J. Chimenos - Academia.edu (original) (raw)
Papers by J. Chimenos
International Journal of Waste Resources, 2015
T main goal in upcycling municipal waste as technical components for the building industry is to ... more T main goal in upcycling municipal waste as technical components for the building industry is to comply with the pressing requirements coming from NZEB policy adopted in EU framework program Horizon 202020. CITERA research center, in cooperation with Lazio District has developed different components for the building envelope up cycling wood pallet, plastic and glass bottle, tires and aluminum cans, with high thermal and acoustic performance according to Italian latest building energy regulation (D.lgs. 311/2006). This component can be used both for vertical elements and for horizontal floors both for new constructions and for main refurbishment. A first application of this technology is a new model of social housing for elderly coming from the needs expressed in the position paper of Italian government on ageing society regarding the built environment. In fact the planning and design approach will need to incorporate the values and perspectives arising from this new cultural and dem...
Journal of Hazardous Materials, 2021
Alkali-activated binders (AABs) stand out as a sustainable alternative to ordinary Portland cemen... more Alkali-activated binders (AABs) stand out as a sustainable alternative to ordinary Portland cement (OPC) as they can be formulated using by-products or waste as raw materials. However, the presence of hazardous compounds in residues can lead to an increase in AABs' toxicity due to the highly alkaline media. Therefore, it is extremely important to evaluate their environmental risks to validate their use as building materials. This study environmentally assessed AABs prepared with two different fractions (0-30 mm and 8-30 mm) of weathered bottom ash (AA-WBA) from WtE plants. The potential leachate toxicity of AA-WBA was assessed using granular and monolithic leaching tests that simulated end-of-life and service life scenarios, respectively. Furthermore, an acute toxicity test with crustacean Daphnia magna as model organisms was conducted to determine the relationship between the leachate metal(loid) concentrations and the ecotoxicity of AA-WBA. The results showed higher metal(loid) concentrations in AA-WBA specimens prepared with the 0-30 mm fraction of WBA. The service life scenario revealed multiple metal(loid)-release mechanisms. The 48 h EC50 value (close to 10%; moderate toxicity) indicated that the use of the coarse fraction of WBA increased the immobilisation of the metal(loid)s. Finally, the correlation between the concentrations of some of the metal(loid)s and toxicity was demonstrated.
Applied Thermal Engineering, 2016
Està subjecte a una llicència de Reconeixement-NoComercial-SenseObraDerivada 4.
Renewable and Sustainable Energy Reviews, 2016
Abstract Anaerobic digestion is a worldwide technology for the treatment of organic waste streams... more Abstract Anaerobic digestion is a worldwide technology for the treatment of organic waste streams with clear environmental benefits including generation of methane as renewable energy. However, the need to improve process feasibility of existing applications as well as to expand anaerobic digestion to a range of new substrates has raised interest on several intensifications techniques. Among them, the supplementation of inorganic and biological additives has shown good results at improving digesters performance. This manuscript presents a comprehensive review about recent advances in the utilization of inorganic and biological additives. On the one hand, reviewed inorganic additives comprise: (i) macro- (e.g. P, N and S) and micro- (e.g. Fe, Ni, Mo, Co, W and Se) nutrients supplements, (ii) ashes from waste incineration, (iii) compounds able to mitigate ammonia inhibition, and (iv) substances with high biomass immobilization capacity. Among them, iron (Fe 0 and Fe(III)) has shown particularly promising results, which have been mainly related to their action as electron donor/acceptor and cofactor of key enzymatic activities. On the other hand, reviewed biological additives include: (i) the dosage of microbial inocula with high hydrolytic or methanogenic activity (bioaugmentation), and (ii) the addition of enzymes able to facilitate particulate organic matter solubilization.
