Luis A Pérez-Maqueda

• PhD
• Research Director at Spanish National Research Council

This work presents a straightforward strategy for achieving specific overheating during flash experiments by adjusting the initial electrical parameters. To do that, an extensive experimental analysis was performed to evaluate the temperature evolution of dense ZnO specimens during controlled‐current ramping at different furnace temperatures, which...

The first demonstration of plasma‐flash sintering (PFS) is presented in this work. PFS is performed under a low‐pressure atmosphere that consecutively generates plasma and flash events. It is shown, by using several combined characterization techniques, that PFS stabilizes metastable phases on the surface of the material, which may be partially, bu...

The correct determination of the kinetic model and the kinetic parameters that describe a heterogeneous process is key to accurately predicting its progress within a wide range of conditions, which is one of the main purposes of kinetic analysis. Albeit ideal kinetic models continue to be used to gain insight about the process mechanism, they are c...

Kinetic models are relevant to describe heterogeneous kinetic processes; a number of kinetic models and their mathematical expressions have been reported in the literature, many of these based on idealistic conditions in terms of geometrical constrain and driving forces. Alternatively, the semi-empirical Sestak–Berggren (SB) conversion function, wh...

Long-term storage capability is often claimed as one of the distinct advantages of the calcium looping process as a potential thermochemical energy storage system for integration into solar power plants. However, the influence of storage conditions on the looping performance has seldom been evaluated experimentally. The storage conditions must be c...

This work presents an extension of the touch‐free flash sintering technique. In the proposed technique, chemical reaction and sintering occur in a single step, without the use of electrodes, in the presence of electric and magnetic fields. We show that a dense, single‐phase strontium hexaferrite magnet can be produced from a mixture of commercial c...

This paper provides a review of negative carbon capture technologies. Based on these technologies, here it is proposed an innovative negative emissions power plant combining the generation and storage of energy from biomass, photovoltaic, and concentrated solar power, capturing and recovering CO2 by producing H2 or CH4 as green energy carriers. The...

Seville is intimately linked to its historic role and extensive cultural heritage. The city has been occupied by Romans, Arabs and Christians, who built important historical buildings. Roman (first–second centuries) and Arabic (eleventh century) buildings, medieval Shipyard (thirteenth century), San Isidoro and Santa Maria de las Cuevas monasteries...

Integrating bioenergy and carbon capture and storage (BECCS) presents a great opportunity for power production with negative global CO2 emissions. This work explores a novel synergetic system that integrates membranes, partial biomass oxycombustion and the calcium looping (CaL) process. Polymeric membranes generate oxygen-enriched air (OEA) with an...

Surface crystallization in fine powder Se70Te30 chalcogenide glass was studied by differential scanning calorimetry (DSC) and optical microscopy. A complex kinetic analysis of these experimental data reveals that the contracting sphere mechanism (R3 model) is the rate determining step of crystal growth, and the conventional Johnson–Mehl–Avrami–Kolm...

Partial oxycombustion using Oxygen-Enriched Air (OEA), produced by air-gas separation with polymeric membranes, combined synergistically with CO2 capture technologies, can reduce the overall energy cost of CO2 capture, and it is a potential alternative to conventional CO2 capture technologies. An exhaustive review of polymeric membranes for this ap...

Kinetic analysis remains a powerful tool for studying a large variety of reactions, which lies at the core of material science and industry. It aims at obtaining the kinetic parameters and model that best describe a given process and using that information to make reliable predictions in a wide range of conditions. Nonetheless, kinetic analysis oft...

LaFeO3 perovskite ceramics have been prepared via reaction flash technique using Fe2O3 and La2O3 as precursors. The obtained pellets have been investigated using several techniques. The formation of LaFeO3 has been clearly confirmed by X-ray diffraction. The scanning electron microscopy micrographs have shown the microporous character of the obtain...

