• Energy Research
• Embargo close
• ES close
• FI close

These 285 documents have been used for the three sections that are part of the results of this article (documents statistics, bibliometric analysis, and literature review statistics). For this purpose, it was necessary to carry out an exhaustive review of the 285 selected documents and to complement this information with the data provided by Scopus. The data-charting process was as follows: the four researchers agreed on the types of data to be extracted, two of them carried out the review while the other two supervised. If any type of data worthy of investigation emerged during the reading, it was discussed, and if appropriate, included, making it an iterative process. For each of the documents, the following variables were collected in a table: author/s, title of the document, year of publication, journal in which it was published, type of document (article or review), number of citations and citations per year, relevance (weighting given by Scopus), DOI, geographical location of researchers, abstract, author keywords and keywords suggested by Scopus, JIF, JCI and H-index information of the journal in which the document is published (with quartiles and percentiles), subject area categories provided by Scopus, territory studied, renewable energy source studied, research technique or methodology used, primary data source used and years collected. In addition, for articles using quantitative techniques, all variables included in each model have been collected.

The phenomenon of global change is prompting the implementation of measures aimed at mitigating various effects, with humans being primarily impacted. The objective of this investigation is to analyse the potential self-sufficiency in the built environment through the utilisation of energy generated by photovoltaic systems. These systems have the capacity to reduce or even eliminate the reliance on grid electricity and non-renewable energy sources. The study commences with the delineation of eight neighbourhoods within the city of Madrid, Spain, each characterised by a distinct building typology. In order to ascertain the degree of self-sufficiency, this study calculates the energy production from solar photovoltaic systems installed on rooftops, and then proceeds to assess the energy consumption of each building. The results of the analysis demonstrate the capacity of photovoltaic installations to meet the electricity demands of buildings, such as single-family houses, almost completely, and partially in others, such as multi-family dwellings with multiple units per floor. Furthermore, the impact of differences in building height and urban context on self-sufficiency potential is explored.

The use of bioethanol as a biofuel make it possible to reduce the dependence on fossil fuel and the greenhouse emissions. The advantage of bioethanol is that is obtained by fermentation of renewable resources that capture carbon dioxide during its growing providing a null net balance of carbon dioxide emissions. Applying the concept of green engineering led to total or partial substitution of fossil fuel. The main drawback is that fermentation is produced in diluted aqueous media and the recovery of ethanol is an energy intensive operation and in Europe, the maximum ethanol content in fuel allowed by legislation is 10% wt (Directive 2009/10/EC). The objective of this project is to provide a process scheme that led to dehydrate bioethanol and blend directly with gasoline and gasoline additive, tert-amyl-methyl ether (TAME). This process must to be viable in terms of energy, economics and environmental aspects. A bibliographic search is presented to determine how much energy is necessary to produce one kilogram of bioethanol. The results of the bibliographic search shown that for a diluted feed stream of ethanol, the best process scheme consist on two distillation columns and one decanter. Hence, five process schemes are presented: (1-3) with the conventional configuration (two distillation column and one decanter) and (4-5) with a novel configuration (one distillation column, with a lateral extraction, and one decanter). The residue curve maps and liquid-liquid equilibrium (RCM-LLE) with their topologies are presented. The RCM-LLE allows to illustrate the thermodynamic behavior of the entrainers used and verify the feasibility. The software used to carry out the rigorous simulations is ASPEN Plus ® v10 using the thermodynamically model NRTL. The annual production established is 18kt/year of a mixture ethanol-gasoline-TAME. The converged results of the simulations allow to compare all the process schemes in terms of energy, sizing and economic aspects, such as raw materials cost, utilities cost, equipment cost and income statement. Beyond this, WAR® is used to compare the environmental impact of each process scheme using coal, oil and natural gas as an energy source Treballs Finals de Màster d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2018-2019, Tutors: Alexandra Bonet Ruiz, Manuel Vicente Buil

