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  • Journal article
    Leonzio G, Shah N, 2026,

    C2 and C+ compound production from carbon dioxide: supply chain design and optimization

    , Computers and Chemical Engineering, Vol: 205, ISSN: 0098-1354

    The use of carbon dioxide to produce chemical products can in principle decrease both fossil resource exploitation and greenhouse gas emissions. Potential compounds that can be obtained are ethylene and polyurethane, characterized by large markets underpinning many industries. The importance of such platform chemicals means that different routes have been investigated in the literature for their alternative synthesis. However, there is lack of a direct comparison of these products and processes in a carbon capture utilization and storage supply chain in the existing literature: a gap which we wish to address here.A mixed integer linear optimization model for a carbon capture utilization and storage supply chain is developed here: carbon dioxide can be extracted from flue gas to be stored and/or utilized for ethylene (via the tandem or methanol to olefin processes), polyethylene or polyurethane production and these can be either sold immediately or stored. The framework is exemplified by a case study localised within the UK Teesside petrolchemical cluster and the best topology is suggested to minimize total costs. Moreover, a dynamic analysis of the system over the years is considered here to suggest the best way to implement carbon dioxide capture and utilisation through to 2050. Results show that the optimal cost is achieved by capturing carbon dioxide and converting it into ethylene via the methanol-to-olefin process; the whole system levelized cost is 7.3 $/kgEthylene. Moreover, ensuring an homogeneous way of capturing carbon dioxide over time maximises the profitability of the overall system.
  • Journal article
    Alanazi K, Shah N, Mittal S, Hawkes Aet al., 2026,

    Competition and equilibrium in future global renewable hydrogen trade: a game-theoretic analysis

    , Applied Energy, Vol: 402, ISSN: 0306-2619

    Global renewable hydrogen trade is expected to play a key role in decarbonizing future energy systems. Yet hydrogen exporters may deviate from perfectly competitive behaviour to influence prices, similarly to the existing fossil fuel market, with important implications for consumer welfare and the pace of the energy transition. This study develops a global renewable hydrogen trade model that captures potential strategic interactions among exporters using a Stackelberg game-theoretic framework. The model is formulated as an Equilibrium Problem with Equilibrium Constraints (EPEC) and solved under three alternative equilibria: a profit-maximizing Nash equilibrium, a cost-minimizing Nash equilibrium, and a welfare-maximizing benchmark representing perfect competition. Results indicate that producers may strategically reduce their export quantities by up to 40 % relative to perfect competition to maximize profits. Such behaviour raises prices to a minimum of 4.5 USD/kg in 2050 across major import markets, thereby significantly eroding consumer surplus. Strategic behaviour of dominant exporters also shifts trade flows, reshaping the global allocation of hydrogen supply. Sensitivity analysis further reveals that financing costs play a key role in shaping strategic producers' behaviour, with lower financing costs helping to reduce prices and stimulate demand. These findings highlight the implications of imperfect competition in global hydrogen trade and suggest that policy measures may be needed to mitigate potential negative consequences.
  • Journal article
    Delpisheh M, Moradpoor I, Souhankar A, Koutsandreas D, Shah Net al., 2026,

    Advancing the hydrogen economy: Economic, technological, and policy perspectives for a sustainable energy transition

    , RENEWABLE & SUSTAINABLE ENERGY REVIEWS, Vol: 226, ISSN: 1364-0321
  • Journal article
    Zanobetti F, Bernardi A, Pio G, Ordonez DF, Danaci D, Chachuat B, Cozzani V, Shah Net al., 2025,