In this review article, the Kinetics Committee of the International Confederation for Thermal Analysis and Calorimetry (ICTAC) delivers a collection of recommendations for the kinetic analysis of thermal decomposition processes. These recommendations specifically focus on the thermal decomposition processes in inorganic, organic, and polymeric mate...

Low temperature magnetic properties of BiFeO3 powders sintered by flash and spark plasma sintering were studied. An anomaly observed in the magnetic measurements at 250 K proves the clear existence of a phase transition. This transformation, which becomes less well-defined as the grain sizes are reduced to nanometer scale, was described with regard...

Heating decarbonisation through electrification requires the development of novel heat batteries. They should be suitable for the specific application and match the operation conditions of domestic renewable energy sources. Supercooled liquids, often considered a drawback of phase change materials, are among the most promising technologies supporti...

The kinetic analysis of solid-state processes aims at obtaining fundamental information that can be used for predicting the time evolution of a process within a wide range of conditions. It is an extended belief that the determination of the kinetic parameters from the analysis of curves recorded under isothermal conditions is strongly conditioned...

Heating decarbonisation through electrification is a difficult challenge due to the considerable increase in peak power demand. This research proposes a novel modelling approach that utilises easily accessible national-level data to identify the required heat storage volume to decrease peak power demand and maximises carbon reductions associated wi...

Steam injection has been proposed to attenuate the decay of CaO reactivity during calcium looping (CaL) under operating conditions compatible with carbon capture and storage. However, it is yet unknown whether the perceived advantages granted by steam hold under the distinct operating conditions required for the integration of the CaL process as a...

This work aims to clarify the influence of AC (up to 50 kHz) vs DC fields on the flash-onset temperature, emphasizing the role of the electrical conduction mechanism. BiFeO3 (BFO) is used as an example of electronic conductor while 8-mol % Yttria-stabilized zirconia (8YSZ) is used as an example of ionic conductor. For 8YSZ, a frequency dependence o...

Reactive flash-sintering technique has been used in order to obtain strontium ferrite magnets from a mixture of SrCO3 and Fe2O3 commercial powders. This technique allows preparing a sintered SrFe12O19 at a furnace temperature of just 973 K during just 2 minutes by applying a modest field of 40 V cm⁻¹, instead of the conventional sintering process e...

Thermochemical energy storage (TCES) has attracted interest in the last years due to the possibility of attaining high energy densities, seasonal storage capacity and greater efficiencies than currently commercial thermal energy storage systems using molten salts. This work analyses the potential of an ultra-high temperature TCES system based on th...

The Calcium-Looping (CaL) process, based on the multicyclic calcination-carbonation of CaCO3/CaO, is considered a promising Thermochemical Energy Storage (TCES) technology to be integrated into Concentrating Solar Power (CSP) plants. This work proposes a novel CaL integration that operates at low-pressure calcination under pure CO2 and a moderated...

Oxyfuel combustion is a promising alternative to decarbonize the power sector. However, the main barrier to commercial deployment of the technology is the high energy consumption associated with oxygen production (∼200–300 kWh per ton of O2), which penalizes the thermal-to-electric efficiency of 8.5–12% compared to traditional air combustion plants...

In this work, a mixture of (NH4)3SiF7/(NH4)2SiF6 powders was obtained as a by-product of the Li extraction process from α-spodumene aluminosilicate with NH4HF2. The thermal behavior of the powders was analyzed by non-isothermal thermogravimetric experiments. The kinetic parameters that describe the processes involved were obtained using mathematica...

This work demonstrates the first proof-of-concept of Multi-Phase Flash Sintering (MPFS). This novel technique essentially consists of applying a rotating electric field to the sample by means of a multi-phase voltage source as furnace temperature increases. Several ceramic materials with different types of electrical conductivities are sintered wit...

Large-scale thermochemical energy storage (TCES) is gaining relevance as an alternative to current thermal energy storage systems in Concentrated Solar Power plants. Among the different systems, the reversible reaction between CaO and CO2 stands out due to the wide availability and low cost of the raw material: limestone. Direct solar absorption of...

