Drying Technology ( IF 3.3 ) Pub Date : 2021-01-18 , DOI: 10.1080/07373937.2020.1870233 Lin Li 1 , Chuandong Ma 1 , Zhihao Li 1 , Mingpu Liu 1 , Mengyu Lin 1 , Meng He 1 , Qingbiao Wang 2 , Xiaofang You 1
Abstract
The surface of low-rank coal has many oxygen functionalities, which leads to poor coal slime dehydration. To improve the effect of coal slime dewatering, sodium dodecyl benzene sulfonate (SDBS) was used as accelerator in the coal slime dehydration process. In addition, the mechanism of acceleration was studied using X-ray photoelectron spectroscopy (XPS) and molecular dynamics (MD) simulations. The results of dehydration experiments showed that adding a certain amount of SDBS into the slurry water was conducive to promoting the removal of water. When the concentration of the SDBS solution was 0.06 g/L, the water content of the filter cake decreased from an initial value of 59.98% to 54.55%. XPS measurements and MD simulations show that the polar groups (sulfonic acid) of SDBS are adsorbed on the oxygen-containing functional groups on the coal surface, thus, exposing the nonpolar groups (alkyl chains) of the molecule to the solution. The calculation of the self-diffusion coefficient (D) of water molecules in the simulated system indicate that the presence of SDBS improves the mobility of water at the coal surface, which is helpful in improving the loss of water from the coal surface, thus, improving its hydrophobicity. Crucially, the results of the MD simulations are consistent with those from experiment.
- Highlights
Addition of a certain amount of SDBS helps to remove moisture from the coal slime.
Oxygen-containing functional groups on the coal surface are effectively covered by SDBS.
The interaction mechanism of SDBS at coal/water interface was studied by combining experiments and theoretical calculations.
中文翻译:
十二烷基苯磺酸钠在促进煤脱水中的作用:实验和理论计算
摘要
低阶煤表面具有较多的氧官能团,导致煤泥脱水不良。为提高煤泥脱水效果,在煤泥脱水过程中采用十二烷基苯磺酸钠(SDBS)作为促进剂。此外,使用 X 射线光电子能谱 (XPS) 和分子动力学 (MD) 模拟研究了加速机制。脱水实验结果表明,在浆水中加入一定量的SDBS有利于促进水的去除。当SDBS溶液的浓度为0.06 g/L时,滤饼的含水量从初始值的59.98%下降到54.55%。XPS 测量和 MD 模拟表明,SDBS 的极性基团(磺酸)吸附在煤表面的含氧官能团上,从而使分子的非极性基团(烷基链)暴露在溶液中。自扩散系数的计算(模拟系统中水分子的D ) 表明 SDBS 的存在提高了水在煤表面的流动性,这有助于改善煤表面水的流失,从而提高其疏水性。至关重要的是,MD 模拟的结果与实验结果一致。
- 强调
添加一定量的 SDBS 有助于去除煤泥中的水分。
SDBS有效地覆盖了煤表面的含氧官能团。
结合实验和理论计算研究了SDBS在煤/水界面的相互作用机理。