Systemraum: Erzförderung bis Ruthenium in regionalen Lagern Geographischer Bezug: Europa Zeitlicher Bezug: 2000 - 2004 Weitere Informationen: vergesellschaftet mit Platin: ca. 1 g/10 g Platin ; Anteil an gesamter PGM-Prod.: ca. 40/542 Die Bereitstellung von Investionsgütern wird in dem Datensatz nicht berücksichtigt. Allgemeine Informationen zur Förderung und Herstellung: Art der Förderung: Untertage- und Tagebau Roherz-Förderung: Südafrika 90%, Russland, Zimbabwe Rohmetall-Herstellung: Deutschland 40% (Heraeus) Abraum: k.A.t/t Produktionsmenge: 40t/a Reserven: k.A.t/a Statische Reichweite: k.A.a
Das Wissen über das biokinetische Verhalten von Radionukliden ist von großer Bedeutung für die Dosisabschätzung nach Inkorporation dieser radioaktiven Stoffe. Für viele Radionuklide liegen jedoch bis heute nur wenige oder unzureichende Informationen zur Biokinetik vor, da diese Daten in vielen Fällen anhand von Tierexperimenten gewonnen wurden und die Übertragbarkeit auf den Menschen damit nicht gesichert ist. Dies gilt im Wesentlichen auch für Zirkonium, Ruthenium und auch für Lanthanide. Radionuklide dieser Elemente können bei kerntechnischen Unfällen signifikant zur Dosis für beruflich Strahlenexponierte und Einzelpersonen der Bevölkerung beitragen. Ziel des Vorhabens war es daher, das Wissen hinsichtlich der biokinetischen Gegebenheiten für diese Elemente direkt am Menschen experimentell zu generieren. Dies konnte durch den Einsatz von stabilen Isotopen ermöglicht werden, die sich aus biokinetischer Sicht von den entsprechenden Radioisotopen nicht unterscheiden. Auf diese Weise war es möglich, Informationen bezüglich des Absorptions-, Retentions- und Ausscheidungsverhaltens der jeweiligen Radionuklide zu gewinnen und daraus verbesserte biokinetische Modelle herzuleiten. Darüber hinaus galt es für das Element Cer aus der Gruppe der Lanthanide den Transfer in die Muttermilch näher zu untersuchen, da hier teilweise widersprüchliche Daten in der Literatur vorlagen. Im Vorfeld von Probandentests mussten die für die Untersuchungen geeigneten stabilen Isotope und deren Verabreichungsmengen ausgewählt werden. Dies wurde sowohl aus toxikologischen sowie aus messtechnischen Gesichtspunkten heraus betrachtet.
technologyComment of chlor-alkali electrolysis, diaphragm cell (RER): In the diaphragm process, all reactions take place in only one cell. A diaphragm is used to separate the feed brine (anolyte) and the chlorine formed at the anode from the sodium hydroxide containing solution (catholyte) and the hydrogen formed at the cathode. Without the diaphragm being present during electrolysis, chlorine and hydrogen would form an explosive mixture and sodium hydroxide and chlorine would react to form sodium hypochlorite (NaOCl). Diaphragms used to be made from asbestos but up-todate technology allows for asbestos-free polymer-based diaphragms. Purified brine is fed to the anode compartment and percolates through the diaphragm into the cathode compartment. The percolation rate is controlled by a difference in liquid level between both compartments. At the anodes (metal oxide coated titanium), chlorine gas is formed which is collected and directed to further processing. Cathodes, where water decomposition takes place, are made of activated carbon steel. Catholyte leaving the cell, also called cell liquor, is a mixture of 10-12 wt.-% sodium hydroxide and 15-17 wt.-% sodium chloride in water. This solution is usually evaporated to 50 wt.-% NaOH. In this process, simultaneously most of the salt is removed by precipitation to a final residual of 1 wt.-%. The resulting salt is typically recirculated to brine preparation. The advantage of diaphragm cells is that the quality requirements for the brine and the electrical energy consumption are low. Disadvantageous are the high amount of thermal energy necessary for sodium hydroxide concentration and the comparably low quality of the produced sodium hydroxide and chlorine. References: Euro Chlor (2013) An Eco-profile and Environmental Product Declaration of the European Chlor-Alkali Industry, Chlorine (The chlor-alkali process). technologyComment of chlor-alkali electrolysis, membrane cell (RER): In the membrane cell process, the anode and cathode compartments are separated by a perfluoropolymer cation-exchange membrane that selectively transmits sodium ions but suppresses the migration of hydroxyl ions (OH-) from the catholyte into the anolyte. Saturated brine flows through the anode compartment, where chlorine gas is produced at the anode. The electric field in the electrolysis cell causes hydrated sodium ions to migrate through the membrane into the cathode compartment. The cathode compartment is fed with diluted sodium hydroxide solution. Water is electrolysed at the cathode releasing gaseous hydrogen and hydroxyl ions, which combine with the sodium ions and thus increase the concentration of sodium hydroxide in the catholyte. Typically, the outlet concentration of sodium hydroxide is around 32 wt.