This study explores the effect of steam addition during carbonation on the multicyclic performance of limestone under calcium looping conditions compatible with (i) CO2 capture from postcombustion gases (CCS) and with (ii) thermochemical energy storage (TCES). Steam injection has been proposed to improve the CO2 uptake capacity of CaO-based sorbent...

Flash Sintering (FS), a relatively new Field-Assisted Sintering Technique (FAST) for ceramic processing, was proposed for the first time in 2010 by Prof. Rishi Raj’s group from the University of Colorado at Boulder. It quickly grabbed the attention of the scientific community and since then, the field has rapidly evolved, constituting a true milest...

Phase change materials (PCM) have been widely investigated for heat storage and transfer applications. Numerous numerical simulation approaches have been proposed for modelling their behaviour and predicting their performance in thermal applications. However, simulation approaches do not consider the kinetics of the phase transition processes, comp...

Due to its technological applications, such as CO2 capture, CaO carbonation kinetics has been extensively studied using a wide array of methods and experimental conditions. A complete understanding of carbonation kinetics is key to optimizing the operating conditions as well as to correctly design the carbonation reactor. However, there is yet no c...

Kinetic models used for the kinetic analysis of solid-state reactions assume ideal conditions that are very rarely fulfilled by real processes. One of the assumptions of these ideal models is that all sample particles have an identical size, while most real samples have an inherent particle size distribution (PSD). In this study, the influence of p...

Parametrization of mechanochemical reactions, or relating the evolution of the reaction progress to the supplied input power, is required both to establish protocols and to gain insight into mechanochemical reactions. Thus, results could be compared, replicated, or scaled up even under different milling conditions, enlarging the domains of applicat...

In this work, the 0.67BiFeO3-0.33BaTiO3 ferroelectric ceramic was prepared by Reaction Flash Sintering (RFS). This preparation technique combines synthesis and sintering in a single Flash experiment. The starting oxides reacted during the flash to produce a stoichiometric well-sintered solid solution at a temperature of 858º C by applying a modest...

In this work, it is proposed a method for studying kinetics of complex processes composed of non-independent stages. In this method, the variable contribution of the different stages as a function of the heating schedule is taken into account. The method involves the simultaneous kinetic analysis of a set of experimental data registered under linea...

Making predictions, such as lifetime estimations, is one of the main objectives of kinetic studies. Thus, from conventional thermal analysis experiments, the behavior of polymeric materials under processing or application conditions, usually far away from those used in the laboratory experiments, could be estimated. Conventional prediction procedur...

In the present work, we explore the use of steam in the CaCO3 calcination step of a calcium looping process devised for integration into a thermochemical energy storage process (CaL-TCES). Steam produces a double benefit: firstly, it fastens the calcination, allowing a reduction of the temperature needed to attain full calcination in short residenc...

Mechanochemistry has attracted a lot of attention over the last few decades with a rapid growth in the number of publications due to its unique features. However, very little is known about how mechanical energy is converted into chemical energy. Most of the published works using mechanochemistry neglect the required attention to the experimental p...

The Calcium-Looping (CaL) process has emerged in the last years as a promising technology to face two key challenges within the future energy scenario: energy storage in renewable energy-based plants and CO2 capture from fossil fuel combustion. Based on the multicycle calcination-carbonation reaction of CaCO3 for both thermochemical energy storage...

The Calcium Looping performance of limestone for thermochemical energy storage has been investigated under novel favorable conditions, which involve calcination at moderate temperatures under CO2 at low pressure (0.01 and 0.1 bar) and carbonation at high temperature under CO2 at atmospheric pressure. Calcining at low CO2 pressures allows to substan...

The commercial deployment of calcium looping (CaL) based technologies relies on the availability of non-toxic, widely available and cheap CaCO3 rich materials. Biomineralized CaCO3 from waste amply fulfil the aforementioned requirements. In the present work, we study the performance of eggshell and snail shell from food waste as CaO precursors for...

