| 1. |
- Limleamthong, P., et al.
(författare)
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Multi-criteria screening of chemicals considering thermodynamic and life cycle assessment metrics via data envelopment analysis: application to CO2 capture
- 2016
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 18:24, s. 6468-6481
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Tidskriftsartikel (refereegranskat)abstract
- With the growing trend of incorporating sustainability principles in the chemical industry, there is a clear need to develop decision-making tools to quantify and optimise the sustainability level of chemical products and processes. In this study, we propose a systematic approach based on Data Envelopment Analysis (DEA) for the multi-criteria screening of molecules according to techno-economic and environmental aspects. The main advantage of our method is that it does not require any articulation of preferences via subjective weighting of the assessment criteria. Furthermore, our approach identifies the most efficient chemicals (according to some sustainability criteria) and for the ones found to be inefficient it establishes in turn improvement targets that can be used to guide research efforts in green chemistry. Our method was applied to the screening of 125 amine-based solvents for CO2 capture considering 10 different performance indicators, which are relevant to technical, health, safety and environmental aspects, including CO2 solubility, molar volume, surface tension, heat capacity, viscosity, vapour pressure, mobility, fire & explosion, acute toxicity and Eco-indicator 99. Our approach eliminates 36% of the solvents (as they are found to be inefficient), identifies the main sources of inefficiency (e.g., properties displaying poor values that should be improved) and ranks the best chemicals according to an objective criterion that does not rely on weights. Overall, our proposed DEA-based framework offers insightful guidance to make chemicals more sustainable.
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| 2. |
- Limleamthong, P., et al.
(författare)
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Screening of Solvents for CO2 Capture considering Sustainability Criteria via Data Envelopment Analysis
- 2017
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Ingår i: Computer Aided Chemical Engineering. - 1570-7946. ; , s. 2011-2016
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The growing trend towards the development of more sustainable chemical products and processes has created a clear need for decision-support tools to evaluate and optimise the sustainability level of a system. In this work, we propose a new methodology to screen and select chemicals according to the extent to which they adhere to sustainability principles that is based on Data Envelopment Analysis (DEA), a technique developed in economics for efficiency assessment. The capabilities of the DEA-based approach in the context of computer aided process engineering are demonstrated through the screening of 125 conventional amine-based solvents for CO 2 capture according to 10 performance indicators, considering technical (economic), environmental and social aspects simultaneously. Our approach eliminates 36% of the solvents (those found inefficient), and establishes in turn quantitative targets and clear guidelines on how to improve them. The DEA models are capable of identifying the practical downsides of amines as main sources of inefficiency, providing clear improvement targets for properties such as vapour pressure, acute toxicity and several life cycle impacts. The final aim of the DEA-based analysis is to facilitate the selection of more sustainable chemicals in the transition towards a more sustainable chemical industry.
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| 3. |
- Efstathiadis, T., et al.
(författare)
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Geometry Optimization of Power Production Turbine For A Low Enthalpy (<= 100 degrees C) ORC System
- 2015
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 75, s. 1624-1630
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Tidskriftsartikel (refereegranskat)abstract
- The present paper is examining the geometry optimization of a power production turbine, in the range of 100kW(el), for a low enthalpy Organic Rankine cycle system (<= 100 degrees C). In the last years, accelerated consumption of fossil fuels has caused many serious environmental problems such as global warming, ozone layer destruction and atmospheric pollution. It is this reason that a growing trend towards exploiting low-enthalpy content energy sources has commenced and led to a renewed interest in small-scale turbines for Organic Rankine Cycle applications. The design concept for such turbines can be quite different from either standard gas or steam turbine designs. The limited enthalpic content of many energy sources imposes the use of organic working media, with unusual properties for the turbine. A versatile cycle design and optimization requires the parameterization of the main turbine design. There are many potential applications of this power-generating turbine, including geothermal and concentrate solar thermal fields or waste heat of steam turbine exhausts. An integrated model of equations has been developed, thus creating a model to assess the performance of an organic cycle for various working fluids such as R134a and isobutane-isopentane mixture. The most appropriate working fluid has been chosen, taking its influence on both cycle efficiency and the specific volume ratio into consideration. This choice is of particular importance at turbine extreme operating conditions, which are strongly related to the turbine size. In order to assess the influence of various design parameters, a turbine design tool has been developed and applied to define the geometry of blades in a preliminary stage. Finally, as far as the working fluid is concerned, the mixture of 85% isopentane-15% isobutane has been chosen as the most suitable fluid for the low enthalpy ORC system, since its output net power is 10% higher compared to the output net power of R134a.
