@misc{SebastiaSaezHernandezArellanoGarciaetal., author = {Sebastia-Saez, Daniel and Hernandez, Leonor and Arellano-Garc{\´i}a, Harvey and Enrique Julia, Jose}, title = {Numerical and experimental characterization of the hydrodynamics and drying kinetics of a barbotine slurry spray}, series = {Chemical Engineering Science}, volume = {195}, journal = {Chemical Engineering Science}, issn = {1873-4405}, doi = {10.1016/j.ces.2018.11.040}, pages = {83 -- 94}, abstract = {Spray drying is a basic unit operation in several process industries such as food, pharmaceutical, ceramic, and others. In this work, a Eulerian-Lagrangian three-phase simulation is presented to study the drying process of barbotine slurry droplets for the production of ceramic tiles. To this end, the simulated velocity field produced by a spray nozzle located at the Institute of Ceramic Technology in Castell{\´o} (Spain) is benchmarked against measurements obtained by means of laser Doppler anemometry in order to validate the numerical model. Also, the droplet size distribution generated by the nozzle is obtained at operating conditions by means of laser diffraction and the data obtained are compared qualitatively to those found in the literature. The characteristic Rosin-Rammler droplet size from the distribution is introduced thereafter in the three-phase simulation to analyse the drying kinetics of individual droplets. The model predicts the theoretical linear evolution of the square diameter (D²-law), and the temperature and mass exchange with the environment. The proposed model is intended to support the design and optimization of industrial spray dryers.}, language = {en} } @misc{FosterSebastiaSaezArellanoGarcia, author = {Foster, Niall and Sebastia-Saez, Daniel and Arellano-Garc{\´i}a, Harvey}, title = {Fractal branch-like fractal shell-and-tube heat exchangers: A CFD study of the shell side performance}, series = {IFAC-PapersOnLine}, volume = {52}, journal = {IFAC-PapersOnLine}, number = {1}, issn = {2405-8963}, doi = {10.1016/j.ifacol.2019.06.044}, pages = {100 -- 105}, abstract = {Nature has provided some of the most ingenious and elegant solutions to complex problems over millions of years of refining through evolution. The adaptation of Nature´s solutions to engineering problems is a recent trend which has opened opportunities for improvement in many areas ranging from Architecture to Chemical Engineering. In particular, the use of fractal geometries on heat exchangers is a recent design trend. Recent investigations highlight the benefit of implementing fractal-based geometries on the tube side of shell and tube heat exchangers. A complete evaluation of such devices by assessing the performance of the shell side has not been undertaken, though. Here, we present a systematic numerical assessment of the shell side of a tree-like shaped heat exchanger. Key performance parameters, i.e. temperature change, pressure drop and coefficient of performance, are obtained and compared to those of a straight tube, in order to fully understand the potential of the application of fractal-based shapes to the design of heat exchangers.}, language = {en} } @misc{DorneanuMashamMechlerietal., author = {Dorneanu, Bogdan and Masham, Elliot and Mechleri, Evgenia and Arellano-Garc{\´i}a, Harvey}, title = {Centralised versus localised supply chain management using a flow configuration model}, series = {Computer Aided Chemical Engineering}, volume = {46}, journal = {Computer Aided Chemical Engineering}, issn = {1570-7946}, doi = {10.1016/B978-0-12-818634-3.50231-9}, pages = {1381 -- 1386}, abstract = {Traditional food supply chains are often centralised and global in nature. Moreover they require a large amount of resource which is an issue in a time with increasing need for more sustainable food supply chains. A solution is to use localised food supply chains, an option theorised to be more sustainable, yet not proven. Therefore, this paper compares the two systems to investigate which one is more environmentally friendly, cost efficient and resilient to disruption risks. This comparison between the two types of supply chains, is performed using MILP models for an ice cream supply chain for the whole of England over the period of a year. The results obtained from the models show that the localised model performs best environmentally and economically, whilst the traditional, centralised supply chain performs best for resilience.