El propòsit de la tesi va ser explorar mitjançant estudis empírics l'evolució de l'ús de les eines Lean a les empreses manufactureres europees i el seu vincle amb les tecnologies de la Indústria 4.0 i les pràctiques green. En primer lloc, es va investigar l'adopció i la internalització de les eines Lean i el seu impacte en el rendiment productiu a les empreses manufactureres espanyoles. Tot seguit, es va analitzar la influència de la internalització de les eines Lean en l'adopció de tecnologies de la Indústria 4.0 a les empreses manufactureres europees. I, finalment, es va examinar la relació entre l'ús conjunt d'eines Lean i les pràctiques green associat a l'exercici mediambiental a les empreses manufactureres espanyoles. La metodologia emprada al llarg dels estudis presentats es va basar en l'anàlisi de dades extretes de la European Manufacturing Survey The purpose of the thesis was to explore through empirical studies the evolution of the use of lean tools in European manufacturing firms and their link with Industry 4.0 technologies and green practices and Circular Economy. First, the adoption and internalisation of lean tools and their impact on production performance in Spanish manufacturing firms were investigated. Next, the influence of the internalisation of Lean tools on the adoption of Industry 4.0 technologies in European manufacturing firms was analysed. Finally, the relationship between the joint use of Lean tools and green practices associated with environmental performance in Spanish manufacturing firms was examined. The methodology employed throughout the studies presented was based on the analysis of data extracted from the European Manufacturing Survey Programa de Doctorat Interuniversitari en Dret, Economia i Empresa

Estimates of wind power potential are relevant for decision-making in energy policy and business. Such estimates are affected by several uncertain assumptions, most significantly related to wind turbine technology and land use. Here, we calculate the technical and economic onshore wind power potentials with the aim to evaluate the impact of such assumptions using the case-study area of Finland as an example. We show that the assumptions regarding turbine technology and land use policy are highly significant for the potential estimate. Modern turbines with lower specific ratings and greater hub heights improve the wind power potential considerably, even though it was assumed that the larger rotors decrease the installation density and increase the turbine investment costs. New technology also decreases the impact of strict land use policies. Uncertainty in estimating the cost of wind power technology limits the accuracy of assessing economic wind power potential.

The data used in "Assessing a Fuel Subsidy: Dynamic Effects on Retailer Pricing and Pass-Through to Consumers" by J. Balaguer and J. Ripollés.

The optical and photovoltaic properties of Si NCs / SiC multilayers (MLs) are investigated using a membrane-based solar cell structure. By removing the Si substrate in the active cell area, the MLs are studied without any bulk Si substrate contribution. The occurrence is confirmed by scanning electron microscopy and light-beam induced current mapping . Optical characterization combined with simulations allows us to determine the absorption within the ML absorber layer, isolated from the other cell stack layers. The results indicate that the absorption at wavelengths longer than 800 nm is only due to the SiC matrix. The measured short-circuit current is significantly lower than that theoretically obtained from absorption within the ML absorber, which is ascribed to losses that limit carrier extraction. The origin of these losses is discussed in terms of the material regions where recombination takes place. Our results indicate that carrier extraction is most efficient from the Si NCs themselves, whereas recombination is strongest in SiC and residual a-Si domains . Together with the observed onset of the external quantum efficiency (EQE) at 700-800 nm, this fact is an evidence of quantum confinement in Si NCs embedded in SiC on device level.

