A framework for the techno-economic screening of absorption-based CO2 capture
File(s)
Author(s)
Brandl, Patrick Christian
Type
Thesis
Abstract
Capturing and storing CO2 (Carbon Capture and Storage, CCS) is integral to the mitigation of climate change, and the transition to a net-zero emissions world. The large-scale deployment of CCS is slower than required, which is widely attributed to its high cost. Significant cost savings are expected to be delivered through developing new solvents, yet is not clear if the thousands of newly proposed materials will significantly reduce the capture cost. In this thesis, a framework for the techno-economic screening of absorption-based capture systems (SQUASH) is presented. The tool combines thermodynamic models with cost-optimal equipment sizing, enabling the computational fast, high-throughput, techno-economic short-cut screening of solvents with embedded error quantification. Its database contains 464 candidate solvents, yet only 18% could be successfully screened due to a substantial lack of data. SQUASH was applied to examine the relationships between operating conditions, utility cost, amine chemical class, thermo-physical properties including their error, process performance, and capture cost. Poly-amines were identified as the most promising class. This work demonstrates
that differences of $2/tCO2 in mean capture cost between solvents can be differentiated with statistical significant confidence within the tool. The differences in capture costs between the solvents reduce with increasing CO2 concentration, and the average relative difference in capture cost between two adjacently ranked solvents is only 1.1% at CO2 concentrations found in cement or steel plants. This means that the solvent selection for industrial applications might become less dependent on the techno-economic performance. Alternative solvents and blends of aqueous amines explore the same thermo-physical property space already investigated by aqueous amines for decades. The theoretical achievable room for cost savings deliverable by solvent R&D over the current benchmark CESAR1 is limited to 29%. Further cost savings can only be realised by creating synergies with modifications to the process.
that differences of $2/tCO2 in mean capture cost between solvents can be differentiated with statistical significant confidence within the tool. The differences in capture costs between the solvents reduce with increasing CO2 concentration, and the average relative difference in capture cost between two adjacently ranked solvents is only 1.1% at CO2 concentrations found in cement or steel plants. This means that the solvent selection for industrial applications might become less dependent on the techno-economic performance. Alternative solvents and blends of aqueous amines explore the same thermo-physical property space already investigated by aqueous amines for decades. The theoretical achievable room for cost savings deliverable by solvent R&D over the current benchmark CESAR1 is limited to 29%. Further cost savings can only be realised by creating synergies with modifications to the process.
Version
Open Access
Date Issued
2023-09-30
Date Awarded
01/08/2025
License URL
Advisor
MacDowell, Niall
Hallett, Jason
Publisher Department
Centre for Environmental Policy
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)