@misc{AlvesAmorimDorneanuValverdePontesetal., author = {Alves Amorim, Ana Paula and Dorneanu, Bogdan and Valverde Pontes, Karen and Arellano-Garc{\´i}a, Harvey}, title = {A framework for decision-making to encourage utilization of residential distributed energy systems in Brazil}, series = {Computer Aided Chemical Engineering}, volume = {Vol. 52}, journal = {Computer Aided Chemical Engineering}, issn = {1570-7946}, doi = {10.1016/B978-0-443-15274-0.50481-9}, pages = {3019 -- 3024}, abstract = {The Distributed Energy Systems (DES) or microgrid arose from the need to reduce greenhouse gases (GHG) emitted into the atmosphere by burning fossil fuels to generate energy. Reduction of energy losses, reconfiguration of the protection system and reduction of costs, and optimizing the configuration of these systems is recommended. Despite new research in literature, there is still a lack of optimization models that address the Brazilian reality. Therefore, the objective of this work is to introduce a decision-making framework for the design and operation of residential DES that takes into account the particularities of Brazil, based on mixed-integer programming models. The applicability of the framework is tested on a case study of a residential DES of 5 houses, located in Salvador, and used to compare scenarios pre- and post-COVID-19. The results show significant reduction in total annual cost and GHG emissions versus the base case without DES. This indicates that, although the country has a mostly "clean" energy matrix due to the use of hydroelectric plants, DES can enable improvement in residential electricity generation.}, language = {en} } @misc{TarifaGonzalezCastanoCazanaetal., author = {Tarifa, Pilar and Gonzalez-Castano, Miriam and Cazana, Fernando and Monzon, Antonio and Arellano-Garc{\´i}a, Harvey}, title = {Hydrophobic RWGS catalysts: valorization of CO2-rich streams in presence of CO/H2O}, series = {Catalysis Today}, volume = {Vol. 423}, journal = {Catalysis Today}, issn = {1873-4308}, doi = {10.1016/j.cattod.2023.114276}, abstract = {Nowadays, the majority of the Reverse Water Gas Shift (RWGS) studies assume somehow model feedstock (diluted CO2/H2) for syngas production. Nonetheless, biogas streams contain certain amounts of CO/H2O which will decrease the obtained CO2 conversion values by promoting the forward WGS reaction. Since the rate limiting step for the WGS reaction concerns the water splitting, this work proposes the use of hydrophobic RWGS catalysts as an effective strategy for the valorization of CO2-rich feedstock in presence of H2O and CO. Over Fe-Mg catalysts, the different hydrophilicities attained over pristine, N- and B-doped carbonaceous supports accounted for the impact on the activity of the catalyst in presence of CO/H2O. Overall, the higher CO productivity (4.12 μmol/(min·m2)) attained by Fe-Mg/CDC in presence of 20\% of H2O relates to hindered water adsorption and unveil the use of hydrophobic surfaces as a suitable approach for avoiding costly pre-conditioning units for the valorization of CO2-rich streams based on RWGS processes in presence of CO/H2O.}, language = {en} } @misc{DorneanuMashamKeykhaetal., author = {Dorneanu, Bogdan and Masham, Elliot and Keykha, Mina and Mechleri, Evgenia and Cole, Rosanna and Arellano-Garc{\´i}a, Harvey}, title = {Assessment of centralised and localised ice cream supply chains using neighbourhood flow configuration models}, series = {Supply Chain Analytics}, volume = {Vol. 4}, journal = {Supply Chain Analytics}, doi = {10.1016/j.sca.2023.100043}, abstract = {Traditional food supply chains are often centralised and global in nature, entailing substantial resource consumption. However, in the face of growing demand for sustainability, this strategy faces significant challenges. Adoption of localised supply chains is deemed a more sustainable option, yet its efficacy requires verification. Supply chain analytics methodologies provide invaluable tools to guide decisions regarding inventory management, demand forecasting and distribution optimisation. These solutions not only