Study of Chemical Structure Changes of Chinese Lignite upon Drying in Superheated Steam, Microwave, and Hot Air
Study of Chemical Structure Changes of Chinese Lignite upon Drying in Superheated Steam, Microwave, and Hot Air
复制标题
中国褐煤过热蒸汽、微波、热风干燥后化学结构变化的研究
DOI：
10.1021/ef300559b
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发表时间：
2012-06-01
期刊：
影响因子：
5.3
通讯作者：
Stokie, David
中科院分区：
文献类型：
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作者：
Tahmasebi, Arash;Yu, Jianglong;Stokie, David
采用傅里叶变换红外光谱（FTIR）技术研究了中国褐煤在过热蒸汽、微波和热空气干燥过程中的化学变化。将原始样品和干燥样品的红外（IR）光谱曲线拟合到脂肪族氢（3000-2800 cm-1）和羰基吸收（1850-1500 cm-1）区的一系列谱带。已经发现，在过热蒸汽干燥过程中，脂肪族氢吸收率随着温度的升高而略微降低，而羧基（COOH）和羰基（C = O）基团的吸收急剧降低，这表明随着干燥温度的升高，氧官能团的损失。在蒸汽干燥期间，芳香碳和芳香环拉伸吸收在高达250 °C时保持相对不变，并且此后由于在较高干燥温度下发生的一些热解反应而显著降低。微波加热使褐煤中的含氧化合物浓度显著降低。
Chemical changes of Chinese lignite upon drying in superheated steam, microwave, and hot air have been studied in this paper using the Fourier transform infrared (FTIR) spectroscopy technique. The infrared (IR) spectra of raw and dried samples were curve-fitted to a series of bands in aliphatic hydrogen (3000–2800 cm–1) and carbonyl absorption (1850–1500 cm–1) zones. It has been found that aliphatic hydrogen absorbance decreased slightly with an increasing temperature during superheated steam drying, while absorption of carboxyl (COOH) and carbonyl (C═O) groups decreased drastically, indicative of the loss of oxygen functionalities with an increasing drying temperature. During steam drying, aromatic carbon and aromatic ring stretch absorption remained relatively unchanged up to 250 °C and decreased significantly thereafter because of some pyrolysis reactions that took place at higher drying temperatures. Microwave heating of lignite resulted in a significant decrease in the concentration of oxygen-contain...