Energy & Fuels, 2015
Dry desulfurization is an attractive alternative to wet flue gas desulfurization (WFGD) since it ... more Dry desulfurization is an attractive alternative to wet flue gas desulfurization (WFGD) since it avoids wastewater management and requires less energy inputs and lower operation costs. In this research, the by-products from a process generating the SO emissions were tested for dry desulfurization. Thus, the same by-products from the calcination of natural magnesite (two cyclone dusts from the air pollution control system-LG-MgO and LG-D-and one fraction obtained after calcination-LG-F-) that were already studied in a WFGD were assessed in a dry desulfurization process. The by-products were tested raw and modified by two hydration methods and in semi-dry conditions. The SO 2 sorption performance was evaluated by means of breakthrough curves (ppm of SO 2 at the outlet vs. time) and desulfurization potential (L of SO 2 adsorbed per kg of by-product). Accordingly, the by-products showed a good performance with respect the lime used as absorbent in conventional dry FGD. The breakthrough curves showed that the process was characterized by a first stage controlled by surface reaction rate and a subsequent product layer diffusion controlled stage. During the former, the three MgO by-products showed the same behaviour although those with a high CaO content presented an enhancement of the latter mechanism. The dust material LG-MgO presented the best desulfurization potential, up to 25.2 L•kg-1 , while LG-D and LG-F achieved 16.5 and 15.9 L•kg-1 respectively. The modification of the by-products significantly improved the adsorption capacity, especially for LG-MgO in semi-dry conditions, to up to 35.0 L•kg-1. The use of these by-products in a dry process avoids generating wastewater effluents and allows obtaining a solid mixture basically made of magnesium and calcium sulfite, which could be further recovered or reutilized. This is, to the knowledge of the authors, the first study considering a closed-loop dry desulfurization process.
Applied Thermal Engineering, 2011
Passive Fire Protection is currently a field of active interest in building technology. One of th... more Passive Fire Protection is currently a field of active interest in building technology. One of the different approaches to obtain a material that provides this protection is to add substances to the initial formulation that are capable to absorb heat when the temperature of the material is increased. This is achieved by means of endothermic reactions that these substances undergo at specified temperatures. In the case of a fire scenario huge amounts of heat are released and such heat absorbing reactions delay the achievement of temperatures that can be critical for structural stability. In this work we specifically analyze the behavior of gypsum, which is commonly used in buildings. In order to enrich its endothermic profile we add magnesium hydroxide, calcium hydroxide and calcium carbonate to the sample. These three alkaline earth components have their heat absorbing peaks located along the temperature domain in a way that the temperature rising is reasonably damped. In this work we find, as the main result, that when these three fillers are added to gypsum, the protection offered by the new combination of materials is significantly improved with respect to the behavior of gypsum alone. Under external heating, the component is able to keep itself under critical temperatures for a longer period. For the theoretical description, we first use non isothermal thermogravimetry (TG) to analyze and characterize the kinetic response of each component of the mixture. We propose a conversion function which is based on the correlation between consecutive reactions in neighboring molecules. The heating rate is included in the model as an analytical variable. Later we perform high temperature tests in a tubular furnace and their corresponding numerical simulations where heat transfer is explicitly carried and mass transfer effects are discussed.
Ceramics International, 2016
Science of The Total Environment, 2021
Ammonia nitrogen management is a recurrent problem in intensive livestock areas. Struvite precipi... more Ammonia nitrogen management is a recurrent problem in intensive livestock areas. Struvite precipitation stands as a mature technology to recover ammonia nitrogen and prevent associated environmental problems. However, the feasibility of struvite technology to recover ammonia nitrogen from pig manure is limited by the reagents cost. This research aimed to optimise the formulation of a stabilizing agent (SA) synthesised using an industrial low-grade MgO by-product (LG-MgO) and phosphoric acid for efficient TAN recovery via struvite precipitation. Experimental results showed that the H3PO4/LG-MgO ratio controls the magnesium phosphate mineral phase of the SA (bobierrite and/or newberyite). Newberyite-rich SA showed the highest TAN removal efficiency from pig manure (66-73%) compared to the SA formed by a mixture of newberyite and bobierrite (51-59%) and by bobierrite (26%). Particle size reduction of LG-MgO did not improve the SA's TAN removal efficiency, although XRD patterns showed that the precipitates from the TAN removal experiments contained some unreacted newberyite. The economic analysis showed that the higher reactivity of the SA formulated using higher H3PO4/LG-MgO ratios compensated reagent costs. The SA synthesised with a H3PO4/LG-MgO ratio of 0.98 showed the most economical treatment cost, which was estimated at 7.5 € per kg of ammonia nitrogen from pig manure. Finally, the optimum SA was successfully synthesised in a 200-L pilot plant, with a TAN removal capacity only 10% lower than the one synthesised at lab-scale.