}, language = {en} } @misc{YentumiDorneanuArellanoGarcia, author = {Yentumi, Richard and Dorneanu, Bogdan and Arellano-Garc{\´i}a, Harvey}, title = {Modelling and optimal operation of a natural gas fired natural draft heater}, series = {Computer Aided Chemical Engineering}, volume = {46}, journal = {Computer Aided Chemical Engineering}, issn = {1570-7946}, doi = {10.1016/B978-0-12-818634-3.50165-X}, pages = {985 -- 990}, abstract = {Current industrial trends promote reduction of material and energy consumption of fossil fuel burning, and energy-intensive process equipment. It is estimated that approximately 75\% of the energy consumption in hydrocarbon processing facilities is used by such equipment as fired heater, hence even small improvements in the energy conservation may lead to significant savings [1, 2]. In this work, a mathematical modelling and optimisation study is undertaken using gPROMS® ProcessBuilder® to determine the optimal operating conditions of an existing API 560 Type-E vertical-cylindrical type natural draft fired heater, in operation at the Atuabo Gas Processing Plant (GPP), in the Western Region of Ghana. It is demonstrated that the optimisation results in significant reduction of fuel gas consumption and operational costs.}, language = {en} } @misc{AlHmoudSebastiaSaezArellanoGarcia, author = {Al-Hmoud, Aya and Sebastia-Saez, Daniel and Arellano-Garc{\´i}a, Harvey}, title = {Comparative CFD analysis of thermal energy storage materials in photovoltaic/thermal panels}, series = {Computer Aided Chemical Engineering}, volume = {46}, journal = {Computer Aided Chemical Engineering}, issn = {1570-7946}, doi = {10.1016/B978-0-12-818634-3.50133-8}, pages = {793 -- 798}, abstract = {Photovoltaic/thermal systems are a novel renewable energy approach to transform incident radiation into electricity and simultaneously store the excess thermal energy produced. Both sensible and latent heat storage materials have been investigated in the past for thermal storage; with desert sand having been recently considered as an efficient and inexpensive alternative. In this work, we use a transient Computational Fluid Dynamics simulation to compare the performance of desert sand to that of well-established phase-change materials used in photovoltaic/thermal systems. The simulation gives as a result the temperature profiles within the device as well as the time evolution of the charge/discharge cycles when using PCMs. The results show the suitability of desert sand as a thermal storage material to be used in photovoltaic/thermal systems.}, language = {en} } @misc{MechleriSidnellDorneanuetal., author = {Mechleri, Evgenia and Sidnell, Tim and Dorneanu, Bogdan and Arellano-Garc{\´i}a, Harvey}, title = {Optimisation and control of a distributed energy resource network using Internet-of-Things technologies}, series = {Computer Aided Chemical Engineering}, volume = {46}, journal = {Computer Aided Chemical Engineering}, issn = {1570-7946}, doi = {10.1016/B978-0-12-818634-3.50014-X}, pages = {79 -- 84}, abstract = {This work investigates the use of variable pricing to control electricity imported and exported to and from both fixed and unfixed distributed energy resource network designs within the UK residential sector. It was proven that networks which utilise much of their own energy and import little from the national grid are barely affected by variable import pricing, but are encouraged to export more energy to the grid by dynamic export pricing. Dynamic import and export pricing increased CO2 emissions due to feed-in tariffs which encourages CHP generation over lower-carbon technologies such as solar panels or wind turbines.}, language = {en} } @misc{ArellanoGarciaDorneanuMechleri, author = {Arellano-Garc{\´i}a, Harvey and Dorneanu, Bogdan and Mechleri, Evgenia}, title = {Devicification of Food Process Engineering}, series = {Reference Module in Chemistry, Molecular Sciences and Chemical Engineering}, volume = {2019}, journal = {Reference Module in Chemistry, Molecular Sciences and Chemical Engineering}, doi = {10.1016/B978-0-12-409547-2.14426-9}, abstract = {Food and beverages industry is facing major challenges in the years to come, as the world population is expected to grow, accompanied by a growing need for energy, feed and fuel. Much of the processing in the food industry is performed in small-scale decentralized plants, with relatively few possibilities of energy recovery. Innovation in areas such as process and product modeling, process intensification and process control enable the development of new manufacturing pathways, more efficient, versatile, selective and sustainable. Furthermore, the addition of Internet of Things elements and the way they connect to the physical process will ensure continuous communication between the various actors of the food value chain. This will enable the design of new compact, scalable, flexible, modular, and automated production equipment that will offer food manufacturers the ability to respond rapidly, economically, accurately and flexibly to the consumer demands.