enhance facilitate operational efficiency, but also pave the way for cost reduction, further aligning with sustainability objectives. This research introduces a novel decision-making approach anchored in mixed integer linear programming (MILP) and neighbourhood flow models defined in cellular automata to compare the environmental benefits and vulnerability to disruption of these two chain configurations. Additionally, a comprehensive cost analysis is integrated to assess the economic feasibility of incorporating layout changes that enhance supply chain sustainability. The proposed framework is applied on an ice cream supply chain across England over a one-year timeframe. The findings indicate the superiority of the localised configuration in terms of economic benefits, leading to savings exceeding \pounds 1 million, alongside important reductions in environmental impact. However, in terms of resilience, the traditional configuration remains superior in three out of the four examined scenarios.}, language = {en} } @misc{CunhaCordeiroSafdarAquinoetal., author = {Cunha Cordeiro, Jos{\´e} Luiz and Safdar, Muddasar and Aquino, Gabrielle S. and Silva, Jefferson S. and Paff, Jessica Sophie and Valverde Pontes, Karen and Dorneanu, Bogdan and Arellano-Garc{\´i}a, Harvey and Mascarenhas, Artur Jos{\´e}}, title = {Sustainable hydrogen production via biogas reforming over NiO-MxOy - Al2O3 catalysts (M = Na, K, Ca and Mg)}, series = {22 Congreso Brasileiro de Catalise}, journal = {22 Congreso Brasileiro de Catalise}, abstract = {A sustainable way to generate hydrogen is through dry biogas reforming, which uses methane gas and carbon dioxide to produce hydrogen. This study reveals partial results of the dry reforming of biogas in NiO-MxOy-Al2O3 catalysts (M=Na, K, Ca and Mg). The CO2 conversion varied between 79\% and 94\%, the CH4 conversion between 58\% and 75\%, the H2/CO ratio between 0.98 and 1.15 and the H2 yield between 37\% and 45\%. These values ​​surpass literary references and the industrial catalyst, highlighting the promise of these materials for sustainable hydrogen production. The catalyst with Ca stood out due to its higher surface basicity, exhibiting the best conversion results and yield in H2.}, language = {en} } @misc{SafdarShezadDorneanuetal., author = {Safdar, Muddasar and Shezad, Nasir and Dorneanu, Bogdan and Jafari, Mitra and Shashank Bhat, Sharvendu and Akhtar, Farid and Arellano-Garc{\´i}a, Harvey}, title = {Dry Reforming of Methane for the Syngas Production Catalyzed by Ni-doped Perovskites}, series = {15Th European Congress on Katakysis EUROPACAT2023}, journal = {15Th European Congress on Katakysis EUROPACAT2023}, abstract = {different perovskite-type supports considering ABO3 (such as A= Al, La with B=Ce and A=Mg, Mn with B=Zr) were prepared via the sol-gel method. Ni metal loading of 10 wt.\% was deposited on prepared perovskite supports via the impregnation method. The catalysts were characterized using XRD and FTIR techniques. The DRM activity was carried out in a tubular reactor as described in our previous study [5]. The catalytic performance was assessed in the temperature range of 500-700 ◦C, CH4/CO2 = 1/1 and under GHSV of 12,000 h-1. Among the prepared catalysts, Ni-doped perovskite combination (i.e. A=Mg with B=Zr)O3-δ exhibited higher (CH4, CO2) conversion ca. (69, 59) percent and syngas yield of ca. (H2/CO =0.72) at 700 oC. This indicates that the magnesium zirconate perovskite catalyst established strong interfacial metal-support interaction, redox properties and surface basic sites that linked with good performance of the catalyst during DRM process.