    Quantitative sustainability assessment of e-fuels for maritime transport

    , Sustainable Energy and Fuels, Vol: 9, Pages: 6506-6521, ISSN: 2398-4902

    Reducing the carbon intensity of maritime transport is essential to achieve global emission reduction targets. Electro-fuels (e-fuels) represent a promising cleaner alternative to conventional marine fossil fuels, offering potential lifecycle greenhouse gas reductions when synthesised from renewable electricity and low-carbon feedstocks. While techno-economic and environmental assessments of e-fuels exist, their broader sustainability implications, spanning technological, economic, environmental and safety factors together, remain largely unexplored. This study introduces a quantitative framework to assess the sustainability of ship fuel systems that integrates key performance indicators (KPIs) across these four areas. A case study is conducted to compare the sustainability of carbon-based e-fuels (e-methanol and e-diesel) and carbon-free e-fuels (hydrogen and ammonia) against marine diesel oil (MDO) under multiple decision-making perspectives. The robustness of the overall sustainability-based ranking of fuel alternatives, as derived under each perspective, against uncertainties in the individual KPIs is confirmed via sensitivity analysis. Environmental and safety aspects are found to be critical in comparing the sustainability of alternative fuels. Both e-methanol and e-diesel achieve higher overall sustainability than MDO, irrespective of the decision-making perspective. Ammonia and hydrogen are hindered by safety concerns in the short term, although ammonia also shows long-term potential for sustainable shipping subject to appropriate risk management and the implementation of inherently safer design measures. Overall, the proposed framework enables a comprehensive assessment of alternative fuel systems for cleaner shipping, guiding future sustainability-driven policy and technology development.
  • Journal article
    Chen Q, Trusler JPM, 2025,

    Olivine dissolution kinetics at elevated temperatures and pressures

    , Chemical Engineering Journal, Vol: 525, ISSN: 1385-8947

    Experimental and modelling studies of the dissolution kinetics and surface chemistry of olivine in CO2-saturated water at elevated temperatures and CO2 pressures are reported. The apparent initial dissolution rates of olivine are reported at temperatures between 373 and 473 K and at pressures between 7.7 and 15.6 MPa. The influence of mass transfer effects on olivine dissolution and the formation of passivation layers were studied, and the minimum stirring speed at which mass transfer resistance was effectively eliminated was determined. The optimum temperature for olivine dissolution in the long term was determined to be approximately 423 K. This study provides the first data for olivine dissolution rates at temperatures above 423 K. The initial olivine dissolution rates did not show a monotonic increasing trend with the increase of temperature due to the formation of various passivation layers on the olivine particle surfaces at different temperatures. A simple model, dependent upon temperature and the activity of H+, was developed to represent the experimental data. This model is generally applicable under similar temperature and pressure conditions, and when the same type of passivation layer is present. Based on the proposed model, the PHREEQC geochemical simulator was used to predict the saturation indices of Fe2O3 (hematite), FeO(OH) (goethite), Fe(OH)3 (ferric hydroxide) and SiO2 (both quartz and amorphous silica). The pH and elemental concentrations were also predicted and these calculations served to partially rationalize the experimental results.
  • Journal article
    Christopher B, Alaa AK, Heleen DC, Kiane DK, Lars J N, Igor B, Steve D, Paul S Fet al., 2025,

    Defining ‘abated’ fossil fuel and industrial process emissions

    , Energy and Climate Change, Vol: 6, ISSN: 2666-2787

    There is scientific consensus that limiting warming in line with the Paris Agreement goals requires reaching net zero CO2 emissions by mid-century and net negative emissions thereafter. Because of the entrenchment of current fossil fuel energy and feedstock demand estimated in almost all global modelled scenarios, 'abated' fossil fuel and industrial process and product use (IPPU) CO2 emissions, using carbon capture and storage (CCS) technologies to perform carbon management, are likely to be part of any transition. In addition to fossil fuel combustion, this will be primarily in cement & lime kilns, chemical production, and possibly waste incineration and iron and steel making, in processes producing maximally concentrated CO2 waste streams. Abated fossil fuel and IPPU CO2 emissions in the context of recent commitments, however, requires consideration of capture rates for fuel processing and end-use, permanence of storage, reduction of upstream production and end-use fugitive methane, and sufficient means to sequester residual emissions. Based on an assessment of evolving CCS technologies in existing sectors and jurisdictions, criteria are proposed for defining a benchmark for 'abated' fossil fuel and IPPU emissions as where near 100 % GHG abatement is to be eventually achieved, with N2O and fluorinated gases considered separately. This can be accomplished through: 1) CO2 capture rates of more than or equal to 95 % of CO2 emitted; 2) permanent storage of captured emissions; 3) reducing upstream and end-use fugitive methane emissions to <0.5 % and towards 0.2 % of gas production & an equivalent for coal; and 4) counterbalancing remaining emissions using permanent carbon dioxide removal. Application of these criteria to just steel and cement yields estimates of more than or equal to 1.37 Gt CO2 per year reductions after all other reasonable and lower cost actions are taken. At the same time, we acknowledge the value of capture rates below 95 %, so as long t
  • Journal article
    Restelli F, Jiao F, Norris B, Trusler JPM, Siahvashi A, May EF, Pellegrini LA, Johns M, Al Ghafri SZSet al., 2025,

