium was studied in this paper, and the microcrystalline cellulose pretreated by white rot fungus was investigated. The supercritical alcoholysis of xylan and basic lignin in methanol gave the mechanism that the pretreatment of white rot fungi might affect the alcoholysis of straw. In this study, the effects of different pretreatment time of white rot fungi on the yield of soluble matter obtained by supercritical alcoholysis of rice stalk and wheat stalk were studied, and the optimum conditions of pretreatment of white rot fungus were determined. The chemical composition of alcoholysis was analyzed by Fourier transform infrared spectrometer (FTIR), gas chromatography / mass spectrometry (GC/MS) and Fourier transform ion cyclotron resonance mass spectrometer (ESI FTICRMS). Scanning electron microscope (SEM) (SEM), X ray photoelectron spectroscopy (SEM), X) (XPS), X ray powder diffractometer (XRD) and thermogravimetric analysis (TGA) were used to analyze the chemical composition of straw pretreated by white rot fungi. The results showed that the optimum conditions of supercritical alcoholysis of straw pretreated by white rot fungi were as follows: after pretreatment with white rot fungi for 10 days, the yield of soluble matter was the highest when rice stalk was treated with white rot fungus for 30 minutes under 260oC. The yield of soluble matter of wheat stalk was the highest after pretreatment with white rot fungi for 5 days, and the yield of soluble substance was the highest under the same reaction conditions. The FTIR and GC/MS analysis of soluble components obtained from the alcoholysis of straw by white rot fungi showed that the chemical components of the soluble compounds obtained from the alcoholysis of the two kinds of straw were complex, including esters, ketones, phenols and ethers. Different pretreatment time has a certain effect on the distribution of components of alcoholysis products. The increase of pretreatment time can increase the yield of ester compounds and selectively grow chain alkanoate, especially methyl palmitate, (9Z, 9Z). 12Z) -octadecyl -9-dienoic acid methyl ester and (E) octadecyl-11-enoic acid methyl ester; The ESI FTICRMS analysis of soluble components obtained from the alcoholysis of straw by white rot fungi showed that the oxygen compounds and nitrogen compounds in the alcoholysis products were significantly different from those obtained from untreated straw alcoholysis. At the same time, the oxygen and nitrogen compounds showed the directional transformation to O _ 4 and N2O4 respectively. FTIR,SEM,XPS,XRD and thermogravimetric analysis showed that the pretreatment of white rot fungi could effectively destroy the crystal structure of straw and promote the alcoholysis of straw. Using microcrystalline cellulose, xylan and alkaline lignin as raw materials, the supercritical alcoholysis of biomass components at different pretreatment time was carried out, and the yield of soluble components was investigated. The results showed that the yield of alcoholysis products could be obtained by cellulose and xylan, but the yield of lignin alcoholysis products did not change obviously. The chemical composition of alcoholysis soluble components of biomass components was analyzed by GC/MS. The results showed that the composition of alcoholysis products of cellulose and xylan after pretreatment was significantly different from that of cellulose and xylan after pretreatment. The contents of ester compounds increased significantly, but the alcoholysis products of lignin showed no significant difference. Combined with its own structure and related literature, the mechanism that pretreatment of white rot fungi may affect supercritical alcoholysis of straw was put forward.
【学位授予单位】：中国矿业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TK6
，
本文编号：2392721
[Abstract]:The supercritical alcoholysis of rice stalk and wheat stalk pretreated by white rot fungi in methanol medium was studied in this paper, and the microcrystalline cellulose pretreated by white rot fungus was investigated. The supercritical alcoholysis of xylan and basic lignin in methanol gave the mechanism that the pretreatment of white rot fungi might affect the alcoholysis of straw. In this study, the effects of different pretreatment time of white rot fungi on the yield of soluble matter obtained by supercritical alcoholysis of rice stalk and wheat stalk were studied, and the optimum conditions of pretreatment of white rot fungus were determined. The chemical composition of alcoholysis was analyzed by Fourier transform infrared spectrometer (FTIR), gas chromatography / mass spectrometry (GC/MS) and Fourier transform ion cyclotron resonance mass spectrometer (ESI FTICRMS). Scanning electron microscope (SEM) (SEM), X ray photoelectron spectroscopy (SEM), X) (XPS), X ray powder diffractometer (XRD) and thermogravimetric analysis (TGA) were used to analyze the chemical composition of straw pretreated by white rot fungi. The results showed that the optimum conditions of supercritical alcoholysis of straw pretreated by white rot fungi were as follows: after pretreatment with white rot fungi for 10 days, the yield of soluble matter was the highest when rice stalk was treated with white rot fungus for 30 minutes under 260oC. The yield of soluble matter of wheat stalk was the highest after pretreatment with white rot fungi for 5 days, and the yield of soluble substance was the highest under the same reaction conditions. The FTIR and GC/MS analysis of soluble components obtained from the alcoholysis of straw by white rot fungi showed that the chemical components of the soluble compounds obtained from the alcoholysis of the two kinds of straw were complex, including esters, ketones, phenols and ethers. Different pretreatment time has a certain effect on the distribution of components of alcoholysis products. The increase of pretreatment time can increase the yield of ester compounds and selectively grow chain alkanoate, especially methyl palmitate, (9Z, 9Z). 12Z) -octadecyl -9-dienoic acid methyl ester and (E) octadecyl-11-enoic acid methyl ester; The ESI FTICRMS analysis of soluble components obtained from the alcoholysis of straw by white rot fungi showed that the oxygen compounds and nitrogen compounds in the alcoholysis products were significantly different from those obtained from untreated straw alcoholysis. At the same time, the oxygen and nitrogen compounds showed the directional transformation to O _ 4 and N2O4 respectively. FTIR,SEM,XPS,XRD and thermogravimetric analysis showed that the pretreatment of white rot fungi could effectively destroy the crystal structure of straw and promote the alcoholysis of straw. Using microcrystalline cellulose, xylan and alkaline lignin as raw materials, the supercritical alcoholysis of biomass components at different pretreatment time was carried out, and the yield of soluble components was investigated. The results showed that the yield of alcoholysis products could be obtained by cellulose and xylan, but the yield of lignin alcoholysis products did not change obviously. The chemical composition of alcoholysis soluble components of biomass components was analyzed by GC/MS. The results showed that the composition of alcoholysis products of cellulose and xylan after pretreatment was significantly different from that of cellulose and xylan after pretreatment. The contents of ester compounds increased significantly, but the alcoholysis products of lignin showed no significant difference. Combined with its own structure and related literature, the mechanism that pretreatment of white rot fungi may affect supercritical alcoholysis of straw was put forward.
【学位授予单位】：中国矿业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TK6
，
本文编号：2392721
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