}, language = {en} } @misc{ArellanoGarciaIfeSanduketal., author = {Arellano-Garc{\´i}a, Harvey and Ife, Maximilian R. and Sanduk, Mohammed and Sebastia-Saez, Daniel}, title = {Hydrogen production via load-matched coupled solar-proton exchange membrane electrolysis using aqueous methanol}, series = {Chemical engineering \& technology}, volume = {42}, journal = {Chemical engineering \& technology}, number = {11}, issn = {1521-4125}, doi = {10.1002/ceat.201900285}, pages = {2340 -- 2347}, abstract = {This study investigates hydrogen production via a directly coupled solar-PEM electrolysis system using aqueous methanol instead of water. The effect of load matching and methanol concentration on hydrogen production rates, electrolysis efficiency, and solar-hydrogen efficiency was investigated. The electrolysis efficiencies were subsequently used in simulation studies to estimate production costs in scaled up systems. The results show that the added hydrogen production associated with the methanol solutions leads to favourable hydrogen production costs at smaller scales.}, language = {en} } @misc{SebastiaSaezRamirezReinaSilvaetal., author = {Sebastia-Saez, Daniel and Ramirez Reina, Tomas and Silva, Ravi and Arellano-Garc{\´i}a, Harvey}, title = {Synthesis and characterisation of n-octacosane@silica nanocapsules for thermal storage applications}, series = {International Journal of Energy Research}, volume = {44}, journal = {International Journal of Energy Research}, number = {3}, issn = {1099-114X}, doi = {10.1002/er.5039}, pages = {2306 -- 2315}, abstract = {This work reports the synthesis and characterisation of a core-shell n-octacosane@silica nanoencapsulated phase-change material obtained via interfacial hydrolysis and polycondensation of tetraethyl orthosilicate in miniemulsion. Silica has been used as the encapsulating material because of its thermal advantages relative to synthesised polymers. The material presents excellent heat storage potential, with a measured melting latent heat varying between 57.1 and 89.0 kJ kg-1 (melting point between 58.2°C and 59.9°C) and a small particle size (between 565 and 227 nm). Degradation of the n-octacosane core starts between 150°C and 180°C. Also, the use of silica as shell material gives way to a heat conductivity of 0.796 W m-1 K-1 (greater than that of nanoencapsulated materials with polymeric shell). Charge/discharge cycles have been successfully simulated at low pressure to prove the suitability of the nanopowder as phase-change material. Further research will be carried out in the future regarding the use of the synthesised material in thermal applications involving nanofluids.}, language = {en} } @misc{KetabchiMechleriArellanoGarcia, author = {Ketabchi, Elham and Mechleri, Evgenia and Arellano-Garc{\´i}a, Harvey}, title = {Increasing operational efficiency through the integration of an oil refinery and an ethylene production plant}, series = {Chemical Engineering Research and Design}, volume = {152}, journal = {Chemical Engineering Research and Design}, issn = {1744-3563}, doi = {10.1016/j.cherd.2019.09.028}, pages = {85 -- 94}, abstract = {In this work, the optimal integration between an oil refinery and an ethylene production plant has been investigated. Both plants are connected using intermediate materials aiming to remove, at least partially, the reliance on external sourcing. This integration has been proven to be beneficial in terms of quality and profit increase for both production systems. Thus, three mathematical models have been formulated and implemented for each plant individually as well as for the integrated system as MINLP models aiming to optimise all three systems. Moreover, a case study using practical data is presented to verify the feasibility of the integration within an industrial environment. Promising results have been obtained demonstrating significant profit increase in both plants.}, language = {en} } @misc{RamirezReinaKetabchiArellanoGarciaetal., author = {Ramirez Reina, Tomas and Ketabchi, Elham and Arellano-Garc{\´i}a, Harvey and Pastor-Perez, Laura}, title = {The Production of Long Chain Hydrocarbons through the Catalytic Upgrade of Biomass-Based Acetone, Butanol and Ethanol (ABE)}, series = {2019 AIChE Annual Meeting}, journal = {2019 AIChE Annual Meeting}, isbn = {978-0-8169-1112-7}, abstract = {One of the main issues that many industrial sectors such as oil refineries have been facing nowadays is their sole dependency on fossil fuel. Not only have price fluctuations affected the products, but their environmental impact is an ever present problem that should be addressed. This has led to the search for alternatives such as biomass based processes in order to reduce the dependency on fossil fuel. Bio-refinery processes, fed by biomass, produce high value chemicals and materials with the advantage of reduced environmental drawbacks, such as CO2 emissions, when compared to the conventional refinery. For the benefit of both systems, an integration approach has been considered connecting bio-refining and conventional refining processes together. In this work we focus on the production of long chain hydrocarbons while maintaining production of chemicals that already originate