Publications
677 results found
Leonzio G, Fennell PS, Shah N, 2022, Air-source heat pumps for water heating at a high temperature: State of the art, Sustainable Energy Technologies and Assessments, Vol: 54, Pages: 1-22, ISSN: 2213-1388
Concerns about climate changes are urging the decarbonisation of the energy sector and heat pumps are evaluated for this purpose here. About half of total energy consumption is caused by heating, and the use of heat pumps for this aim is gaining the attention of the research community.This work shows a comprehensive overview of air-source heat pumps used for water heating at a high temperature, with a particular aim to add the supplied heat into the air capture cycle. Air-source heat pumps use different cycles. The literature analysis shows that high temperatures (up to 90 °C) can be easily achieved by trans-critical cycles, while innovative schemes based on heat recuperative solutions might provide hot water up to 99 °C. Very few studies have been conducted about absorption cycles, although these can potentially ensure higher temperatures for the supplied water (up to 115 °C).Although real industrial air source heat pumps achieve a water temperatures lower than those reported above, their utilization is encouraged because, even at high temperatures (up to 100 °C), there are primary energy consumption, cost and carbon dioxide emission savings compared to a traditional boiler, especially when the renewable electricity is used.
Al-Mufachi NA, Shah N, 2022, The role of hydrogen and fuel cell technology in providing security for the UK energy system, Energy Policy, Vol: 171, Pages: 1-13, ISSN: 0301-4215
It is not yet well understood how hydrogen and fuel cell technology could perform in the UK energy system (ES) and what influence it may have in contributing towards its security. This article aims to discuss the potential of a hydrogen economy examining its ability to reduce dependency on fossil fuels sourced both domestically and internationally. A snapshot of the hydrogen economy is presented introducing the latest development in hydrogen production technologies and distribution infrastructure. It has been postulated that with the introduction of a CO2 tax, integrating carbon capture and sequestration (CCS) systems with commercial hydrogen production technologies such as steam methane reforming (SMR), coal gasification (CG) and biomass gasification could significantly reduce the levelised cost of hydrogen (LCOH) production. The role of hydrogen and fuel cell technology in coupling the building, transport and industrial sectors has been demonstrated. Decarbonisation of heat in the UK is expected to incur a large cost for transitioning the incumbent network and it is expected that government assistance will be necessary to lessen the burden on consumers. Deployment of fuel cell combined heat and power (CHP) systems and integration into the UK ES could make great strides towards improving its security.
Küng L, Strunge T, Sunny N, et al., 2022, An Open-Source Toolkit to Design and Evaluate Net-Zero Pathways for Industrial Clusters
Triantafyllou N, Bernardi A, Lakelin M, et al., 2022, A digital platform for the design of patient-centric supply chains, Scientific Reports, Vol: 12, ISSN: 2045-2322
Chimeric Antigen Receptor (CAR) T cell therapies have received increasing attention, showing promising results in the treatment of acute lymphoblastic leukaemia and aggressive B cell lymphoma. Unlike typical cancer treatments, autologous CAR T cell therapies are patient-specific; this makes them a unique therapeutic to manufacture and distribute. In this work, we focus on the development of a computer modelling tool to assist the design and assessment of supply chain structures that can reliably and cost-efficiently deliver autologous CAR T cell therapies. We focus on four demand scales (200, 500, 1000 and 2000 patients annually) and we assess the tool’s capabilities with respect to the design of responsive supply chain candidate solutions while minimising cost.
Ordonez DF, Halfdanarson T, Ganzer C, et al., 2022, Evaluation of the potential use of e-fuels in the European aviation sector: a comprehensive economic and environmental assessment including externalities, SUSTAINABLE ENERGY & FUELS, Vol: 6, Pages: 4749-4764, ISSN: 2398-4902
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- Citations: 2
Daniel S, Kis Z, Kontoravdi K, et al., 2022, Quality by design for enabling RNA platform production processes, Trends in Biotechnology, Vol: 40, Pages: 1213-1228, ISSN: 0167-7799
RNA-based products have emerged as one of the most promising and strategic technologies for global vaccination, infectious disease control and future therapy development. The assessment of critical quality attributes, product-process interactions, relevant process analytical technologies, and process modeling capabilities can feed into a robust Quality by Design (QbD) framework for future development, design and control of manufacturing processes. Its implementation will help the RNA technology to reach its full potential and will be central in the development, pre-qualification and regulatory approval of rapid response, disease-agnostic RNA platform production processes.
