A Multiinstitutional Spanish Master’s Program in Ecosystem Restoration: Vision and Four-Year Experience

Since 2006, an innovative, multiinstitutional Spanish Master in Ecosystem Restoration (MER) is jointly offered by four major public universities in Madrid. In view of the high student demand—about 900 applications this academic year for only 30 places, a remarkable 75% rate of professional poststudy employment in a period of economic crisis, and the high number (> 40) of prestigious organizations involved in the program, we consider the MER program, although still young, to be very promising for the long term. We explain the process to create the MER and achieve the results obtained thus far. We describe its organization, report its vital statistics in terms of students, and identify some strengths and weaknesses observed to date. The MER program has evolved as a network of knowledge and experience that links universities, lecturers, researchers, students, private and public companies, NGOs, and administration centers. Our aim is to help other groups that may want to launch similar graduate-level ecological restoration degree programs

Determinación del hábitat potencialmente utilizable por la especie Salmo trutta en un tramo del río Lozoya, España

En el presente trabajo se efectua la estimacion del habitat potencialrnente utilizable (HPU) y del caudal que lo maximiza para los estadios de vida adulto, juvenil, alevin y freza de la especie Salmo trutta (trucha comun), especie muy apreciada en la pesca deportiva y para el consumo humane Para tal fin, de acuerdo con la Metodologia IFIM (Instream Flow Incremental Methodology), se efectuo la simulacion del habitat fisico fluvial de un tramo de 609 m del rio Lozoya (Madrid, Espana) utilizando un modelo bidimensional de la hidrodinamica, un modelo para la simulacion del habitat y los modelos de preferencia de habitat de la especie antes mencionada. Los modelos fueron alimentados con informacion hidraulica, geomorfologica, biologica y de caracteristicas especificas del habitat obtenidas en campo. Los valores del habitat potencialrnente utilizable (HPU) obtenidos para los cuatro estadios de desarrollo de la especie Salmo trutta permitieron determinar que el caudal de 1.97 m3/s maximiza el HPU para sus estadios de vida adulto, juvenil y freza, y que el caudal de 1.08 m3/s maximiza el habitat potencialrnente utilizable para su estadio de desarrollo alevin. Las curvas caudal-habitat potencialrnente utilizable obtenidas en el presente trabajo constituyen informacion valiosa para los usuarios y los gestores de los recursos fluviales del rio Lozoya, con miras a establecer un regimen de caudales ecologicos que permita conservar el ecosistema correspondiente y, en caso necesario, evaluar los impactos relacionados con posibles modificaciones del regimen de caudales

Effect of pressure on the behavior of copper-, iron-, and nickel-based oxygen carriers for chemical-looping combustion

8 pages, 8 figures, 2 tables.The combustion process integrated by coal gasification and chemical-looping combustion (CLC) could be used in power plants with a low energy penalty for CO2 capture. This work analyzes the main characteristics related to the CLC process necessary to use the syngas obtained in an integrated gasification combined cycle (IGCC) power plant. The kinetics of reduction with H2 and CO and oxidation with O2 of three high-reactivity oxygen carriers used in the CLC system have been determined in a thermogravimetric analyzer at atmospheric pressure. The iron- and nickel-based oxygen carriers were prepared by freeze-granulation, and the copper-based oxygen carrier was prepared by impregnation. The changing grain size model (CGSM) was used for the kinetic determination, assuming spherical grains for the freeze-granulated particles containing iron and nickel and a platelike geometry for the reacting surface of the copper-based impregnated particles. The dependence of the reaction rates on temperature was low, with the activation energy values varying from 14 to 33 kJ mol-1 for the reduction and 7 to 15 kJ mol-1 for the oxidation. The reaction order depended on the reacting gas and oxygen carrier, with values ranging from 0.25 to 1. However, an increase in the operating pressure for the IGCC + CLC system increases the thermal efficiency of the process, and the CO2 is recovered as a high pressure gas, decreasing the energy demand for further compression. The effect of pressure on the behavior of the oxygen carriers has been analyzed in a pressurized thermogravimetric analyzer at 1073 K and pressures up to 30 atm. It has been found that an increase in total pressure has a negative effect on the reaction rates of all the oxygen carriers. Moreover, the use of the CGSM with the kinetic parameters obtained at atmospheric pressure predicted higher reaction rates than those experimentally obtained at higher pressures, and therefore, the kinetic parameters necessary to design pressurized CLC plants must be determined at the operating pressure. © 2006 American Chemical Society.This work was carried out with financial support from the European Coal and Steel Community Project (7220-PR125) and the Spanish Ministry of Education and Science (Project CTQ 2004-04034). The authors thank Dr. Anders Lyngfelt and Dr. Tobias Mattisson for the preparation of the freeze-granulated particles.Peer Reviewe

