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Journal articlevan de Berg D, Shah N, del Rio-Chanona EA, 2024,
Hierarchical planning-scheduling-control — Optimality surrogates and derivative-free optimization
, Computers and Chemical Engineering, Vol: 188, ISSN: 0098-1354Planning, scheduling, and control typically constitute separate decision-making units within chemical companies. Traditionally, their integration is modelled sequentially, but recent efforts prioritize lower-level feasibility and optimality, leading to large-scale, potentially multi-level, hierarchical formulations. Data-driven techniques, like optimality surrogates or derivative-free optimization, become essential in addressing ensuing tractability challenges. We demonstrate a step-by-step workflow to find a tractable solution to a tri-level formulation of a multi-site, multi-product planning-scheduling-control case study. We discuss solution tractability-accuracy trade-offs and scaling properties for both methods. Despite individual improvements over conventional heuristics, both approaches present drawbacks. Consequently, we synthesize our findings into a methodology combining their strengths. Our approach remains agnostic to the level-specific formulations when the linking variables are identified and retains the heuristic sequential solution as fallback option. We advance the field by leveraging parallelization, hyperparameter tuning, and a combination of off- and on-line computation, to find tractable solutions to more accurate multi-level formulations.
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Journal articleSmith A, Hampson G, Krevor S, 2024,
Global analysis of geological CO2 storage by pressure-limited injection sites
, International Journal of Greenhouse Gas Control, Vol: 137, ISSN: 1750-5836Limiting global warming to a 2 °C rise may require large-scale deployment of carbon capture and storage (CCS). Due to the key role CCS plays in integrated assessment models of climate change mitigation, it is important that fundamental physical constraints are accounted for. We produce a global estimate of CO2 storage resource that accounts for pressure-limits within basin-scale reservoir systems. We use a dynamic physics model of reservoir pressurisation that is sufficiently simple to be incorporated into energy systems models. Our estimates address regionally inconsistent methodologies and the general lack of consideration for pressure limitations in global storage resource estimates. We estimate a maximum pressure-limited resource base and explore scenarios with different injection patterns, and scenarios where the extent of CCS deployment is limited by the history of regional hydrocarbon exploration and the readiness of countries for deployment. The maximum pressure-limited global storage achievable after thirty years of injection is 3640GtCO2 (121GtCO2yr-1), increasing to 5630GtCO2 (70 GtCO2yr-1) at the end of the century. These represent an update to volumetric-based estimates that suggest in excess of 10,000Gt of storage resource available. When CCS deployment is limited to the top ten countries ranked by the GCCSI Storage Readiness Index, our maximum storage estimate decreases to 780GtCO2 (26GtCO2yr-1) at the mid-century and 1177GtCO2 (15GtCO2yr-1) at the end of the century. These latter results fall within the range of projected deployment by the IPCC and IEA and suggest that reservoir pressurisation will limit CCS deployment if development does not rapidly expand beyond the current implementation.
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Journal articleZhang Y, Jackson C, Krevor S, 2024,
The feasibility of reaching gigatonne scale CO<sub>2</sub> storage by mid-century
, NATURE COMMUNICATIONS, Vol: 15 -
Journal articleSendi M, Bui M, Mac Dowell N, et al., 2024,
Geospatial techno-economic and environmental assessment of different energy options for solid sorbent direct air capture
, CELL REPORTS SUSTAINABILITY, Vol: 1- Cite
- Citations: 9
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Journal articleWard A, Pini R, 2024,
Design and performance evaluation of multi-sorbent vacuum-swing adsorption processes for post-combustion carbon capture
, Industrial and Engineering Chemistry Research, Vol: 63, Pages: 13787-13800, ISSN: 0888-5885We present the design and performance evaluation of a novel multisorbent process for CO2/N2 separation based on vacuum-swing adsorption (VSA). We study two process configurations: (i) layered-bed processes, wherein two distinct adsorbent materials are arranged in sequential layers within the adsorption bed, and (ii) mixed-bed processes, wherein two distinct adsorbent materials are homogeneously mixed within the adsorption bed. We develop, validate, and deploy a high-fidelity dynamic adsorption column model for the multisorbent process configurations and apply Bayesian optimization to design processes that achieve maximum separation effectiveness in terms of CO2 purity and recovery with an application to postcombustion carbon capture (PCC) on a coal-fired power plant. We find that the multisorbent process configurations achieve improved CO2/N2 separation effectiveness compared to benchmark classical single-adsorbent processes, increasing the CO2 recovery by up to 5% while achieving high CO2 purity. When operating in compliance with widely adopted performance targets for PCC (PuCO2 ≥ 95%, ReCO2 ≥ 90%), we find that the multisorbent process configurations reduce the energy usage of the separation by approximately 35%. We use the modeling framework to analyze the subcolumn scale adsorption dynamics and identify that the observed improvements in performance are associated with the positioning of the CO2 adsorption front under optimized operating conditions, leading to favorable dynamic interactions with the operation of the VSA process cycle.