from biomass such as Acetone, Butanol and Ethanol (ABE). The ABE used for this process is obtained as a product of sugar fermentation using the bacteria genus Clostridium. Through the upgrading and conversion of ABE, the products obtained will then be incorporated in the proposed integration system, connecting the conventional oil refinery to this process. A reaction involving a complex reaction network towards upgrading ABE with the aim of producing valuable products using economically viable catalysts has been carried out. The vast majority of research in this area either involves the separation of ABE after fermentation to be used in the chemical/or transportation industry that incurs large costs, or noble metal catalysts are used to upgrade this feed, which would also not be economically viable. However, our research has surpassed the necessity of noble metals, leading to a significant cost decrease that also produces outstanding results. The catalysts required for this process were synthesised successfully through the wetness incipient method and characterised by XRD, Raman, BET, TPR and N2 Isotherm. The reaction consists of the self-condensation and cross condensation of the alcohols and acetone, respectively, using a variety of active metals on basic supports as catalysts, at high temperatures and pressure in a batch reactor. The results have shown exceptional performance for the catalysts in terms of conversion and selectivity, having conversions as high as 90\%. The catalysts have proven to yield a range of C3-C15 hydrocarbons identified to be of need in the chemical industry. In conclusion, our route has produced valuable chemicals proven to have a considerably higher market value than the simple alcohol reactants, useful for both the petrochemical and the transportation industries, through the use of novel and economically favourable catalysts.}, language = {en} } @misc{HamdanArellanoGarciaSebastiaSaez, author = {Hamdan, Mustapha and Arellano-Garc{\´i}a, Harvey and Sebastia-Saez, Daniel}, title = {A Novel Circulating Fluidised Bed Solar Receiver Design for Thermal Energy Conversion and Storage}, series = {2019 AIChE Annual Meeting}, journal = {2019 AIChE Annual Meeting}, isbn = {978-0-8169-1112-7}, abstract = {he middle east and northern Africa (MENA) regions rely heavily on fossil fuels as an energy source. The region consumes high amounts of energy for their air cooling and water desalination needs. For the GCC region this amounts to 60-70\% of their energy consumption and has one of the highest carbon dioxide emissions per capita in the world. The GCC countries are in an area of high direct normal irradiance from the sun and thus, investigating the use of solar power as an alternative energy source is valid. Concentrated Solar Power (CSP) technology is a promising energy capture technology that uses optical devices to concentrate the power of the sun on to a surface and in turn generates power by means of a thermal-to-electric conversion. CSP technology integrates Thermal Energy Storage (TES) materials to store heat and thus enable power production in the absence of sunlight, at night or in poor weather conditions. While CSP technology is a promising alternative energy source its high levelized cost of energy (LCOE) is a drawback to its widespread implementation. A major factor to the high LCOE is the use of molten salts as the TES material carrying with it, high capital costs and high operating and maintenance cost. This is due to molten salts being corrosive and having a low working temperature limiting its thermal-to-electric efficiency. This contribution introduces a novel conceptual design of a circulating fluidised bed as the solar receiver for a CSP plant. The use of raw desert sand as an alternative TES material was investigated. An optimum heat transfer fluid (HTF) was selected from Carbon dioxide, Nitrogen, Argon and Air. This work will also argue that these changes to current CSP plants will significantly reduce the LCOE. The results of this study show that the proposed design can allow up to six times higher mass flowrates of the heat transfer fluid to circulate the sand than current designs. Moreover, 1000 oC uniform outlet temperature was also achieved. For this purpose, Carbon dioxide was found to be the optimum HTF, achieving the highest heat transfer rates. Thus, the new configuration of a fluidised bed receiver proves desert sand to be an effective alternative TES material leading to high thermal energy outputs per m2 and a substantial reduction in the LCOE for CSP technology.