Recursos de colección

RUA (125.261 recursos)

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INV - REPIC - Artículos de Revistas

Mostrando recursos 1 - 20 de 34

  1. Physical and chemical evaluation of furniture waste briquettes

    Moreno Caballero, Ana Isabel; Font, Rafael; Conesa, Juan A.
    Furniture waste is mainly composed of wood and upholstery foam (mostly polyurethane foam). Both of these have a high calorific value, therefore, energy recovery would be an appropriate process to manage these wastes. Nevertheless, the drawback is that the energy content of these wastes is limited due to their low density mainly that of upholstery foam. Densification of separate foam presents difficulties due to its elastic character. The significance of this work lies in obtaining densified material by co-densification of furniture wood waste and polyurethane foam waste. Densification of furniture wood and the co-densification of furniture wood waste with polyurethane...

  2. PCDD/F formation from chlorophenols by lignin and manganese peroxidases

    Muñoz Fernández, María; Gómez-Rico, María Francisca; Font, Rafael
    Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) formation was studied, in vitro, with two different chlorophenol mixtures (group “di+tri” 2,4-dichlorophenol; 2,3,4-, 2,3,5-, and 3,4,5-trichlorophenols and group “tri+tetra+penta” with 2,4,5-trichlorophenol, 2,3,4,6-tetrachlorophenol and pentachlorophenol) and two different lignolytic enzymes, lignin and manganese peroxidase (LiP and MnP respectively), which can be found during the composting process of sewage sludge. The concentrations of PCDD/F in final samples are compared to the PCDD/F content of the control samples containing the chlorophenols. High increases were observed for experiments with MnP and phosphate buffer. Experiments that contained tri-, tetra- and pentachlorophenol with MnP resulted in more than 8...

  3. Study of the emissions from pyrolytic and oxidative thermal decomposition of PVC

    Edo Giménez, María del Mar; Aracil, Ignacio; Font, Rafael
    Polyvinyl chloride (PVC) is one of the plastics most extensively used due to its versatility. The demand of PVC resin in Europe during 2012 reached 5000 ktonnes1. PVC waste management is a big problem because of the high volume generated all over the world and its chlorine content. End-of-life PVC is mainly mixed with municipal solid waste (MSW) and one common disposal option for this is waste-to-energy incineration (WtE). The presence of plastics such as PVC in the fuel mix increases the heating value of the fuel. PVC has two times higher energy content than MSW ‒around 20 MJ/kg vs...

  4. Pyrolysis and combustion study of flexible polyurethane foam

    Garrido, María A.; Font, Rafael
    The thermal degradation of flexible polyurethane foam has been studied under different conditions by thermogravimetric analysis (TG), thermogravimetric analysis-infrared spectrometry (TG-IR) and thermogravimetric analysis-mass spectrometry (TG-MS). For the kinetic study, dynamic and dynamic+isothermal runs were performed at different heating rates (5, 10 and 20 °C min−1) in three different atmospheres (N2, N2:O2 4:1 and N2:O2 9:1). Two reaction models were obtained, one for the pyrolysis and another for the combustion degradation (N2:O2 4:1 and N2:O2 9:1), simultaneously correlating the experimental data from the dynamic and dynamic+isothermal runs at different heating rates. The pyrolytic model considered consisted of two consecutive reactions...

  5. Pyrolysis of furniture wood waste: Decomposition and gases evolved

    Moreno Caballero, Ana Isabel; Font, Rafael
    The pyrolysis of furniture wood waste was studied due to its importance as a thermochemical conversion process, and also because it is a step in the combustion process. Furniture wood contains organic additives and inorganic elements (being noteworthy the high content of Ti). These additives cause changes in the thermal processes. A thermogravimetric analysis of the pyrolysis of furniture wood waste was carried out in a TGA apparatus using dynamic and dynamic + isothermal runs. The pyrolysis was modeled with acceptable approximation by three independent reactions, according to the decomposition of the main components of the wood (hemicellulose, cellulose and...

  6. Effect of Temperature, Atmosphere and Metals on the Thermal Degradation of Printed Circuit Boards

    Ortuño García, Nuria; Conesa, Juan A.; Moltó Berenguer, Julia; Font, Rafael
    The permanent expansion of the market of electrical and electronic equipment (EEE) and the shorter innovation cycles, lead to a faster replacement of these appliances, making EEE a fast-growing source of waste (WEEE). As stated in Directive 2012/19/EU1 on waste electrical and electronic equipment, the content of hazardous components in EEE is a major concern during the waste management phase, and recycling of WEEE is not currently undertaken to a sufficient extent, resulting in a loss of valuable resources.