    Dynamic Simulation of a Liquefied Hydrogen Export Terminal

    , Energy, Pages: 139715-139715, ISSN: 0360-5442
  • Journal article
    Wenck N, Muggeridge A, Jackson S, An S, Krevor Set al., 2025,

    The impact of capillary heterogeneity on CO <sub>2</sub> plume migration at the Endurance CO <sub>2</sub> storage site in the UK

    , Geoenergy, Vol: 3

    <jats:p> Predictive modelling of subsurface CO <jats:sub>2</jats:sub> flow is used for optimzing the design of geological CO <jats:sub>2</jats:sub> storage projects e.g. with respect to mass stored and long-term security. However several field scale projects have reported plume dynamics that do not match numerical predictions. Previous work has indicated that upscaling capillary heterogeneity results in different plume dynamics in synthetic 2D cross-sections and at early times (&lt;0.2 PV injected). Here we extend the workflow to 3D and analyse the impacts of longer-term flow behaviour in an industrial scale geological carbon storage site with multi-point CO <jats:sub>2</jats:sub> injection, structural relief and realistic flow rates. The models reveal that capillary heterogeneity in horizontally layered lithologies enhances the formation of preferential flow paths, increases swept volumes and areas, and reduces vertical migration speed near the injectors, all of which improve storage efficiency. At distances far from the injectors, the plume travels faster as a result of the heterogeneity. The results also show that simulations in 3D have qualitatively distinct results from those in 2D due to the increase in flow pathways. </jats:p>
  • Journal article
    Bahzad H, Leonzio G, Soltani SM, Al Jasmi A, Davies WG, Fennell PS, Ali Net al., 2025,

    Techno-economic analyses of a novel hydrogen production process<i> via</i> chemical looping water splitting, integrated with sorption enhanced water gas shift

    , INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, Vol: 188, ISSN: 0360-3199
  • Journal article
    Falugi P, Odwyer E, Zagorowska MA, Kerrigan EC, Nie Y, Strbac G, Shah Net al., 2025,

    Robust co-design framework for buildings operated by predictive control

    , Energy and Buildings, Vol: 346, ISSN: 0378-7788

    Cost-effective decarbonisation of the built environment is a stepping stone to achieving net-zero carbon emissionssince buildings are globally responsible for more than a quarter of global energy-related CO2 emissions. Improving energy utilisation and decreasing costs requires considering multiple domain-specific performance criteria. The resulting problem is often computationally infeasible. The paper proposes an approach based on decomposition and selection of significant operating conditions to achieve a formulation with reduced computational complexity. We present a robust framework to optimise the physical design, the controller, and the operation of residential buildings in an integrated fashion, considering external weather conditions and time-varying electricity prices. The framework explicitly includes operational constraints and increases the utilisation of the energy generated by intermittent resources. A case study illustrates the potential of co-design in enhancing the reliability, flexibility and self-sufficiency of a system operating under different conditions. Specifically, numerical results demonstrate reductions in costs up to 30% compared to a deterministic formulation. Furthermore, the proposed approach achieves a computational time reduction of at least 10 times lower compared to the original problem with a deterioration in the performance of only 0.6 %.
  • Journal article
    Moarrefi S, Naraki MR, Jacob M, Shah N, Skinner S, Jia L, Zhou S-H, Cai W, Fan Let al., 2025,

    Adsorption thermodynamics of methane reforming over solid oxide fuel cell anodes

    , Journal of Power Sources, Vol: 655, ISSN: 0378-7753

    Adsorption kinetics and thermodynamics on nickel base anode materials remain underexplored under reforming conditions when fuelled directly with methane. The kinetics determine how quickly and effectively reactant gases interact on the anode surfaces, affecting the behavior of subsequent electrochemical reactions. However, the complexity of these interactions under operating conditions have led to a limited number of detailed studies in this area. Thus, further investigation into adsorption kinetics could unlock new possibilities for optimizing fuel cell performance. This study examines the adsorption Gibbs free energy of reactants on the anode in solid oxide fuel cell to assess the electrocatalyst activity. Our findings reveal that H2O exhibits more favorable adsorption conditions than CO2 on the catalyst surface, and increased temperature and current density lead to different surface adsorption behaviours. The results show that steam reforming prevents coke formation on the fuel cell anode more effectively than dry reforming. This proposed method can also be used to examine the coke resistance and the performance of anode structures during the investigation and development stages for fuel cell research. The study provides valuable insights into anode performance and offers a foundation for future advancements in SOFC technology.
  • Journal article
    Leonzio G, Shah N, 2025,