}, language = {en} } @misc{KetabchiMechleriArellanoGarcia, author = {Ketabchi, Elham and Mechleri, Evgenia and Arellano-Garc{\´i}a, Harvey}, title = {Towards Sustainable Industries: Industrial Symbiosis of an Oil Refinery and a Petrochemical Plant}, series = {2019 AIChE Annual Meeting}, journal = {2019 AIChE Annual Meeting}, isbn = {978-0-8169-1112-7}, abstract = {A common factor that can be seen in the history of all manufacturing and production sectors is that they all go through significant changes to keep them operating efficiently, thus a constant cycle of system development, obsolescence and advancement is formed. These sectors must be able to maintain the balance between the energy consumption and efficiency to keep the system optimised and preserve the opportunity to create value. Oil refineries are a prime example of one of these sectors that play an important role in our day-to-day lives. Due to an oil refineries{\^a}€™ major dependency on crude oil, the price fluctuation of which, has a profound impact on this industry. Thusly, this drives up prices and forcing a rise in the search for alternative solutions to tackle these efficacy and economic problems. Therefore, in this work, an integration approach has been considered based on the Industrial Symbiosis concept to connect an oil refinery with a petrochemical plant. One main feature of the larger chemical industry that should be considered, is that they require careful management of material and energy to obtain valuable products. Of course, the processes key to the generation of the valuable products also produce fewer desirable chemicals, which have no value as waste products. Some of these waste materials can be used as feed-stock for other processes; turning probable costly chemical disposal into an economic boon. This {\^a}€œgreener{\^a}€ approach opens avenues of improvement compatible with the idea of industrial symbiosis; where the waste from one process can be a feed-stock, useful for another. Taking this into account, a case study is presented involving the connection of an oil refinery with an ethylene production plant through material exchange and stream combination to benefit both plants. As a result, we were able to improve not only product quality but the overall profit of both plants by a significant margin, while also decreasing dependency on outside sources for material supply.}, language = {en} } @misc{DorneanuArellanoGarciaHeshmatetal., author = {Dorneanu, Bogdan and Arellano-Garc{\´i}a, Harvey and Heshmat, Mohamed and Gao, Yang}, title = {Ontology Based Decision Making for Process Control}, series = {2019 AIChE Annual Meeting}, journal = {2019 AIChE Annual Meeting}, isbn = {978-0-8169-1112-7}, abstract = {In the context of Industry 4.0, engineering systems and manufacturing processes are becoming increasingly complex, combining the physical world of the processing units with the cyber world of the wireless sensing and communication networks, big data analytics, ubiquitous computing and other elements that the Industrial Internet of Things technologies. The fields of ontology, knowledge management and decision-making systems have matured significantly in the recent years and their integration with the cyber-physical system (CPS) facilitates and improves the effectiveness of decision-support systems (DSS) [1]. Yet, this comes with an increase in the system{\^a}€™s complexity and a need for deployment of intelligent systems for process systems engineering (PSE) applications, that should adapt to the continuously new requirements of Industry 4.0. Considering the large number of devices existent in a CPS, distributed methods are required to transfer the computational load from centralised to local (decentralised) controllers. This has led to the motivation of applying multi-agent systems (MASs) methodologies as a solution to distributed control as a computational paradigm [2]. An agent can be defined as an entity placed in an environment that can sense different parameters used to make a decision based on the goals of the entity. A MAS is a computerised system composed of multiple interacting agents exploited to solve a problem. Their salient features, which include efficiency, low cost, flexibility, and reliability, make it an effective solution for solving tasks [3]. Usually, DSS adopt a rule-based or logic-based representation scheme [4]. For this reason, ontologies have attracted the attention of the PSE community as a convenient means for knowledge representation [1, 5]. An ontology is a formal representation of a set of concepts within a domain and the relationships between those concepts, and it serves as a library of knowledge to efficiently build intelligent systems and as a shared vocabulary for communication between interacting human and/or software agents [6]. In this paper, a multi-agent cooperative-based model predictive control (MPC) system for monitoring and control of a chemical process is proposed. The system uses ontology to formally represent the system knowledge at process, communication and decision-making level. The application of the proposed framework is discussed for a chemical process that produces iso-octane. A cooperative MPC is implemented to achieve the control of