IOP Conference Series: Materials Science and Engineering, 2017
View the article online for updates and enhancements. Content from this work may be used under th... more View the article online for updates and enhancements. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Renewable Energy, 2015
Biogas upgrading using bottom ash from the incineration of municipal solid waste (MSW) is especia... more Biogas upgrading using bottom ash from the incineration of municipal solid waste (MSW) is especially interesting for integrated treatment facilities as it would allow closing a complete loop in MSW management. The aim of this research was to assess the interaction between bottom ash (BA) and biogas from anaerobic digestion with the outlook of upgrading in terms of CO 2 and H 2 S removal, with particle size and bottom ash aging as the main variables. The finest fraction of fresh bottom ash (FBA) presented the best performance, with a sorption capacity of 30e50 kg CO 2 $t À1 dry FBA. The sorption capacity of weathered bottom ash (WBA) was lower than the recorded for the fresh material. From the results obtained it can be stated that the CO 2 absorption capacity of bottom ash mainly relies in the finest fraction because of its larger surface area and higher CaO content. In what respect to H 2 S sorption capacity, WBA presented a better performance, with values ranging 3.1e5.2 kg H 2 S•t À1 dry WBA. In addition to the energetic enhancement, the proposed technology also allows an immediate stabilization and reuse of bottom ash as the leaching of heavy metals and metalloids remained under regulatory limits.
Fuel Processing Technology, 2014
Fly ash (FA) disposal in landfills has a significant economic and environmental burden. A promisi... more Fly ash (FA) disposal in landfills has a significant economic and environmental burden. A promising approach for FA valorisation aside from building purposes is the recovery of valuable elements since FA has a huge potential role as a source of valuable metals. In most cases, reported work in this area has been of theoretical research and further development work is needed. Germanium and gallium occur in relatively high proportions and mainly as water soluble and oxide species, respectively in the Puertollano Integrated Gasification Combined Cycle (IGCC) fly ash. Both the speciation and concentrations of Ge and Ga in this IGCC FA allowed starting research for developing extraction methods. High but not regular extraction yields were achieved in previous investigations. The aim of this research work is focused on the optimisation of Ge and Ga extraction conditions from IGCC FA for its feasible industrial application regardless the operational conditions of the IGCC plant. To this aim, first the daily, monthly, and yearly variability of Ge and Ga concentrations in IGCC fly ashes were determined. Samples were taken during almost 10 years. Then a number of extraction tests were carried out using different extractants to cover a wide range of extraction conditions (acid, alkaline, complexant, reducing and oxidising), on IGCC FA samples produced under different operating conditions. High and regular Ge extraction yields (up to 83% after 2 h leaching period) may be achieved using a weak acid solution. Gallium yielded up to 70 and 64% extraction after a 24 h leaching period using a weak acid and alkaline solution, respectively.
Ceramics International, 2012
A hard-burner low-grade MgO (LG-MgO) is used to formulate a chemically bonded phosphate ceramic (... more A hard-burner low-grade MgO (LG-MgO) is used to formulate a chemically bonded phosphate ceramic (CBPC) instead of pure MgO. This by-product is 10 times cheaper than pure MgO. The use of this by-product reduce the cost of the final material and therefore an economical construction material could be obtained. This would reinforce the criteria of sustainability and recyclability. In addition, the inert phases contained on LG-MgO act like inorganic fillers, improving the mechanical properties of this CPBC, which can be considered as a mortar. A range from 55% to 65% of LG-MgO is studied, and boric acid is added in order to improve workability and setting times. Design of Experiments (DoE) approach enabled the evaluation of the influence of each component and the interactions between them. According to the setting times and compressive strength results, a formulation range is proposed.
