炼焦煤中噻吩类有机硫对微波的响应规律研究

It is rather difficult to deprive the thiofuran-type organic sulfur in coking coal. The deprivation of sulfur under microwave irradiation finds its basis on the microwave penetrability and microcosmic target energy, with the response of sulfur-bearing structure to extra energy as the basis. With high-sulfur coking coal as the object, we have, on the basis of the microcosmic chemical structure of the recognized organic sulfur-bearing component in the coking, made a screening of a series of the model compounds of the Thiofuran-type Organic Sulfur in the project to research into the substitutes. With the help of the test system of electromagnetic property, we are endeavoring to comprehend the thiofuran-type sulfur-bearing in this respect in an effort to study the conformation, energy and performance of sulfur-bearing keys of the sulfur-bearing molecules in the model compounds with the combination of the theories & methods in quantum chemistry and molecular mechanics, judge the possible routes through which the response of sulfur-bearing keys under the extra energy is in place and explore the mechanism when the microwave plays its role in the thiofuran-type organic sulfur. We plan to set up an efficient transmission mechanism of the microwave, with the design & establishment of a platform of sulfur deprivation under the microwave of reconfigurable frequencies to conduct experiments in sulfur deprivation. We are illustrating the matching relations between the conditions of microwave power, irradiation time, reaction temperature, coupled resonance patterns and the dissociation effects of the thiofuran-type organic sulfur components and keep a track of the property and structure of what is obtained in transient state and sulfur precipitation to reveal the Regularities Regarding the response of the Thiofuran-type Organic Sulfur in Coking Coal. New thoughts will be offered in the analysis of fundamentals in the field of microwave sulfur deprivation and its optimization, thus bearing a significance in the industrial experiments in microwave sulfur deprivation.

煤中噻吩类有机硫最难脱除，煤在微波辐照下脱硫是基于微波的穿透性和微观靶向能量作用，含硫结构对外加能量的响应是微波脱硫的基础。以高硫炼焦煤为研究对象，在认知煤中有机含硫组分微观化学结构基础上，筛选系列噻吩类有机硫模型化合物并开展替代研究。通过电磁特性测试系统掌握煤中噻吩类含硫结构的电磁特性，结合量子化学和分子力学的原理和方法研究模型化合物中含硫分子的构象、能量及含硫键性能，判断外加能量作用下含硫键发生反应的可能路径，探索微波对噻吩类含硫结构的作用机理。建立微波能量高效传输机制，设计并构建频率可重构的微波脱硫平台，开展微波脱硫试验。阐明微波功率、辐照时间、反应温度及耦合谐振方式等条件与噻吩硫组分解离效应的匹配关系，跟踪过渡态及硫析出产物的性质与结构，揭示噻吩类含硫结构对微波的响应规律。为解析微波脱硫的基本原理、优化微波脱硫工艺条件提供思路，对开展微波脱硫工业化试验具有重要意义。

优质的焦煤和肥煤属于稀缺煤种，硫的存在严重制约了炼焦煤的加工和利用。噻吩硫结构最稳定，噻吩硫的脱除是煤脱硫的难点。微波具有穿透性和选择性加热的特点，且无温度梯度，在脱硫的同时，可以避免煤的特性变异，微波脱硫技术具有良好的应用前景。.选择山西高硫炼焦煤，认知煤中有机含硫组分的禀赋特征和微观化学结构，遴选与煤中含硫结构相匹配的系列噻吩类模型化合物，掌握煤及含硫组分对微波的吸收转化特征。研究微波作用下噻吩类模型化合物中含硫分子属性、构象及能量变化，探索微波加快反应速率、改变反应路径机理中是否存在非热效应，解析噻吩类含硫结构对微波的响应规律。为揭示微波脱硫机理、优化脱硫工艺提供理论支持，对推动微波脱硫技术进步，降低硫在炼焦煤利用过程中的危害具有重要意义。.研究表明，山西高硫炼焦煤中硫以有机硫为主，占总硫的70%左右。煤中有机硫包括硫醇、硫醚、噻吩、砜和亚砜等赋存形态，噻吩在部分炼焦煤中含量超过60%。.构建碳原子数为184的炼焦煤含硫大分子结构模型，选择符合硫赋存特征的系列噻吩类模型化合物，开展煤及模型化合物介电参数测试。结果显示，煤和模型化合物具有较好的微波吸收特性，最大介电损耗一般出现在16～17GHz。.基于民用微波频率的限制，考察煤及噻吩硫模型化合物在915MHz和2450MHz两个频点的介电性质，获知煤中噻吩类含硫结构在915MHz具有更强的吸波能力。.煤反射系数随频率的变化规律佐证了煤的介电损耗特征，模型化合物穿透深度与其吸波能力和微波波长具有良好的负相关性。.微波作用后，炼焦煤中噻吩硫相对含量升高。微波加热致使原子相对运动加剧，相互作用减弱，分子结构趋于亚稳态，化学键解离能降低。噻吩硫模型化合物在微波加热过程中，除了热效应，还存在非热效应。.运用密度泛函理论对微观结构模拟计算的结果表明，微波光子能量对噻吩硫分子极性及含硫化学键强弱影响不大，但可以改变模型化合物的分子空间构型。微波场作为矢量场，能量大小和施加方向对化学结构均具有影响。.