the plant. This protocol is defined using a simple algorithm to reach an agreement regarding the state of a number of N agents [7]. The monitoring feature is defined by means of a MAS, consisting of follower agents (FAs), a coordinator agent (CA) and a monitor agent (MoA), that is integrated with the MPC. The MAS has two main tasks: a) decide optimal connectivity between the distributed MPCs for safer and better operation; and b) monitor the system and detect any deviation in the behaviour. The addition of the MAS makes the cooperative MPC controller more efficient by taking advantage of the communication between the various elements of the CPS. Using the knowledge form the ontology and the agents{\^a}€™ sharing capabilities, the system can detect faster any deviation compared to standard operation. The framework can easily be adapted for other control approaches by very simple modifications in the structure and objectives. A practical demonstration in a pilot plant environment is envisaged for the future.}, language = {en} } @misc{YusufDorneanuAvignoneRossaetal., author = {Yusuf, Ifrah and Dorneanu, Bogdan and Avignone-Rossa, Claudio and Arellano-Garc{\´i}a, Harvey}, title = {Synthesis and Characterization of Hydrochars Produced By Hydrothermal Carbonization of Banana Peels}, series = {2019 AIChE Annual Meeting}, journal = {2019 AIChE Annual Meeting}, isbn = {978-0-8169-1112-7}, abstract = {Hydrothermal carbonisation (HTC) is a thermochemical process which imitates the natural coalification of biomass. If the natural process requires some hundred to some million years, depending on the type of coal produced, HTC needs less than half a day for the transformation of biomass into materials quite similar to brown coal [1].The organic feedstock is reacted with water at mild temperature (130-300 0C) compared to other thermochemical processes such as pyrolysis, gasification, or flash carbonisation, and under autogenous pressures (10-96 bar). The result is a homogeneous carbon-rich solid, a high-strength process liquid, and a gaseous product mainly consisting of CO2 [2]. Compared to the biomass feedstock, biochar possesses a higher heating value and higher carbon content, has a lower ash content, more surface oxygen-containing groups, and it can lead to lower emissions of greenhouse gases [3]. The difference in chemical composition of the final products depend on the reaction mechanisms that occur during HTC, which include hydrolysis, dehydration, decarboxylation, aromatization and re-condensation. Although these processes generally occur in this order, they do not operate in a successive manner; instead they occur simultaneously during HTC and are interconnected with each other [4]. The main purpose of this work is to evaluate the technological feasibility of converting banana peel residues in useful products using the HTC, towards a localised production strategy to harness the value of the waste for improving the livelihoods of rural agricultural communities. A study of the prevailing reactions, their rates and products from banana peel processing through HTC is used to support the optimisation of the reactor design. The products{\^a}€™ yield is influenced by factors such as temperature, feed solid content, the nature of the biomass, and residence time. A detailed characterisation of all the products obtained from HTC is conducted. Considerable effort is needed to comprehend their stability and quality and thereby the ongoing process reactions and upgrading needs. Characterisation methods, such as GC/MS NMR, and HPLC for product analysis are critical to understand the nature of the reactive species influencing product quality and yield. Additionally, as efficient separation from an aqueous phase increases the yield of useful products, the separation of the main products and water is investigated. Furthermore, the feasibility of the recycle and re-use of the process water is analysed. The improvement and reuse of the hydrochar are appealing for applications such as solid fuel, pre-cursor for activated carbon, adsorbent, soil amendment or carbon sequestering biochar. Moreover, the use of HTC to convert banana peels into products such as hydrochar or bio-oil will enable the local rural communities create value from something they are discarding as waste. The hydrochar, processed into pellet form to increase its bulk density in order to reduce storage and transportation costs, can be directly used as a solid fuel that can be burned for energy. This is particularly effective for small and medium farms dispersed over extended areas, due to the significant reduction of expenses and environmental impact. The hydrochar can be added to soil to enhance the effects of the fertilisers, by reducing the amount of fertiliser lost through surface run-off. In addition, it increases the amount of water that can be retained by sandy soils, with a low available water capacity. The use of banana peels will produce highly effective sorbent hydrochars to be used for heavy metals removal from water. Moreover, our results suggest that the liquid fraction obtained from the hydrothermal processing of banana peel is a good feedstock for Microbial Fuel Cells. The hydrochar obtained in the process has shown to present several properties, such as the removal of various types of pollutants from contaminated waters. Therefore, the integration of HTC to convert banana peels into hydrochar and the utilization of the liquid by-product as feedstock for bioelectrochemical system (BES) technology enables full utilization of an otherwise recalcitrant waste.