Electrochimica Acta, 1999
The kinetics of conventional gold cyanidation in air has been studied using open circuit potentia... more The kinetics of conventional gold cyanidation in air has been studied using open circuit potential measurements, voltammetry and atomic absorption spectrophotometry. The experimental results show that this is a complex process characterized by the interdependency of the different variables (cyanide concentration, pH, temperature and stirring speed).The measurement of the mixed potentials at which the process takes place gives valuable information to ascertain the influence of each variable. A good correlation between mixed potential and dissolution rate, thus having a potential interest for an industrial application, has been found. The study of the current-potential curves for oxygen reduction on gold surface and anodic dissolution of gold in cyanide solutions gives more insight into the control of the process: depending on the experimental conditions, gold dissolution takes place in the active region (oxygen diffusion control) or in the potential region where dissolution of adsorbed species limits the rate of the process. Depending also on the experimental conditions, two or four electrons are transferred per oxygen molecule.
Materials Science and Engineering: A, 2011
... Study of the effect of eafd in polymer composites usig DoE. Niubó Eslava, Maria; Fernández, A... more ... Study of the effect of eafd in polymer composites usig DoE. Niubó Eslava, Maria; Fernández, Ana Inés; Haurie Ibarra, Laia; Capdevila, XG; Martínez, M; Velasco Perero, José Ignacio. Diseño y caracterización de mezclas EVA/plastómero para su empleo en compuestos de ...
Although waste-to-energy plants allow reducing the mass and volume of municipal solid waste (MSW)... more Although waste-to-energy plants allow reducing the mass and volume of municipal solid waste (MSW) incinerated, an average around 30 % of the total content remains as bottom ash (BA) and air pollution control (APC) ashes at the end of combustion process. While weathered bottom ash (WBA) is considered a non-hazardous residue that can be revalorized as a secondary aggregate, APC fly ashes generated during the flue gas treatment are classified as hazardous waste and are handled in landfill disposal after stabilization, usually with Portland cement (OPC). However, taking into account the amount of APC residues produced and the disposing cost in landfill, their revalorization is an important issue that could be effectively addressed. As MSW can be incinerated producing bottom ashes (BA) or air pollutant control (APC) residues, the development of a mortar formulated with APC fly ash as secondary building material is a significant risk to the environment for their content of heavy metals. I...
Construction and Building Materials, 2015
Magnesium Phosphate Cement (MPC) has become an essential reference for investigators seeking alte... more Magnesium Phosphate Cement (MPC) has become an essential reference for investigators seeking alternatives to the use of Ordinary Portland Cement (OPC) in building sector because of its high environmental impact. The research group developed a MPC formulated with low-grade MgO (LG-MgO) by-product, which could be considered as a sustainable MPC (sust-MPC). This research focuses on the incorporation of different percentages of Microencapsulated Phase Change Materials (MPCM) into sust-MPC, due to their ability to reduce energy consumption of heating, ventilating, and air conditioning (HVAC) systems. The study consists of an exhaustive characterization of thermal sustainable MPC (TS-MPC) dosages which incorporate air-entraining additive (AEA) and MPCM to improve their thermal behaviour. Thus, TS-MPC would reduce the use of HVAC systems contributing to the decrease of CO2 emissions and increasing energy efficiency in buildings. Moreover, properties such as bulk density, porosity, thermal conductivity, modulus of elasticity, compressive strength, and flexural strength are analysed to evaluate the potential use of these cements as a part of a passive conditioning system. Results show the proper behaviour of these cements to reduce thermal oscillation in buildings. Experimental results demonstrated the relation between the amount of the MPCM and the AEA percentage as well as the thermal and mechanical properties of the TS-MPC due to their contribution to increase the porosity. Furthermore, it should be noted the increase of porosity and the reduction of thermal conductivity of the optimal formulation, which are 60% higher and 50% lower than the sust-MPC obtained without MPCM and additive, respectively.
IOP Conference Series: Materials Science and Engineering
View the article online for updates and enhancements.
IOP Conference Series: Materials Science and Engineering
Microencapsulation of phase change materials with carbon nanotubes reinforced shell for enhanceme... more Microencapsulation of phase change materials with carbon nanotubes reinforced shell for enhancement of thermal conductivity Weiwei Cui, Yongpeng Xia, Huanzhi Zhang et al.