The present recommendations have been developed by the Kinetics Committee of the International Confederation for Thermal Analysis and Calorimetry (ICTAC). The recommendations provide guidance on kinetic analysis of multi-step processes as measured by thermal analysis methods such as thermogravimetry (TGA) and differential scanning calorimetry (DSC)...

The inherent potential of reaction flash sintering for the preparation of complex oxides is evidenced by the one-step synthesis and densification of a ceramic of complex stoichiometry. The system Bi0.93La0.07FeO3, a multiferroic ceramic with promising technological applications, has been chosen. This system presents three different metals in its co...

A thermogravimetric instrument that works at high pressure of different gases has been designed and assembled. The instrument has been devised to work in a temperature range from room temperature to 1000 °C in various controlled pressures of selected gas up to 15 bar, and under conventional rising temperature and constant rate thermal analysis (CRT...

The calcium looping process, based on the reversible reaction between CaCO3 and CaO, is recently attracting a great deal of interest as a promising thermochemical energy storage system to be integrated in Concentrated Solar Power plants (CaL-CSP). The main drawbacks of the system are the incomplete conversion of CaO and its sintering-induced deacti...

We show that flash sintering produces single‐phase, nanograin‐sized polycrystals of isovalent‐substituted multiferroic ceramics of complex compositions. Single‐phase polycrystals of Bi0.98R0.02FeO3 (R = La, Sm, Y) were produced at a furnace temperature of ~650°C in a few seconds by the application of an electric field of 50 V cm⁻¹, with the current...

Energy storage based on thermochemical systems is gaining momentum as a potential alternative to molten salts in Concentrating Solar Power (CSP) plants. This work is a detailed review about the promising integration of a CaCO3/CaO based system, the so-called Calcium-Looping (CaL) process, in CSP plants with tower technology. The CaL process relies...

BiFeO3 has a Curie temperature (TC) of 825 °C, making it difficult to sinter using conventional methods while maintaining the purity of the material, as unavoidably secondary phases appear at temperatures above Tc. Flash sintering is a relatively new technique that saves time and energy compared to other sintering methods. BiFeO3 was flash sintered...

High energy density, cycling stability, low cost and scalability are the main features required for thermochemical energy storage systems to achieve a feasible integration in Concentrating Solar Power plants (CSP). While no system has been found to fully satisfy all these requirements, the reversible CaO/CaCO3 carbonation reaction (CaL) is one of t...

The eutectic mixture Li2CO3-Na2CO3-K2CO3 is investigated as a high temperature heat transfer fluid and storage medium alternative for molten salt solar thermal power plants. This salt has an operating temperature range of 400ºC – 700ºC, enabling the use of higher temperature/efficiency power cycles. However, this carbonate mixture is known to therm...

In this work, the multicycle activity of natural CaO precursors (limestone and dolomite) and Ca-based composites (Ca3Al2O6/CaCO3 and ZrO2/CaCO3 mixtures) has been studied for Thermochemical Energy Storage (TCES) in Concentrated Solar Power (CSP) plants by means of the Calcium-Looping process (CaL), using two integration schemes proposed elsewhere t...

Bi2Fe4O9 was prepared by solid-state reaction and the electrical properties measured by impedance spectroscopy. After annealing in O2 at 900 °C, Bi2Fe4O9 is an electrically-homogeneous insulator. Its high frequency permittivity is constant (∼14.1) over the temperature range 300–400 °C and shows no evidence of incipient ferroelectricity at lower tem...

The potential of controlled rate thermal analysis (CRTA) for studying high‐pressure gas‐solid processes has been evaluated. CRTA is a type of smart temperature program based on a feedback system that uses any experimental signal related to the process evolution for commanding the temperature evolution. In this work, an instrument that uses the grav...

