Advancing sustainability in the water-energy nexus : optimization of reverse electrodialysis energy recovery from salinity gradients | Avanzando en la sostenibilidad del nexo agua-energía. Optimización de la recuperación de energía de gradientes salinos mediante electrodiálisis reversa

La energía del gradiente salino (EGS) es una fuente renovable abundante ampliamente desaprovechada para complementar y diversificar el mix energético actual, intensivo en emisiones y uso de agua, y apoyar la sostenibilidad y circularidad del, intensivo en energía, sector del agua. Esta tesis doctoral propone un marco metodológico para avanzar en el diseño óptimo en costes y medioambientalmente sostenible del proceso electrodiálisis reversa (EDR) en la recuperación de EGS de corrientes residuales del sector del agua. Este marco integra un modelo matemático del dispositivo EDR validado experimentalmente, una caracterización medioambiental mediante análisis de ciclo de vida, y un modelo de programación disyuntivo generalizado para la optimización de sistemas EDR a gran escala implementados en plantas desaladoras o estaciones depuradoras de aguas residuales. La herramienta de diseño propuesta puede ser de interés en del proceso de toma de decisiones que apoye la promoción y despliegue comercial de la EDR.

Salinity gradient energy (SGE) is a vast yet largely untapped renewable source for complementing and diversifying the current carbon- and water-intensive energy mix and supporting the sustainability and circularity of the energy-intensive water sector. This doctoral thesis proposes a methodological framework for advancing the cost-optimal and environmentally sustainable design of reverse electrodialysis (RED) process for SGE recovery from waste streams in the water sector. This framework combines an experimentally validated mathematical model of the RED device, an environmental characterization through life cycle assessment, and a generalized disjunctive programming model to optimize large-scale RED systems deployed in desalination plants or wastewater treatment plants. The proposed design tool may be of interest in the decision-making process that supports the promotion and commercial deployment of RED technology.

This research was financially supported through the R&D Projects CTM2017-87850-R and RTI2018-093310-B-I00 funded by the Spanish Ministry of Science and Innovation (MCIN/AEI/ 10.13039/501100011033) and by “ERDF A way of making Europe”, the R&D Project PDC2021-120786-I00 funded by the MCIN/AEI/10.13039/501100011033 and “European Union NextGenerationEU/PRTR, the R&D Project RM16-XX-046- SODERCAN/FEDER funded by SODERCAN, and the R&D Project LIFE19 ENV/ES/000143 funded by the LIFE Programme of the European Union. Carolina Tristán acknowledges the financial support from the research fellowship PRE2018-086454 funded by the Spanish Ministry of Science and Innovation (MCIN/AEI/ 10.13039/501100011033) and “ESF Investing in your future”.