Leonzio G, Fennell PS, Shah N, 2022, Modelling and analysis of direct air capture systems in different locations, Chemical Engineering Transactions, Vol: 96, Pages: 1-6, ISSN: 1974-9791
Direct air capture is an important negative emission technology with the aim to reduce carbon dioxide emissions in the atmosphere and to face the current environmental problems such as global warming and climate change. This emerging technology can be based on an adsorption system affected by the used sorbent (physisorbents or chemisorbents). Efficiencies can be measured through the use of key performance indicators that allow a comparison among different processes. An independent analysis was conducted in our previous research to evaluate key performance indicators (total cost, energy consumption, environmental impact and capture capacity) for a direct air capture system based on adsorption using different sorbents (three metal organic frameworks and two amine functionalized sorbents). In this research, the same analysis was extended to several Countries around the world, changing the ambient air temperature according to the yearly average value of the location. Results show that by increasing the air temperature, the adsorption capacity decreases, in a more significant way for metal organic frameworks compared to amine functionalized sorbents. An opposite effect is for energy consumption. Moreover, by increasing the ambient air temperature, a higher environmental impact (in terms of climate change) is present. A trend with the air temperature was not found for total costs. Overall, locations with lower ambient air temperatures are preferred due to a lower environmental impact and energy consumption.
Acha Izquierdo S, vieira G, Bird M, et al., 2022, Modelling UK electricity regional costs for commercial buildings, Energy and Buildings, Vol: 271, Pages: 1-15, ISSN: 0378-7788
Motivated by rising electricity prices UK non-domestic consumers are being required to develop smart energy management practices. However, most of these consumers lack awareness of the spatial-temporal dynamics of electricity prices and their tariff components. To help overcome these barriers and contribute to energy prices digitalisation, this paper presents a Modelling UK Electricity Regional Costs (MUKERC) framework. A bottom-up methodology that defines all the tariff components and then aggregates them to quantify the cost of a kWh across each half-hour of the day. The framework not only facilitates understanding which tariffs components have a higher impact during different time periods but also depicts how they vary spatially across regions. This model was used to estimate and analyse the evolution of electricity costs from 2017 to 2024. Case studies from buildings in the education sector are showcased depicting their energy costs derived from their load profiles. Results show that the London area has the lowest average prices, while the Northern Wales & Merseyside is the most expensive. From the case studies conducted, peak period charges account for 17% of annual electricity costs (occurring between 4 to 7 p.m.). Winter period charges represented about 53% of the charges. The MUKERC framework showcases the valuable insights data-driven costing models offer as it allows to understand the dynamics of electricity charges and identifies “when” and “where” the cost of electricity is more expensive; thus, supporting the development of bespoke cost-effective energy measures that improve resource efficiency and smart energy management initiatives.
Broukos P, Fragkogios A, Shah N, 2022, A Linearized Mathematical Formulation for Combined Centralized and Distributed Waste Water Treatment Network Design, Operations Research Forum, Vol: 3
Waste water treatment (WWT) is a very important issue affecting both the environment and public health in the twenty-first century. The increasing earth’s population together with the growing urbanism leads to the need of redesigning effective WWT. In this paper, the problem of optimal Waste Water Treatment Network Design (WWTND) is addressed. To this end, various parameters affecting the problem have been taken into consideration, such as the distance between the residential areas and the treatment plants, estimations for future population of towns and costs of expanding existing network or building a new one. The last parameter of cost has a lot of components (pipeline cost, treatment plant cost, etc.), all of which are non-linear functions depending on the amount of waste water produced and treated within the network. The authors have developed a mathematical model for the solution of WWTND problem and have applied piecewise linearization in order to deal with the non-linear terms. The developed model has been implemented on an area in Luxemburg, for which data were collected. The results prove the model’s validity and usefulness, while its solution is computationally affordable.