    Sustainability analysis of electrochemical direct air capture technologies

    , RSC Sustainability, Vol: 3, Pages: 4632-4650, ISSN: 2753-8125

    Global warming caused by anthropogenic greenhouse gas emissions, particularly carbon dioxide in the atmosphere, has garnered significant attention due to its detrimental environmental impacts. Carbon capture from both point and dilute sources is amongst the critical technologies needed to mitigate these negative phenomena. Carbon dioxide capture from flue gas is a well-established technology, while carbon capture from the air through direct air capture processes remains under research and development. In recent years, attention has focused on fully electrified direct air capture systems as potential candidates for large-scale direct air capture applications capable of exploiting renewable energy sources. However, economic and environmental analyses are missing in the literature. In this work, a scale-up analysis of different electrified direct air capture technologies (based on electrolysis, bipolar membrane electrodialysis, electro-swing adsorption, and proton-coupled electron transfer systems) is conducted through a hybrid learning curve methodology in order to evaluate total costs and environmental impact (according to scopes 1 and 2). The analysis is conducted for different geographic locations, times of year, and types of renewable energy source. Results show that electro-swing adsorption and proton-coupled electron transfer processes are both characterized by lower costs and environmental burdens, while electrolysis and electrodialysis systems have higher costs and environmental impacts. A technique for order preference by similarity to ideal solution analysis is carried out to determine the most sustainable process considering technical, economic, social, and environmental aspects. Results indicate that the proton coupled electron transfer system, built in China, in 2040–2050, exploiting wind offshore energy is the most sustainable process.
  • Journal article
    Kucherenko S, Shah N, Klymenko OV, 2025,

    Identification of feasible regions using R-functions

    , Journal of Process Control, Vol: 154, ISSN: 0959-1524

    The primary objective of feasibility analysis is to identify and define the feasibility region, which represents the range of operational conditions (e.g., variations in process parameters) that ensure safe, reliable, and feasible process performance. This work introduces a novel feasibility analysis method that requires only that model constraints (e.g., defining product Critical Quality Attributes or process Key Performance Indicators) be explicitly provided or approximated by a closed-form function, such as a multivariate polynomial model. The method is based on V.L. Rvachev's R-functions, enabling an explicit analytical representation of the feasibility region without relying on complex optimization-based approaches. R-functions offer a framework for describing intricate geometric shapes and performing operations on them using implicit functions and inequality constraints. The theory of R-functions facilitates the identification of feasibility regions through algebraic manipulation, making it a more practical alternative to traditional optimization-based methods. The effectiveness of the proposed approach is demonstrated using a suite of well-known test cases from the literature.
  • Journal article
    Aboulrous AA, Darraj NM, Cunsolo V, Uko D, Trusler JPM, Blunt MJet al., 2025,

    Effect of imidazolium-based ionic liquid on CO2 sequestration: a study on solubility, interfacial properties, and X-ray imaging in water-wet formations

    , Journal of Molecular Liquids, Vol: 435, ISSN: 0167-7322

    The efficiency of geological CO₂ sequestration is often limited by low CO₂ solubility, which poses challenges for long-term storage stability. This study addresses these limitations by exploring the potential of 1-butyl-3-methylimidazolium bromide (BMIM-Br) to enhance CO₂ storage in water-wet subsurface formations. BMIM-Br was synthesized via a microwave-assisted method and the structure was confirmed using different spectroscopic methods including Fourier Transform Infrared Spectroscopy (FTIR), and Proton Nuclear Magnetic Resonance (1H NMR) analysis.Under conditions of 3 MPa and 323.15 K, the solubility of CO₂ in a 5 wt% BMIM-Br solution was more than double the solubility in pure water. At 0.3 MPa, the interfacial tension (IFT) between CO₂ and the BMIM-Br solution decreased from 36.3 mN/m to 32.9 mN/m at 293.15 and 323.15 K, respectively compared to the pure water values 69.9 mN/m and 63.8 mN/m respectively at the same conditions. When CO2 was injected into a Bentheimer sandstone rock sample fully saturated with the aqueous phase. There was a significant increase in CO₂ saturation (SCO2), rising from 0.58 with pure water to 0.72 with BMIM-Br. The lowered interfacial tension allows more of the pore space to be accessed at the same imposed capillary pressure. When the aqueous phase was injected to displace CO2, the residual saturation was 0.21 with pure water, but only 0.16 for the BMIM-Br solution. This is likely a consequence of increased dissolution of CO2 in BMIM-Br. These results suggest that BMIM-Br significantly improves CO₂ solubility and injectivity by reducing interfacial tension. Its overall impact points to a promising strategy for optimizing CO₂ sequestration in subsurface formations.
  • Journal article
    Suleman MY, Judah HL, Bexis P, Fennell P, Hallett JP, Brandt-Talbot Aet al., 2025,