[eng] Aqueous zinc ion batteries (AZIBs) have garnered significant research attention due to their remarkably high-volume energy density, reaching up to 5,851 mAh mL-1. This surpasses the capabilities of state-of-the-art lithium-ion batteries (LIBs), making AZIBs a promising candidate for advanced energy storage technology. Additionally, the natural abundance, low cost, and non-toxic nature of zinc offer economic advantages and environmental sustainability, particularly beneficial for large-scale applications. One notable advantage of AZIBs is their ability to be fabricated in an air atmospheric environment, thanks to the air stability of the AZIBs system. This characteristic significantly simplifies the fabrication process, further enhancing the attractiveness of AZIBs for widespread adoption. However, the practical implementation of AZIBs still suffers from several intractable technical challenges, such as limited energy density and inadequate cycle life, which seriously hinder this technology from yielding practically viable energy density and cyclability. Selecting appropriate cathode materials and implementing rational structural design engineering can effectively overcome the aforementioned challenges. In Chapter 1, I summarize the state of the art on advanced cathode materials for AZIBs and particularly detail structural engineering strategies to achieve high energy density and extended cycle life. In Chapter 2, I detail my work on the design and engineering of K+ pre-intercalated MnO2 nanorods (K-MnO2-NR) as an efficient cathode to overcome the limitations of AZIBs. The K-MnO2-NR is synthesized by a facile one-step chemical method with a size of less than 10 nm. Their unique structure provides a large surface area, abundant active sites for ion storage, and a short diffusion path for ion transport. The intercalation of K+ also improves the conductivity of the electrode and stabilizes the tunnel structure. Consequently, this K-MnO2-NR configuration delivers a high capacity of 285 mAh g-1 at 0.1 A g-1, while retaining 222 mAh g-1 at 2 A g-1. Kinetic reaction analysis reveals that even under high charging/discharging rates, ion diffusion-controlled capacity plays a crucial role, which is beneficial for achieving high capacity under such conditions. Assembled pouch cells with K-MnO2-NR also exhibit promising application prospects. This work has been accepted for publication in the journal Ceramics International and it is already available online (https://doi.org/10.1016/j.ceramint.2024.04.324). However, the capacity of the enhanced MnO2 still falls short of expectations, hampering its practical application. The primary reason for this limitation is that the prepared crystalline MnO2 possess few defects, resulting in a reduced ion storage capacity. Hence, there arises a necessity to devise a novel defect engineering methodology to address this issue and obtain materials with high-density active sites, thereby enhancing their performance. In Chapter 3, to further improve MnO2-based cathodes, I introduce a method to obtain manganese oxide materials with high-density active sites through the in situ phase transformation of MnSe, thereby regulating the defect structure. I detail my work on the structural engineering of reduced graphene oxide (rGO)-coated MnSe nanoparticles (MnSe@rGO) as a cathode material for AZIBs. The introduction of rGO provides a surface-confining effect against morphological evolution, thus preventing structural failure of the electrode. Furthermore, the intrinsically high electronic conductivity of rGO facilitates the MnSe phase transition, enabling the utilization of its full capacity potential. The optimized MnSe@rGO-3 cathode demonstrates a significant specific capacity of 290 mAh g-1 at 0.1C and retains a specific capacity of 178 mAh g-1 even at 5C. Through quantitative electrochemical analyses, first-principles calculations, and in situ characterization, the enhanced capacitive zinc-ion storage behavior and phase transformation mechanism of MnSe@rGO cathode materials are elucidated. Moreover, the mechanical stability of rGO ensures the successful electrohydrodynamic (EHD) jet printing of flexible ZIBs into a flexible integrated functional system. As an illustration, a flexible touch-controlled light-emitting diode (LED) array system incorporating as-fabricated MnSe@rGO-3-based ZIBs is developed. This approach showcases effective performance in both flat and bent configurations, offering the added advantages of enhanced safety and environmental