Bird M, Daveau C, O'Dwyer E, et al., 2022, Real-world implementation and cost of a cloud-based MPC retrofit for HVAC control systems in commercial buildings, Energy and Buildings, Vol: 270, Pages: 1-13, ISSN: 0378-7788
Many businesses are looking for ways to improve the energy and carbon usage of their buildings, particularly through enhanced data collection and control schemes. In this context, this paper presents a case study of a food-retail building in the UK, detailing the design, installation and cost of a generalisable model predictive control (MPC) framework for its Heating, Ventilation and Air Conditioning (HVAC) system. The hardware/software solution to collect relevant data, as well as the formulation of the MPC scheme, is presented. By utilising cloud-based microservices, this approach can be applied to all modern building management systems with little upfront capital, and an ongoing monthly cost as low as $6.39/month. The MPC scheme calculates the optimal temperature setpoint required for each Air-Handling Unit (AHU) to minimise its overall cost or carbon usage, while ensuring thermal comfort of occupants. Its performance is then compared to the existing legacy controller using a simulation the building’s thermal behaviour. When simulated across two months the MPC approach performed better, able to achieve the same thermal comfort for a lower overall cost. The economic optimisation resulted in an energy saving of 650 kWh, with an associated cost savings of $240 (1.7% compared to the baseline), while the carbon optimisation gave negligible CO2 savings due to the inability of the building to shift heating to low-carbon periods. Findings from this study indicate the potential for improving building performance via MPC strategies but impact will depend on specific building attributes.
Li K, Acha Izquierdo S, Sunny N, et al., 2022, Strategic transport fleet analysis of heavy goods vehicle technology for net-zero targets, Energy Policy, Vol: 168, ISSN: 0301-4215
This paper addresses the decarbonisation of the heavy-duty transport sector and develops a strategy towards net-zero greenhouse gas (GHG) emissions in heavy-goods vehicles (HGVs) by 2040. By conducting a literature review and a case study on the vehicle fleet of a large UK food and consumer goods retailer, the feasibilities of four alternative vehicle technologies are evaluated from environmental, economic, and technical perspectives. Socio-political factors and commercial readiness are also examined to capture non-technical criteria that influences decision-makers. Strategic analysis frameworks such as PEST-SWOT models were developed for liquefied natural gas, biomethane, electricity and hydrogen to allow a holistic comparison and identify their long-term deployment potential. Fossil and renewable natural gas are found to be effective transitional solutions. Technology innovation is needed to address range and payload limitations of electric trucks, whereas government and industry support are essential for a material deployment of hydrogen in the 2030s. Given the UK government’s plan to phase out new diesel HGVs by 2040, fleet operators should commence new vehicle trials by 2025 and replace a considerable amount of their lighter diesel trucks with zero-emission vehicles by 2030, and the remaining heavier truck fleet by 2035.
Hoseinpoori P, Olympios AV, Markides CN, et al., 2022, A whole-system approach for quantifying the value of smart electrification for decarbonising heating in buildings, Energy Conversion and Management, Vol: 268, Pages: 1-24, ISSN: 0196-8904
This paper uses a whole system approach to examine system design and planning strategies that enhance the system value of electrifying heating and identify trade-offs between consumers’ investment and infrastructure requirements for decarbonising heating in buildings. We present a novel integrated model of heat, electricity and gas systems, HEGIT, to investigate different heat electrification strategies using the UK as the case study from two perspectives: (i) a system planning perspective regarding the scope and timing of electrification; and (ii) a demand-side perspective regarding the operational and investment schemes on the consumer side. Our results indicate that complete electrification of heating increases peak electricity demand by 170%, resulting in a 160% increase in the required installed capacity in the electricity grid. However, this effect can be moderated by implementing smart demand-side schemes. Grid integration of heat pumps combined with thermal storage at the consumer-end was shown to unlock significant potential for diurnal load shifting, thereby reducing the electricity grid reinforcement requirements. For example, our results show that a 5 b£ investment in such demand-side flexibility schemes can reduce the total system transition cost by about 22 b£ compared to the case of relying solely on supply-side flexibility. In such a case, it is also possible to reduce consumer investment by lowering the output temperature of heat pumps from 55 °C to 45 °C and sharing the heating duty with electric resistance heaters. Furthermore, our results suggest that, when used at a domestic scale, ground-source heat pumps offer limited system value since their advantages (lower peak demand and reduced variations in electric heating loads) can instead be provided by grid-integration of air-source heat pumps and increased thermal storage capacity at a lower cost to consumers and with additional flexibility benefits for the electricity gr
Leonzio G, Shah N, 2022, Innovative process integrating air source heat pumps and direct air capture processes, Industrial and Engineering Chemistry Research, Vol: 61, Pages: 13221-13230, ISSN: 0888-5885
Most integrated assessment models indicate a need for technological carbon dioxide removal from the atmosphere to achieve climate mitigation targets. Currently, direct air capture (DAC) appears to be one the “backstop” technologies suitable to provide this service. These technologies usually require low-carbon heat as part of their operation cycle. Here, we consider a way of providing this heat when no local heat source is available. Air source heat pump (ASHP) water heaters are a well-known technology that takes heat from the air to supply hot water. Variations on their operating conditions could provide water at 100 °C, when a trans-critical cycle is used. This level of temperature is required by several DAC adsorption processes as the thermal energy for the regeneration stage. For this reason, an innovative process integrating an ASHP and a DAC adsorption system is proposed here. The heat pump provides not only heating but also cooling, while three separate stages (adsorption, cooling, and regeneration) are considered for the DAC. In the integrated process, the air is sent to the adsorbent bed at first and after that to the evaporator of the heat pump and then used for the cooling stage. The hot water supplied by the heat pump is used for the desorption. Different working fluids (CO2, CO2-ethane, CO2-R41), with low ozone depletion and global warming potentials, are investigated. The results show that a high level of efficiency is possible for heat pumps supplying hot water at 100 °C. Moreover, energetic advantages are present with reference to the base case, where heat is provided by a municipal water incinerator and cooling by a cooling tower. Savings in the energy consumption of 55, 60, and 53% for the integrated process using CO2, CO2/R41, and CO2/ethane, respectively, are possible. Economic benefits are present when economic incentives are provided, ensuring lower costs up to 39 $/tonCO2, and the technology benefits from location flexibili
Leonzio G, Fennell PS, Shah N, 2022, Analysis of technologies for carbon dioxide capture from the air, Applied Sciences-Basel, Vol: 12, ISSN: 2076-3417
Gonzalez-Garay A, Heuberger-Austin C, Fu X, et al., 2022, Unravelling the potential of sustainable aviation fuels to decarbonise the aviation sector, Energy and Environmental Science, Vol: 15, Pages: 3291-3309, ISSN: 1754-5692
The aviation industry is responsible for approximately 2% of the total anthropogenic greenhouse gas emissions. With an expected four to six-fold growth by 2050, increased attention has been paid to reduce its carbon footprint. In this study, we analyse the requirements to promote Sustainable Aviation Fuels (SAFs) from solar energy to reduce the emissions of the sector. Using a discrete spatio-temporal mathematical description of the region of Spain, we present the key elements required to produce jet fuel via Fischer–Tropsch (FT) and Methanol to fuels (MtF). We have found that solar PV, electricity storage, and alkaline water electrolysis are the key drivers for the performance of solar SAFs while the optimal location of the facilities is driven by the availability of solar radiation, underground H2 storage, and high jet fuel demand. We show that the constant supply of H2 requires an over sizing of technologies, which in turn decreases the utilisation of solar panels and electrolysers. While higher usage rates could be attained by a constant supply of electricity (e.g., via the electricity grid), the use of renewable sources is essential to guarantee a reduction in CO2 emissions compared to fossil-based jet fuel. We found that production costs in 2020 per kgfuel in Spain varied from 3.90 € (MtF) to 4.95 € (FT) using solar radiation as a sole source of energy and a point source of CO2, cutting CO2 life cycle emissions by ∼25% compared to their fossil-based counterpart (2.5–2.7 kgCO2eq per kgfuel). Potential technological improvements could reduce jet fuel production costs to 2.5–3.3 € per kgfuel for CO2 point sources while emissions could reach ∼1.0 kgCO2eq per kgfuel. Ultimately, the impact of these routes in the cost of a flight ticket would result in a minimum increase of 100–150% at present and 40–80% by 2050, accounting for current projections on technologies and carbon prices. This shows that future minimum c