Calcination of calcium-based sorbents at pressure in a broad range of CO2 concentrations

11 figures, 3 tablesThe calcination reaction of two limestones and a dolomite with different porous structures was studied by thermogravimetric analysis. The effects of calcination temperature (1048-1173 K), particle size (0.4 2.0 mm), CO2 concentration (0 80%) and total pressure (0.1 1.5 MPa) were investigated. SEM analysis indicated the existence of two different particle calcination models depending on the sorbent type: a shrinking core model with a sharp limit between the uncalcined and calcined parts of the particle and a grain model with changing calcination conversion at the particle radial position. The appropriate reaction model was used to determine the calcination kinetic parameters of each sorbent. Chemical reaction and mass transport in the particle porous system were the main limiting factors of the calcination reaction at the experimental conditions. A Langmuir-Hinshelwood-type kinetic model using the Freundlich isotherm was proposed to account for the effect of the CO2 during sorbent calcination. This allowed us to predict the calcination conversion of very different sorbents in a broad range of CO2 partial pressures. Total pressure also inhibited the sorbent calcination. This fact was accounted for by an additional decrease in the molecular diffusion coefficient with increasing total pressure with respect to that indicated by Fuller's equation.This research was carried out with the financial support from the Comisión Interministerial de Ciencia y Tecnología (CICYT) (Project No. AMB 98-0883). The authors thank Dr. Diego Alvárez for his assistance with the SEM technique.Peer Reviewe

Continuous multi-criteria methods for crop and soil conservation planning on La Colacha (Río Cuarto, Province of Cordoba, Argentina)

Agro-areas of Arroyos Menores (La Colacha) west and south of Rand south of R?o Cuarto (Prov. of Cordoba, Argentina) basins are very fertile but have high soil loses. Extreme rain events, inundations and other severe erosions forming gullies demand urgently actions in this area to avoid soil degradation and erosion supporting good levels of agro production. The authors first improved hydrologic data on La Colacha, evaluated the systems of soil uses and actions that could be recommended considering the relevant aspects of the study area and applied decision support systems (DSS) with mathematic tools for planning of defences and uses of soils in these areas. These were conducted here using multi-criteria models, in multi-criteria decision making (MCDM); first of discrete MCDM to chose among global types of use of soils, and then of continuous MCDM to evaluate and optimize combined actions, including repartition of soil use and the necessary levels of works for soil conservation and for hydraulic management to conserve against erosion these basins. Relatively global solutions for La Colacha area have been defined and were optimised by Linear Programming in Goal Programming forms that are presented as Weighted or Lexicographic Goal Programming and as Compromise Programming. The decision methods used are described, indicating algorithms used, and examples for some representative scenarios on La Colacha area are given

Titanium substituted manganese-ferrite as an oxygen carrier with permanent magnetic properties for chemical looping combustion of solid fuels

