Life Cycle GHG Emissions Analysis of Building-Level Carbon-Capturing Technologies

Abstract

AbstractThe building sector contributes 12% of the greenhouse gas (GHG) emissions in Canada. Building heating is the main contributor to building-level GHG emissions, primarily due to natural gas combustion. Although carbon-capturing is an emerging technology used to curb the GHG emissions in the fossil fuel-based power generation sector, the possibility of implementing this technology in natural gas building heating systems has not been comprehensively explored. This paper aims to evaluate the life cycle GHG emission reduction potential of integrating carbon capturing systems in residential and commercial building heating systems. The GHG emission reduction potential of commercially available building level carbon-capturing system (which uses Potassium Hydroxide (KOH) to capture CO2 and generate Potassium Carbonate as a by-product) and a carbon-capturing technology used in fossil fuel power generation plants (which uses Mono Ethanol Amine (MEA) based chemical absorption to separate CO2) were compared. Life cycle GHG assessment was conducted using TRACI 2.0 impact assessment method. The percentage reduction of life cycle GHG emissions was lower than the operational GHG emission reduction in MEA based systems due to the embodied emissions associated with the carbon-capturing process life cycle. The KOH-based system also consists of a substantial amount of embodied GHG emissions. However, the life cycle GHG emissions reduction of the KOH-based system was higher than the GHG emissions reduced during the operation when avoided emissions of the by-products were accounted. The findings of this paper will assist building owners, community developers, and policymakers in assessing the feasibility of implementing building-level carbon-capturing in the future.