天然气中汞的来源及脱汞技术

汞是天然气中常见的有毒有害气体。根据国内外研究现状,阐述了天然气中汞对天然气采、储、运设备及对人体的危害,讨论了汞的烃源岩和岩浆热液2种成因模式;利用汞同位素分馏特征来鉴别煤型气和油型气的成因,认为煤型气表现为负的汞非质量分馏特征,而油型气表现为正的汞非质量分馏特征;提出了高汞天然气的富集条件,主要与烃源岩中汞含量、热力条件和岩浆热液的活动有关;介绍了天然气中汞的实验室测定和现场检测方法与仪器。针对化学吸附法、溶液吸收法、低温分离技术、阴离子树脂和膜分离5种天然气脱汞技术进行了对比分析,指出载硫活性炭吸附是目前使用最广泛的脱汞技术。

Sources of mercury in natural gas and mercury removal technology

Mercury is a kind of common poisonous and harmful gas in natural gas.According to the present research situation at home and abroad,the harm of mercury in natural gas to natural gas collection,storage,transportation equipment and human body is expounded and two genetic models of mercury are discussed:source rock genetic model and magmatic hydrothermal genetic model.The origin of coal-type gas and oil-type gas can be identified by mercury isotope fractionation.It is considered that coal-type gas shows negative mercury mass-independent fractionation,while oil-type gas shows positive mercury mass-independent fractionation.The enrichment conditions of high mercury natural gas are put forward,which are mainly related to mercury content in source rocks,thermal conditions and magmatic hydrothermal activity,and the laboratory and field detection methods and instruments of mercury in natural gas are introduced.Five kinds of natural gas mercury removal technologies are compared and analyzed:chemical adsorption,solution absorption,low temperature separation technology,anion resin and membrane separation technology.At present,the sulfur-loaded activated carbon adsorption technology is the most widely used.