    The acetate anion promotes hydrolysis of poly(ethylene terephthalate) in ionic liquid-water mixtures

    , GREEN CHEMISTRY, Vol: 27, Pages: 11475-11490, ISSN: 1463-9262
  • Journal article
    Jing R, Wu X, Weng T, Qvist S, Bartela Ł, Lee JI, Li N, Wu J, Shah N, Zhao Y, Zhang Yet al., 2025,

    Uncovering the technical potential of coal-to-nuclear (C2N) power generation on a global scale

    , Nexus, Vol: 2, ISSN: 2950-1601

    Decarbonization urgently calls for a substantial replacement of coal-fired power with carbon-free energy in the global energy landscape. However, the prevailing substitution of coal with variable renewable energy cannot be implemented universally due to possible higher cost and lack of power system flexibility. What is more, well-trained coal-fired power workers and surrounding communities are facing challenges. Therefore, we emphasize the unique value of coal-to-nuclear (C2N) in the energy transition by investigating 9,470 coal-fired power units globally. We identified that 14.3% (i.e., 371.6 GW) of them can be prioritized for C2N. The currently available nuclear technologies are feasible for C2N in three ways. A competitive levelized cost of electricity of US$71.84– US$101.48/MWh could be a strong driver when compared to coal+carbon capture and storage. Overall, C2N offers multifaceted benefits, and it can be a good supplement to the prevailing solar and wind renewables.
  • Report
    Corujo Simon E, Chachuat B, Kucherenko S, Jackson G, Mitchell H, Heng J, Verma V, Livingston AG, Williams D, Sorensen E, Lee LYS, Besenhard M, Garcia-Munoz S, Cruz CN, Galindo A, Shah N, Adjiman Cet al., 2025,

    Making peptides: enabling a medical revolution

    , Making peptides: enabling a medical revolution, Publisher: Sargent Centre for Process Systems Engineering
  • Journal article
    Yang SM, Muazu RI, Tran E, Talbot CB, Shah N, Shaffer MSP, Brandt-Talbot Aet al., 2025,

    Sustainable low-cost carbon fibres produced by integrating wood fractionation with lignin fibre spinning

    , RSC Sustainability, Vol: 3, Pages: 3972-3986, ISSN: 2753-8125

    Conventional carbon fibre manufacturing is costly and relies on fossil-based raw materials with significant environmental impacts. This study presents a new, low-cost route to biobased carbon fibres generated directly from wood by integrating ionosolv wood fractionation with carbon fibre spinning. The approach avoids isolating lignin powders by spinning lignin directly from the black liquor, offering a simpler process with a lower environmental impact. The concept is demonstrated using lignin extracted from eucalyptus wood into the recyclable ionic liquid (IL) N,N-dimethylbutylammonium hydrogen sulfate with 20% water, generating delignified cellulose pulp as a co-product. After adding non-toxic poly(vinyl alcohol) (PVA) into the lignin-containing ionic liquid (with up to a 4.7 : 1 lignin : PVA ratio) continuous lignin–PVA fibres were generated by spinning into an aqueous coagulation bath. Circular, homogenous fibres were formed, which were carbonised at 1000 °C, with carbon fibre yields of up to 37%. The proof-of-concept monofilament carbon fibres (452 MPa tensile strength and 43 GPa tensile modulus) outperformed carbon fibres generated from pre-isolated ionosolv eucalyptus lignin using the same fibre spinning approach. A techno-economic analysis (TEA) of the modelled process at scale suggests that carbon fibre production costs were $9.02 kg−1 for the integrated process and $9.69 kg−1 for the redissolution-spun carbon fibres, while life cycle assessment (LCA) indicated that 20.7 kg CO2-eq and 25.3 kg CO2-eq greenhouse gas emissions were associated with integrated and redissolution spinning, respectively, providing strong motivation for future optimisation of the carbon fibres' mechanical performance and for process development.
  • Journal article
    Gasós A, Pini R, Becattini V, Mazzotti Met al., 2025,