sustainability. This work was published in ACS Nano in 2023 (https://doi.org/10.1021/acsnano.3c00672). Despite the significant strides made in enhancing the specific capacity of Mn-based cathode materials through defect engineering, the persisting limitations associated with manganese dissolution and moderate cycle life continue to raise concerns. These issues indeed cast doubt on their viability for high-energy-density applications, particularly in application fields like wearables. In Chapter 4, to increase the energy density of AZIBs, I explain my work on the development of a new cathode material based on a layered metal chalcogenide (LMC), bismuth telluride (Bi2Te3) nanodisks, coated with polypyrrole (PPy) as cathode material for aqueous ZIBs, and then explore its storage mechanism. In situ X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS) measurements, and density functional theory (DFT) calculations are employed to elucidate that the energy storage mechanism of Bi2Te3 is the insertion/extraction of protons rather than Zn ions within the (0 0 6) interlayers, coupled with the formation/deposition of Zn4SO4(OH)6·5H2O on the electrode surface. The PPy coating enhances the ionic conductivity of the LMC while preventing surface oxidation. Consequently, the Bi2Te3@PPy cathode exhibits remarkable rate performance and long-term cycling stability with ultra-long lifespans of over 5,000 cycles. They also present outstanding stability even under bending. This work was published in Advanced Materials in 2023 (https://doi.org/10.1002/adma.202305128). Finally, the main conclusions of this thesis, including a comparison chart of the three cathode materials developed in the thesis, and some perspectives for future work are presented. [spa] Las baterías de iones de zinc en electrolito acuoso (AZIBs) han atraído notable atención por su excelente densidad volumétrica de energía, alcanzando hasta 5,851 mAh mL-1, superando a las baterías de iones de litio (LIB). Además, el zinc es abundante, económico y no tóxico, lo que beneficia aplicaciones a gran escala. Las AZIBs pueden fabricarse en un ambiente atmosférico, simplificando significativamente el proceso de fabricación. Sin embargo, enfrentan desafíos técnicos como densidad de energía limitada y vida útil corta. En el Capítulo 1, se revisa el estado del arte sobre materiales catódicos avanzados para AZIBs, y se detallan estrategias para lograr alta densidad de energía y ciclo de vida extendido. En el Capítulo 2, se presenta el diseño e ingeniería de nanobarras de MnO2 preintercaladas con K+ (K-MnO2-NR) como cátodos. Este material, sintetizado mediante un método electroquímico sencillo, ofrece una alta capacidad de 285 mAh g 1 a 0.1 A g-1 y retiene 222 mAh g-1 a 2 A g-1. La intercalación de K+ mejora la conductividad y estabiliza la estructura, proporcionando una gran superficie y sitios activos para el almacenamiento de iones. Este trabajo se ha publicado en International Ceramics. En el Capítulo 3, se introduce un método para mejorar aún más el cátodo a base de MnO2 mediante la transformación de fase de MnSe, creando materiales con alta densidad de sitios activos. Se diseñaron nanopartículas de MnSe recubiertas con óxido de grafeno reducido (rGO) (MnSe@rGO). El recubrimiento de rGO mejora la conductividad y estabiliza la estructura, evitando fallos estructurales. El cátodo MnSe@rGO-3 demuestra una capacidad específica de 290 mAh g-1 a 0.1 C y retiene 178 mAh g-1 a 5C. Este trabajo fue publicado en ACS Nano. En el Capítulo 4, se explora un nuevo material catódico basado en nanodiscos de telururo de bismuto (Bi2Te3) recubiertos con polipirrol (PPy) para ZIBs acuosas. Mediante análisis XRD in situ, mediciones XPS y cálculos DFT, se dilucida que el mecanismo de almacenamiento de Bi2Te3 implica la inserción/extracción de protones y la formación de Zn4SO4(OH)6·5H2O. El recubrimiento de PPy mejora la conductividad iónica y previene la oxidación. El cátodo Bi2Te3@PPy exhibe excelente rendimiento y estabilidad a largo plazo, con una vida útil de más de 5,000 ciclos, incluso bajo flexión. Este trabajo fue publicado en Materiales Avanzados. A pesar de estos avances, persisten desafíos como la disolución del manganeso y la vida útil limitada, cuestionando su viabilidad para aplicaciones de alta densidad de energía. La tesis concluye con una comparación de los tres cátodos desarrollados y ofrece perspectivas para futuros trabajos. Programa de Doctorat en Nanociències / Tesi realitzada a l'Institut de Recerca en Energia de Catalunya (IREC)