夹带剂辅助超临界CO2萃取钻井废物特征

Modifier Effect on the Properties of Oil-based Drilling Mud Employing Supercritical CO2 Extraction

钻井废物性质特殊,易对环境造成潜在危害,如何资源化利用是急需解决的问题.实验采用超临界CO2萃取技术对钻井废物中含油组分进行提取和回用,对比了2种夹带剂条件下超临界CO2的萃取效果,重点研究了压强对萃取效果的影响,并且通过FTIR,SEM,XRD和GC-MS等手段考察了钻井废物萃取前后官能团、微观形貌、矿物组成和含油组分的构成与变化.结果表明:夹带剂可提升超临界CO2的萃取率,乙醇作为夹带剂效果更优,在压强为20 MPa条件下萃取率最高可达到92.2%,最低残油率0.9%,萃取后粒径更加均匀并降低至5~10μm;残留物中矿物成分主要为SiO2,Ba SO4及CaCO3,在超临界环境下,碳原子数在11~17之间含油物质更易被萃取.最后提出了可能的萃取机理与途径.

Drilling mud is often contaminated environment due to its special toxic properties. How to use it as resources is an urgent problem. Supercritical carbon dioxide extraction of oil-based drilling mud was examined by comparing two kinds of modifiers of changing extraction pressure at a time. Moreover,the various of functional group,microstructure,mineral component,and oil composition were confirmed by using FTIR,SEM,XRD and GC-MS,respectively. The result revealed that the better extraction performance can be obtained by using ethanol as a modifier. Under the relative optimum pressure of 20 MPa,the highest extraction rate can reach 92.2% and the lowest residual oil ratio is 0.9%. The particle size of residual solid product reduce to the range of 5 ~ 10 μm. SiO2,BaSO4 and CaCO3 consist of its main mineral component. The oil which consist the number of carbon from 11 to 17 is the main extraction substance. And a proposed pathway of supercritical carbon dioxide extraction is provided.