Kusumo K, Kuriyan K, Vaidyaraman S, et al., 2022, Probabilistic framework for optimal experimental campaigns in the presence of operational constraints, Reaction Chemistry and Engineering, Vol: 7, Pages: 2359-2374, ISSN: 2058-9883
The predictive capability of any mathematical model is intertwined with the quality of experimentaldata collected for its calibration. Model-based design of experiments helps compute maximallyinformative campaigns for model calibration. But in early stages of model development it is crucial toaccount for model uncertainties to mitigate the risk of uninformative or infeasible experiments. Thisarticle presents a new method to design optimal experimental campaigns subject to hard constraintsunder uncertainty, alongside a tractable computational framework. This computational frameworkinvolves two stages, whereby the feasible experimental space is sampled using a probabilistic approachin the first stage, and a continuous-effort optimal experiment design is determined by searching overthe sampled feasible space in the second stage. The tractability of this methodology is demonstratedon a case study involving the exothermic esterification of priopionic anhydride with significant risk ofthermal runaway during experimentation. An implementation is made freely available based on thePython packages DEUS and Pydex.
Baharudin L, Rahmat N, Othman NH, et al., 2022, Formation, control, and elimination of carbon on Ni-based catalyst during CO<inf>2</inf>and CH<inf>4</inf>conversion via dry reforming process: A review, Journal of CO2 Utilization, Vol: 61, ISSN: 2212-9820
Dry reforming of methane (DRM) promises to reduce greenhouse gas emission by converting CO2 and CH4 (produced e.g. in anaerobic digestion processes) into syngas with an almost equimolar H2/CO ratio suitable for use in Fischer-Tropsch (FT) synthesis for the production of varieties of high value chemicals and liquid fuels. Ni-based catalyst is the most viable catalyst to catalyse the reaction, but its use faces a great challenge due to its propensity to form and accumulate carbonaceous materials on its active surface. In this article, the mechanisms involved in the deactivation of Ni-based catalyst in DRM reaction by carbon deposition and other carbon-induced deactivation mechanisms, which understanding is vital for the improvement of the process, are reviewed. Based on a thorough assessment of literature, perspectives are given on ways to control and mitigate carbon deposition problems related to the use of Ni-based catalysts in DRM by means of manipulating reaction conditions and process parameters as well as through designing and developing highly active coke-resistant Ni-based catalysts.
Palmieri E, Kis Z, Ozanne J, et al., 2022, GMMA as an alternative carrier for a glycoconjugate vaccine against Group A streptococcus, Vaccines, Vol: 10, Pages: 1-17, ISSN: 2076-393X
Group A Streptococcus (GAS) causes about 500,000 annual deaths globally, and no vaccines are currently available. The Group A Carbohydrate (GAC), conserved across all GAS serotypes, conjugated to an appropriate carrier protein, represents a promising vaccine candidate. Here, we explored the possibility to use Generalized Modules for Membrane Antigens (GMMA) as an alternative carrier system for GAC, exploiting their intrinsic adjuvant properties. Immunogenicity of GAC-GMMA conjugate was evaluated in different animal species in comparison to GAC-CRM197; and the two conjugates were also compared from a techno-economic point of view. GMMA proved to be a good alternative carrier for GAC, resulting in a higher immune response compared to CRM197 in different mice strains, as verified by ELISA and FACS analyses. Differently from CRM197, GMMA induced significant levels of anti-GAC IgG titers in mice also in the absence of Alhydrogel. In rabbits, a difference in the immune response could not be appreciated; however, antibodies from GAC-GMMA-immunized animals showed higher affinity toward purified GAC antigen compared to those elicited by GAC-CRM197. In addition, the GAC-GMMA production process proved to be more cost-effective, making this conjugate particularly attractive for low- and middle-income countries, where this pathogen has a huge burden.