-%. A part of the product stream is diluted with demineralised water to about 30 wt.-% and used as catholyte inlet. In some units, a more diluted 23 wt.-% NaOH solution is produced. In these cases, the inlet concentration is adjusted to 20-21 wt.-%. Usually the NaOH solution is evaporated to the marketable concentration of 50 wt.-% using steam. Depleted brine leaving the anode compartment is saturated with chlorine and is therefore sent to a dechlorination unit to recover the dissolved chlorine before it is resaturated with salt for recirculation. The advantages of the membrane cell technique are the very high purity of the sodium hydroxide solution produced and the comparably low energy demand. Disadvantages comprise the high requirements on brine purity, the need for sodium hydroxide evaporation to increase concentration, and the comparably high oxygen content in the produced chlorine. In general, multiple cell elements are combined into a single unit, called electrolyser, of whom the design can be either monopolar or bipolar. In a monopolar electrolyser, the anodes and cathodes of the cells are connected electrically in parallel, whereas in the bipolar design, they are connected in series. Therefore, monopolar electrolysers require high current and low voltage, whereas bipolar electrolysers require low current and high voltage. Since bipolar systems allow higher current densities inside the cells, investment and operating costs are usually lower than for monopolar systems. References: Euro Chlor (2013) An Eco-profile and Environmental Product Declaration of the European Chlor-Alkali Industry, Chlorine (The chlor-alkali process). technologyComment of chlor-alkali electrolysis, mercury cell (RER): The mercury cell process comprises an electrolysis cell and a decomposer. Purified and saturated brine (25-28 wt.-% NaCl in water) is fed to the electrolysis cell on top of a film of mercury (Hg) flowing down the inclined base of the cell. The base of the cell is connected to the negative pole of a direct current supply forming the cathode of the cell. Anodes consisting of titanium coated with oxides of ruthenium and titanium are placed in the brine without touching the mercury film. At the anodes, chlorine gas is formed which is collected and directed to further processing. Due to a high overpotential of hydrogen at the mercury electrode, no gaseous hydrogen is formed; instead, sodium is produced and dissolved in the mercury as an amalgam (mercury alloy). The liquid amalgam is removed from the electrolytic cell and fed to a decomposer, where it reacts with demineralised water in the presence of a graphite-based catalyst to form sodium hydroxide solution and hydrogen. The sodium-free mercury is recirculated back into the cell. Cooling of hydrogen is essential to remove any water and mercury. The sodium hydroxide solution is very pure, almost free from chloride contamination and has usually a concentration of 50 %. Further treatment comprises cooling and removal of catalyst and mercury traces by centrifuges or filters. Advantages of the mercury cell process are the high quality of chlorine and the high concentration and purity of sodium hydroxide solution produced. The consumption of electric energy for electrolysis is, however, higher than for the other techniques and a high purity of the feed brine is required. Inherently, the use of mercury gives rise to environmental releases of mercury. References: Euro Chlor (2013) An Eco-profile and Environmental Product Declaration of the European Chlor-Alkali Industry, Chlorine (The chlor-alkali process). technologyComment of potassium hydroxide production (RER): Potassium hydroxide is manufactured by the electrolysis of potassium chloride brine in electrolytical cells. Hydrogen and chlorine are withdrawn from the cell. The rest of the reaction mixture contains KOH, water, and unreacted potassium chloride. This reaction mixture is then concentrated in an evaporator. Most of the potassium chloride crystallizes by evaporation, and is recycled. After evaporation, the potassium hydroxide is precipitated. Potassium hydroxide, chlorine and hydrogen are obtained from potassium chloride brine according to the following reaction: 2 KCl + 2 H2O -> 2 KOH + Cl2 + H2 Reference: Jungbluth, N., Chudacoff, M., Dauriat, A., Dinkel, F., Doka, G., Faist Emmenegger, M., Gnansounou, E., Kljun, N., Schleiss, K., Spielmann, M., Stettler, C., Sutter, J. 2007: Life Cycle Inventories of Bioenergy. ecoinvent report No. 17, Swiss Centre for Life Cycle Inventories, Dübendorf, CH. technologyComment of sodium chloride electrolysis (RER): Sodium chloride electrolysis
