Phenomenological based model of hydrogen production using an alkaline self-pressurized electrolyzer

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The aim of this work is to develop the phenomenological based modeling of a self-pressurized alkaline electrolyser with the objective of predicting the cross-contamination of the gases produced. A proposed model, built in Matlab®, represents the dynamical evolution in real electrolysers, and anticipates operational variables: level, pressure and all concentrations. Dynamic responses in the concentrations of the electrolytic cell, and variations in both level and pressure at the chamber due to the change in current and diffusivity, are reported. The equations by which the variables can be computed are also presented. The proposed model is ready for the corresponding adjustment of parameters based on experimental measurements taken from an available prototype and through a suitable identification process.Peer ReviewedPostprint (author's final draft

Mathematical modelling and advanced control design applied to high-pressure electrolyzers for hydrogen production

Tesi en modalitat de cotutela: Universitat Politècnica de Catalunya i Instituto Tecnológico de Buenos Aires. Aplicat embargament des de la defensa de la tesi fins al dia 30 de setembre de 2022This thesis is mainly dedicated to the study of high-pressure alkaline electrolysis. Alkaline electrolysis is a well established technology and is commercially available. However, the operation at high pressure for dispensing compressors was not fully investigated. Moreover, there is a lack of dynamic models and publications related to control strategies. Therefore, this thesis contributes especially in the modelling and control of high pressure alkaline electrolyzers in order to improve purity of produced gases. The thesis is framed within a general idea about the renewed concern for the care of the environment, which involves reducing greenhouse gas emissions without sacrificing modern comforts. Widespread proposal focuses on energy produced from renewable sources and its subsequent storage and transportation based on hydrogen. Currently, this gas applies to the chemical industry and its production is based on fossil fuels. The introduction of this energy vector requires the development of environmental-friendly methods for obtaining it. Existing techniques are presented and the main focus is made on electrolysis, a mature procedure. In turn, some developed proposals as previous steps to the hydrogen economy are presented. Moreover, some lines of research to improve electrolysis technology are commented. Afterwards, a phenomenological-based semiphysical model for a self-pressurized alkaline electrolyzer is proposed. The model, based on mass and energy balances, represents the dynamic behavior of hydrogen and oxygen production using electrolysis. The model allows to anticipate operational variables as dynamic responses in the concentrations of the electrolytic cell, and variations in both, level and pressure, at the gas separation chambers due to the change in electric current. The model parameters have been adjusted based on experimental measurements taken from an available prototype and through a suitable identification process. Simulation results replicate the current dynamic response of the experimental self-pressurized electrolyzer assembly. This model proves to be useful in the improvement of the control of gas production rate in this kind of assemblies, both as a validated simulation platform and as a source of reduced order models for model-based control design. Later, this thesis presents two control strategies that mitigate the cross contamination of H2 and O2 in a high-pressure alkaline electrolyzer, which consequently increases the supplied purity of the gases: one based on a decoupled PI scheme and the other based on optimal control tools. In order to reduce the diffusion of gases through the membrane, the controllers establish the opening of two outlet valves based on the pressure of the system and the difference in liquid level between both separation chambers. Therefore, two multiple input - multiple output controllers are designed. For this purpose, the high-fidelity model previously mentioned was simplified in order to obtain a control-oriented model. The proposed controllers were evaluated in simulation using the high-fidelity nonlinear model in a wide operating range, which resulted in less than 1% impurity of gases. In addition, tests were carried out in the prototype electrolyzer where the operation of the PI control was verified, obtaining even better results, with a maximum contamination of 0.2%.Aquesta tesi es dedica principalment a l'estudi de l'electròlisi alcalina d'alta pressiò. L'electròlisi alcalina és una tecnologia ben establerta i està disponible comercialment. Tanmateix, no s'ha investigat completament el funcionament a alta pressiò per a la distribuciò de compressors. A més, falten models dinàmics i publicacions relacionades amb les estratègies de control. Per tant, aquesta tesi contribueix especialment en el modelatge i control d'electrolitzadors alcalins d'alta pressió per tal de millorar la puresa dels gasos produïts. La tesi s'emmarca dins d'una idea general sobre la renovada preocupació per la cura del medi ambient, que consisteix a reduir les emissions de gasos d'efecte hivernacle sense sacrificar les comoditats modernes. Una proposta generalitzada es centra en l'energia produïda a partir de fonts renovables i el seu posterior emmagatzematge i transport basat en hidrogen. Actualment, aquest gas s'aplica a la indústria química i la seva producció es basa en combustibles fòssils. La introduccio d'aquest vector energètic requereix el desenvolupament de mètodes respectuosos amb el medi ambient per obtenir-lo. Es presenten les tècniques existents i es centra principalment en l'electròlisi, un procediment madur. Al seu torn, es presenten algunes propostes desenvolupades