Coordinating industrial production and cogeneration systems to exploit electricity price fluctuations

Las fluctuaciones en el precio de la electricidad, procedentes de la aplicación de programas de respuesta de la demanda, son una oportunidad para que las industrias que cuenten con sistemas de cogeneración puedan reducir sus costes de producción mientras hacen que la red eléctrica sea más estable y segura en su conjunto. Dada la cantidad de factores involucrados y la dificultad que esto supone a la hora de tomar decisiones, en esta tesis se presenta una metodología basada en optimización dinámica que permite la gestión óptima de ambos sistemas y se aplica en simulación al caso de estudio de una industria azucarera. Como principales resultados, se ha obtenido que utilizando la metodología propuesta los costes variables de producción se pueden reducir hasta un 2.55% si se utiliza una tarifa por tramos típica, y en torno a un 5.41% si se utilizan los precios dados por el mercado eléctrico directamente.Departamento de Ingeniería de Sistemas y AutomáticaDoctorado en Ingeniería Industria

Producción de biobutanol a partir de subproductos de industria agroalimentaria. Análisis de estrategias en operación en continuo

Se ha estudiado la viabilidad de la operación en continuo de la fermentación ABE utilizando sacarosa como sustrato. Se han empleado dos biorreactores colocados en serie, tratando así de imitar las fases de crecimiento en discontinuo llevadas a cabo por la bacteria Clostridium beijerinckii DSM 6422. Para ello primeramente se han llevado a cabo una serie de experimentos en discontinuo a partir de los cuales se ha encontrado la concentración de sustrato más conveniente, y los parámetros necesarios para un posterior dimensionado de la planta piloto en continuo. En dicha planta finalmente se han efectuado varios experimentos empleando diversas estrategias de arranque hasta alcanzar la que se ha considerado como más conveniente. Como resultados se ha obtenido una concentración final de butanol en régimen estacionario de 1,01 g/l, y de 0,35 g/l de acetona utilizando una concentración de sacarosa de 30 g/l tras 250 horas de experimentación.Departamento de Ingeniería Química y Tecnología del Medio AmbienteGrado en Ingeniería Químic

Diseño en simulación de estructuras de control de una sección de evaporación de la indústria azucarera orientado a una mejora de la eficiencia energética.

En este trabajo se desarrolla un modelo de la sección de evaporación de una industria azucarera utilizando una herramienta de simulación dinámica orientada a objetos como es EcosimPro. Después de analizar las carencias de los sistemas de control que habitualmente se usan en la planta real, se ha utilizado el modelo creado para diseñar algunas estrategias de control que traten de solventar los problemas actuales. En particular, dada la naturaleza multivariable del proceso modelado se ha realizado un estudio de la interacción entre las distintas variables, de manera que las estrategias presentadas pudieran ser controlables presentando el menor grado de acoplamiento posible. Una vez simuladas se ha seleccionado la mejor para proponer una serie de índices que midan la eficiencia energética del sistema bajo estudio. Dichos índices pueden ser usados por un controlador ubicado por encima de la estructura de control presentada para calcular los valores óptimos de ciertas consignas. Palabras clave: EcosimPro, evaporación, industria azucarera, eficiencia energética, estructura de control.Departamento de Ingeniería de Sistemas y AutomáticaMáster en Investigación en Ingeniería de Procesos y Sistemas Industriale

Infraestructura para explotación de datos de un simulador azucarero

[Resumen] En este trabajo mostramos el desarrollo de una posible infraestructura para implementar algoritmos RTO (Real Time Optimization, optimización en tiempo real) en un sistema industrial. Para ello, construiremos el sistema sobre un simulador de una factoría azucarera que nos permita probar los algoritmos en simulación. Como base de datos industrial que permita el almacenamiento y análisis de los datos usaremos el PI System de la empresa Osisoft®. Finalmente, como entorno desde el que probar los algoritmos RTO usaremos Matlab de la empresa Mathworks®.Ministerio de Economía y Competitividad; DPI2015-70975-

Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Modeling On-Site Combined Heat and Power Systems Coupled to Main Process Operation

