煤中有机硫的电化学脱硫机理

Mechanism of Organic Sulfur Removal from Coal by Electrolysis

在研究煤中有机硫的电化学脱硫基础上,利用X光电子能谱(XPS)和红外光谱(FT-IR)等现代测试手段研究了煤中有机硫的电化学脱硫机理。研究表明煤中有机硫在不同介质中脱硫机理不同。酸性条件下的脱硫机理是以锰离子为催化剂,在阳极表面Mn2+被氧化为Mn3+,后者氧化煤中有机硫为亚砜,亚砜进一步被氧化为砜,砜在热水中水解为可溶的磺酸根或硫酸根。碱性条件下脱硫机理是在碱性条件下脱硫反应以电解阳极产生的活性氧为氧化剂,将煤中有机硫氧化为亚砜和砜,砜在碱的作用下于热水中水解为能溶于水的磺酸根或硫酸盐。

The effect of coal and electrolytic conditions on organic sulfur removal was studied. It is very clear that the rate of different organic sulfur removal from coal is not same. Usually aliphatic sulfur is easily removed and thiophenic sulfur is difficultly oxidized. Then, the mechanism of organic sulfur removal from coal by electrolysis in acid or alkaline media was investigated by the use of XPS and FT-IR. It is obvious that organic sulfur in coal is oxidized into sulfone or sulfoxide by the active oxygen from anode surface. Then sulfone or sulfoxide can be eliminated by hydrolysis in alkaline media. In acid media, the organic sulfur can react with Mn3+ or Fe3+ and a part of them can be oxidized into sulfone or sulfoxide. At last sulfone or sulfoxide is leached into solutions as SO42- or-HSO3- by hydrolysis.