    Correction: Carbon footprint of oil produced through enhanced oil recovery using carbon dioxide directly captured from air

    , Energy and Environmental Science, Vol: 18, Pages: 8088-8088, ISSN: 1754-5692

    Correction for ‘Carbon footprint of oil produced through enhanced oil recovery using carbon dioxide directly captured from air’ by Antonio Gasós et al., Energy Environ. Sci., 2025, https://doi.org/10.1039/d5ee01752a.
  • Journal article
    Meka W, Rachmaniah O, Pamungkas BWB, Akbar F, Prakoso A, Lalasari LH, Retnawaty SF, Binti Salleh SF, Soltani SM, Fennell Pet al., 2025,

    Compositional Chemical Property Analysis and Evaluation of Liquid Smoke Produced from Microwave-assisted Pyrolysis of Mixtures of Oil Palm Solid Waste

    , Journal of Multidisciplinary Applied Natural Science, Vol: 5, Pages: 998-1030

    <jats:p>Microwave-assisted pyrolysis (MAP) was employed to valorise oil palm solid waste, namely empty fruit bunches (EFBs), kernel shells (KSs), and mesocarp fibres (MFs), into liquid smoke at 300 and 400 °C. Unlike conventional pyrolysis systems, which rely on slow, external heating and often yield broad, less selective chemical profiles; MAP offers rapid, volumetric heating and non-thermal effects that enhance product specificity and energy efficiency. This study investigates how MAP temperature and binary blending ratios (EFB-to-KS and EFB-to-MF) influence liquid smoke yield, chemical composition, and antioxidant capacity. Liquid smoke yields were significantly affected by temperature in EFB-KS mixtures, with higher yields at 400 °C, while EFB–MF mixtures showed yield stability across conditions. Gas chromatography–mass spectrometry (GC-MS) analysis revealed phenol as the dominant compound across all samples, with compound diversity and antioxidant activity varying by feedstock. KS-rich mixtures favoured catechol and cresol formation, MF-rich mixtures produced cyclopentenones and carboxylic acids, and EFB-rich mixtures yielded more carbonyl-containing compounds. Antioxidant capacities, measured via DPPH assay, were highest in KS-derived liquid smoke due to its catechol content, while EFB-rich samples exhibited lower activity. Principal component analysis (PCA) was applied to GC-MS data to elucidate the chemical transformation pathways, revealing distinct degradation routes for cellulose, hemicellulose, and lignin under MAP conditions. These routes were further supported by compound clustering in PCA loading plots, highlighting the influence of temperature and biomass composition on product speciation. This study demonstrates the innovative integration of MAP with oil palm waste valorisation, offering a sustainable alternative to wood-based pyrolysis. By tailoring feedstock ratios and operating temperatures, MAP enables the targeted prod
  • Journal article
    Gasos A, Pini R, Becattini V, Mazzotti Met al., 2025,

    Carbon footprint of oil produced through enhanced oil recovery using carbon dioxide directly captured from air

