微波辐射炼焦煤中噻吩硫结构的非热效应研究

A Research into the Nonthermal Effect of Thiophenic Sulfur Structure in the Coking Coal under Mocrowave Radiation

采用XANES和XPS解析山西炼焦煤中有机硫的赋存特征,选择与煤中结构匹配的噻吩硫模型化合物进行微波辐射和水浴加热,通过Raman光谱比较研究两者对模型化合物中含硫结构的作用机制,利用Materials Studio构建、优化模型化合物结构,用密度泛函理论计算模拟微波场中模型化合物分子构型参数,解析含硫结构对微波的响应机理。结果表明:噻吩硫是炼焦煤中有机硫最主要的赋存形式。微波辐射后,模型化合物碳硫键和硫硫键的Raman谱吸收峰发生红移,温升速度快的模型化合物红移较小;相同温升的水浴加热后,几乎没有红移现象。微波能量不足以使模型化合物中碳硫键和硫硫键断裂,但能够改变分子构型,模型化合物含硫键在微波场中可能存在某种过渡态。微波作用对煤中噻吩硫结构存在非热效应。

With the adoption of XANES and XPS,an analysis of occurrence characteristics i n the organic sulfur of coking coal in Shanxi Province is conducted,with the c hoice of model compounds of thiophenic sulfur that matches the structure in the coal for the microwave radiation and water bath heating.Through a comparison o f Raman Spectrum,a research is carried out into the action of mechanism of sul fur-bearing structure in the model compounds from what is mentioned above,wit h Materials Studio in place to construct and optimize the structure of model com pounds and the application of the theory of density function to conduct computat ional simulation of the parameters of molecular configuration of model compounds in the microwave field to analyze the response mechanism of sulfur-bearing str ucture to the microwave.The outcome has established that thiophene is the main occurrence of organic sulfur in the coking coal.After the microwave radiation,there comes a red shift of the absorption peak of Raman regarding carbon-sul fur bonds and sulfur-sulfur bonds in the model compounds,with a comparatively smaller shift with respect to the model compounds that have a rapid temperature rise.There is almost no shift after the water bath heating under the same temperature.The microwave energy is not powerful enough to break carbon-sulf ur bonds and sulfur-sulfur bonds in the model compounds,but with a change in the molecular configuration.It is likely that the sulfur-bearing bo nds in the model compounds have a transition state in the microwave field.As a result,the existence of the nonthermal effect in the thiophenic sulfur structure unde r the microwave.