Aunedi M, Yliruka M, Dehghan S, et al., 2022, Multi-model assessment of heat decarbonisation options in the UK using electricity and hydrogen, Renewable Energy, Vol: 194, Pages: 1261-1276, ISSN: 0960-1481
Delivering low-carbon heat will require the substitution of natural gas with low-carbon alternatives such as electricity and hydrogen. The objective of this paper is to develop a method to soft-link two advanced, investment-optimising energy system models, RTN (Resource-Technology Network) and WeSIM (Whole-electricity System Investment Model), in order to assess cost-efficient heat decarbonisation pathways for the UK while utilising the respective strengths of the two models. The linking procedure included passing on hourly electricity prices from WeSIM as input to RTN, and returning capacities and locations of hydrogen generation and shares of electricity and hydrogen in heat supply from RTN to WeSIM. The outputs demonstrate that soft-linking can improve the quality of the solution, while providing useful insights into the cost-efficient pathways for zero-carbon heating. Quantitative results point to the cost-effectiveness of using a mix of electricity and hydrogen technologies for delivering zero-carbon heat, also demonstrating a high level of interaction between electricity and hydrogen infrastructure in a zero-carbon system. Hydrogen from gas reforming with carbon capture and storage can play a significant role in the medium term, while remaining a cost-efficient option for supplying peak heat demand in the longer term, with the bulk of heat demand being supplied by electric heat pumps.
Gonzalez-Garay A, Bui M, Freire Ordóñez D, et al., 2022, Hydrogen production and its applications to mobility, Annual Review of Chemical and Biomolecular Engineering, Vol: 13, Pages: 501-528, ISSN: 1947-5438
Hydrogen has been identified as one of the key elements to bolster longer-term climate neutrality and strategic autonomy for several major countries. Multiple road maps emphasize the need to accelerate deployment across its supply chain and utilization. Being one of the major contributors to global CO2 emissions, the transportation sector finds in hydrogen an appealing alternative to reach sustainable development through either its direct use in fuel cells or further transformation to sustainable fuels. This review summarizes the latest developments in hydrogen use across the major energy-consuming transportation sectors. Rooted in a systems engineering perspective, we present an analysis of the entire hydrogen supply chain across its economic, environmental, and social dimensions. Providing an outlook on the sector, we discuss the challenges hydrogen faces in penetrating the different transportation markets.
O'Dwyer E, Falugi P, Shah N, et al., 2022, Automating the data-driven predictive control design process for building thermal management, ECOS 2022 35th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems
Huang Y, Kang J, Liu L, et al., 2022, A hierarchical coupled optimization approach for dynamic simulation of building thermal environment and integrated planning of energy systems with supply and demand synergy, ENERGY CONVERSION AND MANAGEMENT, Vol: 258, ISSN: 0196-8904
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- Citations: 9
Leonzio G, Mwabonje O, Fennell PS, et al., 2022, Environmental performance of different sorbents used for direct air capture, Sustainable Production and Consumption, Vol: 32, Pages: 101-111, ISSN: 2352-5509
Currently, conventional carbon dioxide (CO2) mitigation solutions may be insufficient to achieve the stringent environmental targets set for the coming decades. CO2 removal (CDR) technologies, such as direct air capture (DAC), capturing CO2 from the ambient air, are required.In this research, an independent life cycle assessment (LCA) of DAC adsorption systems based on three physisorbents (metal organic frameworks) and two chemisorbents (amine functionalized sorbents) is presented. These capture processes have been optimised by us in previous work.Results show that for the overall capture process, negative CO2 emissions are ensured by using a cellulose-based amine sorbent (cradle-to-gate) ensuring even the net removal of CO2 from the atmosphere (cradle-to-grave). Processes using physisorbents have poorer performances. Chemisorbents yield operating conditions allowing lower impacts on the environment. In 2050, these processes could reduce climate change but can generate other environmental impacts.With the aim to have better environmental performances of DAC systems, future research should be focused on improving the physical properties of sorbents such as the silica gel based amine sorbent to increase their capture capacities. If metal organic frameworks are to be used, it is necessary to drop their energy consumption (by increasing the loading) and the required mass of sorbent.
