煤焦油脱盐脱水助剂筛选及评价

Evaluation of Coal Tar Demineralization and Dewatering Auxilaries

煤焦油加氢改质生产清洁燃料油工艺是目前煤焦油加工的重要手段。在煤焦油物料进入加氢阶段前,原料的脱盐、脱水、脱渣等净化预处理是保证煤焦油加氢工艺得以顺利进行的关键。由于煤焦油密度大且与水接近、黏度高、热稳定性差、含杂元素的极性类物质含量高的特点,导致煤焦油乳化液非常稳定,给煤焦油原料脱盐脱水的预处理带来更高难度。针对煤焦油的特点,设计了煤焦油脱盐脱水助剂评价筛选装置和方法,分别以中低温煤焦油和高温煤焦油为原料,开展煤焦油脱盐、脱水助剂筛选评价实验,并进一步考察了煤焦油在电场条件下脱盐脱水的效果。采用筛选出的助剂,中低温煤焦油经过二级脱盐脱水处理后,盐含量脱除率达到96%以上,脱水率达到91%以上,可以满足煤焦油后续加工基本进料要求。而高温煤焦油需经过四级电场处理后,原料盐含量脱除率才能达到90%以上,水含量脱除率在95%以上。

Coal tar hydrogenation to produce clean fuel oil is an important means of coal tar processing at present.The purification pretreatment of coal tar include desalting,dehydration and desagging is the key to ensure the smooth progress of coal tar hydrogenation process.Due to its similar density to water,high viscosity,poor thermal stability,and high content of polar substances containing miscellaneous elements,the coal tar emulsion is very stable,which brings more difficulty to the pretreatment of coal tar raw materials for desalination and dehydration.In this paper,evaluation and screening device and method for coal tar demineralization and dewatering auxilaries were designed according to the characteristics of coal tar.The experiments of screening and evaluating coal tar demineralization and dewatering auxilaries were carried out with medium and low temperature coal tar and high temperature coal tar as raw materials,and the effect of coal tar demineralization and dewatering under electric field was further investigated.By using the selected additives,the salt content removal rate could be more than 96%,and the dehydration rate could be more than 91%after secondary desalination and dehydration treatment of medium and low temperature coal tar,which can basically meet the basic feed requirements of coal tar subsequent processing.After the high temperature coal tar was treated by four-stage electric field,the removal rate of raw material salt content could be more than 90%,and the removal rate of water content could be more than 95%.