technologyComment of chlor-alkali electrolysis, diaphragm cell (RER, RoW): In the diaphragm process, all reactions take place in only one cell. A diaphragm is used to separate the feed brine (anolyte) and the chlorine formed at the anode from the sodium hydroxide containing solution (catholyte) and the hydrogen formed at the cathode. Without the diaphragm being present during electrolysis, chlorine and hydrogen would form an explosive mixture and sodium hydroxide and chlorine would react to form sodium hypochlorite (NaOCl). Diaphragms used to be made from asbestos but up-todate technology allows for asbestos-free polymer-based diaphragms. Purified brine is fed to the anode compartment and percolates through the diaphragm into the cathode compartment. The percolation rate is controlled by a difference in liquid level between both compartments. At the anodes (metal oxide coated titanium), chlorine gas is formed which is collected and directed to further processing. Cathodes, where water decomposition takes place, are made of activated carbon steel. Catholyte leaving the cell, also called cell liquor, is a mixture of 10-12 wt.-% sodium hydroxide and 15-17 wt.-% sodium chloride in water. This solution is usually evaporated to 50 wt.-% NaOH. In this process, simultaneously most of the salt is removed by precipitation to a final residual of 1 wt.-%. The resulting salt is typically recirculated to brine preparation. The advantage of diaphragm cells is that the quality requirements for the brine and the electrical energy consumption are low. Disadvantageous are the high amount of thermal energy necessary for sodium hydroxide concentration and the comparably low quality of the produced sodium hydroxide and chlorine. References: Euro Chlor (2013) An Eco-profile and Environmental Product Declaration of the European Chlor-Alkali Industry, Chlorine (The chlor-alkali process). technologyComment of chlor-alkali electrolysis, membrane cell (CA-QC, RER, RoW): In the membrane cell process, the anode and cathode compartments are separated by a perfluoropolymer cation-exchange membrane that selectively transmits sodium ions but suppresses the migration of hydroxyl ions (OH-) from the catholyte into the anolyte. Saturated brine flows through the anode compartment, where chlorine gas is produced at the anode. The electric field in the electrolysis cell causes hydrated sodium ions to migrate through the membrane into the cathode compartment. The cathode compartment is fed with diluted sodium hydroxide solution. Water is electrolysed at the cathode releasing gaseous hydrogen and hydroxyl ions, which combine with the sodium ions and thus increase the concentration of sodium hydroxide in the catholyte. Typically, the outlet concentration of sodium hydroxide is around 32 wt.-%. A part of the product stream is diluted with demineralised water to about 30 wt.-% and used as catholyte inlet. In some units, a more diluted 23 wt.-% NaOH solution is produced. In these cases, the inlet concentration is adjusted to 20-21 wt.-%. Usually the NaOH solution is evaporated to the marketable concentration of 50 wt.-% using steam. Depleted brine leaving the anode compartment is saturated with chlorine and is therefore sent to a dechlorination unit to recover the dissolved chlorine before it is resaturated with salt for recirculation. The advantages of the membrane cell technique are the very high purity of the sodium hydroxide solution produced and the comparably low energy demand. Disadvantages comprise the high requirements on brine purity, the need for sodium hydroxide evaporation to increase concentration, and the comparably high oxygen content in the produced chlorine. In general, multiple cell elements are combined into a single unit, called electrolyser, of whom the design can be either monopolar or bipolar. In a monopolar electrolyser, the