Many production processes work with on-site Combined Heat and Power (CHP) systems to reduce their operational cost and improve their incomes by selling electricity to the external grid. Optimal management of these plants is key in order to take full advantage of the possibilities offered by the different electricity purchase or selling options. Traditionally, this problem is not considered for small cogeneration systems whose electricity generation cannot be decided independently from the main process production rate. In this work, a non-linear gray-box model is proposed in order to deal with this dynamic optimization problem in a simulated sugar factory. The validation shows that with only 52 equations, the whole system behavior is represented correctly and, due to its structure and small size, it can be adapted to any other production process working along a CHP with the same plant configuration

HMI for the optimal management of the electricity production in a sugar factory

[Resumen] La optimización de la operación de procesos industriales, se erige como una base fundamental de la nueva revolución industrial. Sin embargo, su implementación en el día a día de las empresas, muchas veces es lastrada debido a la necesidad de conocimientos de programación por parte del usuario final, y lo poco intuitivos que son los entornos desde los cuales se puede ejecutar. En este artículo, se presenta una propuesta para la interacción y manejo de un algoritmo desarrollado en Python, que trata de optimizar la operación de una planta azucarera simulada que participa en el mercado diario eléctrico español. Para ello, se ha desarrollado una Interfaz Hombre Máquina, que actúa como enlace entre optimización y usuario, y que ha sido implementada mediante el software industrial Wonderware y el estándar de comunicaciones OPC UA. Como resultado, el operario es capaz de lanzar optimizaciones con facilidad, e interpretar sus resultados sin necesitar conocimiento alguno de programación.[Abstract] The optimization of the operation of industrial processes, stands as a fundamental basis of the new industrial revolution. However, its implementation in the industry daily work is often limited due to the operator’s lack of programming knowledge, and the counter-intuitive environments where the optimization is programmed and executed. In this article, we present a proposal for the interaction and management of an algorithm developed in Python, which seeks to optimize the operation of a simulated sugar plant that participates in the Spanish electricity daily market. For this purpose, a Human Machine Interface has been developed, which works as a link between the optimization and the final user. It has been implemented using the industrial software Wonderware and the communication standard OPC UA. As a result, the operator is able to run optimizations easily, and interpret their results without the need of any programming knowledge. This is key in order to push the use of optimization in the industry.Ministerio de Ciencia, Innovación y Universidades; PGC2018-099312-B-C31Gobierno de Castilla y León; CLU 2017-0

Optical properties of transparent glass–ceramics containing Er3+-doped sodium lutetium fluoride nanocrystals

Transparent glass–ceramics containing Er3+-doped sodium lutetium fluoride nanocrystals for photonic applications have been synthesized. Glass transition temperature, softening temperature, and crystallization temperature were estimated by dilatometry and differential thermal analysis. Proper heat treatments were selected to crystallize lutetium fluoride nanocrystals. X-ray diffraction analysis was carried out to identify the crystalline phase and the crystal size. HRTEM indicates that the base glass is phase separated in droplets enriched in Lu, Na, F, and also Er ions. The thermal treatment induces the crystallization inside the droplets. The optical characterization, which includes absorption and steady-state and time-resolved emission spectroscopy under one- and two-photon excitation, shows the differences between the phase-separated base glass and its corresponding glass–ceramic. The reduction of the Judd–Ofelt parameter Ω2 together with the increase of the fluorescence lifetimes as compared to the glass sample confirms the presence of Er3+ ions in a crystalline environment in the glass–ceramic samples. Moreover, an enhancement of the green and red up-converted emissions (as well as the weak blue emission) is observed in the glass–ceramic, indicating the Er3+ incorporation into the nanocrystals. The possible excitation mechanisms responsible for this up-conversion luminescence are discussed on the basis of lifetime measurement results.This work was supported by the Spanish Government under projects MAT2013-48246-C2-1-P and MAT2013-48246-C2-2-P, and Basque Country Government IT-659-13. A. Miguel acknowledges financial support from the University of the Basque Country UPV-EHU. A. de Pablos-Martín thanks FhG Internal Programs under Grant No.Attract 692 280.Peer reviewe