Waste and Biomass Valorization
International Journal of Waste Resources, 2015
T main goal in upcycling municipal waste as technical components for the building industry is to ... more T main goal in upcycling municipal waste as technical components for the building industry is to comply with the pressing requirements coming from NZEB policy adopted in EU framework program Horizon 202020. CITERA research center, in cooperation with Lazio District has developed different components for the building envelope up cycling wood pallet, plastic and glass bottle, tires and aluminum cans, with high thermal and acoustic performance according to Italian latest building energy regulation (D.lgs. 311/2006). This component can be used both for vertical elements and for horizontal floors both for new constructions and for main refurbishment. A first application of this technology is a new model of social housing for elderly coming from the needs expressed in the position paper of Italian government on ageing society regarding the built environment. In fact the planning and design approach will need to incorporate the values and perspectives arising from this new cultural and dem...
Journal of Hazardous Materials, 2021
Alkali-activated binders (AABs) stand out as a sustainable alternative to ordinary Portland cemen... more Alkali-activated binders (AABs) stand out as a sustainable alternative to ordinary Portland cement (OPC) as they can be formulated using by-products or waste as raw materials. However, the presence of hazardous compounds in residues can lead to an increase in AABs' toxicity due to the highly alkaline media. Therefore, it is extremely important to evaluate their environmental risks to validate their use as building materials. This study environmentally assessed AABs prepared with two different fractions (0-30 mm and 8-30 mm) of weathered bottom ash (AA-WBA) from WtE plants. The potential leachate toxicity of AA-WBA was assessed using granular and monolithic leaching tests that simulated end-of-life and service life scenarios, respectively. Furthermore, an acute toxicity test with crustacean Daphnia magna as model organisms was conducted to determine the relationship between the leachate metal(loid) concentrations and the ecotoxicity of AA-WBA. The results showed higher metal(loid) concentrations in AA-WBA specimens prepared with the 0-30 mm fraction of WBA. The service life scenario revealed multiple metal(loid)-release mechanisms. The 48 h EC50 value (close to 10%; moderate toxicity) indicated that the use of the coarse fraction of WBA increased the immobilisation of the metal(loid)s. Finally, the correlation between the concentrations of some of the metal(loid)s and toxicity was demonstrated.
Applied Thermal Engineering, 2016
Està subjecte a una llicència de Reconeixement-NoComercial-SenseObraDerivada 4.
Renewable and Sustainable Energy Reviews, 2016
Abstract Anaerobic digestion is a worldwide technology for the treatment of organic waste streams... more Abstract Anaerobic digestion is a worldwide technology for the treatment of organic waste streams with clear environmental benefits including generation of methane as renewable energy. However, the need to improve process feasibility of existing applications as well as to expand anaerobic digestion to a range of new substrates has raised interest on several intensifications techniques. Among them, the supplementation of inorganic and biological additives has shown good results at improving digesters performance. This manuscript presents a comprehensive review about recent advances in the utilization of inorganic and biological additives. On the one hand, reviewed inorganic additives comprise: (i) macro- (e.g. P, N and S) and micro- (e.g. Fe, Ni, Mo, Co, W and Se) nutrients supplements, (ii) ashes from waste incineration, (iii) compounds able to mitigate ammonia inhibition, and (iv) substances with high biomass immobilization capacity. Among them, iron (Fe 0 and Fe(III)) has shown particularly promising results, which have been mainly related to their action as electron donor/acceptor and cofactor of key enzymatic activities. On the other hand, reviewed biological additives include: (i) the dosage of microbial inocula with high hydrolytic or methanogenic activity (bioaugmentation), and (ii) the addition of enzymes able to facilitate particulate organic matter solubilization.