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Journal articleRichter M, Trusler JPM, 2024,
Vibrating-wire viscometry
, International Journal of Thermophysics, Vol: 45, ISSN: 0195-928XThe theory and application of the vibrating-wire technique for the measurement of viscosity, as well as both viscosity and density, are reviewed. Theory is presented in the form of practical working equations and well-established limitations on their ranges of validity. The cases of both transient and steady-state excitation of the vibrating wire are considered in detail. For the steady-state mode, we describe a variant of the method in which the density is also measured. Practical details including wire materials, magnet systems and instrumentation are discussed, and several design examples from the literature are reviewed. Relative uncertainties in vibrating-wire viscometry vary from, at best, 0.2 % to about 2 % at 95 % confidence. In an appropriately designed instrument, density can be measured simultaneously with a relative uncertainty of about 0.2 %.
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Journal articleKucherenko S, Sopittakamol N, Shah N, 2024,
Design space identification of a coupled two-stage batch reactor system
, Computers and Chemical Engineering, Vol: 187, ISSN: 0098-1354The design space (DS) is defined as the combination of materials and process conditions that guarantees the assurance of quality. This principle ensures that as long as a process operates within DS, it consistently produces a product that meets specifications. It was originally developed for a single unit system. Many industrial processes frequently involve multiple unit operations. Assessing the interaction of Critical Process Parameters (CPPs) with Critical Quality Attributes (CQAs) across stages enables informed decision-making and the capacity to balance different requirements. Analysis and visualization of the complex, multi-dimensional DS is a challenging task. This paper presents a framework for identification such DSs, considering both joint and decoupled strategies using a detailed analysis of a two-stage batch reactor case study. We assess and discuss the practicality and relevance of these methods.
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Journal articleStreb A, Danaci D, Lively R, et al., 2024,
Towards carbon neutral scientific societies:a case study with the International Adsorption Society
, Adsorption, Vol: 30, ISSN: 0929-5607 -
Journal articleLeonzio G, Hankin A, Shah N, 2024,
CO2 electrochemical reduction: a state-of-the-art review with economic and environmental analyses
, Chemical Engineering Research and Design, Vol: 208, Pages: 934-955, ISSN: 0263-8762The electrochemical reduction of carbon dioxide is an emerging strategy to reduce emissions, allowing the storage of renewable energy and the electrification of the chemical industry according to the principle of carbon dioxide utilization. Valuable fuels and chemical commodities can be obtained by ensuring a closed carbon loop and the main important products are carbon monoxide, formic acid, methanol, methane, ethylene, ethanol, and propanol. Inside this context, here, we explore the state-of-the-art of carbon dioxide electrolysis technologies, showing that efforts have been put into the development of reactor cell architectures and catalysts able to provide high selectivity and efficiency. New insights are currently about the study of reaction mechanisms, optimization of cell design, and development of more performing electro-catalysts. Moreover, an overview of economic and environmental studies based on carbon dioxide electrochemical reduction is conducted in this work and a preliminary screening based on the levelized production cost and climate change impact of several products obtained through carbon dioxide electrochemical reduction is proposed for a large-scale plant. Today, carbon monoxide and formic acid are the primary carbon dioxide reduction product targets from an economic point of view. In the future, production costs are expected to decrease, and other low-carbon products could be competitive with market prices. Renewable energy sources and carbon dioxide with a low carbon footprint contribute to an environmentally friendly electrochemical production process.