}, language = {en} } @misc{MappasVassiliadisDorneanuetal., author = {Mappas, Vassileios and Vassiliadis, Vassilios S. and Dorneanu, Bogdan and Arellano-Garc{\´i}a, Harvey}, title = {Use of Multistage Optimal Control Principles for Novel Design and Implementation of Classical Controllers}, series = {AIChE Annual Meeting}, journal = {AIChE Annual Meeting}, abstract = {Classical controllers, such as Proportional-Integral (PI) and Proportional-Integral Derivative (PID) controllers, are the most long-established and widely used in industry. Various methods for tuning these types of controllers exist (Ziegler et al., 1942; Blondin et al., 2018; Do et al., 2021), and up to this point, there is no fruitful avenue to improve their performance. In this contribution, a new approach for PI and PID controller implementation, based on a Multistage Optimal Control (MSOCP) approach is introduced. Our approach incorporates path and end-point constraints during its controller tuning phase, as well as parameter and disturbance uncertainty. The proposed framework is applied for different case studies and is able to reject any disturbances introduced to the examined systems, with or without uncertainty, satisfies end-point constraints and exhibits quicker response for switching steady states, compared to classical methods. Other aspects of controller design and incorporation within industrial process models, as related to using rigorous optimization methodologies and implementations, will further be highlighted within the context of the PI and PID controllers.}, language = {en} } @misc{MappasVassiliadisDorneanuetal., author = {Mappas, Vassileios and Vassiliadis, Vassilios S. and Dorneanu, Bogdan and Arellano-Garc{\´i}a, Harvey}, title = {Automated Control Loop Selection Via Multistage Optimal Control Formulation and Nonlinear Programming}, series = {Chemical Engineering Research and Design}, volume = {195}, journal = {Chemical Engineering Research and Design}, issn = {1744-3563}, doi = {10.1016/j.cherd.2023.05.041}, pages = {76 -- 95}, abstract = {In this work, a novel approach based on the multistage optimal control formulation of the control loop selection problem is introduced. Currently, state-of-the-art approaches for controller loop design have been focused on data that yield only the pairings between input-output variables, and are not able to incorporate path and end-point constraints. Thus, they only produce the optimal loops for control purposes, without the simultaneous consideration of their optimal tuning. This formulation overcomes these drawbacks by producing an automated integrated solution for the task of control loop design, which also obviates the need for any form of combinatorial optimisastion to be used. To illustrate the procedure, as well as the advantages of the proposed scheme, different practical case studies are discussed and the results compared with those obtained with standard controller loop selection methods and their tuning. The results of the proposed approach show improved performance over previous methodologies found in the literature. Furthermore, the framework is extended to the selection of the control loops that must obey path and end-point constraints imposed by the underlying dynamical process. This task is usually difficult for classical methods, which violate them or exhibit underdamped response in some cases.}, language = {en} } @misc{JafariSafdarDorneanuetal., author = {Jafari, Mitra and Safdar, Muddasar and Dorneanu, Bogdan and Gonzalez-Casta{\~n}o, Miriam and Arellano-Garc{\´i}a, Harvey}, title = {Green and sustainable fuel from syngas via the Fischer-Tropsch synthesis process: Bifunctional cobalt-based catalysts}, series = {14th European Congress of Chemical Engineering and 7th European Congress of Applied Biotechnology}, journal = {14th European Congress of Chemical Engineering and 7th European Congress of Applied Biotechnology}, abstract = {This paper reviews and compares state-of-the-art cobalt-based catalysts and catalytic systems used to produce green and sustainable fuels using FTS. Being focused on comparing the effect of the catalyst formulation and synthesis method, the reactor type and operating parameters, as well as the quality of the obtained fuels, the aim is to identify the research gaps between these relevant research areas concerning production of green and sustainable fuels.