Topography modelling for potentially leaked CO2 diffusion and its application in human health risk assessment for carbon capture, utilisation, and storage engineering in China

Abstract

The lack of topography modelling and human health risk assessment for the latent leaked CO2 results in low public acceptance, which is a major obstacle for the industrial application of carbon capture, utilisation, and storage (CCUS). In this study, a methodology for topography modelling of potentially leaked CO2 was devised. Mainstream software was coupled sequentially to build a 3D computing domain for computational fluid dynamics to study the occurrence of CO2 dispersion. The adverse health effects of CO2 were used to establish risk levels and the corresponding CO2 concentration thresholds, and safety boundaries for human health were characterised with a high level of resolution. This methodology can simulate gas diffusion under different source-sink conditions, and can digitise the spatiotemporal characteristics of CO2 diffusion in less time and using less hardware. It presents a high level of resolution and operability, which is required for project and public health management of CCUS engineering. This novel methodology was applied to assess human health risks in a CCUS engineering oil field in the Yan'an area of Shaanxi province, China. Human health risks in various types of leakage scenarios were systematically evaluated. Pre-control measures were proposed based on the spatial characteristics of the various health risk categories, including the prevention of leakage sources and the setting of safety distances, land use adjustment, and contingency plans. It is worth noting that this study, for the first time, discusses the spatiotemporal evolution of CO2 diffusion and human health risks for trace leakages from the surface source in a CCUS area. The results of this study provide measures for risk mitigation and control for the case study of a CCUS project and propose a complete research framework and data support for similar engineering.