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Journal articleBakkaloglu S, Mersch M, Sunny N, et al., 2024,
The role of negative emissions technologies in the UK’s net-zero strategy
, Cell Reports Sustainability, Vol: 1, ISSN: 2949-7906The role of negative emissions technologies (NETs) in climate change mitigation remains contentious. Although numerous studies indicate significant carbon dioxide removal (CDR) requirements for Paris Agreement mitigation goals to be achieved, others point out challenges and risks associated with high CDR strategies. Using a multiscale modeling approach, we explore NETs’ potential for a single country, the United Kingdom (UK). Here, we report that the UK has cost-effective potential to remove 79 MtCO2 per year by 2050, rising to 126–134 MtCO2 per year with well-integrated NETs in industrial clusters. Results highlight that biomass gasification for hydrogen generation with CCS is emerging as a key NET, despite biomass availability being a limiting factor. Moreover, solid DACCS systems utilizing industrial waste heat integration offer a solution to offsetting increases in demand from transportation and industrial sectors. These results emphasize the importance of a multiscale whole-systems assessment for integrating NETs into industrial strategies.
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Journal articleDriver JG, Bernard E, Patrizio P, et al., 2024,
Global decarbonization potential of CO2 mineralization in concrete materials
, Proceedings of the National Academy of Sciences of USA, Vol: 121, ISSN: 0027-8424CO2 mineralization products are often heralded as having outstanding potentials to reduce CO2-eq. emissions. However, these claims are generally undermined by incomplete consideration of the life cycle climate change impacts, material properties, supply and demand constraints, and economic viability of CO2 mineralization products. We investigate these factors in detail for ten concrete-related CO2 mineralization products to quantify their individual and global CO2-eq. emissions reduction potentials. Our results show that in 2020, 3.9 Gt of carbonatable solid materials were generated globally, with the dominant material being end-of-life cement paste in concrete and mortar (1.4 Gt y–1). All ten of the CO2 mineralization technologies investigated here reduce life cycle CO2-eq. emissions when used to substitute comparable conventional products. In 2020, the global CO2-eq. emissions reduction potential of economically competitive CO2 mineralization technologies was 0.39 Gt CO2-eq., i.e., 15% of that from cement production. This level of CO2-eq. emissions reduction is limited by the supply of end-of-life cement paste. The results also show that it is 2 to 5 times cheaper to reduce CO2-eq. emissions by producing cement from carbonated end-of-life cement paste than carbon capture and storage (CCS), demonstrating its superior decarbonization potential. On the other hand, it is currently much more expensive to reduce CO2-eq. emissions using some CO2 mineralization technologies, like carbonated normal weight aggregate production, than CCS. Technologies and policies that increase recovery of end-of-life cement paste from aged infrastructure are key to unlocking the potential of CO2 mineralization in reducing the CO2-eq. footprint of concrete materials.
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Journal articleChen Q, Trusler JPM, 2024,
Solubility of CO in water and NaCl(aq) at high pressures
, Chemical Engineering Science, Vol: 293, ISSN: 0009-2509Experimental measurements of CO solubility in water and in NaCl(aq) solutions are reported at temperatures, pressures and salt molalities of relevance to geological carbon storage: (323.15 to 423.15) K, (2 to 28) MPa and (2 and 4) mol·kg−1, respectively. The expanded relative uncertainty of the CO solubility is estimated to be 4.4% at 95% confidence intervals. This study provides the first data for CO solubility in brine with high molality of salt. The results from this study were used to develop simple models for the solubility of CO in aqueous NaCl solutions as a function of temperature, pressure and salt molality dependent, up to 4 mol·kg−1.
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Journal articleSachio S, Ward A, Pini R, et al., 2024,
Operability-economics trade-offs in adsorption-based CO2 capture processes
, Communications Engineering, Vol: 3, ISSN: 2731-3395Dispatchable low-carbon power underpins the transition to a sustain16 able energy system, providing balancing load for the integration of intermittent renewable power. In such load-following operation, the post-combustion carbon capture process must be capable of highly transient operation. Here we have developed a computational frame work that integrates process design, operability and techno-economicassessment of a pressure-vacuum swing adsorption process for CO2 capture. We demonstrate that the cost-optimal design has limited process flexibility, challenging reactiveness to disturbances in the flue gas conditions. Flexibility can be introduced by relaxing the CO2 recovery constraint on the operation, albeit at the expense of thecapture efficiency of the process. We discover that adsorption-based processes can be designed to enhance flexibility, while improving per formance with respect to the operational constraints on CO2 recovery and purity. The results herein demonstrate a trade-off between process economics and process operability, which must be ratio nalised to integrate CO2 capture units in low-carbon energy systems.