Kis Z, Tak K, Ibrahim D, et al., 2022, Pandemic-response adenoviral vector and RNA vaccine manufacturing, npj Vaccines, Vol: 7, ISSN: 2059-0105
Rapid global COVID-19 pandemic response by mass vaccination is currently limited by the rate of vaccine manufacturing. This study presents a techno-economic feasibility assessment and comparison of three vaccine production platform technologies deployed during the COVID-19 pandemic: (1) adenovirus-vectored (AVV) vaccines, (2) messenger RNA (mRNA) vaccines, and (3) the newer self-amplifying RNA (saRNA) vaccines. Besides assessing the baseline performance of the production process, impact of key design and operational uncertainties on the productivity and cost performance of these vaccine platforms is evaluated using variance-based global sensitivity analysis. Cost and resource requirement projections are computed for manufacturing multi-billion vaccine doses for covering the current global demand shortage and for providing annual booster immunisations. The model-based assessment provides key insights to policymakers and vaccine manufacturers for risk analysis, asset utilisation, directions for future technology improvements and future pidemic/pandemic preparedness, given the disease-agnostic nature of these vaccine production platforms.
Bahzad H, Fennell P, Shah N, et al., 2022, Techno-economic assessment for a pumped thermal energy storage integrated with open cycle gas turbine and chemical looping technology, Energy Conversion and Management, Vol: 255, Pages: 1-23, ISSN: 0196-8904
Pumped thermal energy storage offers a high energy density, potentially resulting in a relatively low cost per unit of energy stored. In this study, two novel energy storage systems were developed. The first system was developed by integrating pumped thermal energy storage and chemical looping technologies, whereas the second was formed by merging the first system with an open cycle gas turbine. Both systems used an oxygen depleted stream as a working fluid and iron-based oxygen carriers from a chemical looping water splitting process storage material for the pumped thermal energy storage system. In addition, hydrogen from the chemical looping process was employed for the gas turbine in the second system. Both systems were evaluated thermodynamically via the determination of the roundtrip efficiency. The results presented here indicate that the roundtrip efficiency of both systems developed was 77%. Furthermore, the capital requirements, operating costs, and daily profits from electricity generation were calculated for both systems over several days within the year. The capital and operating costs for the several days that were simulated for the integrated pumped thermal energy storage system were lower than that of a gas turbine based system. Consequently, the daily profit was estimated and found to be between 4.9% and 72.9% higher for the integrated pumped storage relative to the gas turbine based system. Moreover, an economic sensitivity analysis was performed to identify the factors that strongly affect the daily profits of the gas turbine system relative to the pumped storage system. Based on the analysis, the optimal hydrogen fuel percentage fed to the open cycle gas turbine was calculated for the days simulated. Finally, the impact of % error on the estimated capital and fuel production costs on daily profits were investigated. The outcome revealed a higher impact of computational errors on the fuel costs relative to the costs of the capital.
Leonzio G, Fennell PS, Shah N, 2022, A comparative study of different sorbents in the context of direct air capture (DAC): evaluation of key performance indicators and comparisons, Applied Sciences-Basel, Vol: 12, ISSN: 2076-3417
Direct air capture can be based on an adsorption system, and the used sorbent (chemisorbents or physisorbents) influences process. In this work, two amine-functionalized sorbents, as chemisorbents, and three different metal organic frameworks, as physisorbents, are considered and compared in terms of some key performance indicators. This was carried out by developing a mathematical model describing the adsorption and desorption stages. An independent analysis was carried out in order to verify data reported in the literature. Results show that the equilibrium loading is a critical parameter for adsorption capacity, energy consumption, and cost. The considered metal organic frameworks are characterized by a lower equilibrium loading (10−4 mol/kg) compared to chemisorbents (10−1 mol/kg). For this reason, physisorbents have higher overall energy consumptions and costs, while capturing a lower amount of carbon dioxide. A reasonable agreement is found on the basis of the operating conditions of the Climeworks company, modelling the use of the same amine cellulose-based sorbent. The same order of magnitude is found for total costs (751 USD/tonneCO2 for our analysis, compared to the value of 600 USD/tonneCO2 proposed by this company)
O'Dwyer E, Indranil P, Shah N, 2022, Decarbonisation of the urban landscape: integration and optimization of energy systems, Intelligent Decarbonisation: Can Artificial Intelligence and Cyber-PhysicalSystems Help Achieve Climate MitigationTargets?, Editors: Inderwildi, Kraft, Publisher: Springer, ISBN: 978-3030862145
We highlight the key pillars of urban energy systems which would leverage on AI and digital technologiesfor a low carbon future. We summarise a couple of real world applications where optimisation, intelligentcontrol systems and cloud based infrastructure have played a transformative role in improving systemperformance, cost effectiveness and decarbonisation. The case studies show that AI and digitaltechnologies can be implemented for standalone unit operations to achieve such benefits. However, moreimportantly as the second case study shows, applying such technologies at a system level by integratingmultiple energy vectors would give much more flexibility in terms of operation, resulting in betterperformance improvements and decarbonisation strategies. We conclude by highlighting the strategictrends in this fast evolving field and giving a broad outlook in terms of cost reductions and emissionssavings for similar intelligent energy systems.
