Tim Langhorst


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Langhorst

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Tim

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0000-0002-6362-1192

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2022 - 20258
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Publications 1 - 8 of 8
  • Inventory estimation for chemical processes from the reaction stoichiometry by decision trees
    Item type: Other Conference Item
    Langhorst, Tim; Tuchschmid, Moritz; Winter, Benedikt; et al. (2024)
    Abstract Book SETAC Europe 34th Annual Meeting
  • Prospective life cycle assessments of chemicals: Improving stoichiometry-based methods
    Item type: Other Conference Item
    Langhorst, Tim; Winter, Benedikt; Roskosch, Dennis; et al. (2023)
    Abstract Book SETAC Europe 33rd Annual Meeting
  • AI-powered Framework to Predict Environmental Impacts of Organic Chemicals via Retrosynthesis
    Item type: Other Conference Item
    Chen, Shaohan; Langhorst, Tim; Winter, Benedikt; et al. (2024)
    Book of Abstract of the 34th European Symposium on Computer Aided Process Engineering / 15th International Symposium on Process Systems Engineering (ESCAPE34/PSE24)
    The transition toward a sustainable chemical industry relies on the ability to quantify the environmental impacts of chemical production. Life cycle assessment (LCA) is a holistic method that quantifies the environmental impacts of chemical productions across multiple impact categories. However, conducting a thorough LCA study is challenging in the early process design stages due to limited LCA data availability. This work estimates LCA data of organic chemicals by designing a pathway-resolved framework using machine-learning-based retrosynthesis. Our method automatically predicts the life cycle inventories (LCI) and the corresponding environmental impacts solely using SMILES codes of target chemicals as the input. We verify this framework with a benchmark dataset of 136 organic chemicals, including industrially validated LCIs. The results show that our framework can accurately predict LCIs and the environmental impact of all impact categories. Our framework thus allows for filling data gaps in LCA databases for early-stage process design and accelerates the transition toward a sustainable chemical industry.
  • Techno-Economic Assessment & Life Cycle Assessment Guidelines for CO2 Utilization (Version 2.0)
    Item type: Report
    Langhorst, Tim; McCord, Stephen; Zimmermann, Arno; et al. (2022)
    Climate change is one of the greatest challenges of our time. Under the auspices of the UN Framework Convention on Climate Change and through the Paris Agreement, there is a commitment to keep global temperature rise this century to well below two degrees Celsius compared with pre-industrial levels. This will require a variety of strategies, including increased renewable power generation, broad-scale electrification, greater energy efficiency, and carbon-negative technologies. With increasing support worldwide, innovations in carbon capture and utilization (CCU) technologies are now widely acknowledged to contribute to achieving climate mitigation targets while creating economic opportunities. To assess the environmental impacts and commercial competitiveness of these innovations, consistent and transparent Life Cycle Assessment (LCA) and Techno-Economic Assessment (TEA) are needed. Against this background, guidelines (Version 1.0) on LCA and TEA were published in 2018 and updated (Version 1.1) in 2020 as a valuable toolkit for evaluating and guiding CCU technology development. Ever since, an open community of practitioners, commissioners, and users of such assessments has been involved in gathering feedback on the document. That feedback has informed the improvements and the expansion incorporated in Version 2.0 of the Guidelines. This revised and expanded version 2.0 of the Guidelines has again been developed by a team of researchers at RWTH Aachen, TU Berlin, the Institute for Advanced Sustainability Studies Potsdam, the University of Sheffield, and the University of Michigan. Several workshops, the work of the International CCU Assessment Harmonization Group, and feedback from practitioners and users of LCA and TEA studies, have contributed to this updated version. Version 2.0 includes new chapters on integrated assessments that combine LCA and TEA, how to assess early-stage technologies, and how to include social impact in LCA and TEA.
  • From Reaction Stoichiometry to Life Cycle Assessment: Decision Tree-Based Estimation Tool
    Item type: Journal Article
    Langhorst, Tim; Winter, Benedikt; Tuchschmid, Moritz; et al. (2025)
    ACS Environmental Au
    Decision-making during the early stages of research and development (R&D) should be informed by both economic and ecological perspectives. While early stage cost assessments are well established, life cycle assessment (LCA) is still largely descriptive but should expand to a more prospective tool for early assessing the ecological effects of future processes. Chemical processes should be first assessed as early as when only the reaction equation is known. Our previous comparison of estimation methods based on the reaction equation identified three requirements to foster early stage LCA: (1) estimate inventories rather than final impacts to ensure flexibility, (2) distinguish between processes, as single values cannot reflect the variety of chemical processes, (3) provide a measure of uncertainty. In this publication, we propose regression trees to estimate key inputs for industry-scale life-cycle inventories of chemical processes directly from the underlying reaction equation. In detail, the regression trees yield the raw materials' impact, the direct greenhouse gas (GHG) emissions in CO2eq, and the demands for electricity, steam, natural gas, cooling water, and process water. The regression trees outperform the current best available proxy values and provide inventory information that is as accurate as cost estimates. Thus, our work enables decision-makers to consider environmental aspects with the same level of accuracy as costs projections.
  • Stoichiometry-based prediction of life cycle inventories: Benchmarking & best practices
    Item type: Other Conference Item
    Langhorst, Tim; Winter, Benedikt; Roskosch, Dennis; et al. (2023)
  • Stoichiometry-Based Estimation of Climate Impacts of Emerging Chemical Processes: Method Benchmarking and Recommendations
    Item type: Journal Article
    Langhorst, Tim; Winter, Benedikt; Roskosch, Dennis; et al. (2023)
    ACS Sustainable Chemistry & Engineering
    Current chemical process development aims to improve sustainability. Decision-making thus needs to assess potential environmental benefits. However, reliable life cycle inventory data is often unavailable at early design stages. Without process information, life cycle assessment practitioners usually estimate inventories solely based on the reaction stoichiometry and proxies for energy and utility demands. However, the quality of these proxies has not been tested on a comprehensive data set. In this study, we compare and benchmark stoichiometry-based estimation methods that employ proxies for the yield and utility demands from the literature to a new benchmark database of 474 processes. This benchmark data set is based on industrially validated processes from the Process Economics Program (PEP) yearbook. Most estimation methods are shown to underestimate the global warming impact. We found that the yield range assumed by Geisler et al. (2004) closely reflects the actual raw material demands, while the average process energy demands, calculated by Kim and Overcash (2003), perform best as a proxy for energy demands. Thus, we propose to combine both proxies to improve predictions of the inventory data and the overall global warming impact.
Publications 1 - 8 of 8