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Book chaptervan de Berg D, Shah N, del Rio-Chanona A, 2024,
High-dimensional derivative-free optimization via trust region surrogates in linear subspaces
, Computer Aided Chemical Engineering, Publisher: Elsevier, Pages: 3193-3198, ISBN: 9780443288241Maintaining the benefits of derivative-free optimization in higher-dimensional decision spaces presents challenges for existing optimization methods. We introduce CUATRO_PLS - an extension of the CUATRO quadratic trust region optimizer that leverages intrinsic structures across high-dimensional black-box variables. CUATRO_PLS shows competitive convergence with leading derivative-free optimization algorithms in three high-dimensional chemical engineering case studies even in the absence or underestimation of known intrinsic dimensionality and is significantly faster than other model-based derivative-free optimization algorithms.
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Journal articleBöckler H-B, de Huu M, Maury R, et al., 2024,
Metrology infrastructure for high-pressure gas and liquified hydrogen flows. A brief outline of the MetHyInfra project, measurement challenges, and first results
, Measurement, Vol: 232, ISSN: 0263-2241This paper gives an overview of the ongoing Joint Research Project (JRP) 20IND11 “Metrology infrastructure for high pressure gas and liquefied hydrogen flows” (MetHyInfra), which will ensure traceability in the hydrogen distribution chain. For this purpose, very precise nozzles with well-defined geometries have been produced. In this project, Critical Flow Venturi Nozzles (CFVNs) will be traceably calibrated for the first time with hydrogen and pressures up to 100 MPa using a Coriolis Flow Meter (CFM) as a secondary standard. A CFM has been successfully calibrated with hydrogen against a gravimetric primary standard.Equations of State (EoS) are important for the high-pressure calibration of the nozzles, but also for Computational Fluid Dynamics (CFD) simulations. With regard to CFD, a numerical model has been developed to simulate high pressure hydrogen flow in the CFVN. In a parameter study, non-ideal nozzle shapes are investigated using a shape variation parameter. New Speed of Sound (SoS) measurements were conducted at temperatures from 273 to 323 K and pressures from 1 to 100 MPa. These new data were then used to develop a new EoS for normal hydrogen, optimized for gas phase calculations. In addition to gaseous hydrogen, the project has a strong focus on liquefied hydrogen. Here a three-pronged approach allows traceable measurements. Each of the approaches presented is based on a unique flow calibration principle and relies on independent traceability schemes. The results of the project will ensure traceable measurements and thus a higher level of confidence among end users.
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Journal articleWensink G, Mosalman MKS, Geurts P, et al., 2024,
In-situ 3D measurements of water films on the natural grain surface of porous rocks
, ADVANCES IN WATER RESOURCES, Vol: 188, ISSN: 0309-1708 -
Book chapterKucherenko S, Shah N, Zaccheus O, 2024,
Application of active subspaces for model reduction and identification of design space
, Large-Scale Scientific Computations, Editors: Lirkov, Margenov, Publisher: Springer Nature Switzerland AG, Pages: 412-418, ISBN: 978-3-031-56207-5The design space is defined as the combination of materials and process conditions which provides assurance of quality. Identification of the design space is a computationally demanding task especially in high dimensional settings. The active subspaces method is a technique that identifies the most important directions in the parameter space, enabling significant dimension reduction. We show how to apply the active subspaces method for model reductions and identification of design space. The results of constraint global sensitivity analysis match those obtained with the active subspaces method for the considered test case.
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Journal articleFirth AEJ, Nakasu PYS, Fennell PS, et al., 2024,
An Ionic Liquid-Based Biorefinery Approach for Duckweed Utilization.
