油气田采出水锂资源回收可行性、技术现状及展望

Feasibility,technical status and prospects of lithium recovery from produced water in oil and gas fields

锂资源高需求低产量的供需矛盾使得开发新的锂资源刻不容缓,而油气田采出水中锂资源丰富,是潜在的液体锂资源,因此分析油气田采出水提锂可行性并提出可行技术路线具有重要的现实意义。首先通过对油气田采出水的组成进行分析,明确了油气田采出水的水质特性;然后对国内主要盆地锂资源禀赋进行分析,强调其复杂的有机-无机高度混杂体系中有机物浓度高且离子组成丰富对提锂的挑战;最后从水质特性、水处理技术和油气田采出水锂资源高效回收技术出发,阐述盐湖提锂技术如沉淀法、膜分离、吸附法、溶剂萃取法和耦合技术对于油气田采出水提锂的适用性。结合提锂实践和产业现状,认为“预处理+富集浓缩(吸附/萃取-膜分离)+沉淀”是可行的提锂技术路线。

The contradiction between high demand and low production of lithium resources makes it urgent to develop new lithium resources.The produced water of oil and gas fields is rich in lithium elements,which is a potential liquid lithium resource.Therefore,it is of great practical significance to analyze the feasibility of lithium extraction from produced water of oil and gas field and propose a feasible technical route.First,the composition of produced water in oil and gas fields was analyzed,and the water quality characteristics of the produced water in oil and gas fields were defined.Then,the lithium resource endowment of major basins in China was analyzed,and the challenges of lithium extraction due to the high concentration of organic matter and rich ion composition in the complex organic-inorganic hybrid system were emphasized.Finally,the water characteristics,water treatment technology and high-efficient lithium extraction technology were comprehensively analyzed and the applicability of those lithium recovery technologies(precipitation,adsorption,extraction and membrane separation)for produced water was discussed.Combined with the practice of lithium extraction and the current situation of the industry,it was recommended to develop a lithium extraction technical route of"pretreatment+enrichment concentration(adsorption/extraction-membrane separation)+precipitation".