com a passos previs a l'economia de l'hidrogen. A més, es comenten algunes línies de recerca per millorar la tecnologia d'electròlisi. Posteriorment, es proposa un model semifísic de base fenomenològica per a un electrolitzador alcalí auto-pressuritzat. El model, basat en els balanços de massa i energia, representa el comportament dinàmic de la producció d'hidrogen i oxigen mitjançant electròlisi. El model permet anticipar variables operatives com a respostes dinàmiques en les concentracions de la cèl·lula electrolítica i variacions en el nivell i la pressió de les cambres de separació de gas a causa del canvi de corrent elèctric. Els paràmetres del model s'han ajustat en funció de mesures experimentals obtingudes en d'un prototip disponible i mitjançant un procés d'identificació adequat. Els resultats de la simulació repliquen la resposta dinàmica actual del conjunt experimental d'electrolitzador auto-pressuritzat. Aquest model demostra ser útil per millorar el control de la taxa de producció de gas en aquest tipus d'assemblatges, tant com a plataforma de simulació validada com a font de models d'ordre reduït per al disseny de control basat en models. Posteriorment, aquesta tesi presenta dues estratègies de control que mitiguen la contaminació creuada de H2 i O2 en un electrolitzador alcalí d'alta pressió, que en conseqüència augmenta la puresa subministrada dels gasos: una basada en un esquema de PI desacoblat i l'altra basada en un esquema de control òptim. Per tal de reduir la difusió de gasos a través de la membrana, els controladors estableixen l'obertura de dues vàlvules de sortida en funció de la pressió del sistema i de la diferència de nivell de líquid entre les dues cambres de separació. Per tant, es dissenyen dos controladors d'entrada i sortida múltiple. Amb aquest propòsit, el model d'alta fidelitat esmentat anteriorment s'ha simplificat per obtenir un model orientat al control. Els controladors proposats han estat avaluats en simulació mitjançant el model no lineal d'alta fidelitat en un ampli rang operatiu, el qual ha resultat en una impuresa de gasos inferior a 1%. A més, es van realitzar assajos al electrolitzador prototip on es va constatar el funcionament de l'control PI, obtenint inclusivament millors resultats, amb una contaminació màxima de 0,2%.Esta tesis está dedicada principalmente al estudio de la electrólisis alcalina de alta presión. La electrolisis alcalina es una tecnología bien establecida y está disponible comercialmente. Sin embargo, la operación a alta presión para dispensar el uso de compresores no ha sido investigada completamente. Además, hay una falta de modelos dinámicos y publicaciones relacionadas con las estrategias de control. Por tanto, esta tesis contribuye especialmente en el modelado y control de electrolizadores alcalinos de alta presión para mejorar la pureza de los gases producidos. La tesis se enmarca dentro de una idea general sobre la renovada preocupación por el cuidado del medio ambiente, que pasa por reducir las emisiones de gases de efecto invernadero sin sacrificar las comodidades modernas. La propuesta generalizada se centra en la energía producida a partir de fuentes renovables y su posterior almacenamiento y transporte a base de hidrogeno. Actualmente, este gas se utiliza en la industria química y su producción se basa en combustibles fósiles. La introducción de este vector energético requiere el desarrollo de métodos amigables con el medio ambiente para su obtención. Se presentan las técnicas existentes y se hace hincapié en la electrolisis, un procedimiento maduro. A su vez, se presentan algunas propuestas desarrolladas como pasos previos a la economía del hidrogeno. Además, se comentan algunas líneas de investigación para mejorar la tecnología de electrolisis. Posteriormente, se propone un modelo semifísico de base fenomenológica para un electrolizador alcalino autopresurizado. El modelo, basado en balances de masa y energía, representa el comportamiento dinámico de la producción de hidrogeno y oxígeno mediante electrolisis. El modelo permite anticipar variables operativas como respuestas dinámicas en las concentraciones de la celda electrolítica y variaciones tanto de nivel como de presión en las cámaras de separación de gases debido al cambio de corriente eléctrica. Los parámetros del modelo se han ajustado en base a medidas experimentales tomadas de un prototipo disponible y mediante un proceso de identificación adecuado. Los resultados de la simulación replican la respuesta dinámica actual del conjunto electrolizador autopresurizado experimental. Este modelo demuestra ser útil en la mejora del control de la tasa de producción de gas en este tipo de montajes, tanto como plataforma de simulación validada como fuente de modelos de orden reducido para el diseño de control basado en modelos. Después, esta tesis presenta dos estrategias de control que mitigan la contaminación cruzada de H2 y O2 en un electrolizador alcalino de alta presión, lo que consecuentemente aumenta la pureza suministrada de los gases: una basada en un esquema de PI desacoplado y otra basada en herramientas de control óptimo. Para reducir la difusión de gases a través de la membrana, los controladores establecen la apertura de dos válvulas de salida en función de la presión del sistema y la diferencia de nivel de líquido entre ambas cámaras de separación. Por lo tanto, se diseñan dos controladores de múltiples entradas y múltiples salidas. Para ello, se simplificó el modelo de alta fidelidad anteriormente mencionado para obtener un modelo orientado al control. Los controladores propuestos se evaluaron en simulación utilizando el modelo no lineal de alta fidelidad en un amplio rango operativo, lo que resultó en menos de 1% de impureza de gases. Además, se realizaron ensayos en el electrolizador prototipo donde se constató el funcionamiento de los controles PI y H1, obteniendo inclusive mejores resultados, con una contaminación máxima de 0;2 %.Postprint (published version