, ACS Sustain Resour Manag, Vol: 1, Pages: 842-856This study establishes a foundation for the ionic liquid (IL) pretreatment of duckweed biomass. An optimized IL-based process was designed to exploit the unique properties of duckweed including efficient metal removal, potential starch accumulation, and protein accumulation. Two ILs, namely, dimethylethanolammonium formate ([DMEtA][HCOO]) and N,N-dimethylbutylammonium hydrogen sulfate ([DMBA][HSO4]), were investigated for the pretreatment of two duckweed species (Spirodela polyrhiza and Lemna minor). The evaluation focused on starch recovery, sugar release, protein recovery, and metal extraction capabilities. [DMEtA][HCOO] demonstrated near-quantitative starch recoveries at 120 °C, while [DMBA][HSO4] showed similar performance at 90 °C within a reaction time of 2 h. Saccharification yields for most pulps exceeded 90% after 8 h of hydrolysis, outperforming "traditional" lignocellulosic biomasses such as miscanthus or sugarcane bagasse. Approximately 50 and 80 wt % of the protein were solubilized in [DMEtA][HCOO] and [DMBA][HSO4], respectively, while the remaining protein distributed between the pulp and lignin. However, the solubilized protein in the IL could not be recovered due to its low molecular weight. Regarding metal extraction, [DMEtA][HCOO] demonstrated higher efficiency, achieving 81% removal of Ni from Lemna minor's pulps, whereas [DMBA][HSO4] extracted only 28% of Ni with slightly higher pulp concentrations. These findings indicate the need for further optimization in concurrent metal extraction using ILs.
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Journal articleWu Y, An S, Tahmasebi P, et al., 2024,
An end-to-end approach to predict physical properties of heterogeneous porous media: Coupling deep learning and physics-based features (vol 352, 128753, 2023)
, FUEL, Vol: 364, ISSN: 0016-2361 -
Journal articleSharifzadeh M, Cooper N, van't Noordende H, et al., 2024,
Operational strategies and integrated design for producing green hydrogen from wind electricity
, International Journal of Hydrogen Energy, Vol: 64, Pages: 650-675, ISSN: 0360-3199Realizing the potential of renewable hydrogen production requires flexible operation of electrolysis systems to integrate with intermittent power sources. This work develops an optimization model to assess flexible operational strategies for alkaline and proton exchange membrane (PEM) electrolysers powered by wind energy. The model quantitatively analyses trade-offs between electrolyser shutdown strategies, overloading capacities, and battery integration to identify optimal regimes balancing efficiency, flexibility, and economics. The results reveal a mixed-integer linear programming approach can optimize system configurations and control strategies to minimize the levelized cost of hydrogen production. Optimal near-minimum load operation is achieved by independently optimizing the load of each electrolyser block, while avoiding shutdowns above a critical load level. Strategic electrolyser overloading can provide economic benefits by reducing installed capital costs, if technical feasibility and accelerated degradation are addressed. Battery energy storage integration significantly improves economics by enhancing asset utilization, provided excess renewable energy is available. The model provides novel insights on integrating alkaline and PEM electrolysis with intermittent wind power to advance renewable hydrogen production. Quantifying trade-offs between operational flexibility and economics will help guide flexible design and control strategies for cost-optimal renewable electrolysis systems.
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Journal articleLiyanage R, Fu X, Pini R, et al., 2024,
Direct comparison of density-driven convective mixing in a three-dimensional porous medium using experiments and simulation
, PHYSICAL REVIEW FLUIDS, Vol: 9, ISSN: 2469-990X -
Journal articleXie M, Zhou M, Chen L, et al., 2024,
Techno-economic assessment of the modified Allam cycle configurations with multi-stage pump/compressor for efficient operation in hot regions
, Energy Conversion and Management, Vol: 306, ISSN: 0196-8904The Allam cycle is renowned for its zero-carbon power generation and high efficiency. However, it faces challenges in hot regions where there is no available cold source for carbon dioxide liquefaction, leading to deterioration in its performance. In this study, a multi-stage pump/compressor is introduced, aiming to enhance the net electric efficiency of the conventional Allam cycle. Various potential enhancement methods are explored and analyzed through comprehensive thermodynamic and economic analyses. Among the configurations under consideration, the Allam cycle combined with two-stage pump/compressor and bypass compressor exhibits the best performance, achieving a 6.71 % increase in the efficiency of the conventional cycle. For the conventional Allam cycle, the efficiency decreases by 0.42 % for every 1 ℃ increase in ambient temperature, however, it is 0.17 % for the Allam-MPC cycle, which indicates it is less responsive to changes in ambient temperature. Moreover, the economic performance of the proposed cycle is better than that of the conventional cycle, which has higher revenue and lower levelized cost of electricity. The capital costs of the modified equipment represent around 1.43 % of the total capital costs of the conventional Allam cycle, and the investment-increment payback period is less than 0.5 years when the ambient temperature exceeds 30 ℃. Sensitivity analyses suggest that the proposed cycle will be more economically viable in hot regions with lower natural gas prices and higher electricity prices. Overall, this study provides a promising approach to improving the performance of Allam cycle in hot regions and offering valuable references for its practical implementation.
