【摘要】 为进一步研究温度对微波辅助萃取(microwave-assisted extraction,MAE)的影响,采用四氢呋喃作为萃取溶剂,在不同温度水平下对神府煤进行了微波辅助萃取实验研究。结合柱层析分离和傅立叶红外光谱(FTIR),分别定量半定量分析研究了萃取温度对萃取物组成及萃取残煤化学结构的影响。结果表明:随着萃取温度的增加,神府煤的MAE萃取率在140℃下达到最高值,并在150℃左右受到活性含氧化合物(主要为萃取物极性组分)裂解反应的影响。随着萃取温度从100℃增加至140℃,萃取残煤中脂肪族化合物含量比芳香族化合物含量受萃取温度影响更为明显,而MAE萃取率则与萃取残煤中含氧官能团C=O与C—O的相对含量之比(β)存在反相关关系,这表明温度的升高明显促进了溶质内含C=O官能团与溶剂的溶剂-溶质相互作用。更多还原

【Abstract】 Compared with traditional organic solvent extraction method,microwave assisted extraction(MAE)shows better extraction efficiency.In order to study the effect of temperature on MAE further,microwave assisted extraction was carried out for Shenfu coal using tetrahydrofuran(THF)as extraction solvent at different temperature levels.The effects of extraction temperature on the composition of extract and chemical structure of the residues were studied by using Fourier transform infrared spectroscopy(FTIR).Results show that with the increase of extraction temperature,the MAE yield of Shenfu coal under 140℃is the highest(5.50%),and is influenced by the cracking reaction of active oxygen-containing compounds(polarity portion)at about 150 ℃.When the extraction temperature increases from 100 ℃ to 140 ℃,compared to aromatic compounds,the relative content of aliphatic compounds in residues is more easily affected by extraction temperature change,and the MAE yield has an inverse relationship with the ratio of contentof C=O and C—O functional groups in the residues.This phenomenon shows that the increase of temperature significantly promotes THF microwave-assisted extraction process by the solvent-solute interactions between C=O functional groups in coal and THF.更多还原