}, language = {en} } @misc{DeMelMechleriDemisetal., author = {De Mel, Ishanki and Mechleri, Evgenia and Demis, Panagiotis and Dorneanu, Bogdan and Klymenko, Oleksiy and Arellano-Garc{\´i}a, Harvey}, title = {A Methodology for Global Sensitivity Analysis for the Operation of Distributed Energy Systems Using a Two-Stage Approach}, series = {2019 AIChE Annual Meeting}, journal = {2019 AIChE Annual Meeting}, isbn = {978-0-8169-1112-7}, abstract = {Optimisation-based models are often employed for the design and operation of distributed energy systems (DES). A two-stage approach often involves the optimisation of the design of a distributed energy system for a specified location or scale, and the subsequent optimisation of the operational model based on the structure recommended by the design model. The structure includes what types of generation and storage technologies should be used in the operation, related capacities and sizes, and potential locations. Often, both design and operational models are deterministic in nature, as either past or fictitious data is fed into the models to minimise an objective function such as the total cost or environmental impact due to carbon emissions. Consequently, the operational models encounter challenges when real-time data is fed, as time-variant input variables such as electricity demand, heating demand and solar insolation can be deemed uncertain. These variables could have unexpected and significant impacts on the total costs involved with the operation of distributed energy systems, leading to sub-optimality or even infeasibilities. Identifying these input variables, quantifying their uncertainties (which are then described in the models), and evaluating the influence of these variables on the outputs can lead to the design of more robust models. Such models can then be used to design and operate optimal distributed energy systems. This paper presents a novel methodology for using global sensitivity analysis (GSA) on an operational optimisation-based model of a distributed energy system. The operational model also utilises Model Predictive Control (MPC) rolling horizon concepts (as done by [1]) to determine hourly total operational costs. The paper also addresses how some challenges and limitations encountered in the operational model can be attributed to the deterministic design model on which the structure of the operational model has been based. Furthermore, the research explores how the design can be improved to support more robust operation. Another novel aspect of this paper highlights the use of the optimisation tool GAMS alongside SobolGSA, a global sensitivity analysis software [2]. This software uses the variance-based Sobol method to generate N samples and perform global sensitivity analysis, allowing users to understand how variations in the inputs can influence the outputs, whilst accounting for the different combinations of the uncertain parameters without varying one uncertain parameter at a time.}, language = {en} } @misc{MechleriShafieiDorneanuetal., author = {Mechleri, Evgenia and Shafiei, Zarif and Dorneanu, Bogdan and Arellano-Garc{\´i}a, Harvey and Klymenko, Oleksiy}, title = {A Blockchain Model for Residential Distributed Energy Resources Networks}, series = {2019 AIChE Annual Meeting}, journal = {2019 AIChE Annual Meeting}, isbn = {978-0-8169-1112-7}, abstract = {The energy production landscape is reshaped by distributed energy resources (DERs) {\^a}€" photovoltaic (PV) panels, combined heat and power (CHP), wind turbines (WT), fuel cells or battery storage systems, to name just a few [1]. Microgrids, collections of units or DERs that are locally controlled, close to the consumption point and cooperating with each other and the centralised grid [2], allow for the reduction in energy losses compared to traditional generation due to the close proximity to end users. Due to its volatility, the integration of this non-controllable generation poses severe challenges to the current energy system and ensuring a reliable balance of energy becomes an increasingly demanding task [3]. The optimal design and scheduling of the DERs and subsequent microgrid is of high importance in order to increase the reliability and determine