Energy & Fuels, 2015
Dry desulfurization is an attractive alternative to wet flue gas desulfurization (WFGD) since it ... more Dry desulfurization is an attractive alternative to wet flue gas desulfurization (WFGD) since it avoids wastewater management and requires less energy inputs and lower operation costs. In this research, the by-products from a process generating the SO emissions were tested for dry desulfurization. Thus, the same by-products from the calcination of natural magnesite (two cyclone dusts from the air pollution control system-LG-MgO and LG-D-and one fraction obtained after calcination-LG-F-) that were already studied in a WFGD were assessed in a dry desulfurization process. The by-products were tested raw and modified by two hydration methods and in semi-dry conditions. The SO 2 sorption performance was evaluated by means of breakthrough curves (ppm of SO 2 at the outlet vs. time) and desulfurization potential (L of SO 2 adsorbed per kg of by-product). Accordingly, the by-products showed a good performance with respect the lime used as absorbent in conventional dry FGD. The breakthrough curves showed that the process was characterized by a first stage controlled by surface reaction rate and a subsequent product layer diffusion controlled stage. During the former, the three MgO by-products showed the same behaviour although those with a high CaO content presented an enhancement of the latter mechanism. The dust material LG-MgO presented the best desulfurization potential, up to 25.2 L•kg-1 , while LG-D and LG-F achieved 16.5 and 15.9 L•kg-1 respectively. The modification of the by-products significantly improved the adsorption capacity, especially for LG-MgO in semi-dry conditions, to up to 35.0 L•kg-1. The use of these by-products in a dry process avoids generating wastewater effluents and allows obtaining a solid mixture basically made of magnesium and calcium sulfite, which could be further recovered or reutilized. This is, to the knowledge of the authors, the first study considering a closed-loop dry desulfurization process.
Applied Thermal Engineering, 2011
Passive Fire Protection is currently a field of active interest in building technology. One of th... more Passive Fire Protection is currently a field of active interest in building technology. One of the different approaches to obtain a material that provides this protection is to add substances to the initial formulation that are capable to absorb heat when the temperature of the material is increased. This is achieved by means of endothermic reactions that these substances undergo at specified temperatures. In the case of a fire scenario huge amounts of heat are released and such heat absorbing reactions delay the achievement of temperatures that can be critical for structural stability. In this work we specifically analyze the behavior of gypsum, which is commonly used in buildings. In order to enrich its endothermic profile we add magnesium hydroxide, calcium hydroxide and calcium carbonate to the sample. These three alkaline earth components have their heat absorbing peaks located along the temperature domain in a way that the temperature rising is reasonably damped. In this work we find, as the main result, that when these three fillers are added to gypsum, the protection offered by the new combination of materials is significantly improved with respect to the behavior of gypsum alone. Under external heating, the component is able to keep itself under critical temperatures for a longer period. For the theoretical description, we first use non isothermal thermogravimetry (TG) to analyze and characterize the kinetic response of each component of the mixture. We propose a conversion function which is based on the correlation between consecutive reactions in neighboring molecules. The heating rate is included in the model as an analytical variable. Later we perform high temperature tests in a tubular furnace and their corresponding numerical simulations where heat transfer is explicitly carried and mass transfer effects are discussed.
Ceramics International, 2016
Science of The Total Environment, 2021
Ammonia nitrogen management is a recurrent problem in intensive livestock areas. Struvite precipi... more Ammonia nitrogen management is a recurrent problem in intensive livestock areas. Struvite precipitation stands as a mature technology to recover ammonia nitrogen and prevent associated environmental problems. However, the feasibility of struvite technology to recover ammonia nitrogen from pig manure is limited by the reagents cost. This research aimed to optimise the formulation of a stabilizing agent (SA) synthesised using an industrial low-grade MgO by-product (LG-MgO) and phosphoric acid for efficient TAN recovery via struvite precipitation. Experimental results showed that the H3PO4/LG-MgO ratio controls the magnesium phosphate mineral phase of the SA (bobierrite and/or newberyite). Newberyite-rich SA showed the highest TAN removal efficiency from pig manure (66-73%) compared to the SA formed by a mixture of newberyite and bobierrite (51-59%) and by bobierrite (26%). Particle size reduction of LG-MgO did not improve the SA's TAN removal efficiency, although XRD patterns showed that the precipitates from the TAN removal experiments contained some unreacted newberyite. The economic analysis showed that the higher reactivity of the SA formulated using higher H3PO4/LG-MgO ratios compensated reagent costs. The SA synthesised with a H3PO4/LG-MgO ratio of 0.98 showed the most economical treatment cost, which was estimated at 7.5 € per kg of ammonia nitrogen from pig manure. Finally, the optimum SA was successfully synthesised in a 200-L pilot plant, with a TAN removal capacity only 10% lower than the one synthesised at lab-scale.