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| 4. |
- Grane, P, et al.
(författare)
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Septic and aseptic post-operative discitis in the lumbar spine--evaluation by MR imaging
- 1998
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Ingår i: Acta radiologica (Stockholm, Sweden : 1987). - : SAGE Publications. - 0284-1851 .- 1600-0455. ; 39:2, s. 108-115
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: the aim of this study was to determine whether it was possible to differentiate septic from aseptic post-operative discitis in the lumbar spine by means of MR imaging Material and Methods: the study was a retrospective evaluation of 12 patients with prior lumbar discectomy and suspected post-operative discitis displaying low-back pain and typical MR findings. Six patients had elevated serum C-reactive protein (CRP) (septic) and 6 had normal CRP (aseptic). We used MR imaging to assess the distribution and degree of changes in the disc, in adjacent bone marrow, and in surrounding soft tissue Results: of the 6 patients with increased CRP levels, 3 had extensive MR changes typical of septic post-operative discitis: 1 found soon after surgery; 2 found later. the other 3 patients with septic discitis, who were examined in the early post-operative period, showed MR changes similar to those in the 6 patients with aseptic discitis Conclusion: Suspicion of septic post-operative discitis should be confirmed by MR imaging, serum CRP, and disc puncture. MR imaging is not reliable as the sole method for distinguishing septic from aseptic discitis in the early post-operative stage
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| 5. |
- Papadopoulos, A. I., et al.
(författare)
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A Framework for the Integration of Holistic Sustainability Assessment in Computer-Aided Molecular Design
- 2019
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Ingår i: Computer Aided Chemical Engineering. - 1570-7946. ; , s. 13-18
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- We propose the integration of a holistic sustainability assessment framework in computer-aided molecular design (CAMD). The framework enables the assessment of life cycle (LCA) and safety, hazard and environmental (SHE) impacts from cradle-to-gate of chemicals designed through CAMD. It enables the calculation of an overall of 14 sustainability-related indices, with some of them aggregating several impact categories. Lack of models and data gaps in property prediction are addressed systematically through a data mining approach which exploits on-line similarity assessment with existing molecules for which data exist or can be predicted. The framework is implemented both simultaneously with CAMD or after CAMD to assess the designed solvents. A case study is presented on the design of phase-change solvents for chemisorption-based post-combustion CO2 capture. Results indicate that the proposed approach enables the identification of verifiably useful phase-change solvents which exhibit favourable performance trade-offs compared to a reference CO2 capture solvent.
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| 6. |
- Papadopoulos, A. I., et al.
(författare)
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An approach for simultaneous computer-aided molecular design with holistic sustainability assessment: Application to phase-change CO2 capture solvents
- 2020
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Ingår i: Computers and Chemical Engineering. - : Elsevier BV. - 0098-1354. ; 135
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Tidskriftsartikel (refereegranskat)abstract
- We propose an approach for the simultaneous consideration of a holistic sustainability assessment framework in computer-aided molecular design (CAMD). The framework supports the assessment of life cycle (LCA) and safety, hazard and environmental (EHS) impacts from cradle-to-gate of chemicals designed through CAMD. It enables the calculation of a total of 11 sustainability-related indicators, aggregating several impact categories. A lack of models and data gaps in property prediction are addressed through a data mining approach which deploys on-line similarity assessment against existing molecules. The LCA and EHS assessment are conducted simultaneously with CAMD or after CAMD to assess the designed solvents. A case study is presented on the design of phase-change solvents for chemisorption-based post-combustion CO2 capture. The proposed approach identifies verifiably useful phase-change solvents that exhibit favourable performance trade-offs compared to a reference CO2 capture solvent. The on-line use in CAMD of sustainability criteria favours the design of hydroxyl-containing solvents.