    , Energy and Environmental Science, Vol: 18, Pages: 7440-7446, ISSN: 1754-5692

    Some argue that using CO2 from direct air capture (DAC) in enhanced oil recovery (CO2-EOR) can produce carbon-neutral oil by permanently storing more CO2 than is emitted when using the extracted fossil fuels. However, existing analyses often provide case-specific insights based on short-term operations without considering the full life cycle of reservoir exploitation, including primary, secondary, and tertiary (EOR) recovery phases. Here, we present a general, top-down approach based on mass and volume conservation to assess the potential carbon footprint of oil production, applicable to different temporal perspectives of reservoir exploitation. Supported by field data from 16 EOR projects, our analysis shows that 30% of projects appear carbon-neutral when EOR is considered in isolation, but they all become significantly carbon-positive when the full reservoir lifetime is considered. The volume of emitted CO2 exceeds the pore space freed for storage by at least a factor of three, making carbon-neutral oil physically unattainable in conventional reservoirs. The favorable conditions for low-carbon oil production during CO2-EOR exist solely because of extensive prior oil extraction and water injection, and only residual oil zones may truly offer potential for carbon-neutral oil due to their low oil saturation and lack of legacy emissions. While omitting legacy emissions from previously depleted fields may be justifiable and may enable claims of carbon neutrality during the EOR phase, newly developed fields, i.e., developed now or in the future, should be held accountable for the full life-cycle emissions they generate. This necessitates clear and transparent accounting policy frameworks. Although CO2-EOR may reduce oil's carbon footprint, promoting it as a pathway to carbon-neutrality risks legitimizing continued fossil fuel production, ultimately undermining global climate targets.
  • Journal article
    Soh QY, Acha S, Shah N, ODwyer Eet al., 2025,

    Simultaneous design and control optimisation of combined rainwater harvesting and flood mitigation systems

    , Resources, Conservation and Recycling, Vol: 222, ISSN: 0921-3449

    The design and operational parameters of large-scale rainwater harvesting (RWH) systems should be optimised for its local environment to maximise their efficiency. This paper looks to address the barriers in RWH system performances when their design and operational strategies are optimised separately. This is achieved using a framework which identifies a set of candidate optimal designs with their corresponding optimal control policies by optimising each possible combination of control policy and actuator location. The globally optimal configuration is then determined using a high-resolution simulation model that evaluates their performance under a wide range of historically observed rainfall profiles. When implemented for a RWH system in a tropical city, the optimal configuration was found to improve harvested water yields by 15%–27% in comparison to when only its design is optimised. The 15% improvement is also achieved with a 25% reduction in capacity, reducing spatial competition with other key utilities for the estate.
  • Journal article
    Laksahapsoro B, Bird M, Acha S, Shah Net al., 2025,

    Optimisation of photovoltaic and battery systems for cost-effective energy solutions in commercial buildings

    , Applied Energy, Vol: 392, Pages: 125907-125907, ISSN: 0306-2619
  • Journal article
    Kucherenko S, Shah N, Klymenko OV, 2025,

    Analytical identification of process design spaces using R-functions

    , Computers and Chemical Engineering, Vol: 198, ISSN: 0098-1354

    A process design space (DS) is defined as the combination of process design and operational conditions that guarantees the assurance of product quality. This principle ensures that, as long as a process operates within its DS, it consistently yields a product that meets specifications. A novel DS identification method called the R-DS identifier has been developed in this work. It makes no assumptions about the underlying model - the only requirement is that each model constraint (e.g., defining product Critical Quality Attributes or process Key Performance Indicators) should be approximated by a closed-form function, e.g., a multivariate polynomial model. The method utilizes the methodology of V.L. Rvachev's R-functions and allows for explicit analytical representation of the DS with only a limited number of model runs. R-functions provide a framework for representing complex geometric shapes and performing operations on them through implicit functions and inequalities defining the regions. The theory of R-functions enables the solution of geometric problem such as identification of DS through algebraic manipulation. It is more practical than traditional sampling or optimization-based methods. The method is illustrated using a batch reactor model.
  • Journal article
    Dezashibi AHM, Hallett JP, Fennell PS, 2025,

    Design and operation of a cost-effective reactor for large protic ionic liquid synthesis

    , CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION, Vol: 213, ISSN: 0255-2701
  • Report
    Moustafa N, Saenz Cavazos P, Beath H, Morris O, Liu E, Morimoto Y, Muuls M, Nishide A, Pearse W, Rogelj J, Rolandi T, Shah N, Taylor Pet al., 2025,

    Destination Net-Zero: what is your best path? Insights for decision-makers navigating the low carbon transition
  • Journal article
    Eluwah C, Fennell PS, 2025,