Automatic lay-up and in-situ consolidation with thermoplastic composite materials is a technology under research for its expected use in the profitable manufacturing of structural aeronautical parts. This study is devoted to analysing the possible effects of thermal degradation produced by this manufacturing technique. Rheological measurements show...

The sintering mechanism of BiFeO3 has been investigated in-situ by energy dispersive X-ray diffraction (ED-XRD) using a high-energy white collimated X-ray beam from the Advanced Photon Source (Argonne National Laboratories). Such radiation is very penetrating thereby allowing measurements of the sample even when placed inside the flash sintering se...

Here, a kinetic study of the thermal decomposition of synthesized hydrotalcite, Mg6 Al2 CO3 (OH)16·4H2O, has been carried out using thermogravimetric experiments in air atmosphere. It is shown that the thermal decomposition occurs in two well differentiated stages. The first one is a single-step dehydration process that comprises the release of fou...

In this work, we studied the thermal decomposition of a widely employed silicone elastomer, polydimethylsiloxane, in an inert atmosphere. This silicone elastomer has several applications due to its high thermal stability such as MEMS (microelectromechanical systems) precursors, microfluidic components, adhesives, lubricants, and precursors for non-...

Thermochemical energy storage (TCES) is considered as a promising technology to accomplish high energy storage efficiency in concentrating solar power (CSP) plants. Among the various possibilities, the calcium-looping (CaL) process, based on the reversible calcination-carbonation of CaCO3 stands as a main candidate due to the high energy density ac...

This work is focused on the use of the Calcium-Looping process (CaL) in Concentrated Solar Power (CSP) plants for Thermochemical Energy Storage (TCES). Cheap, abundant and non-toxic natural carbonate minerals, such as limestone and dolomite, can be employed in this application to store energy through the cyclic calcination/carbonation of CaCO3. In...

Crystallization is one key aspect in the resulting properties of nanocrystalline functional materials and much effort has been devoted to understanding the physical mechanisms involved in these processes as a function of temperature. The main problems associated to crystallization kinetic studies come from the limitations of the employed techniques...

This work analyzes the relevant influence of milling on the CO2 capture performance of CaO derived from natural limestone. Diverse types of milling mechanisms produce contrasting effects on the microstructure of the CaO formed after calcination of the milled limestone samples, which affects crucially the kinetics of carbonation at conditions for CO...

An ever more environmentally conscious society demands the use of green, sustainable and high-efficiency renewable energy resources. However, large-scale energy storage remains a challenge for a deep penetration of power produced from renewables into the grid. The Calcium-Looping (CaL) process, based on the reversible carbonation/calcination of CaO...

Multiferroic compounds are multifunctional complex materials with significant potential applications in devices, due to the interactions between their ferroic properties. Thermoanalytical methods are of the most interest for the characterization of different properties of these materials as a function of temperature. In this chapter, the use of met...

Mixed powders of Bi2O3 and Fe2O3 are shown to yield single-phase, dense nanostructured polycrystals of BiFeO3 in reaction flash sintering experiments, carried out by applying a field of 50 V cm ⁻¹ and with the current limit set to 35 mA mm⁻². The furnace was heated at a constant rate with the reaction sintering taking place abruptly upon reaching 6...

The Calcium Looping (CaL) process, based on the carbonation/calcination of CaO, has been proposed as a feasible technology for Thermochemical Energy Storage (TCES) in Concentrated Solar Power (CSP) plants. The CaL process usually employs limestone as CaO precursor for its very low cost, non-toxicity, abundance and wide geographical distribution. Ho...

This work reports the Calcium-Looping (CaL) multicycle performance under energy storage and CO2 capture conditions of different Al-composites prepared by milling mixtures of nanoalumina and natural limestone powders. The micro- and nanostructure of the composites have been analyzed by X-ray diffraction, scanning electron microscopy and high-resolut...

BiFeO3 attracts considerable attention for its rich functional properties, including room temperature coexistence of magnetic order and ferroelectricity and more recently, the discovery of conduction pathways along ferroelectric domain walls. Here, insights into the defect chemistry and electrical properties of BiFeO3 are obtained by in situ measur...

