@misc{GonzalezCastanoHaniKourGonzalezAriasetal., author = {Gonz{\´a}lez-Casta{\~n}o, Miriam and Hani Kour, M. and Gonz{\´a}lez-Arias, Judith and Baena-Moreno, Francisco Manuel and Arellano-Garc{\´i}a, Harvey}, title = {Promoting bioeconomy routes: From food waste to green biomethane. A profitability analysis based on a real case study in eastern Germany}, series = {Journal of Environmental Management}, volume = {300}, journal = {Journal of Environmental Management}, issn = {0301-4797}, doi = {10.1016/j.jenvman.2021.113788}, abstract = {Profitability studies are needed to establish the potential pathways required for viable biomethane production in the Brandenburg region of Germany. This work study the profitability of a potential biomethane production plant in the eastern German region of Brandenburg, through a specific practical scenario with data collected from a regional biogas plant located in Alteno (Schradenbiogas GmbH \& Co. KG). Several parameters with potential economic influence such as distance of the production point to the grid, waste utilization percentage, and investment, were analyzed. The results illustrate a negative overall net present value with the scenario of no governmental investment, even when considering trading the CO2 obtained throughout the process. Subsidies needed to reach profitability varied with distance from 13.5 €/MWh to 19.3 €/MWh. For a fixed distance of 15 kms, the importance of percentage of waste utilization was examined. Only 100\% of waste utilization and 75\% of waste utilization would reach profitability under a reasonable subsidies scheme (16.3 and 18.8 €/MWh respectively). Concerning the importance of investment, a subsidized investment of at least 70\% is demanded for positive net present values. Besides, the sensitivity analysis remarks the energy consumption of the biogas upgrading stage, the electricity price, and the energy consumption of biogas production as major parameters to be tackled for the successful implementation of biogas upgrading plants. The results here obtained invite to ponder about potential strategies to further improve the economic viability of this kind of renewable projects. In this line, using the CO2 separated to produce added-value chemicals can be an interesting alternative.}, language = {en} } @book{OdriozolaRamirezReinaArellanoGarcia, author = {Odriozola, Jos{\´e} Antonio and Ramirez Reina, Tomas and Arellano-Garc{\´i}a, Harvey}, title = {Engineering Solutions for CO2 Conversion}, publisher = {Wiley-VCH}, address = {Berlin ; Boston}, isbn = {978-3-527-34639-4}, pages = {496}, abstract = {A comprehensive guide that offers a review of the current technologies that tackle CO2 emissionsThe race to reduce CO2 emissions continues to be an urgent global challenge. "Engineering Solutions for CO2 Conversion" offers a thorough guide to the most current technologies designed to mitigate CO2 emissions ranging from CO2 capture to CO2 utilization approaches....}, language = {en} } @misc{BaenaMorenoCidCastilloArellanoGarciaetal., author = {Baena-Moreno, Francisco Manuel and Cid-Castillo, N. and Arellano-Garc{\´i}a, Harvey and Ramirez Reina, Tomas}, title = {Towards emission free steel manufacturing - Exploring the advantages of a CO2 methanation unit to minimize CO2 emissions}, series = {Science of The Total Environment}, volume = {781}, journal = {Science of The Total Environment}, issn = {1879-1026}, doi = {10.1016/j.scitotenv.2021.146776}, abstract = {This paper demonstrates the benefits of incorporating CO2 utilisation through methanation in the steel industry. This approach allows to produce synthetic methane, which can be recycled back into the steel manufacturing process as fuel and hence saving the consumption of natural gas. To this end, we propose a combined steel-making and CO2 utilisation prototype whose key units (shaft furnace, reformer and methanation unit) have been modelled in Aspen Plus V8.8. Particularly, the results showed an optimal performance of the shaft furnace at 800°C and 6 bar, as well as 1050°C and atmospheric pressure for the reformer unit. Optimal results for the methanation reactor were observed at 350°C. Under these optimal conditions, 97.8\% of the total CO2 emissions could be mitigated from a simplified steel manufacturing scenario and 89.4\% of the natural gas used in the process could be saved. A light economic approach is also presented, revealing that the process could be profitable with future technologic developments, natural gas prices and forthcoming increases of CO2 emissions taxes. Indeed, the cash-flow can be profitable (325 k€) under the future costs: methanation operational cost at 0.105 €/Nm³; electrolysis operational cost at 0.04 €kWh, natural gas price at 32 €/MWh; and CO2 penalty at 55€/MWh. Hence this strategy is not only environmentally advantageous but also economically appealing and could represent an interesting route to contribute towards steel-making decarbonisation.