Characterization of coal char surface behavior after a heterogeneous oxidative treatment
Characterization of coal char surface behavior after a heterogeneous oxidative treatment
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非均相氧化处理后煤焦表面行为的表征
DOI：
10.1016/j.fuel.2017.08.030
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发表时间：
2017
期刊：
影响因子：
7.4
通讯作者：
Ismail TM
中科院分区：
文献类型：
--
作者：
Wang Zhuo-Zhi;Sun Rui;Xu Jie;Zhang Xing-Zhou;Li Yu-Peng;Ismail Tamer M.;Ismail TM;Ismail TM
采用两种典型烟煤（JN和SH）进行彻底脱挥发，然后在1073 K下用o2进行功能化，得到不同转化率（JN: 0.21、0.34、0.40、0.53和0.63;SH: 0.15、0.22、0.32、0.42和0.52）的样品，然后用傅里叶变换红外光谱（FT-IR）和程序升温脱附（TPD）对表面含氧配合物C(O)进行定性和半定量表征。采用反卷积法对红外光谱中1800 ~ 1000 cm−1的C(O)吸附进行了分析，结果表明，这些官能团的类型和热稳定性依次为：羧基(1250 K) <苯酚(1350 K) <醚/酸酐(1550 K) <内酯/醌（1650 K）。TPD结果表明，在o2气氛下氧化处理后，颗粒表面产生了更多的活性位点，特别是低转化率的样品（J2、S2和S3）、煤的类型和转化率对亚稳配合物与稳定配合物Cwea(O)/Cstr(O)的比例影响较小。在程序升温还原（TPR）过程中，每单位质量的氧化炭比原煤还原更多的NO，在高温条件下（1173 ~ 1600 K），苯酚、醚和酸酐是参与NO还原反应的主要反应物。
Two typical types of bituminous coal (JN and SH) were employed for thorough devolatilization, then the samples were functionalized by O2at 1073 K to different conversion ratios (JN: 0.21, 0.34, 0.40, 0.53 and 0.63; SH: 0.15, 0.22, 0.32, 0.42 and 0.52) before the surface oxygen containing complexes C(O) were qualitatively and semi-quantitatively characterized by Fourier transform infrared spectroscopy (FT-IR) and temperature programmed desorption (TPD). A deconvolution method was applied to analyze the C(O) adsorption in the spectral region of 1800–1000 cm−1in the FT-IR spectra, and the results indicated that the type and thermal stability of these functional groups were as follows: carboxylic (1250 K) < phenol (1350 K) < ether/anhydride (1550 K) < lactone/quinone (1650 K). The TPD results demonstrated that more active sites were generated on the particle surface after the oxidative treatment under O2atmosphere, especially the samples with low conversion degree (J2, S2, and S3), coal type and conversion ratio had small effects on the ratios of metastable stable complexes to stable complexes Cwea(O)/Cstr(O) under the experimental conditions. The oxidized char samples were significantly more reactive than the raw char, and per unit mass of each oxidized sample could reduce more NO than raw char during the temperature programmed reduction (TPR) process, and phenol, ether and anhydride were the main reactants participated in the NO reduction reaction under high-temperature condition (1173–1600 K).