29 research outputs found
Kinetic Investigation of Polyurethane Rubber Formation from CO2‐Containing Polyols
A novel CO2 utilization technology allows for the inclusion of CO2 as carbonate units and double bond moieties to give additional functionality in polyether polyols. This study examines the chain‐elongation kinetics of these diols with diisocyanates to polyurethane rubbers by means of thermal analysis. A reaction order of 1 indicates a strong influence of the chains' mobility on the reaction rate. Spectrometry and comparison with non‐double‐bond polyols reveal that the effect cannot be attributed to a substantial occurrence of side reactions but is rather due to the intertwining of lengthy chains.BMBF, 033R350A‐D, Production DreamsTU Berlin, Open-Access-Mittel - 202
Frequent co-occurrence of high-grade dysplasia in large flat colonic polyps (>20 mm) and synchronous polyps
Techno-economic assessment of CO2-containing polyurethane rubbers
Carbon capture and utilization technologies can open up new synthesis routes with economic benefits. Recently, the inclusion of carbon dioxide in polyols was extended by copolymerizing double bond agents. This allows for subsequent chain-extension with diisocyanates to polyurethane rubbers. This paper assesses their economic viability. A preliminary techno-economic assessment based on extended block flow diagrams reveals substantial uncertainty in profitability indicators due to applying a short-cut capital expenditure estimation method. Consequently, a process design for the polyol production was carried out, enabling a refined TEA incorporating an equipment-cost-based approach. Positive net present values are reported for multiple [double bond agent]-[diisocyanate]-[benchmark] combinations. The net present value is most sensitive to the sales and propylene oxide prices. The choice of the double bond moiety has decisive effect; the choice of the diisocyanate has minor effect on the TEA. Finding a favorable market position remains the biggest challenge for CO2-containing synthetic polyurethane rubbers
Apples and apples: A shortcut assessment framework for early‐stage carbon capture and utilization technologies based on efficiency, feasibility, and risk
Climate change is one of the largest current challenges to humankind, requiring a steep emissions reduction. One promising approach is using CO2 as a resource. Research and development of carbon capture and utilization (CCU) technologies have increased in recent years, putting early‐stage techno‐economic assessment (TEA) in a key role to derive recommendations systematically, to allocate resources efficiently, and overall to push commercialization successfully. Shortcut TEA assessment approaches that reduce assessment detail and effort compared with conventional, full‐scope studies have gained popularity in recent years but have been criticized as comparing apples with oranges. Several open methodological questions remain such as how to implement global assessment standards, how to reduce subjective judgments, and how to compare technologies at different maturities. Herein, a shortcut assessment framework for early‐stage CCU technologies is proposed, based on the perspectives of efficiency, feasibility, and risk (Efferi). The Efferi framework implements the Global CO2 Initiative's Guidelines, enables comparisons at different technology maturities, and systematically reduces subjective judgments. The Efferi framework provides a starting point for a more robust and easy assessment of early‐stage CCU technologies, leading to clearer go/no‐go recommendations at reduced assessment effort and enabling fairer, “apples to apples” comparisons.TU Berlin, Open-Access-Mittel – 202
Techno-economic assessment framework for the chemical industry—Based on technology readiness levels
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, first, the rating of RD&D progress which is closely linked to data availability and, second, 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
Specifying technology readiness levels for the chemical industry
Technology readiness levels (TRLs) 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
Integration of techno-economic and life cycle assessment: Defining and applying integration types for chemical technology development
Both an environmental and an economic assessment are needed to judge the potential of sustainable chemical technologies. However, decision-makers may be challenged by conflicting conclusions. The integration of life cycle assessment (LCA) and techno-economic assessment (TEA) can enhance decision-making, as integrated assessments provide more information than a simple reporting of separate TEA and LCA results. The analysis of integration approaches reveals a lack of consistency in terms of defining criteria and methodological aspects for integration. A gap remains where guidance for practitioners is needed on how to select a suitable integration type for their different purposes. To fill this gap, we conclude that a one-size-fits-all solution of integration cannot adequately serve all purposes along the technology development phases. Therefore, a framework to guide through integration in three distinct parts is proposed. In Part I, a four-phase approach for every integrated assessment to link the results from TEA and LCA is defined. Part II develops three integration types classified by their core characteristics: qualitative discussion-based (Type A), quantitative combined indicator-based (Type B), and quantitative preference-based (Type C). Finally, in Part III, a step-by-step method to select the appropriate integration type according to the assessment purpose, while considering restrictions imposed by technology maturity and resource availability is introduced. Thus, the framework is a basis for increasing the number of integrated assessments by guiding practitioners towards tailored studies
OPTIMIZING HAND-ASSISTED RETROPERITONEOSCOPIC LIVING DONOR NEPHRECTOMY (HARP) WITH A PASSIVE POLARIZING THREE-DIMENSIONAL DISPLAY SYSTEM
Gallerie zur Cotta-Göschen'schen Volks-Bibliothek der Deutschen Klassiker : Göthe, Schiller, Klopstock, Lessing, Wieland, Platen, Thümmel, Pyrker und Lenau ; 144 Stahlstiche nach Original-Zeichnungen / von J. Buchner, J. Köckert, G. Osterwald ...
GALLERIE ZUR COTTA-GÖSCHEN'SCHEN VOLKS-BIBLIOTHEK DER DEUTSCHEN KLASSIKER : GÖTHE, SCHILLER, KLOPSTOCK, LESSING, WIELAND, PLATEN, THÜMMEL, PYRKER UND LENAU ; 144 STAHLSTICHE NACH ORIGINAL-ZEICHNUNGEN / VON J. BUCHNER, J. KÖCKERT, G. OSTERWALD ...
Gallerie zur Cotta-Göschen'schen Volks-Bibliothek der Deutschen Klassiker : Göthe, Schiller, Klopstock, Lessing, Wieland, Platen, Thümmel, Pyrker und Lenau ; 144 Stahlstiche nach Original-Zeichnungen / von J. Buchner, J. Köckert, G. Osterwald ... (1)
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