    Novel onboard ammonia cracker for light-duty automotive fuel cell vehicles

    , Energy Advances, ISSN: 2753-1457

    This work introduces an innovative onboard ammonia cracker module integrated with a 100-kW fuel cell system for light-duty automotive fuel cell vehicles. Utilizing a hollow fibre palladium membrane reactor (HFMR), two configurations are explored: a 3 × 3 simultaneous heating and cracking module and a 4 × 4 intermediate heating and cracking module. The 3 × 3 module, arranged in a serpentine configuration, exhibits superior performance with a calculated required volume of 8.9 liters, a total module area of 1.2 m2 and a process thermal efficiency of 93.5%. Each reactor in this module operates isothermally at an exit temperature of 475 °C, achieving ammonia conversion rates that increase from 15.8% in the first reactor (R1) to an impressive 99.99% in the final reactor (R8), facilitated by in situ hydrogen removal through the palladium membrane. The steady-state analysis was carried out using Aspen Plus Software, and validated against experimental data from existing literature. The results demonstrated a high degree of agreement, confirming the model's capability to accurately predict system performance. For transient analysis, Aspen Plus Dynamics was employed to assess the system's responsiveness to varying driving conditions. Utilizing the Hyundai Nexo fuel cell car as a case study, the worldwide harmonised light vehicle test procedure (WLTP) was simulated, to model realistic driving cycles, allowing for a rigorous interrogation of the transient performance of the on-board ammonia cracker. Overall, this research establishes a 3 × 3 simultaneous heating and cracking HFMR module as the optimal configuration for on-board ammonia cracking for hydrogen production in fuel-cell vehicles, highlighting its operational efficiency and potential contribution to sustainable transportation solutions. Future research should focus on optimizing heat management and temperature control within the HFMR module, as well as enhancing transient response characteri
  • Journal article
    Khan SN, Zhao M, Fennell PS, Anthony EJet al., 2025,

    Construction of Highly Mesoporous Metal-Organic Frameworks via Green Metallic Solvents Assisted Route for Chemical CO<sub>2</sub> Fixation

    , SMALL, Vol: 21, ISSN: 1613-6810
  • Journal article
    Riorda A, Negro V, Pantaleo AM, Matteucci F, Shah N, Chiaramonti Det al., 2025,

    Sustainable hydrogen from biomass: what is its potential contribution to the European defossilization targets?

    , Energy and Fuels, Vol: 39, Pages: 6412-6425, ISSN: 0887-0624

    This study investigates the potential role of hydrogen production from biomass in the EU hydrogen objectives. With the EU aiming to produce 10 million tons of renewable hydrogen by 2030 and significantly scaling this production by 2050, diverse hydrogen production pathways must be explored. Our research focuses on assessing whether biomass-derived hydrogen can serve as a viable and substantial component of the hydrogen production mix alongside and complementing established methods such as electrolysis powered by renewable electricity. Through a comprehensive literature review, the main hydrogen production pathways from biomass have been assessed, including thermochemical and biological methods, with an emphasis on hydrogen yield, production costs, and technology readiness levels (TRLs). The work also considers the availability of biomass resources and potential production scenarios for 2030 and 2050. Our findings suggest that biomass-derived hydrogen can meaningfully contribute to the defossilization of the hydrogen sector, particularly in the midterm scenario for 2030. The analysis suggests that biomass has the potential to contribute a substantial share of the EU’s 2030 hydrogen target, ranging from under 0.1 Mt to over 16 Mt per year. Biomass-derived hydrogen offers additional flexibility and security of supply in the transition to a sustainable hydrogen economy, other than the possibility to benefit from negative emissions in some cases and added value from the coproduction of defossilized materials and chemicals, relying on domestic resources available in Europe.
  • Conference paper
    Lewin DR, Shah N, Barzilai A, 2025,

    One-week flipped workshop on heat integration

    , Pages: 110-120, ISSN: 1749-7728

    This paper describes the first implementation of a flipped, one-week workshop on heat integration that was taught in Spring 2024 to the 3rd Year cohort of 138 students in Chemical Engineering at Imperial College, London. The “flipped” workshop consisted of three online lessons that cover the core materials on pinch design of heat exchanger networks, which the students were required to complete ahead of each of the corresponding three face-to-face class meetings, which focused on problem-solving exercises largely carried out by the students themselves. The paper describes the teaching methodology applied, presents and analyses the results of a survey conducted to assess the students’ perceptions and degree of satisfaction with the workshop. Learning outcomes relevant to the workshop topic, that is, the ability to design and optimize heat exchanger networks in realistic plant-wide settings, are also presented and compared to those of previous years. The main conclusion is that the short workshop format can successfully achieve the learning objectives, even for relatively large class sizes. Evidently, this workshop can be taught effectively in this concentrated form provided that the workshop participants are given access to the online lessons in advance of the class exercises.

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