H2 purity control for highpressure alkaline electrolyzers

This paper proposes a control strategy that mitigates the cross contamination of H2 and O2 in a high-pressure alkaline electrolyzer, which consequently increases the supplied gases purity. In order to reduce the diffusion of gases through the membrane, the controller establishes the opening of two outlet valves based on the pressure of the system and the difference in liquid level between both separation chambers. Therefore, a multiple input - multiple output optimal controller is designed here. For this purpose, an available high-fidelity model was simplified in order to obtain a control-oriented model. The proposed controller was evaluated in simulation using the high-fidelity nonlinear model in a wide operating range and was compared with a pair of decoupled PI controllers. The resulting impurity of gases was below 1% in all cases.This work has been partially funded by the DEOCS project (DPI2016-76493-C3-3R).Peer ReviewedPostprint (author's final draft

Space Electrochemical Research and Technology

The proceedings of NASA's third Space Electrochemical Research and Technology (SERT) conference are presented. The objective of the conference was to assess the present status and general thrust of research and development in those areas of electrochemical technology required to enable NASA missions in the next century. The conference provided a forum for the exchange of ideas and opinions of those actively involved in the field, in order to define new opportunities for the application of electrochemical processes in future NASA missions. Papers were presented in three technical areas: the electrochemical interface, the next generation in aerospace batteries and fuel cells, and electrochemistry for nonenergy storage applications

Space Electrochemical Research and Technology

This document contains the proceedings of NASA's fourth Space Electrochemical Research and Technology (SERT) Conference, held at the NASA Lewis Research Center on April 14-15, 1993. The objective of the conference was to assess the present status and general thrust of research and development in those areas of electrochemical technology required to enable NASA missions into the next century. The conference provided a forum for the exchange of ideas and opinions of those actively involved in the field, in order to define new opportunities for the application of electrochemical processes in future NASA missions. Papers were presented in three technical areas: advanced secondary batteries, fuel cells, and advanced concepts for space power. This document contains the papers presented

