高含水含油污泥二甲醚预处理同步脱水除油技术与机理

Oily sludge is a recalcitrant residue characterized as a stable W/O emulsion of water, solids, the petroleum hydrocarbons. Generally, the contents of three component are in the range of 30-50%、30-50%、10-20% by mass. The high water content hinders the application of extraction method because of the emulsification in Mud-water-oil three phase interface in actual application, which induces poor applicability of extraction. The applicability will significantly improved if both dewatering and deoiling of oily sludge can been achieved synchronously, where dewatering plays a promotion role of deoiling..Extraction method is poor applicability of oily sludge with high water content, this study intends to adopting a pretreatment method on synchronous dewatering and deoiling using dimethyl ether, which aims to achieve the three-phase separation of oil and water and sludge, achieves the effect of pure oil, clear water, dried sludge. The effcet of replacement dewatering and extraction deoiling are studied in order to further clarify the process and mechanism. synergistic effects and mechanism are studied about dewatering and deoiling in order to explore the relation between dewatering and deoiling, and the fundamental of sychronous dewatering and deoiling is researched from the perspective of thermodynamics and kinetics. then a new pretreatment method is then established based on the DME pretreatment research results. The system of efficient and economic is constructed by using process simulation, which can provide new approach for pretreatment of oily sludge..The method has the advantages of dewatering and deoiling synchronization, good effect and lower power consumption ,which can solve the commonly encountered problem of interface emulsification and poor applicability and pretreatment difficult about oily sludge by usig solvent extraction, it has important reality meanings.

含油污泥是由石油烃、乳化液、固体悬浮物等组成的复杂混合物，含量通常约占总质量30-50%、30-50%、10-20%。其高含水性特点阻碍了萃取法有效应用，在实际萃取过程，泥-水-油三相界面易乳化，适用性差，若能够同步脱水除油，发挥脱水对萃取除油的促进作用，则会显著提高萃取法的适用性。.本研究拟采用二甲醚预处理含油污泥同步脱水除油，实现油、水、泥三相的基本分离。首先，通过研究二甲醚置换脱水和萃取除油效果，分别明确其独立作用过程与机理。其次，通过深入研究脱水除油的协同效应，探讨脱水和除油之间的相对关系，并进而从热力学和动力学角度解析同步脱水除油基本原理。最后，建立基于二甲醚预处理同步脱水除油的新方法，并利用过程模拟构建新的工艺系统。.方法具有脱水除油同步、效果好、能耗低的优点，为含油污泥预处理提供了新的技术途径，对于解决当下普遍遇到的含油污泥预处理难等问题，具有重要现实意义。

背景：在原油开采、运输、储存和炼制过程会产生大量含油污泥。含油污泥是一种良好的潜在能源，油分回收可以减少固废产量和污染物浓度。萃取法回收油分较为有效，但全部研究只针对含水率在3.2-28.6%全干和半干含油污泥，利用萃取法高效回收高含水性状含油污泥中的油分，简略预脱水环节，减少溶剂和能量消耗，具有广阔的应用前景。.主要研究内容：本研究构建了二甲醚同步脱水除油体系，研究了二甲醚同步脱水除油耦合过程的作用效果，揭示了二甲醚脱水除油的基本规律，探讨了基于二甲醚同步脱水除油的机理和机制，为高含水性状含油污泥应用二甲醚脱水除油提供了理论依据和技术指导，可以有效推动二甲醚同步脱水除油技术的应用和发展。.重要结果：针对高含水含油污泥，可采用化学调调质低速离心法对含油污泥进行预脱水。针对含油污泥中油资源的脱水与回收，研究了液态二甲醚在不同萃取液固比、搅拌速率和萃取时间对油回收效率的影响，提出油相在油泥中的吸附与解析平衡模型，并基于多级萃取反应，在不同液固比下将实验与理论进行了拟合。二甲醚萃取回收到的油与传统索氏萃取方法油性质进行了比较，发现二甲醚溶剂萃取油分中分子量较小的链烷烃含量更高。针对脱水除油后的含油污泥，考察利用硅酸盐水泥稳定固化含油污泥效果和特性，为最终处置探讨了技术路径。.关键数据：2000rpm离心、含水率90%、总含油量4%离心条件下，31-32um为可分离的表层颗粒最大直径。含油污泥中油和水可被液态二甲醚同步去除，在液固比50ml/g，搅拌速度50rpm，萃取时间45min的最佳条件下，含油污泥含油率有51.1%降低至残渣中的1.9%，含油污泥中含水率由29.6%降低至1.99%，萃油萃水效率均大于99%。含油污泥和水泥1：4配比固化，可以保证含油污泥中重金属和油分的有效固化。.科学意义：利用DME萃取法高效回收高含水性状含油污泥中的油分，充分发挥脱水对除油的促进作用，提高了萃取的传质效率，减少了溶剂和能量消耗，揭示了二甲醚同步脱水除油的机理和调控机制。