IOP Conference Series: Materials Science and Engineering, 2017
View the article online for updates and enhancements. Content from this work may be used under th... more View the article online for updates and enhancements. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Renewable Energy, 2015
Biogas upgrading using bottom ash from the incineration of municipal solid waste (MSW) is especia... more Biogas upgrading using bottom ash from the incineration of municipal solid waste (MSW) is especially interesting for integrated treatment facilities as it would allow closing a complete loop in MSW management. The aim of this research was to assess the interaction between bottom ash (BA) and biogas from anaerobic digestion with the outlook of upgrading in terms of CO 2 and H 2 S removal, with particle size and bottom ash aging as the main variables. The finest fraction of fresh bottom ash (FBA) presented the best performance, with a sorption capacity of 30e50 kg CO 2 $t À1 dry FBA. The sorption capacity of weathered bottom ash (WBA) was lower than the recorded for the fresh material. From the results obtained it can be stated that the CO 2 absorption capacity of bottom ash mainly relies in the finest fraction because of its larger surface area and higher CaO content. In what respect to H 2 S sorption capacity, WBA presented a better performance, with values ranging 3.1e5.2 kg H 2 S•t À1 dry WBA. In addition to the energetic enhancement, the proposed technology also allows an immediate stabilization and reuse of bottom ash as the leaching of heavy metals and metalloids remained under regulatory limits.
Fuel Processing Technology, 2014
Fly ash (FA) disposal in landfills has a significant economic and environmental burden. A promisi... more Fly ash (FA) disposal in landfills has a significant economic and environmental burden. A promising approach for FA valorisation aside from building purposes is the recovery of valuable elements since FA has a huge potential role as a source of valuable metals. In most cases, reported work in this area has been of theoretical research and further development work is needed. Germanium and gallium occur in relatively high proportions and mainly as water soluble and oxide species, respectively in the Puertollano Integrated Gasification Combined Cycle (IGCC) fly ash. Both the speciation and concentrations of Ge and Ga in this IGCC FA allowed starting research for developing extraction methods. High but not regular extraction yields were achieved in previous investigations. The aim of this research work is focused on the optimisation of Ge and Ga extraction conditions from IGCC FA for its feasible industrial application regardless the operational conditions of the IGCC plant. To this aim, first the daily, monthly, and yearly variability of Ge and Ga concentrations in IGCC fly ashes were determined. Samples were taken during almost 10 years. Then a number of extraction tests were carried out using different extractants to cover a wide range of extraction conditions (acid, alkaline, complexant, reducing and oxidising), on IGCC FA samples produced under different operating conditions. High and regular Ge extraction yields (up to 83% after 2 h leaching period) may be achieved using a weak acid solution. Gallium yielded up to 70 and 64% extraction after a 24 h leaching period using a weak acid and alkaline solution, respectively.
Ceramics International, 2012
A hard-burner low-grade MgO (LG-MgO) is used to formulate a chemically bonded phosphate ceramic (... more A hard-burner low-grade MgO (LG-MgO) is used to formulate a chemically bonded phosphate ceramic (CBPC) instead of pure MgO. This by-product is 10 times cheaper than pure MgO. The use of this by-product reduce the cost of the final material and therefore an economical construction material could be obtained. This would reinforce the criteria of sustainability and recyclability. In addition, the inert phases contained on LG-MgO act like inorganic fillers, improving the mechanical properties of this CPBC, which can be considered as a mortar. A range from 55% to 65% of LG-MgO is studied, and boric acid is added in order to improve workability and setting times. Design of Experiments (DoE) approach enabled the evaluation of the influence of each component and the interactions between them. According to the setting times and compressive strength results, a formulation range is proposed.