Effect of the air pressure on electro-Fenton process

Electro-Fenton process is considered a very promising tool for the treatment of waste waters contaminated by organic pollutants refractant or toxic for microorganisms used in biological processes [1-6]. In these processes H2O2 is continuously supplied to an acidic aqueous solution contained in an electrolytic cell from the two-electron reduction of oxygen gas, directly injected as pure gas or bubbled air. Due to the poor solubility of O2 in aqueous solutions, two dimensional cheap graphite or carbon felt electrodes give quite slow generation of H2O2, thus resulting in a slow abatement of organics. In this context, we report here a series of studies [7-9] on the effect of air pressure on the electro-generation of H2O2 and the abatement of organic pollutants in water by electro-Fenton process. The effect of air pressure, current density, mixing and nature of the organic pollutant was evaluated. [1] E. Brillas, I. Sirés, M.A. Oturan, Chem. Rev., 109 (2009) 6570-6631. [2] C.A. Martínez-Huitle, M.A. Rodrigo, I. Sirés, O. Scialdone, Chem. Rev. 115 (2015) 13362–13407. [3] M. Panizza, G. Cerisola, Chem. Rev. 109 (2009) 6541–6569. [4] I. Sirés, E. Brillas, M.A. Oturan, M.A. Rodrigo, M. Panizza, Environ. Sci. Pollut. Res. 21 (2014) 8336–8367. [5] C.A. Martínez-Huitle, S. Ferro, Chem. Soc. Rev. 35 (2006) 1324–1340. [6] B.P.P. Chaplin, Environ. Sci. Process. Impacts. 16 (2014) 1182–1203. [7] O. Scialdone, A. Galia, C. Gattuso, S. Sabatino, B. Schiavo, Electrochim. Acta, 182 (2015) 775-780. [8] J.F. Pérez, A. Galia, M.A. Rodrigo, J. Llanos, S. Sabatino, C. Sáez, B. Schiavo, O. Scialdone, Electrochim. Acta, 248 (2017) 169-177. [9] A.H. Ltaïef, S. Sabatino, F. Proietto, A. Galia, O. Scialdone, O. 2018, Chemosphere, 202, 111-118

Pressurized CO2 Electrochemical Conversion to Formic Acid: From Theoretical Model to Experimental Results

To curb the severely rising levels of carbon dioxide in the atmosphere, new approaches to capture and utilize this greenhouse gas are currently being investigated. In the last few years, many researches have focused on the electrochemical conversion of CO2 to added-value products in aqueous electrolyte solutions. In this backdrop, the pressurized electroreduction of CO2 can be assumed an up-and-coming alternative process for the production of valuable organic chemicals [1-3]. In this work, the process was studied in an undivided cell with tin cathode in order to produce formic acid and develop a theoretical model, predicting the effect of several operative parameters. The model is based on the cathodic conversion of pressurized CO2 to HCOOH and it also accounts for its anodic oxidation. In particular, the electrochemical reduction of CO2 to formic acid was performed in pressurized filter press cell with a continuous recirculation of electrolytic solution (0.9 L) at a tin cathode (9 cm2) for a long time (charge passed 67’000 C). It was shown that it is possible to scale-up the process by maintaining good results in terms of faradaic efficiency and generating significantly high concentrations of HCOOH (about 0.4 M) [4]. It was also demonstrated that, for pressurized systems, the process is under the mixed kinetic control of mass transfer of CO2 and the reduction of adsorbed CO2 (described by the Langmuir equation), following our proposed reaction mechanism [5]. Moreover, the theoretical model is in good agreement with the experimental results collected and well describes the effect of several operating parameters, including current density, pressure, and the type of reactor used. 1. Ma, S., & Kenis, P. J. (2013). Electrochemical conversion of CO2 to useful chemicals: current status, remaining challenges, and future opportunities. Current Opinion in Chemical Engineering, 2(2), 191-199. 2. Endrődi, B., Bencsik, G., Darvas, F., Jones, R., Rajeshwar, K., & Janáky, C. (2017). Continuous-flow electroreduction of carbon dioxide. Progress in Energy and Combustion Science, 62, 133-154. 3. Dufek, E. J., Lister, T. E., Stone, S. G., & McIlwain, M. E. (2012). Operation of a pressurized system for continuous reduction of CO2. Journal of The Electrochemical Society, 159(9), F514-F517. 4. Proietto, F., Schiavo, B., Galia, A., & Scialdone, O. (2018). Electrochemical conversion of CO2 to HCOOH at tin cathode in a pressurized undivided filter-press cell. Electrochimica Acta, 277, 30-40. 5. Proietto, F., Galia, A., & Scialdone, O. (2019) Electrochemical conversion of CO2 to HCOOH at tin cathode: development of a theoretical model and comparison with experimental results. ChemElectroChem, 6, 162-172