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Journal articleLeonzio G, Shah N, 2024,
Recent advancements and challenges in carbon capture, utilization and storage
, Current Opinion in Green and Sustainable Chemistry, Vol: 46, ISSN: 2452-2236This short paper suggests a review of the latest developments and current challenges associated with carbon dioxide capture, utilization and storage. Recent research has been conducted to reduce energy consumption, costs, and improve efficiency. In carbon dioxide capture, catalysts have been added to solvents while new membranes and sorbent materials have been investigated. In mineral carbon dioxide storage, studies have been carried out to improve reaction rates. Regarding the utilization path, attention has been focused on the development of sustainable chemicals (mainly based on electrochemical conversion), biochemical routes and power generation. Considering the respective challenges, future efforts should be focused toward the optimization of these systems at all levels, in addition to a public acceptance and new policies and regulations for their spread.
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Journal articleMartin Trusler JP, 2024,
Measurement of diffusion coefficients in binary mixtures and solutions by the Taylor Dispersion method
, International Journal of Thermophysics, Vol: 45, ISSN: 0195-928XThe theory and application of the Taylor Dispersion technique for measuring diffusion coefficients in binary systems is reviewed. The theory discussed in this paper includes both the ideal Taylor–Aris model and the estimation of corrections required to account for small deviations from this ideal associated with a practical apparatus. Based on the theoretical treatment, recommendations are given for the design of practical instruments together with suggestions for calibration, data acquisition and reduction, and the rigorous estimation of uncertainties. The analysis indicates that relative uncertainties on the order of 1% are achievable in practice.
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Journal articleNyhus AH, Yliruka M, Shah N, et al., 2024,
Green ethylene production in the UK by 2035: a techno-economic assessment
, Energy and Environmental Science, Vol: 17, Pages: 1931-1949, ISSN: 1754-5692Olefins production in the UK is the most emission-intensive sector of the chemical industry. Bringing thermocatalytic and electrocatalytic processes together, this paper compares nine process routes for green ethylene production from air-captured CO2 and off-shore wind electricity in order to displace fossil-based ethylene, with a particular focus on technology readiness for near-future deployment. The methanol-mediated thermocatalytic route has the lowest projected levelised cost at £2900 per ton of ethylene by 2035, closely followed by direct and tandem CO2 electroreduction routes in the range £2900–3200. The price of green ethylene at three times or more its current market price is confirmed through a sensitivity analysis varying the levelised cost of electricity, stack cost, and market price of propylene or oxygen simultaneously. While these green ethylene production processes would be carbon negative from a cradle-to-gate viewpoint, displacing a conventional ethane cracker with annual production capacity of 800 kt could consume as much as 46–66 TW h of renewable electricity, which is a major barrier to deployment.
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Journal articleRovelli A, Brodie J, Rashid B, et al., 2024,
Effects of core size and surfactant choice on fluid saturation development in surfactant/Polymer corefloods
, Energy and Fuels, Vol: 38, Pages: 2844-2854, ISSN: 0887-0624Surfactant/polymer flooding allows for a significant increase in oil recovered at both laboratory and field scales. Limitations in application at the reservoir scale are, however, present and can be associated with both the complexity of the underlying displacement process and the time-intensive nature of the up-scaling workflow. Pivotal to this workflow are corefloods which serve to both validate the extent of oil recovery and extract modeling parameters used in upscaling. To enhance the understanding of the evolution of the saturation distribution within the rock sample, we present the utilization of X-ray computed tomography to image six distinct surfactant/polymer corefloods. In doing so, we visualize the formation and propagation of an oil bank by reconstructing multidimensional saturation maps. We conduct experiments on three distinct core sizes and two different surfactants, an SBDS/isbutanol formulation and an L-145-10s 90 formulation, in order to decouple the effect of these two parameters on the flow behavior observed in situ. We note that the oil production post oil bank breakthrough is primarily influenced by the surfactant choice, with the SDBS/isobutanol formulation displaying longer tailing production of a low oil cut. On the other hand, the core size dominated the extent of self-similarity of the saturation profiles with smaller cores showing less overlap in the self-similarity profiles. Consequently, we highlight the difference in applicability of a fractional flow approach to larger and smaller cores for upscaling parameter extraction and thus provide guidance for corefloods where direct imaging is not available.