Mixed oxides of Mn-Fe have been identified as suitable materials for Chemical Looping Combustion (CLC) with solid fuels both via in-situ Gasification Chemical Looping Combustion (iG-CLC) and Chemical Looping with Oxygen Uncoupling (CLOU) processes. These materials show the property of react with gaseous fuels as well as release oxygen under given conditions, while cheap metals are used. In addition, these materials can show magnetic properties that can be used for an easy separation from ash in CLC with solid fuels. Thus, losses of oxygen carrier material in the ash drain stream would be reduced. Different cations have been proposed for improving the magnetic properties of manganese ferrites, including Ti4+. In this context, the present work accomplishes a screening of (MnxFe1-x)2O3 doped with 7 wt.% TiO2, with x ranging from 0 to 1. The influence of Mn:Fe ratio on their physical and chemical properties was evaluated. In general, particles with high crushing strength values (>4 N) were obtained, and magnetic characteristics were highlighted when x ¿ 0.66. The oxygen uncoupling capability depended on the Mn:Fe ratio and the oxidation conditions, i.e. temperature and oxygen partial pressure. Broader oxidation conditions to take advantage of the oxygen uncoupling capability were found for materials with low Mn content. On contrary, the reactivity with fuel gases (CH4, H2 and CO) increased with the Mn content. Thus, oxygen carriers with Mn/(Mn + Fe) molar ratio in the 0.5–0.9 interval showed interesting properties at suitable temperatures for the iG-CLC and CLOU processes (i.e. 850–980 °C). The material with Mn/(Mn + Fe) = 0.55 was preferred considering a trade-off between reactivity and magnetic properties

The use of ilmenite as oxygen-carrier in a 500Wth Chemical-Looping Coal Combustion unit

12 pages, 13 figures, 6 tablesChemical-Looping Combustion, CLC, is a promising technology to capture CO2 at low cost in fossil-fuelled power plants. In CLC the oxygen from air is transferred to the fuel by a solid oxygen-carrier that circulates between two interconnected fluidized-bed reactors: the fuel- and the air-reactor. This work studies the CLC technology in a 500Wth facility fuelled with bituminous coal with ilmenite as oxygen-carrier. The effect of temperature and coal particle size on coal conversion and combustion efficiency was assessed. Char gasification and combustion of both gasification products and volatile matter were evaluated. At higher temperatures, gasification and combustion reactions are promoted. Carbon capture and combustion efficiencies grow with the temperature, with faster increase at temperatures higher than 910°C. The outgoing unburnt gases come from volatile matter that was not fully oxidized by ilmenite. Little CH4 was measured and there were neither hydrocarbons heavier than CH4 nor tars in the fuel-reactor outlet. At 870°C the char conversion was 15% and reached 82% at 950°C. The combustion efficiency in the fuel-reactor increased from 70% at 870°C to 95% at 950°C. The results show that ilmenite has good behavior as oxygen-carrier and that optimizing CLC with coal can lead to energy production with high CO2 capture.This work was partially supported by the European Commission, under the RFCS program (ECLAIR Project, Contract RFCP-CT-2008-0008), from Alstom Power Boilers and by the Spanish Ministry of Science and Innovation (Project ENE2010-19550). A. Cuadrat thanks CSIC for the JAE Pre. fellowship. Alberto Abad thanks to the Ministerio de Ciencia e Innovación for the financial support in the course of the I3 Program.Peer Reviewe

Characterization for disposal of Fe-based oxygen carriers from a CLC unit burning coal

Chemical Looping Combustion (CLC) is an emerging low cost CO2 capture technology for large scale power units. The oxygen needed for combustion is supplied by a solid oxygen carrier circulating between two reactors. Fe-based oxygen carriers have been proposed for CLC of coal due to their low cost. Some of them are minerals or industrial residues which can contain toxic trace elements. After its use, the oxygen carrier should be disposed in a landfill and therefore, the presence of soluble toxic elements in the oxygen carrier should be analyzed. In this study, lixiviation tests were carried out with three different Fe-based oxygen carriers used in coal CLC experiments in a continuous unit: ilmenite, a bauxite waste and an iron ore. All the spent oxygen carriers, except the bauxite waste, can be classified as a stable non-reactive hazardous waste and therefore can be disposed in a landfill for non-hazardous residues. An estimation of the amount of solid waste generated in the process based on the fly ash content of the coal and the oxygen carrier particle lifetime was made.The authors thank the Spanish Ministry for Science and Innovation (MICCIN) for the financial support via the ENE2011-26354 project. This work was also partially supported by FEDER funds. T. Mendiara thanks for the “Ramón y Cajal” post-doctoral contract awarded by the Ministry of Economy and Competitiveness.Peer reviewe