Charakterisierung der Leistungsfähigkeit von PEM-Wasser-Elektrolysezellen, die mit und ohne Strömungskanäle arbeiten, basierend auf experimentell validierten semi-empirischen gekoppelten physikalischen Modellen

PEM water electrolysis is a clean technology for hydrogen production. In spite of its many advantages, the costs of the conventional PEM electrolysis cell makes it commercially less competitive vis-à-vis its peers. An alternative cell design has been proposed which has up to a 25 % costs advantage over the conventional cell. In this alternative cell design, the flow channel plate which bears the most costs in the conventional cell design has been replaced with a 3-D Porous Transport Layer (PTL) structure. It has however, been observed that the conventional cell by far out performs the low cost cell at high current density operations, due to increased mass transport limitation in the later. Industrial and commercial hydrogen production efforts are focused towards high current density operation (> 3 A/cm²), so the alternative cell design must be optimized for mass transport limitation. PEM water electrolysis is a clean technology for hydrogen production. In spite of its many advantages, the costs of the conventional PEM electrolysis cell makes it commercially less competitive vis-à-vis its peers. An alternative cell design has been proposed which has up to a 25 % costs advantage over the conventional cell. In this alternative cell design, the flow channel plate which bears the most costs in the conventional cell design has been replaced with a 3-D Porous Transport Layer (PTL) structure. It has however, been observed that the conventional cell by far out performs the low cost cell at high current density operations, due to increased mass transport limitation in the later. Industrial and commercial hydrogen production efforts are focused towards high current density operation (> 3 A/cm²), so the alternative cell design must be optimized for mass transport limitation. This work seeks to understand the source of, and to eliminate the mass transport losses in the alternative cell design to get it performing at least as good as the conventional cell at current densities up to 5 A/cm². A 2-D non-isothermal semi-empirical fully-coupled models of both cell designs have been developed and experimentally validated. The developed validated models were then used as tools to simulate and predict the best operating conditions, design parameters and micro-structural properties of the PTL at which the mass transport issues in the alternate cell will be at its minimum, at high current densities. The models are based on a multi-physics approach in which thermodynamic, electrochemical, thermal and mass transport sub-models are coupled and solved numerically, to predict the cell polarization and individual overpotentials, as well as address heat and water management issues. The most unique aspect of this work however, is the development of own semi-empirical equations for predicting the mass transport overpotential imposed by the gas phase (bubbles) at high current densities. For the very first time, calculated polarization curves up to 5 A/cm² have been validated by own experimental data. The results show that, the temperature and pressure, water flowrate and thickness of the PTL are the critical parameters for mitigating mass transport limitation. It was found that, for the size of the cells studied (25 cm² active area each), when both cells are operating at the same temperature of 60 °C, alternative design will have a comparable performance to the conventional designed cell even at 5 A/cm² current density when; the operating pressure is ≥ 5 bar, the feed water flowrate is ≥ 0.024l/min∙cm², PTL porosity is 50 %, PTL pore size is ≥ 11 µm and PTL thickness is 0.5 mm. At these operating, design and micro-structural conditions, the predicted difference between the polarizations of both cells will be only ~10 mV at 5 A/cm² operating current density.Die PEM Wasser Elektrolyse gilt als effiziente Technologie zur Herstellung von sauberem Wasserstoff zur Energiespeicherung. Trotz der vielen Vorteile führen hohe Kosten für die Produktion konventioneller Komponenten und Stacks zu einer nicht konkurrenzfähigen Technologie. Ein alternatives und kostengünstiges Zelldesign wurde vorgestellt, das, verglichen mit einem konventionellen Design, einen Kostenvorteil von bis zu 25 % hervorbringt. Bei diesem alternativen Zelldesign wird die Platte mit Strömungskanälen, die den größten Kostenanteil birgt, durch eine 3-D poröse Struktur (PTL) ersetzt. Bei hohen Stromdichten zeigt aber ein Design ohne Strömungskanäle niedrigere Leistungsdaten, was durch eine gesteigerte Limitierung des Massentransportes erklärt werden kann. Da sich die industrielle und kommerzielle Wasserstoffproduktion in Richtung hoher Stromdichten (> 3 A/cm²) entwickelt, scheint das erforderliche Verständnis von Massentransporteffekten offensichtlich das kosteneffiziente Design gegenüber dem konventionellen Design voran zu treiben. Diese Arbeit versucht den Ursprung von Massentransportlimitierung des kostengünstigen Zelldesigns zu verstehen und zu eliminieren. Um diese Zielvorgabe zu erreichen, wurden 2-D nicht-isotherme, semi-empirische, vollständig gekoppelte Modelle beider Zelldesigns entwickelt und experimentell validiert. Die entwickelten und validierten Modelle wurden als Werkzeug zur Simulation und Vorhersage der am besten geeigneten Betriebs- und Designparameter, sowie Eigenschaften der Mikrostrukur der PTL verwendet. Die hierin entwickelten Modelle basieren auf einem multiphysikalischen Ansatz, worin thermodynamische, elektrische und thermische Effekte sowie Massentransportuntermodelle gekoppelt und gelöst wurden, um sowohl die Zellpolarisation und individuelle Überpotentiale vorherzusagen, als auch Wärme- und Wassermanagement zu adressieren. Das Alleinstellungsmerkmal dieser Arbeit ist jedoch die Entwicklung von semi-empirischen Gleichungen, um die Überpotentiale der Massentransporthemmung, ausgehend von Gasblasen, vorhersagen zu können. Ebenso wurden zum ersten Mal berechnete PEM Wasser Elektrolyse Polarisationskurven bis zu einer Stromdichte von 5 A/cm² mit eigenen Daten validiert. Die Ergebnisse zeigen, dass Temperatur und Druck, sowie Wasserflußrate und Dicke der PTL die kritischen Parameter sind, um Massentransportlimitierung zu vermeiden. Es wurde sogar gezeigt, dass bei der verwendeten Zellgröße (aktive Fläche = 25 cm²) vergleichbare Leistungsdaten bei 60 °C und 5 A/cm² erreicht werden können, sofern der Betriebsdruck 5 bar übersteigt, die Wasserflussrate größer als 0.024 l/min ist, die Porosität der PTL 50 % übersteigt, die Porendurchmesser größer als 11 µm sind und die PTL Dicke bei 0.5 mm liegt. Bei diesen Parametern wurden Unterschiede zwischen den beiden Zelldesigns von etwa 10 mV bei 5 A/cm² vorhergesagt