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Journal articleLombardo G, Menegazzo D, Wedler C, et al., 2024,
Speed of sound measurements and correlation of {(1-x)3,3,3-trifluoropropene (HFO-1243zf) + x2,3,3,3-tetrafluoropropene (H FO-1234yf)} with x= (0.1582, 0.4625, 0.7623) at temperatures from 243.15 to 343.15 K and pressures up to 90 MPa
, International Journal of Thermophysics, Vol: 45, Pages: 142-142 -
Journal articleIbrahim D, Kis Z, Papathanasiou MM, et al., 2024,
Strategic Planning of a Joint SARS-CoV-2 and Influenza Vaccination Campaign in the UK
, Vaccines, Vol: 12, ISSN: 2076-393XThe simultaneous administration of SARS-CoV-2 and influenza vaccines is being carried out for the first time in the UK and around the globe in order to mitigate the health, economic, and societal impacts of these respiratory tract diseases. However, a systematic approach for planning the vaccine distribution and administration aspects of the vaccination campaigns would be beneficial. This work develops a novel multi-product mixed-integer linear programming (MILP) vaccine supply chain model that can be used to plan and optimise the simultaneous distribution and administration of SARS-CoV-2 and influenza vaccines. The outcomes from this study reveal that the total budget required to successfully accomplish the SARS-CoV-2 and influenza vaccination campaigns is equivalent to USD 7.29 billion, of which the procurement costs of SARS-CoV-2 and influenza vaccines correspond to USD 2.1 billion and USD 0.83 billion, respectively. The logistics cost is equivalent to USD 3.45 billion, and the costs of vaccinating individuals, quality control checks, and vaccine shipper and dry ice correspond to USD 1.66, 0.066, and 0.014, respectively. The analysis of the results shows that the choice of rolling out the SARS-CoV-2 vaccine during the vaccination campaign can have a significant impact not only on the total vaccination cost but also on vaccine wastage rate.
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Journal articleMutailipu M, Song Y, Yao Q, et al., 2024,
Solubility and interfacial tension models for CO₂–brine systems under CO₂ geological storage conditions
, Fuel, Vol: 357, Pages: 1-15, ISSN: 0016-2361Thermodynamic properties of the CO2–brine pseudo-binary system are essential for the design of geological carbon storage (GCS) projects, especially those utilizing saline aquifers. The gas–liquid–solid interactions manifest in the interfacial tensions (IFTs) and contact angle determine the injectability, sealing capacity, and storage security of the GCS process. Dissolution of CO2 in the reservoir brine occurs throughout the entire GCS process, leading to enhanced storage capacity but also to acidification of the brine, possibly leading to reservoir or seal damage. Two of the most important thermodynamic properties of the fluids are the mutual solubility and the IFT of the CO2–brine pseudo-binary system. In this work, we report a new correlative model for the IFT between CO2- and water-rich phases over wide ranges of temperature (273 to 473 K) and pressure (up to 100 MPa). The model is parameterized for brines comprising any combinations of sodium, potassium, calcium and magnesium cations with chloride, sulphate and bicarbonate anions up to a total molality of at least 5 mol·kg−1. The independent variables in this new model are reduced temperature, ion molalities and the mole fraction of CO2 dissolved in the aqueous phase. The latter is related to temperature, pressure and ion molalities by an improved model for the mutual solubility. More than 2000 experimental data points were used in the development of the two models. For the IFT of the CO2-H2O binary system, the overall root-mean-square deviation (RMSD) is 0.65 mN·m−1 while the absolute average relative deviation (AARD) is 1.8%. In the case of mutual solubility, the RMSD of CO2 mole fraction in the aqueous phase is 0.0003 and the AARD is 5.5% while, in the non-aqueous phase, the RMSD of H2O mole fraction is 0.0035 and the corresponding AARD is 8.7%. Similar results are found for the CO2-brine systems.
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Journal articleRuffine L, Trusler JPM, 2024,
Corrigendum to “Phase behaviour of mixed-gas hydrate systems containing carbon dioxide” [J. Chem. Thermodyn. 42 (2010) 605–611]
, The Journal of Chemical Thermodynamics, Vol: 189, ISSN: 0021-9614
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