}, language = {en} } @misc{KetabchiRamirezReinaDorneanuetal., author = {Ketabchi, Elham and Ramirez Reina, Tomas and Dorneanu, Bogdan and Arellano-Garc{\´i}a, Harvey}, title = {An identification approach to a reaction network for an ABE catalytic upgrade}, series = {Computer Aided Chemical Engineering}, volume = {50}, journal = {Computer Aided Chemical Engineering}, issn = {1570-7946}, doi = {10.1016/B978-0-323-88506-5.50102-9}, pages = {643 -- 648}, abstract = {This contribution presents a kinetic study for the identification of the complex reaction mechanism occurring during the ABE upgrading, and the development of a kinetic model. Employing graph theory analysis, a directed bipartite graph is constructed to reduce the complexity of the reaction network, and the reaction rate constants and reaction orders are calculated using the initial rate method, followed by the calculation of the activation energy and frequency factor for an Arrhenius-type law. Subsequently, using general mass balancing a proposed mathematical model is produced to determine the apparent reaction rates, which are successfully in line with the experimental results.}, language = {en} } @misc{ClarkeDorneanuMechlerietal., author = {Clarke, Fiona and Dorneanu, Bogdan and Mechleri, Evgenia and Arellano-Garc{\´i}a, Harvey}, title = {Optimal design of heating and cooling pipeline networks for residential distributed energy resource systems}, series = {Energy}, volume = {235}, journal = {Energy}, issn = {1873-6785}, doi = {10.1016/j.energy.2021.121430}, abstract = {This paper presents a mixed integer linear programming model for the optimal design of a distributed energy resource (DER) system that meets electricity, heating, cooling and domestic hot water demands of a neighbourhood. The objective is the optimal selection of the system components among different technologies, as well as the optimal design of the heat pipeline network to allow heat exchange between different nodes in the neighbourhood. More specifically, this work focuses on the design, interaction and operation of the pipeline network, assuming the operation and maintenance costs. Furthermore, thermal and cold storage, transfer of thermal energy, and pipelines for transfer of cold and hot water to meet domestic hot water demands are additions to previously published models. The application of the final model is investigated for a case-study of a neighbourhood of five houses located in the UK. The scalability of the model is tested by also applying the model to a neighbourhood of ten and twenty houses, respectively. Enabling exchange of thermal power between the neighbours, including for storage purposes, and using separate hot and cold pipeline networks reduces the cost and the environmental impact of the resulting DER.}, language = {en} } @misc{SidnellDorneanuMechlerietal., author = {Sidnell, Tim and Dorneanu, Bogdan and Mechleri, Evgenia and Vassiliadis, Vassilios S. and Arellano-Garc{\´i}a, Harvey}, title = {Effects of Dynamic Pricing on the Design and Operation of Distributed Energy Resource Networks}, series = {Processes}, volume = {9}, journal = {Processes}, number = {8}, issn = {2227-9717}, doi = {https://doi.org/10.3390/pr9081306}, abstract = {This paper presents a framework for the use of variable pricing to control electricity im-ported/exported to/from both fixed and unfixed residential distributed energy resource (DER) network designs. The framework shows that networks utilizing much of their own energy, and importing little from the national grid, are barely affected by dynamic import pricing, but are encouraged to sell more by dynamic export pricing. An increase in CO2 emissions per kWh of energy produced is observed for dynamic import and export, against a baseline configuration utilizing constant pricing. This is due to feed-in tariffs (FITs) that encourage CHP generation over lower-carbon technologies. Furthermore, batteries are shown to be expensive in systems receiving income from FITs and grid exports, but for the cases when they sell to/buy from the grid using dynamic pricing, their use in the networks becomes more economical. Keywords: distributed energy resource (DER); dynamic pricing; mixed-integer linear programming (MILP); renewable heat incentive (RHI); feed-in tariff (FIT); electricity storage in batteries.}, language = {en} } @misc{SidnellClarkeDorneanuetal., author = {Sidnell, Tim and Clarke, Fiona and Dorneanu, Bogdan and Mechleri, Evgenia and Arellano-Garc{\´i}a, Harvey}, title = {Optimal design and operation of distributed energy resources systems for residential neighbourhoods}, series = {Smart Energy}, volume = {4}, journal = {Smart Energy}, issn = {2666-9552}, doi = {10.1016/j.segy.2021.100049}, abstract = {Different designs of distributed energy resources (DER) systems could lead to different performance in reducing cost, environmental impact or use of primary energy in residential networks. Hence, optimal design and management are important tasks to promote diffusion against the centralised grid. However, current operational models for such systems do not adequately analyse their complexity. This paper presents the results of a mixed-integer linear programming (MILP) model of distributed energy systems in the residential sector which builds up on previous work in this field. A superstructure optimisation model for design and operation of DER systems is obtained, providing a more holistic overview of such systems by including the following novel elements: a) Design and utilisation of a network with integrated heating/cooling pipelines and microgrid connections between neighbourhoods; b) Exploration of use of feed-in tariffs (FITs), renewable heat incentives (RHIs) and the ability to buy/sell from/to the national grid. It is shown that the (DER network mitigates around 30-40\% of the CO2 emissions per household, compared with "traditional generation". Money from FITs, RHIs and sales to the grid, as well as reduced grid purchases, make DER networks far more economical, and even profitable, compared to the traditional energy consumption.