Human health risks of post- and oxy-fuel combustion carbon dioxide capture technologies: Hypothetically modeled scenarios

Abstract

Carbon dioxide (CO2) capture technology has become an available technology for ensuring reduction of greenhouse gas emissions from fossil-fuel based electricity generating plants. Since public acceptance of this technology depends critically on a reliable demonstration of its safety, it is important that the risks associated with carbon capture technology be fully understood so that standards and regulatory frameworks required for its deployment can be formulated.The objective of this paper is to evaluate the predicted risk to human health associated with the Boundary Dam Power Station (BDPS) close to Estevan, Saskatchewan, Canada. This study aims to predict the potential instead of actual risks to human health because real data from the power plants’ stacks are unavailable. Instead, the study relies on data that were entirely derived from the Life Cycle Assessment (LCA) studies (Koiwanit et al., 2014a,b; Manuilova, 2011). The risk assessment was conducted based on two tools: (i) the American Meteorological Society's Environmental Protection Agency Regulatory Model (AERMOD), and (ii) Health Canada's Air Quality Benefits Assessment Tool (AQBAT). The conventional lignite-fired electricity generation station at the BDPS is used as a reference case. This work presents the predicted risks to human health due to exposure to air pollution which has been released by the post-combustion carbon dioxide capture process, and compare the risks with those posed by the oxy-fuel CO2 capture technology.Nitrogen dioxide (NO2), particulates less than 2.5μm in diameter (PM2.5), and sulfur dioxide (SO2) emissions were modeled in a circular pattern of 10 degree increments with 25 zones of 100m on each increment. This study demonstrates that the reductions in the atmospheric concentrations of NO2, PM2.5, and SO2 accounted for the largest improvements in human health impacts, particularly in terms of acute respiratory, asthma symptoms, and restricted activity health outcomes. In addition, the oxy-fuel CO2 capture system reduced emissions to the atmosphere more effectively than the post-combustion CO2 capture technology. Therefore, the former technology's contribution to reducing air pollution is more significant than that of the latter.