Prompt considerations on the design of chemical-looping combustion of coal from experimental tests

13 Figures, 5 TablesThe Chemical-Looping Combustion of coal in the reactor system has been proposed as an interesting option to process a solid fuel in a CLC system. In this process, a solid fuel is directly fed to the fuel reactor in a CLC system. Solid fuel pyrolysis, char gasification and oxidation of gaseous products by reaction with the oxygen-carrier are the main chemical processes happening in the fuel reactor. The aim of this study is to analyze the performance of ilmenite as oxygen-carrier for CLC of coal regarding to the conversion of gaseous products from char gasification. Successive reduction-oxidation cycles were carried out in a fluidized bed using bituminous coal char as reducing agent. The changes on chemical and physical properties of ilmenite particles were determined. An activation process of ilmenite through the redox cycles was evidenced which was justified by an increase of porosity. The results showed that the activation for ilmenite reduction reaction was completed after 7 redox cycles. However, the oxidation reaction rate was increasing still after 16 redox cycles because the porosity was not fully developed. The gasification reaction rate and the ilmenite reactivity were analyzed. The effect of ilmenite itself and the influence of the gasification agent, i.e. H2O, CO2 or H2O/CO2 mixtures, and temperature on the gasification rate were evaluated. Limited use of CO2 in the fluidizing gas was identified in order to maintain high gasification rates. Higher temperature improved the char gasification rate, mainly using steam as gasification agent, and the combustion efficiency of the gasification products. Nevertheless, the effect of temperature on the combustion efficiency was of lower relevance than that on the gasification rate. Finally, a theoretical approach was developed to easily evaluate the conversion of char in the fuel-reactor by gasification.This work was partially supported by the European Commission, under the RFCS program (ECLAIR Project, Contract RFCP-CT-2008-0008), from Alstom Power Boilers and by the Spanish Ministry of Science and Innovation (Project ENE2010- 19550). A. Cuadrat thanks CSIC for the JAE Pre. fellowship. Alberto Abad thanks to the Ministerio de Ciencia e Innovación for the financial support in the course of the I3 Program.Peer reviewe

Kinetic analysis of a Cu-based oxygen carrier: Relevance of temperature and oxygen partial pressure on reduction and oxidation reactions rates in Chemical Looping with Oxygen Uncoupling (CLOU)

The kinetic of reduction of CuO to Cu2O with N2+O2 mixtures and the oxidation of Cu2O to CuO with O2 of a Cu-based oxygen carrier for the CLOU process has been determined in a TGA. For kinetic determination, the O2 concentrations were varied between 0 and 9 vol.% for reduction, and between 21 and 1.5 vol.% for oxidation reactions; temperature was varied between 1148 and 1273 K for the reduction and between 1123 and 1273 K for the oxidation. The oxygen carrier showed high reactivity both in oxidation and reduction reactions. The nucleation and nuclei growth model with chemical reaction control properly described the evolution of solids conversion with time. The Langmuir-Hinshelwood model was able to describe the effect of oxygen concentration on reduction and oxidation rates. The reaction order was 0.5 for reduction and 1.2 for the oxidation. The kinetic constant activation energies were 270 kJ mol-1 for the reduction and 32 kJ mol-1 for the oxidation. The kinetic model was used to calculate the solids inventory needed in the fuel reactor for complete combustion of three different rank coals. It was possible to use a low oxygen carrier inventory in the fuel reactor (160 kg/MWth) to supply the oxygen required to full lignite combustion. However, to reach high CO2 capture efficiencies (³95%), oxygen carrier inventories in fuel reactor higher than 600 kg/MWth were needed with the lignite.This work was supported by the European Commission, under the RFCS program (ACCLAIM Project, Contract RFCP-CT-2012-00006), the Spanish Ministry of Science and Innovation (MICINN Project: ENE2011-26354) and the European Union FEDER Funds. I. Adánez-Rubio thanks CSIC for the JAE fellowship co-financed by the European Social Fund.Peer reviewe