}, language = {en} } @misc{SaavedraAlejandroParedesFloresSantosetal., author = {Saavedra, Stephy and Alejandro-Paredes, Luis and Flores-Santos, Juan Carlos and Flores-Fern{\´a}ndez, Carol Nathali and Arellano-Garc{\´i}a, Harvey and Zavaleta, Amparo Iris}, title = {Optimization of lactic acid production by Lactobacillus plantarum strain Hui1 in a medium containing sugar cane molasses}, series = {Agronom{\´i}a Colombiana}, volume = {39}, journal = {Agronom{\´i}a Colombiana}, number = {1}, issn = {0120-9965}, doi = {10.15446/agron.colomb.v39n1.89674}, pages = {98 -- 107}, abstract = {The aim of this study was to optimize lactic acid production by a native strain (Huil) of Lactobacillus plantarum isolated from a Peruvian Amazon fruit (Genipa americana) in a medium supplemented with an agroindustrial by-product such as sugar cane molasses. Optimization was performed though one-factor-at-a-time studies followed by the Placket-Burman and central composite designs. The data were analyzed by using the Statistica® 10 software. Several carbon, nitrogen and ion sources were tested, and the optimum concentration of lactic acid achieved was 84.2 g L-1 in a medium containing as follows (in g L-1): meat extract, 18.69; tryptone, 7.88; sugar cane molasses, 140; calcium carbonate, 15; dipotassium phosphate, 1; manganese phosphate, 0.03; sodium acetate, 5, and magnesium sulphate, 0.2. In addition, a high degree of conversion from sugar cane molasses to lactic acid was obtained (Yp/e 0.898 g g-1). These results indicate the potential of Lactobacil-lus plantarum strain Hui1 to produce lactic acid in a medium supplemented with sugar cane molasses, an underutilized industrial by-product.}, language = {en} } @incollection{SebastiaSaezMechleriArellanoGarcia, author = {Sebastia-Saez, Daniel and Mechleri, Evgenia and Arellano-Garc{\´i}a, Harvey}, title = {Advancing CCSU Technologies with Computational Fluid Dynamics (CFD): A Look at the Future by Linking CFD and Process Simulations}, series = {Engineering Solutions for CO2 Conversion}, booktitle = {Engineering Solutions for CO2 Conversion}, editor = {Ramirez Reina, Tomas and Arellano-Garc{\´i}a, Harvey and Odriozola, Jos{\´e} Antonio}, edition = {1st edition}, publisher = {Wiley-VCH GmbH}, address = {Weinheim, Germany}, doi = {10.1002/9783527346523.ch2}, pages = {29 -- 84}, abstract = {This chapter discusses the state of the art of the numerical modeling for carbon capture, storage and utilization (CCSU) technologies, covering the entire chain. The chapter opens with a note on the different modeling techniques available depending on the length and time scale and focuses thereafter on the application of computational fluid dynamics to CCSU and their link to process simulations. The chapter intends to provide the reader with guidelines on the numerical techniques available and how these methods can help gain insight into features relevant to the design and performance evaluation in the field of CCSU.}, language = {en} } @misc{GonzalezAriasGonzalezCastanoArellanoGarcia, author = {Gonzalez-Arias, Judith and Gonzalez-Castano, Miriam and Arellano-Garc{\´i}a, Harvey}, title = {Utilization of CO2-Rich Residues for Syngas Production: Strategies for Catalyst Design}, series = {AIChE Annual Meeting, November 15, 2021}, journal = {AIChE Annual Meeting, November 15, 2021}, isbn = {978-0-8169-1116-5}, abstract = {Compared to a Reverse Water Gas Shift (RWGS) process carried out under ideal conditions, the valorization of CO2-rich residues involve additional challenges. Indeed, for an ideal RWGS reaction unit, the CO2 methanation reaction and the constitution of carbon deposits via Boudouard reaction are the main side reactions to take into consideration. For CO2-rich residues derived from biomass treatment and heavy metal industries, the presence of CH4 and CO species (among others) constitute an, although often disregarded, much complex panorama where side reactions like CO methanation, dry reforming of methane, the forward Water Gas Shift reaction and the decomposition of CO and CH4 resulting in carbon deposits, are occurring to some extent within the catalytic reactor. This work aimed at designing advanced catalytic systems capable of converting the CO2/CO/CH4 feedstocks into syngas mixtures. Thus, with the RWGS reaction considered as the major process, this work focusses on the side reactions involving CO/CH4 species. In this context, a series Cu-MnOx/Al2O3 spinel derived catalysts were optimized for syngas production in presence of CO and CH4 fractions. Once the optimal active phase was determined, the optimal Cu contents and the impact of the support nature (Al2O3, SiO2-Al2O3 and CeO2-Al2O3) was evaluated for the valorization of realistic CO2-rich feedstocks. Remarkably, the obtained outcomes underline operative strategies for developing catalytic systems with advanced implementation potential. For that aim, the catalyst design should present, along with an active and selective phase for RWGS reaction, superior cooking resistances, activities towards methane reforming and low tendencies towards the forward WGS reaction. Further developments should tackle difficult tasks like improving the RWGS reaction rate while inhibiting the forwards WGS reaction as well as improving the CH4 conversion to CO without affecting the process selectivity. Strategies towards advancing catalytic systems capable of operating under variable conditions also arise as appealing routes.}, 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} }