Carbon Capture and Utilization (CCU) is an emerging technology field that can replace fossil carbon value chains, and that has a significant potential to achieve emissions mitigation or even "negative emissions"-however in many cases with challenging technology feasibility and economic viability. Further challenges arise in the decision making for CCU technology research, development, and deployment, in particular when allocating funding or time resources. No generally accepted techno-economic assessment (TEA) standard has evolved, and assessment studies often result in "apples vs. oranges" comparisons, a lack of transparency and a lack of comparability to other studies. A detailed guideline for systematic techno-economic (TEA) and life cycle assessment (LCA) for CCU technologies was developed; this paper shows a summarized version of the TEA guideline, which includes distinct and prioritized (shall and should) rules and which allows conducting TEA in parallel to LCA. The TEA guideline was developed in a co-operative and creative approach with roughly 50 international experts and is based on a systematic literature review as well as on existing best practices from TEA and LCA from the areas of industry, academia, and policy. To the best of our knowledge, this guideline is the first TEA framework with a focus on CCU technologies and the first that is designed to be conducted in parallel to LCA due to aligned vocabulary and assessment steps, systematically including technology maturity. Therefore, this work extends current literature, improving the design, implementation, and reporting approaches of TEA studies for CCU technologies. Overall, the application of this TEA guideline aims at improved comparability of TEA studies, leading to improved decision making and more efficient allocation of funds and time resources for the research, development, and deployment of CCU technologies.

The intended audience for this document are practitioners that want to learn how to create comprehensible and consistent techno-economic assessments and life cycle assessments in the CCU field. These practitioners may come from academia, industry or government and may work in technology assessment and technology research and development, or funding, they may be part of the CCU community, the TEA community or the LCA community. Readers of TEA and LCA, such as investors, policy Part A: General Assessment Principles Part B: TEA guidelines Part C: LCA guidelines PART A: GENERAL ASSESSMENT PRINCIPLES TEA & LCA Guidelines for CO2 Utilization 8makers or funding decision makers are not the intended audience for these TEA and LCA guidelines, but may use this document to understand the challenges and pitfalls for TEA and LCA. A.2.4 Limitations of this documentThese guidelines have been developed to enable consistent and comparable LCA and TEA studies for CCU. They are not intended to serve as an assessment standard or rulebook. Instead they are meant to help practitioners to conduct sound assessments efficiently, avoid common mistakes and to derive meaningful results that can be compared to other studies. This document serves as an addition to conventional existing standards (in particular for LCA) and literature and does not replace any chemical engineering, economics or project planning principles. However, since the guidelines aim to enhance the comparability and transparency of studies, the LCA guidelines are more restrictive than the general ISO-framework. In some cases, there may be need to add further tasks to the ones discussed in this guideline since they are important to a specific study. Such additions are not excluded by the present guideline. However, the guidelines provide a consistent methodological core for conducting all LCA and TEA CCU studies.This document is intended as the first step of a longer framework development process. TEA and LCA remain two separate approaches in this document as is common in current assessment practice in academic literature and industry. However, a combined approach is in strong demand to include trade-offs in decision making. The integration of TEA and LCA into one singular study is a next major development step that is subject to future work. This document provides some initial guidance to those who wish to carry out an integrated TEA & LCA study, however many facets of the integration process are still to be determined. A.2.5 The guidelinesThe guidelines for TEA are presented in part B of this document and LCA in part C. At the end of each guideline chapter there is a box listing rules that these guidelines recommend. The box contains three categories, shall, should and may:TEA & LCA Guidelines for CO2 Utilization 9TEA & LCA Guidelines for CO2 Utilization 14 A.4.2.4 GuidelinesGuideline A.1 -Technology maturity Shall 1) Technology maturity shall be defined in each assessment -first for each system element and second for the overall product system 2) The maturity of the over...

For profit-oriented stakeholders techno-economic assessment (TEA) is the most important basis for decisions about research, development and deployment (RD&D). Two key challenges are: Firstly, the rating of RD&D progress which is closely linked to data availability; and secondly, the selection of TEA methods that adequately fit the available data in order to achieve the best possible decision basis. Technology readiness levels (TRLs) are a popular concept for rating the maturity of RD&D according to available data. Since existing TRL scales remain unspecific to technologies, an understanding of TRL in the chemical industry is presented. TRLs are subsequently used in a framework for TEA. Cost estimation is structured (with focus on capital expenditure) and estimation methods are sorted by TRL. Appropriate profitability indicators for the assessment of economic prospects are discussed for each TRL. Static indicators are favored in earlier TRLs, while dynamic calculations are preferred for detailed forecasts later on.

Carbon Capture and Utilization (CCU) is an emerging field proposed for emissions mitigation and even negative emissions. These potential benefits need to be assessed by the holistic method of Life Cycle Assessment (LCA) that accounts for multiple environmental impact categories over the entire life cycle of products or services. However, even though LCA is a standardized method, current LCA practice differs widely in methodological choices. The resulting LCA studies show large variability which limits their value for decision support. Applying LCA to CCU technologies leads to further specific methodological issues, e.g., due to the double role of CO 2 as emission and feedstock. In this work, we therefore present a comprehensive guideline for LCA of CCU technologies. The guideline has been development in a collaborative process involving over 40 experts and builds upon existing LCA standards and guidelines. The presented guidelines should improve comparability of LCA studies through clear methodological guidance and predefined assumptions on feedstock and utilities. Transparency is increased through interpretation and reporting guidance. Improved comparability should help to strengthen knowledge-based decision-making. Consequently, research funds and time can be allocated more efficiently for the development of technologies for climate change mitigation and negative emissions.

Technology readiness levels (TRL) have received increasing recognition throughout academia, industry and policy-making as a tool for evaluating and communicating a technology's maturity.Conventional scales are unspecific to technologies as they aim at evaluating and comparing technologies combining different fields. Hence, they present vague descriptions which leave considerable room for interpretation and subjective choices. For the chemical industry, adaptions and specific criteria are needed for more comprehensible TRL ratings. This paper specifies the nine conventional TRLs for the chemical industry as: Idea, Concept, Proof of concept, Preliminary process development, Detailed process development, Pilot trials, Demonstration and full-scale engineering, Commissioning, and Production. Adjusted descriptions and additional criteria with detailed indicators are presented, depicting the logical progression of a typical chemical innovation in the phases of applied research, development and deployment. The specified TRLs facilitate evaluation and communication of a technology's maturity and substantially improve the basis for data availability-based assessment.Issuing institution Purpose and background of the scale US National Aeronautics and Space Administration (NASA) 2,6,7 Space technology planning as a measurement system that "supports assessments of the maturity of a particular technology and the consistent comparison of maturity between different types of technology" 2 US Department of Defense (US DoD) 13 Focus on "critical technologies" 13 , used in 'Major Defense Acquisition Programs', evaluates the degree of risk associated with each TRL and recommends mitigation measures US Department of Energy (US DoE) 8 Based on NASA and US DoD, adapted to DoE needs, incorporates scale of testing, system fidelity and environment (waste) as criteria in the description, provides appendix with questions for general TRL rating and detailed questions for critical technical elements US Department of Health and Human Services (US HHS) 9Biomedical adaption: designed for evaluating the maturity of medical countermeasure products (drugs and biologics)European Commission, horizon 2020 framework