their effectiveness in reducing losses, emissions and costs compared to conventional generation so that they may be implemented at faster rates to reduce global emissions and fossil fuel usage. In distributed energy systems, individual users typically have flexible tariffs while they also have the capability not only to use, but also to store and trade electric power. Direct transactions schemes can save money for end users, generate revenues for producers, reduce transmission losses and promote the use of renewable energy [4]. But it must be a robust, efficient and low-cost trading system to handle the rapid changes of information and value in the system. The blockchain technology can fulfil these requirements by enabling the implementation of optimal energy management strategies through distributed databases. Since its introduction as the underlying technology of Bitcoin, the blockchain technology has emerged from its use as a verification mechanism for cryptocurrencies and heads to a broader field of applications. Blockchain-based systems are basically a combination of a distributed ledger, a decentralised consensus mechanism, and cryptographic security measures [5]. More precisely, it allows the resolution of conflicts and dismantles information asymmetries by providing transparent and valid records of past transactions that cannot be altered retrospectively [6]. With the help of specific algorithms and applications, multiple operations can be performed automatically on the blockchain, using this information together with information from the Internet or the real world (e.g. on whether, energy pricing, etc.). Furthermore, smart contracts can be implemented between the nodes of the microgrid. This paper introduces a model for the implementation of a blockchain and smart contracts into the scheduling of a residential DER network. The blockchain is implemented in terms of energy rather than voltages [7], to allow for the decentralised operation of the microgrid without a centralised microgrid aggregator. Thus, the model will minimise only the operational cost. Furthermore, the DER network model is improved by the addition of more detailed transmission losses and costs within the microgrid and between the microgrid and the national grid. The resulted energy flows are stored and information on the availability/demand are exchanged between the network nodes. To appropriately compensate the DER operators in the microgrid for their services and to charge the consumers for withdrawals, nodal clearing prices are determined and implemented through smart contracts. The resulting MILP model minimises the overall investment and operating costs of the system.}, language = {en} } @misc{HajizeinalibiokiSebastiaSaezKlymenkoetal., author = {Hajizeinalibioki, Sahar and Sebastia-Saez, Daniel and Klymenko, Oleksiy and Arellano-Garc{\´i}a, Harvey}, title = {Investigation of Two-Phase Flow Characteristics in a Fractal-Branching Microchannel}, series = {AIChE Annual Meeting, November 10, 2019 to November 15, 2019}, journal = {AIChE Annual Meeting, November 10, 2019 to November 15, 2019}, isbn = {978-0-8169-1112-7}, abstract = {Inspiration from nature to solve advanced engineering problems has attracted the interests of engineers, designers and scientists. Biomimetics is to imitate and apply the elements, systems and mechanisms from nature to solve technological challenges as stated by Gleich et al. (2009). They also added that one of nature's solution which is being explored is fractal shapes. Fractal shapes appeared in a variety of cases such as snowflakes, blood vessels and plant root systems in nature. Fractal shapes consistently appear in situations which require mass or heat transfer throughout a large space. The optimal spreading and transfer throughout the space characteristics of fractal shapes, making them a practical solution to design more efficient heat and mass transfer devices. Fractal shapes were first employed to improve fluid mechanics designs by West et al. (1997) to minimise the workflow for bulk fluid transportation through a network of branching tubes. On the other hand, two-phase flow in microscale channels has great applicability due to its diverse range of applications. As expressed by Serizawa et al. (2002), modern and advanced technologies such as micro-electro-mechanical systems, chemical process engineering, medical engineering and electronic cooling utilise multiphase flow in microchannels. This work aims to investigate the application of nature-inspired fractal geometries as multiphase microscale flow passage using CFD analysis. ANSYS Fluent software has been utilised to investigate the flow characteristics numerically in order to improve the pressure drop and heat transfer. Also, this question will be raised whether two-phase flow patterns in fractal microchannels are different from straight channels or not.}, language = {en} }