}, language = {en} } @misc{PlattfautSuckowKlepeletal., author = {Plattfaut, Julia and Suckow, Matthias and Klepel, Olaf and Erlitz, Marcel and Arellano-Garc{\´i}a, Harvey}, title = {Modellierung und Simulation der templatgest{\"u}tzten Synthese von por{\"o}sen Kohlenstoffger{\"u}sten mittels COMSOL Multiphysics}, series = {Chemie Ingenieur Technik}, volume = {96(2024)}, journal = {Chemie Ingenieur Technik}, number = {3}, issn = {1522-2640}, doi = {10.1002/cite.202300014}, pages = {318 -- 328}, abstract = {Mithilfe einer templatgest{\"u}tzten Synthese wurden por{\"o}se Kohlenstoffger{\"u}ste unter Verwendung von Silicagel als Templat hergestellt. Die chemische Gasphaseninfiltration (CVI) wurde hierbei als Synthese verwendet. Unter Variation verschiedener Reaktionsparameter zur Optimierung der Kohlenstoffabscheidung wurde dieser Prozess mathematisch modelliert and simuliert. Dabei konnten die experimentellen Ergebnisse gut mit den Modellen nachgebildet werden. Die zus{\"a}tzliche Beschreibung der laminaren Str{\"o}mung verbessert die {\"U}bereinstimmung deutlich.}, language = {de} } @misc{ZhangVassiliadisDorneanuetal., author = {Zhang, Sushen and Vassiliadis, Vassilios S. and Dorneanu, Bogdan and Arellano-Garc{\´i}a, Harvey}, title = {Hierarchical multi-scale parametric optimization of deep neural networks}, series = {Applied Intelligence}, volume = {53}, journal = {Applied Intelligence}, number = {21}, issn = {1573-7497}, doi = {10.1007/s10489-023-04745-8}, pages = {24963 -- 24990}, abstract = {Traditionally, sensitivity analysis has been utilized to determine the importance of input variables to a deep neural network (DNN). However, the quantification of sensitivity for each neuron in a network presents a significant challenge. In this article, a selective method for calculating neuron sensitivity in layers of neurons concerning network output is proposed. This approach incorporates scaling factors that facilitate the evaluation and comparison of neuron importance. Additionally, a hierarchical multi-scale optimization framework is proposed, where layers with high-importance neurons are selectively optimized. Unlike the traditional backpropagation method that optimizes the whole network at once, this alternative approach focuses on optimizing the more important layers. This paper provides fundamental theoretical analysis and motivating case study results for the proposed neural network treatment. The framework is shown to be effective in network optimization when applied to simulated and UCI Machine Learning Repository datasets. This alternative training generates local minima close to or even better than those obtained with the backpropagation method, utilizing the same starting points for comparative purposes within a multi-start optimization procedure. Moreover, the proposed approach is observed to be more efficient for large-scale DNNs. These results validate the proposed algorithmic framework as a rigorous and robust new optimization methodology for training (fitting) neural networks to input/output data series of any given system.}, language = {en} } @misc{ArellanoGarciaSafdarShezadetal., author = {Arellano-Garc{\´i}a, Harvey and Safdar, Muddasar and Shezad, Nasir and Dorneanu, Bogdan and Akhtar, Farid}, title = {Synthesis and Characterizations of Ni-doped Perovskite-Type Oxides for Effective CO2 methanation}, series = {14th European Congress of Chemical Engineering and 7th European Congress of Applied Biotechnology}, journal = {14th European Congress of Chemical Engineering and 7th European Congress of Applied Biotechnology}, doi = {10.5281/zenodo.10376612}, pages = {2}, abstract = {This work proposes Ni metal supported over rare earth-based emerging perovskite-type oxides as potential catalysts for the CO2 methanation. Presence of oxygen vacancies in perovskite-like materials enable them to exhibit higher catalytic activity. Furthermore, to tune the surface basicity, metal-support interaction and to enhance the activation of CO2, rare earth metals (La, Ce, etc.) are considered best candidates. Moreover, different perovskite-type supports (AxMnxO3, A= La, Ce) based on A-side substitution of rare earth metals were prepared with Ni metal loading of 10 wt.\% via impregnation method.}, language = {en} }