The 7th International Symposium on Design, Operation and Control of Chemical Processes (PSE ASIA 2016)

Producción CientíficaA Solar-Energy Powered Desalination System is proposed and evaluated here. It is based on the use of Solar Multi-effect Distillation (S-MED) plants that integrate osmotic energy recovery systems, which makes it possible to improve the efficiency of the process, providing a cost-effective approach for desalination using solar energy.This work was funded by Ministerio de Ciencia e Innovación (Spain) under grant DPI2014-54530-R

Osmotic energy recovery from Reverse Osmosis using two-stage Pressure Retarded Osmosis.

Producción CientíficaThe integration of Pressure Retarded Osmosis (PRO) with Seawater Reverse Osmosis (SWRO) is studied here, concentrating on the effect on the overall energy consumption and on the effluents. For this, two alternative designs are evaluated: a previously studied one-stage PRO (SWRO-1PRO) and a newly proposed two-stage PRO (SWRO-2PRO). The analysis results obtained from extrapolation of laboratory data using models show better performance for SWRO-2PRO (without using external impaired low-salinity water flows). The improvement of performance thanks to PRO increases with the increase of the feed concentration and flow.CICYT DPI2014-54530-

Green energy generation by pressure retarded osmosis: State of the art and technical advancement—review

Producción CientíficaPressure-retarded osmosis (PRO) is a method for converting salinity gradients to power by allowing water to flow through a semi-permeable membrane against an applied hydraulic pressure. PRO already has a long history, starting from the middle of the last century, and has rapidly improved in recent years. In this paper, we present a historical development of PRO since its inception: the development of this renewable energy process has gone through several stages, depending on technological developments, worldwide energy demands, and environmental concerns. The technological progress of the process is also studied, as well as its cost viability and environmental impact. Finally, some ideas to further develop the PRO process and mitigate its detrimental effects are discussed.This work was funded by Ministerio de Ciencia e Innovación (Spain) under grant DPI2014-54530-R

Offshore hydrogen production from wave energy

The aim of this paper is to present and evaluate a proposal for designing an off-grid offshore electrolysis plant powered by wave energy. This plant includes PEM electrolyzers, a Reverse Osmosis system to produce water with adequate conductivity, a compression unit to store the hydrogen for transport, and batteries for temporary storage of electricity for short-time balances. First, the systems that compose the proposed plant are justified and described. Then a proposal for sizing these subsystems is given, based on using buoy-measured data at the expected location and simple mathematical models of the different sections of the plant. Finally the performance of the plant in a specific location is tested in detailed by using measured data, studying the influence of sizing on the expected performance

Potential and analysis of an osmotic power plant in the Magdalena River using experimental field-data

Producción CientíficaThe Magdalena River mouth in Colombia is studied as a candidate site for a renewable power plant via osmotic energy technology, using pressure retarded osmosis. This power generation plant would operate through the controlled mix of two flows with different salinities (river water and seawater in this case study). A preliminary design of a pressure retarded osmosis power plant is proposed here by means of experimental data acquisition on-site at the river mouth. The obtained net power production is shown to reach 6 MW, with adequate membrane power densities above 5 W/m2. These promising results consider energetic losses involved in the process, which have been further analysed to propose improvement targets in pretreatment processes and membrane permeability.Spanish Ministry of Economy through the project DPI2014-54530-R and the predoctoral grant BES-2015-073871, by the Junta de Castilla y León and European Regional Development Fund, UIC 233, and by the Banco Santander Iberoamérica Research Grants program. Field data acquisition was funded by COLCIENCIAS -Department of Science, Technology and Innovation of Colombia- by the project: 121571451074, resolution 881 – 2015

Integrating dynamic economic optimization and nonlinear closed-loop GPC: Application to a WWTP

Producción CientíficaIn this paper, a technique that integrates methods of dynamic economic optimization and real-time control by including economic model predictive control and closed-loop predictive control has been developed, using a two-layer structure. The upper layer, which consists of an economic nonlinear MPC (NMPC), makes use of the updated state information to optimize some economic cost indices and calculates in real time the economically optimal trajectories for the process states. The lower layer uses a closed-loop nonlinear GPC (NCLGPC) to calculate the control actions that allow for the outputs of the process to follow the trajectories received from the upper layer. This paper also includes the theoretical demonstration proving that the deviation between the state of the closed-loop system and the economically time varying trajectory provided by the upper layer is bounded, thus guaranteeing stability. The proposed approach is based on the use of nonlinear models to describe all the relevant process dynamics and cover a wide operating range, providing accurate predictions and guaranteeing the performance of the control systems. In particular, the methodology is implemented in the N-Removal process of a WWTP and the results demonstrate that the method is effective and can be used profitably in practical cases such as the chemical, refinery and petrochemical process industries.Ministerio de Economía y Competitividad - (project DPI2015- 67341C21R)Junta de Castilla y Leon y Fondo Europeo de Desarrollo Regional (FEDER) - (grants CLU 2017-09 and UIC 233

21st World Hydrogen Energy Conference 2016

This work deals with a ruled-based control strategy to produce hydrogen from wind and wave energy in an offshore platform. These renewable energies feed a set of alkaline electrolyzers that produce H2. The proposed control system allows regulating the operation of the electrolyzers, taking into account the energy available and optimizing the performance of the plant. Simulation results obtained are presented, showing correct operation of the platform under this proposed control.Ministerio de Ciencia e Innovación (Proyect DPI2014-54530-R

Effect of the operating temperature on hydrodynamics and membrane parameters in pressure retarded osmosis

Producción CientíficaThe osmotic energy recovered by pressure-retarded osmosis from flows of different salinities is affected by the temperature, so its effect on hydrodynamic and membrane parameters is studied here. It is shown by models and experimental results that raising the temperature of the solutions leads to a variation in the mass transfer coefficient, the boundary layer, the diffusion coefficient, the solute resistivity, and the permeability, therefore, affecting the water flux. Consequently, the expected power density is improved at high temperatures, although, the salt flux diffusion increases. Laboratory results are presented using solutions at different concentrations and temperatures to validate the analysis.Funded by Mineco Project DPI2014-54530-R and FEDER fund

Offshore desalination using wave energy

This paper evaluates the design of an offshore desalination plant currently under preliminary development.The purpose is to test the feasibility of producing drinkable water using wave energy in out-of-sight installations, as an alternative for those locations where land use, civil engineering works, and/or environmental impact make a coast-based solution inadequate. After describing the components, a proposal for sizing them is studied, based on using buoy-measured data at the expected location and their mathematical models of the different sections of the plant. Finally, by using measured buoy data, the influence of sizing on the expected performance is studied for a specific location, and one of the designs is developed in detail

XIV Simposio CEA de Ingeniería de Contro

Este proyecto de tesis propone un Sistema de Gestión de Energía (EMS) para equilibrar la producción de energías renovables con su consumo en un conjunto de unidades de electrólisis basado en ideas de Modelo de Control Predictivo (MPC). Este EMS regula el punto de operación para cada electrolizador y sus conexiones y desconexiones usando un algoritmo de Programación- Cuadrática-Mixta-Entera (MIQP). Un caso de estudio se muestra para una instalación compuesta por fuentes de energía provenientes del viento y de las olas de mar y un conjunto de 3 electrolizadores. Se ha validado usando datos meteorológicos en una localización concreta y se ha comprobado un funcionamiento correcto del EMS propuesto.Ministerio de Ciencia e Innovación (Proyect DPI2014-54530-R