IEAGHG workshop on comparative technoeconomic assessment of commercially available CO₂ conditioning technologies

Publication Overview

IEAGHG organized a virtual expert workshop titled ‘Comparative Techno-economic Assessment of Commercially Available CO₂ Conditioning Technologies’ on the 20th of February 2024. The workshop aimed to facilitate the exchange of knowledge and insights among a panel of international experts on CO₂ conditioning, with the goal of informing the scope of a technical specification for a comprehensive IEAGHG report. This report synthesises the presentations and discussions from the workshop.

Publication Summary

• The development of metrology infrastructure for monitoring CO₂ in industrial processes cannot be overemphasized. This involves creating new traceable facilities, including primary power standards for calibration and systems for quantifying CO₂ leaks from pipelines, ships, and storage locations. The METCCUS project is geared to produce the necessary primary standards, sampling methods, analytical techniques, and models to support the industry in specifying operational conditions and performing the required measurements in CO₂ capture, transport, and storage.
• The challenges of establishing a unified CO₂ stream specification across the entire CCS value chain reveal the complexity of harmonizing standards amidst inherent impurities and varied requirements from emission to injection. A significant issue is the absence of a universal specification, highlighting the need for a Europe-wide standard to ensure consistency and safety across CCS operations.
• The evolving nature of CO₂ specifications within the CCS value chain underscores the critical balance between technical requirements and commercial considerations for ensuring safe operations. Recent technical findings, such as the corrosive potential of CO₂ streams with high levels of NOx and the need to limit mercury levels, reflect the industry’s evolving understanding and the necessity to continuously update CO₂ specifications. These updates are not just technical corrections but responses to the complex interplay of safety, integrity, and marketability within the CCS framework.
• Shipping options, which typically demand higher CO₂ purity due to the necessity of transporting CO₂ in liquid form, present unique challenges compared to pipeline transport. This includes the significant impact of impurities on transport design, material integrity, and the heightened corrosion risks associated with certain contaminants. The evolving understanding of these risks, especially with new contaminants from anthropogenic CO₂ sources, necessitates stricter CO₂ transportation specifications to mitigate corrosion and ensure safe, efficient transport.
• The introduction of technologies such as nitrogen sparging and the Dissolved Oxygen Removal Apparatus (DORA) presents innovative approaches to remove dissolved oxygen from capture solvents, each offering distinct advantages in terms of operational and economic efficiency. DORA, with its targeted removal process and the potential for lower capital and operational expenditures, demonstrates a promising advancement towards integrating oxygen removal directly within the CO₂ capture process.
• Intermittent operations may add a layer of complexity to the conditioning process due to the variability in CO₂ composition and flow rates stemming from fluctuating industrial activity. Such fluctuations may introduce operational inefficiencies and complicate the management of the conditioning process. This variability may necessitate a highly adaptable conditioning process, and flexible operational protocols, to ensure the CO₂ consistently meets quality standards despite changing inputs. Further, these challenges may have an economic impact, as adapting to the intermittent nature of operations can lead to higher capital and operational costs.
• The importance of upstream improvements and advanced pollution control equipment in enhancing the efficiency and feasibility of CO₂ capture and conditioning processes was highlighted. Furthermore, it emphasizes the need for dehydration to prevent issues like freezing and corrosion, alongside exploring emerging conditioning options.
• An often-overlooked aspects of conditioning and CO₂ stream specification for CCU technologies was highlighted. It sheds light on the unique purity requirements for CCU applications, which significantly differ from those for traditional T&S and examines how these requirements influence the selection and cost of purification technologies. The study reveals that trace impurities, especially NOx and SO2, adversely affect the efficiency and longevity of CO₂ electrolysers, a crucial component for CCU technologies, thereby emphasizing the need for stringent purification standards.
• Despite advances in CO₂ conditioning technologies, significant gaps persist in our comprehension and practical experience with handling heavily contaminated CO₂ streams. These gaps are particularly pronounced in the application of specialist adsorbents and catalysts tailored for the removal of BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes), hydrocarbons, and VOCs. The intricacies of identifying the specific components of VOCs present in these streams and fully understanding the mechanisms and efficiencies of their removal processes underscore critical areas for further investigation.
• The discussions illuminated the evolving challenges faced in conditioning CO₂ from power and industrial sources, highlighting two distinct strategies: conditioning at the source to address smaller volumes of CO₂ or establishing a gathering network for conditioning at larger volumes. Each strategy is characterised with its own economic and operational implications. This reveals a pivotal decision-making juncture for the industry in determining the most effective locations and methods for CO₂ conditioning, fundamentally impacting the operational, safety, and economic outlook of CCS infrastructure.
• The discussion on conditioning technologies advocated for practical, effective solutions, emphasizing turnkey systems that streamline processing steps and facilitate deployment across different contexts. Further, and importantly, the management of waste streams from CO₂ conditioning was identified as a critical, yet often overlooked, consideration, significantly influencing the CCS value chain.