Li L, Wang J, Zhong X, et al., 2022, Combined multi-objective optimization and agent-based modeling for a 100% renewable island energy system considering power-to-gas technology and extreme weather conditions, APPLIED ENERGY, Vol: 308, ISSN: 0306-2619
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- Citations: 20
Cooper N, Horend C, Roben F, et al., 2022, A framework for the design & operation of a large-scale wind-powered hydrogen electrolyzer hub, International Journal of Hydrogen Energy, Vol: 47, Pages: 8671-8686, ISSN: 0360-3199
Due to the threat of climate change, renewable feedstocks & alternative energy carriers are becoming more necessary than ever. One key vector is hydrogen, which can fulfil these roles and is a renewable resource when split from water using renewable electricity. Electrolyzers are often not designed for variable operation, such as power from sources like wind or solar. This work develops a framework to optimize the design and operation of a large-scale electrolyzer hub under variable power supply. The framework is a two-part optimization, where designs of repeated, modular units are optimized, then the entire system is optimized based on those modular units. The framework is tested using a case study of an electrolyzer hub powered by a Dutch wind farm to minimize the levelized cost of hydrogen. To understand how the optimal design changes, three power profiles are examined, including a steady power supply, a representative wind farm power supply, and the same wind farm power supply compressed in time. The work finds the compressed power profile uses PEM technology which can ramp up and down more quickly. The framework determines for this case study, pressurized alkaline electrolyzers with large stacks are the cheapest modular unit, and while a steady power profile resulted in the cheapest hydrogen, costing 4.73 €/kg, the typical wind power profile only raised the levelized cost by 2%–4.82 €/kg. This framework is useful for designing large-scale electrolysis plants and understanding the impact of specific design choices on the performance of a plant.
van de Berg D, Savage T, Petsagkourakis P, et al., 2022, Data-driven optimization for process systems engineering applications, Chemical Engineering Science, Vol: 248, Pages: 117135-117135, ISSN: 0009-2509
Most optimization problems in engineering can be formulated as ‘expensive’ black box problems whose solutions are limited by the number of function evaluations. Frequently, engineers develop accurate models of physical systems that are differentiable and/or cheap to evaluate. These models can be solved efficiently, and the solution transferred to the real system. In the absence of gradient information or cheap-to-evaluate models, one must resort to efficient optimization routines that rely only on function evaluations. Creating a model can itself be considered part of the expensive black box optimization process. In this work, we investigate how perceived state-of-the-art derivative-free optimization (DFO) algorithms address different instances of these problems in process engineering. On the algorithms side, we benchmark both model-based and direct-search DFO algorithms. On the problems side, the comparisons are made on one mathematical optimization problem and five chemical engineering applications: model-based design of experiments, flowsheet optimization, real-time optimization, self-optimizing reactions, and controller tuning. Various challenges are considered such as constraint satisfaction, uncertainty, problem dimension and evaluation cost. This work bridges the gap between the derivative-free optimization and process systems literature by providing insight into the efficiency of data-driven optimization algorithms in the process systems domain to advance the digitalization of the chemical and process industries.
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