Life Cycle and Economic assessment of CO2 mineralization pathways in Austria - Thesis

[Geoengineering News]

https://repositum.tuwien.at/handle/20.500.12708/217128

Authors: Amini Khoei, Mahmoud

https://doi.org/10.34726/hss.2025.119627

Abstract

In Austria, annual CO2 emissions are approximately 73 million tons, significantly contributing to greenhouse gas concentrations. This study evaluates the environmental and economic feasibility of two carbon mineralization processes in Austria: (1) the utilization of biogenic CO2 from biogas upgrading with recycled concrete aggregates (RCA), and (2) the carbonation of steel slag using process-generated CO2 from steel production. A combined life cycle assessment (LCA) and techno-economic analysis (TEA) framework was applied to assess these processes, focusing on key operational parameters such as RCA particle size, CO2 delivery pressure, and electricity sources. For biogenic CO2 mineralization, results indicate that coarser RCA fractions (2–4 mm) yield the lowest global warming potential (GWP) of 0.12 kg CO2-eq per kg CO2 mineralized, driven by reduced crushing energy. However, economic viability is highly sensitive to RCA costs and product value, with levelized costs ranging from 127.7 EUR/ton CO2 at optimal conditions (60 bar pressure, zero RCA cost and for 0.1 kg/s CO2). Steel slag car bonation demonstrated a GWP of 0.023 kg CO2-eq per kg CO2 mineralized, with levelized costs of 126.59 EUR/ton for base case (100 kg CO2/h) and 16.10 EUR/ton for large-scale plant (e.g., Voestalpine Linz), highlighting the critical role of economies of scale. Sensitivity analyses highlighted the dominance of energy costs and economies of scale. While both processes offer significant CO2 sequestration potential, their deployment hinges on policy support for carbon pricing (>65 EUR/ton), subsidized energy, and valorisation of by-products (e.g., calcium carbonate). The study underscores the trade-offs between en vironmental benefits and financial feasibility, providing actionable insights for scaling car bon mineralization technologies in industrial applications.

Source: TU Wien