Diseño y simulación de un controlador predictivo multivariable para un electrolizador alcalino

En este trabajo se diseña y simula un controlador predictivo basado en modelo multiobjetivo para un sistema complejo de un electrolizador alcalino. Se explica y se comenta el análisis de los datos y la información que se ha podido extraer sobre el electrolizador alcalino de alta presión con límite inferior de explosividad del H2 del 4 %. Los gases de H2 y O2, deben suministrarse a altas presiones para evitar el uso de compresores. Dado que la pureza del gas disminuye con las altas presiones, se espera aumentar la presión de funcionamiento posible evitando la contaminación con una estrategia de control adecuada. En la búsqueda de aumentar la presión de funcionamiento de los electrolizadores alcalinos, se necesitan estrategias de control para disminuir la contaminación cruzada de los gases y, en consecuencia, aumentar la pureza del hidrógeno suministrado. Cabe resaltar que este trabajo ha tomado como base el modelo desarrollado anteriormente por el grupo de investigación correspondiente, con lo que se inicia el diseño de los controladores predictivos teniendo como base el conocimiento del comportamiento del sistema en lazo cerrado con otros controladores diseñados e incluso implementados experimentalmente. El diseño parte del modelo lineal a controlar ya desarrollado e incorpora el cálculo de los cambios óptimos en las variables manipuladas para lograr el resultado deseado y comprobar su precisión frente a otros controladores planteados en ese trabajo precedente. En este sentido, la modelización y el control son cuestiones clave para mejorar el funcionamiento y el diseño. El controlador se probará en un modelo lineal de alta fidelidad del electrolizador y debe ser capaz de mantener la impureza por debajo del 1 % en todos los casos, manteniendo, prácticamente en todos los escenarios, la diferencia de nivel de solución líquida entre ambos SC por debajo de 4 mm y un error de presión máximo de 0,5 %. Naturalmente, se mostrará las pruebas realizadas en el sistema real para validar el modelo, una vez más, y la estrategia de control desarrollada. Finalmente, se presentan y discuten todos los resultados obtenidos del sistema de lazo cerrado resultante basado en control predictivo con sus consecuentes conclusiones