  7. Kinetics of tetrabromobisphenol A pyrolysis. Comparison between correlation and mechanistic models

    Font, Rafael; Moltó Berenguer, Julia; Ortuño García, Nuria
    Brominated flame retardants are well recognized as being highly effective flame retardants. 4-4′-Isopropylidenebis(2,6-dibromophenol), commonly known as tetrabromobisphenol A, is the brominated flame retardant with the largest production volume and is used to improve fire safety, mainly of laminates in electrical and electronic equipment. A kinetic study of the pyrolysis of TBBA has been carried out to obtain decomposition parameters under different operating conditions and taking into account that TBBA is a compound with a high boiling point and that vaporization occurs simultaneously to decomposition. Dynamic runs and dynamic + isothermal run at different heating rates and using different masses of...

  8. Analysis of the vaporization process in TG apparatus and its incidence in pyrolysis

    Font, Rafael; Gómez-Rico, María Francisca; Ortuño García, Nuria
    An analysis of the evaporation process of n-hexadecane in a thermogravimetric apparatus was carried out. n-Hexadecane represents a typical example of a high boiling point compound and its study is interesting for understanding those processes where vaporization takes place in parallel with pyrolysis during thermal treatment. The process has been studied under different operating conditions: nitrogen and air atmospheres, and isothermal and dynamic runs with three different heating rates from 5 K/min to 20 K/min. The experimental data were satisfactorily correlated to a n-order model with zero process order and the same apparent activation energy for all runs, but the...

  9. Pollutant emissions during pyrolysis and combustion of waste printed circuit boards, before and after metal removal

    Ortuño García, Nuria; Conesa, Juan A.; Moltó Berenguer, Julia; Font, Rafael
    The constant increase in the production of electronic devices implies the need for an appropriate management of a growing number of waste electrical and electronic equipment. Thermal treatments represent an interesting alternative to recycle this kind of waste, but particular attention has to be paid to the potential emissions of toxic by-products. In this study, the emissions from thermal degradation of printed circuit boards (with and without metals) have been studied using a laboratory scale reactor, under oxidizing and inert atmosphere at 600 and 850 °C. Apart from carbon oxides, HBr was the main decomposition product, followed by high amounts...

  10. De novo synthesis of brominated dioxins and furans

    Ortuño García, Nuria; Conesa, Juan A.; Moltó Berenguer, Julia; Font, Rafael
    On the basis of laboratory experiments with model mixtures (active carbon + CuBr2 at different loads), this work studies the formation of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) by de novo synthesis. For the different samples, the temperature of the maximum carbon oxidation rate was determined by thermogravimetric analysis, and a kinetic model was proposed for the degradation of the materials in an oxidizing atmosphere (synthetic air). The effect of the addition of different amounts of CuBr2 was studied, finding that its presence accelerates the degradation of the carbonaceous structure in the presence of oxygen. The thermal degradation of the samples...

  11. Characterization of lorry washing sludge

    Moreno Caballero, Ana Isabel; Font, Rafael; Gómez-Rico, María Francisca
    The sludge generated by washing lorry refuse and some fractions of municipal solid waste have been studied, to justify that washing sludge presents no danger and can therefore be managed adequately in a landfill, as well as other municipal solid waste fractions. One problem attributed to this type of sludge is its high level of sulfide content, which causes this waste to be considered hazardous. The determination of sulfide content in the studied samples was carried out according to environmental protection agency methods 9030B and 9034, and the results show that the sulfide concentration in the sludge is less than...

  12. Chemical characterization of emissions from a municipal solid waste treatment plant

    Moreno Caballero, Ana Isabel; Arnaiz Arnaiz, Noelia; Font, Rafael; Carratalá, Adoración
    Gaseous emissions are an important problem in municipal solid waste (MSW) treatment plants. The sources points of emissions considered in the present work are: fresh compost, mature compost, landfill leaks and leachate ponds. Hydrogen sulphide, ammonia and volatile organic compounds (VOCs) were analysed in the emissions from these sources. Hydrogen sulphide and ammonia were important contributors to the total emission volume. Landfill leaks are significant source points of emissions of H2S; the average concentration of H2S in biogas from the landfill leaks is around 1700 ppmv. The fresh composting site was also an important contributor of H2S to the total...

  13. Potential kinetic model for thermal decomposition of complex organic compounds: Significance of parameters and engineering application

    Font, Rafael
    This paper analyzes the significance of the apparent activation energies and the reaction orders in potential kinetic models, their great interrelation and their influence in the design of reactors. The interrelation between the pre-exponential factor, the apparent activation energy and the reaction order is considered for a single reaction model and for a scheme of reactions. In addition, some simulated results of schemes of reactions were correlated satisfactorily by a single reaction model with surprising results concerning the activation energy and the reaction order. The potential model is compared with other correlation models proposed in literature. Finally, an analysis is...

  14. Production of Carbon Nanotubes from Polyethylene Pyrolysis Gas and Effect of Temperature

    Arnaiz Arnaiz, Noelia; Gómez-Rico, María Francisca; Martín Gullón, Ignacio; Font, Rafael
    Carbon nanotubes (CNTs) were produced by catalytic chemical vapor deposition using, as carbon source, a mixture of hydrocarbons and hydrogen that simulates the effluent gases from pyrolysis of polyethylene (PE). An Fe/Al3O3 catalyst was used in a range of temperatures from 600 to 800 °C. Multiwall carbon nanotubes of 20 nm in diameter and length on the order of micrometers were obtained. Higher yields were observed at 650 °C, where no prior catalyst reduction was necessary. Transmission electron microscopy, X-ray diffraction, and Raman spectrometry show a higher crystalline quality at 750 °C, although the balance yield–quality indicates that 650 °C...