Thermochemical energy storage in Concentrated Solar Power plants by means of the Calcium-Looping process is a promising novel technology that would allow for a higher share of renewables. A main benefit of this technology is the use of widely available, non-toxic and environmentally friendly calcium carbonate minerals as raw materials to store ener...

The present work is focused on thermochemical energy storage (TCES) in Concentrated Solar Power (CSP) plants by means of the Calcium-Looping (CaL) process using cheap, abundant and non-toxic natural carbonate minerals. CaL conditions for CSP storage involve calcination of CaCO3 in the solar receiver at relatively low temperature whereas carbonation...

We show that BiFeO3, that is electrically homogeneous, is a good insulator, and has a low dielectric constant (the properties desired in its applications), can be produced by flash sintering, which is nominally difficult to achieve by conventional and spark plasma sintering processes. The flash-sintered specimens had a uniform microstructure with a...

The Calcium Looping (CaL) process, based on the cyclic carbonation/calcination of CaO, has emerged in the last years as a potentially low cost technique for CO2 capture at reduced energy penalty. In the present work, natural limestone and dolomite have been pretreated with diluted acetic acid to obtain Ca and Ca-Mg mixed acetates, whose CO2 capture...

The historical development of the thermal analysis methods that imply an intelligent control of the reaction temperature by the own sample (SCTA) is outlined. It has been shown that the precise control of the reaction rate involved in SCTA enables a control, either direct or indirect, of both the partial pressure of the gases generated/consumed by...

High-quality samples, in terms of phase purity and dielectric properties, of composition Bi1−xSmxFeO3 (0.05 ≤ x ≤ 0.20) have for the first time been prepared by mechanosynthesis. Close inspection of the powder diffraction data, analysis via Rietveld refinement and TEM microscopy demonstrates that the Bi1−xSmxFeO3 samples contain only perovskite pha...

The share of renewable energies is rapidly growing partly in response to the urgent need of mitigating CO2 emissions from fossil fuel power plants. However, cheap and efficient large-scale energy storage technologies are not yet available to allow for a significant penetration of renewable energies into the grid. Recently, it has been proposed a po...

Deep penetration of renewable energies into the grid relies on the development of large-scale energy storage technologies using cheap, abundant and non-toxic materials. Concentrated Solar Power (CSP) is particularly suitable to massively store thermal energy for dispatchable electricity generation. This is currently accomplished in a few demonstrat...

In this paper, the thermal degradation properties of Viton A and Fluorel are investigated by both isoconversional and combined kinetic analysis methods using non-isothermal thermogravimetry technique. It has been found that the heating rate has little affect on the degradation residue of Fluorel and Viton A, where around 1.3% char was formed for Fl...

Constant Rate Thermal Analysis (CRTA) method implies controlling the temperature in such a way that the reaction rate is maintained constant all over the process. This method allows determining simultaneously both the kinetic parameters and the kinetic model from a single experiment as the shape of the CRTA α-T curves strongly depends on the kineti...

The multicycle CO2 capture performance of CaO derived from the calcination of ball-milled limestone and dolomite have been tested under “realistic” operation conditions (high CO2 concentration environment and temperature) for the first time. Here it is shown that the CO2 capture capacity of CaO is inversely related to the milling power applied to t...

The polymer-to-ceramic transformation kinetics of two widely employed ceramic precursors, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane (TTCS) and polyureamethylvinylsilazane (CERASET), have been investigated using coupled thermogravimetry and mass spectrometry (TG-MS), Raman, XRD and FTIR. The thermally induced decomposition of the pre-...

The multicycle CO2 capture performance of CaO derived from the calcination of ball-milled limestone and dolomite have been tested under “realistic” operation conditions (high CO2 concentration environment and temperature) for the first time. Here it is shown that the CO2 capture capacity of CaO is inversely related to the milling power applied to t...