Electrochimica Acta, 1999
The kinetics of conventional gold cyanidation in air has been studied using open circuit potentia... more The kinetics of conventional gold cyanidation in air has been studied using open circuit potential measurements, voltammetry and atomic absorption spectrophotometry. The experimental results show that this is a complex process characterized by the interdependency of the different variables (cyanide concentration, pH, temperature and stirring speed).The measurement of the mixed potentials at which the process takes place gives valuable information to ascertain the influence of each variable. A good correlation between mixed potential and dissolution rate, thus having a potential interest for an industrial application, has been found. The study of the current-potential curves for oxygen reduction on gold surface and anodic dissolution of gold in cyanide solutions gives more insight into the control of the process: depending on the experimental conditions, gold dissolution takes place in the active region (oxygen diffusion control) or in the potential region where dissolution of adsorbed species limits the rate of the process. Depending also on the experimental conditions, two or four electrons are transferred per oxygen molecule.
Materials Science and Engineering: A, 2011
... Study of the effect of eafd in polymer composites usig DoE. Niubó Eslava, Maria; Fernández, A... more ... Study of the effect of eafd in polymer composites usig DoE. Niubó Eslava, Maria; Fernández, Ana Inés; Haurie Ibarra, Laia; Capdevila, XG; Martínez, M; Velasco Perero, José Ignacio. Diseño y caracterización de mezclas EVA/plastómero para su empleo en compuestos de ...
Although waste-to-energy plants allow reducing the mass and volume of municipal solid waste (MSW)... more Although waste-to-energy plants allow reducing the mass and volume of municipal solid waste (MSW) incinerated, an average around 30 % of the total content remains as bottom ash (BA) and air pollution control (APC) ashes at the end of combustion process. While weathered bottom ash (WBA) is considered a non-hazardous residue that can be revalorized as a secondary aggregate, APC fly ashes generated during the flue gas treatment are classified as hazardous waste and are handled in landfill disposal after stabilization, usually with Portland cement (OPC). However, taking into account the amount of APC residues produced and the disposing cost in landfill, their revalorization is an important issue that could be effectively addressed. As MSW can be incinerated producing bottom ashes (BA) or air pollutant control (APC) residues, the development of a mortar formulated with APC fly ash as secondary building material is a significant risk to the environment for their content of heavy metals. I...
Construction and Building Materials, 2015
Magnesium Phosphate Cement (MPC) has become an essential reference for investigators seeking alte... more Magnesium Phosphate Cement (MPC) has become an essential reference for investigators seeking alternatives to the use of Ordinary Portland Cement (OPC) in building sector because of its high environmental impact. The research group developed a MPC formulated with low-grade MgO (LG-MgO) by-product, which could be considered as a sustainable MPC (sust-MPC). This research focuses on the incorporation of different percentages of Microencapsulated Phase Change Materials (MPCM) into sust-MPC, due to their ability to reduce energy consumption of heating, ventilating, and air conditioning (HVAC) systems. The study consists of an exhaustive characterization of thermal sustainable MPC (TS-MPC) dosages which incorporate air-entraining additive (AEA) and MPCM to improve their thermal behaviour. Thus, TS-MPC would reduce the use of HVAC systems contributing to the decrease of CO2 emissions and increasing energy efficiency in buildings. Moreover, properties such as bulk density, porosity, thermal conductivity, modulus of elasticity, compressive strength, and flexural strength are analysed to evaluate the potential use of these cements as a part of a passive conditioning system. Results show the proper behaviour of these cements to reduce thermal oscillation in buildings. Experimental results demonstrated the relation between the amount of the MPCM and the AEA percentage as well as the thermal and mechanical properties of the TS-MPC due to their contribution to increase the porosity. Furthermore, it should be noted the increase of porosity and the reduction of thermal conductivity of the optimal formulation, which are 60% higher and 50% lower than the sust-MPC obtained without MPCM and additive, respectively.
IOP Conference Series: Materials Science and Engineering
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IOP Conference Series: Materials Science and Engineering
Microencapsulation of phase change materials with carbon nanotubes reinforced shell for enhanceme... more Microencapsulation of phase change materials with carbon nanotubes reinforced shell for enhancement of thermal conductivity Weiwei Cui, Yongpeng Xia, Huanzhi Zhang et al.
Waste and Biomass Valorization