咸水层CO2地质封存泄漏监测的示踪剂优选

Screening gas tracers for leakage monitoring of CO geological storage in saline aquifer

碳捕集与封存(CCS)是大规模减少温室气体排放最经济、可行的方法。在CO2地质封存过程中,由于地质原因造成的封存泄漏会对人体健康、生态环境带来巨大的危害和影响,因此亟需寻求一种对CO2封存的安全性进行持续监测的方法。本文针对我国第一个咸水层CO2封存全流程CCS项目—神华10×10^4t/a CCS,基于鄂尔多斯盆地CO2封存的地质条件,通过对各示踪剂的稳定性、安全性和经济可行性的比较分析,建立了一种用于监测咸水层CO2地质封存泄漏的气体示踪剂优选标准,优选出化学性质稳定、环境背景值低的六氟化硫(SF6)作为鄂尔多斯盆地CO2地质封存的气体示踪剂,并考察了SF6-CO2体系在咸水层和空气中的吸附扩散行为。结果表明,SF6具有咸水层吸附量少,示踪配伍性好的特点,可作为神华CCS项目的CO2封存泄漏监测的一种气体示踪剂。

Carbon capture and storage(CCS) is the most economical and feasible way to reduce greenhouse gas emissions on a large scale. In the process of CO2 geological storage, the leakage of stored CO2 caused by geological reasons will bring great harm and impact on human health and ecological environment, so it is necessary to find a method to continuously monitor the safety of CO2 storage. In this paper, based on the geological conditions of CO2 storage in Ordos Basin, which was the storage site of the Shenhua 100 kt/a CCS project, the first full process CCS project for storing CO2 in saline aquifer in China, through the comparative analysis of the stability, safety and economic feasibility of various tracers, a gas tracer optimization standard for monitoring the leakage of CO2 geological storage in saline aquifer is established. SF6 with stable chemical property and low environmental background value is selected as the gas tracer of CO2 geological storage, and the diffusion behaviors of SF6-CO2 system in saline aquifer and air are investigated. The results show that SF6 has the characteristics of less adsorption capacity and good tracer compatibility, and is suitable for monitoring CO2 leakage in geological storage in the Shenhua CCS project.