  15. Biogas from MSW landfill: Composition and determination of chlorine content with the AOX (adsorbable organically bound halogens) technique

    Rey Martínez, María Dolores; Font, Rafael; Aracil, Ignacio
    An exhaustive characterization of the biogas from some waste disposal facilities has been carried out. The analysis includes the main components (methane, carbon dioxide, nitrogen and oxygen) as well as trace components such as hydrogen sulphide, ammonia and VOCs (volatile organic compounds) including siloxanes and halogenated compounds. VOCs were measured by GC/MS (Gas Chromatography/Mass Spectrometry) using two different procedures: thermal desorption of the Tenax TA and Carbotrap 349 tubes and SPME (Solid Phase Micro-Extraction). A method has been established to measure the total halogen content of the biogas with the AOX (adsorbable organically bound halogens) technique. The equipment used to...

  16. Viability study of automobile shredder residue as fuel

    Edo Giménez, María del Mar; Aracil, Ignacio; Font, Rafael; Anzano, Manuela; Fullana, Andres; Collina, Elena
    Car Fluff samples collected from a shredding plant in Italy were classified based on particle size, and three different size fractions were obtained in this way. A comparison between these size fractions and the original light fluff was made from two different points of view: (i) the properties of each size fraction as a fuel were evaluated and (ii) the pollutants evolved when each size fraction was subjected to combustion were studied. The aim was to establish which size fraction would be the most suitable for the purposes of energy recovery. The light fluff analyzed contained up to 50 wt.%...

  17. Kinetics of olive oil pyrolysis

    Font, Rafael; Rey Martínez, María Dolores
    A kinetic study of olive oil pyrolysis has been carried out under different conditions by thermogravimetry. Nine TG runs were performed at nitrogen atmosphere, seven under dynamic conditions and two under dynamic + isothermal regime (constant heating rate until the set temperature was reached and then the set temperature was maintained constant). On the other hand, three dynamic runs were carried out with used olive oil. In addition, a study of the thermal decomposition was also carried out in dynamic runs at helium atmosphere using TG–MS and TG–IR at nitrogen atmosphere in order to observe the evolution of some compounds...

  18. Use of thermogravimetry for single characterisation of samples of the composting process from sewage sludge

    Muñoz Fernández, María; Gómez-Rico, María Francisca; Font, Rafael
    Pyrolysis and combustion of different samples from a sewage sludge composting tunnel plant were studied by thermogravimetry. Two series of samples were analyzed: initially, 8 samples were taken at 8 different points from different stages of the process; later, 5 samples from different points at the end of the composting tunnel were taken. The experiments were carried out at 10 °C/min, in N2 atmosphere and N2:O2 4:1 atmosphere. The results were discussed to analyze the heterogeneity of the samples. In addition, the compositions of the samples taken for the analysis were deduced using the decomposition kinetics as correlation of weight...

  19. Thermogravimetric study of the decomposition of printed circuit boards from mobile phones

    Ortuño García, Nuria; Moltó Berenguer, Julia; Egea Ruiz, Silvia; Font, Rafael; Conesa, Juan A.
    Thermal decomposition of printed circuits boards (PCB) is studied, using thermogravimetric analysis to compare the thermal behavior of PCB of mobile phones before and after the removal of the metallic fraction by acid washing. Several dynamic and dynamic + isothermal runs have been carried out at different heating rates (5, 10 and 20 K min−1), from room temperature to more than 1100 K. Also runs in the presence and in the absence of oxygen were performed (combustion and pyrolysis runs). Moreover, TG–MS experiments were performed (both in inert and oxidizing atmosphere) in order to better understand the thermal decomposition of...

  20. Decomposition of two types of electric wires considering the effect of the metal in the production of pollutants

    Conesa, Juan A.; Egea Ruiz, Silvia; Moltó Berenguer, Julia; Ortuño García, Nuria; Font, Rafael
    Combustion runs at 700 °C in a horizontal laboratory furnace were carried out on two different electric wires (PVC and halogen-free wire). Tests were performed in the presence and in the absence of the metal conductor of the wires. The analyses of the polycyclic aromatic hydrocarbons (PAHs), chlorobenzenes (CBzs), chlorophenols (CPhs), mono- to octa-chlorodibenzo-p-dioxin and dibenzofurans (PCDD/Fs), and dioxin-like PCBs are shown. Regarding semivolatile compounds, PAHs production decreases in the presence of metal, while a higher amount of chlorinated compounds are emitted. Respect to the PCDD/Fs, the PVC wire in the presence of metal presents the highest emission, with a...

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