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| 7. |
- Papadopoulos, A. I., et al.
(författare)
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Molecular engineering of sustainable phase-change solvents: From digital design to scaling-up for CO 2 capture
- 2021
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 420:Part 2
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Tidskriftsartikel (refereegranskat)abstract
- Phase-change solvents promise reduced energetic and environmental footprints for separation systems, including absorption-based CO2 abatement technologies. The search for efficient phase-change solvents is limited by challenges in vapour-liquid–liquid equilibrium (VLLE) prediction and in sustainability assessment. We overcome these with a digital approach to screen billions of structures and design the novel phase-change solvent S1N (N1-cyclohexylpropane-1,3-diamine) and mixture S1N/DMCA (N,N-dimethylcyclohexylamine). Screening criteria include thermodynamic and process-related properties, reactivity and sustainability of solvent production and use. VLLE phase envelopes are predicted using the SAFT-γ Mie (Statistical Associating Fluid Theory) equation of state thanks to its transferability to any structure and the implicit modelling of ionic species. Experimental validation confirms the suitability of S1N/DMCA for scaling-up, with a cyclic capacity of 1.19 mol CO2/ kg-solvent, a regeneration energy of 2.3 GJ/ton-CO2, and vapour losses and viscosity lower by 10% and 70% than those of other solvents. S1N is also safer for plant operation and working personnel.
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| 8. |
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| 9. |
- Shavalieva, Gulnara, 1987, et al.
(författare)
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Environmental, health and safety assessment of post-combustion CO2 capture processes with phase-change solvents
- 2021
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Ingår i: Sustainable Production and Consumption. - : Elsevier BV. - 2352-5509. ; 25, s. 60-76
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Tidskriftsartikel (refereegranskat)abstract
- A class of solvents for chemisorption-based CO2 capture, phase-change solvents, promises significant energy reductions due to liquid-liquid phase separation and partial solvent recycling before CO2 desorption. Although energy consumption is a critical aspect of the CO2 capture process sustainability, a holistic evaluation of health, safety, and environmental impacts is required to confirm the beneficial performance of processes employing phase-change solvents compared to conventional alternatives. This study outlines a method for combining the life cycle and environmental, health and safety hazard assessment. The method is applied for the first time on processes employing two different exemplary phase-change solvents, a reference aqueous solution of methylcyclohexylamine (MCA) and a novel mixture of cyclohexylpropane-1,3-diamine (S1N) and dimethylcyclohexylamine (DMCA). The results show that phase-change solvents have the potential to be a better alternative to conventional amine (i.e., MEA) solvent systems due to the reduced reboiler duty and lower impact on the environment. However, additional care might need to be taken to prevent the potential accumulation of the carcinogenic nitrosamines in the system.
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| 10. |
- Shavalieva, Gulnara, 1987, et al.
(författare)
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Sustainability analysis of phase-change solvents for post-combustion CO2 capture
- 2019
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Ingår i: Chemical Engineering Transactions. - 2283-9216. ; 76, s. 1045-1050
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Tidskriftsartikel (refereegranskat)abstract
- Phase-change solvents is a solution to the energy penalty problem of post-combustion CO2 capture. While the improved thermodynamic performance of processes using phase-change solvents is previously demonstrated, there is no research done on the environmental and health aspects of such processes. The purpose of this study is to bridge this gap with the help of combined life cycle and safety, health and environment hazard assessment. In terms of life cycle analysis, steam for the reboiler, CO2 compression for transport and electricity consumption by the flue gas blower are the main contributors to the impact, however, in comparison with the conventional solvents, phase-change solvents will require additional electricity and reclaimer steam input due to phase-separation and potential increase of degradation compounds, the overall energy requirement is, however, smaller. The assessment indicated that phase-change solvent systems may experience additional problems of accumulation of harmful solvent degradation products due to the design of the process. The study highlights that in comparison with the conventional systems, phase-change solvent process might require additional safety equipment, but the overall environmental and health impact of the system is expected to be lower.
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