anodes and cathodes of the cells are connected electrically in parallel, whereas in the bipolar design, they are connected in series. Therefore, monopolar electrolysers require high current and low voltage, whereas bipolar electrolysers require low current and high voltage. Since bipolar systems allow higher current densities inside the cells, investment and operating costs are usually lower than for monopolar systems. References: Euro Chlor (2013) An Eco-profile and Environmental Product Declaration of the European Chlor-Alkali Industry, Chlorine (The chlor-alkali process). technologyComment of chlor-alkali electrolysis, mercury cell (RER, RoW): The mercury cell process comprises an electrolysis cell and a decomposer. Purified and saturated brine (25-28 wt.-% NaCl in water) is fed to the electrolysis cell on top of a film of mercury (Hg) flowing down the inclined base of the cell. The base of the cell is connected to the negative pole of a direct current supply forming the cathode of the cell. Anodes consisting of titanium coated with oxides of ruthenium and titanium are placed in the brine without touching the mercury film. At the anodes, chlorine gas is formed which is collected and directed to further processing. Due to a high overpotential of hydrogen at the mercury electrode, no gaseous hydrogen is formed; instead, sodium is produced and dissolved in the mercury as an amalgam (mercury alloy). The liquid amalgam is removed from the electrolytic cell and fed to a decomposer, where it reacts with demineralised water in the presence of a graphite-based catalyst to form sodium hydroxide solution and hydrogen. The sodium-free mercury is recirculated back into the cell. Cooling of hydrogen is essential to remove any water and mercury. The sodium hydroxide solution is very pure, almost free from chloride contamination and has usually a concentration of 50 %. Further treatment comprises cooling and removal of catalyst and mercury traces by centrifuges or filters. Advantages of the mercury cell process are the high quality of chlorine and the high concentration and purity of sodium hydroxide solution produced. The consumption of electric energy for electrolysis is, however, higher than for the other techniques and a high purity of the feed brine is required. Inherently, the use of mercury gives rise to environmental releases of mercury. References: Euro Chlor (2013) An Eco-profile and Environmental Product Declaration of the European Chlor-Alkali Industry, Chlorine (The chlor-alkali process).
Das Projekt "Measurements of fission products in the experiments mol 7C/6 and mol 7C/7" wird vom Umweltbundesamt gefördert und von Forschungszentrum Karlsruhe GmbH Technik und Umwelt durchgeführt. Objective: During core melt-down accidents, significant fractions of the fission product inventory can be released from the molten fuel to the sodium, and subsequent to vessel failure; a further release of fission products from the evaporating sodium-pool to the atmosphere will occur. The physical processes which occur in the mol 7c experiments, melting of the fuel in presence of sodium, being comparable with a real accident, interesting and important information can be obtained with respect to the source term problem of core melt-down accidents. Measurement of the activity concentration of the different fission products in the sodium and relating it to the mass of disrupted and molten fuel could provide nuclide-specific transfer factors. The unique features offered by the mol 7c experiments (release of radio nuclides from genuine molten LMFBR fuel through sodium vapour and liquid) can be fully utilized with the addition of a fission products measuring device, without interfering with the main objective of the experiment. General information: the upper part of the sodium circuit of the mol 7c in-pile section extends above the reactor top cover. So, fission product activity measurements can be made in front of the expansion tank which forms the upper part of the mol 7c loop. Activity measurements are made with a ge-li detector incorporated in an under water measuring device. This device has been conceived and used for the scanning of LWR fuel elements in the reactor pool. Between the detector and the mol 7c loop a collimator tube is installed. In front of the detector the lead shield around the upper part of the mol 7c loop is provided with a window. A preliminary evaluation of the detection limits of the fission products under theses circumstances gives the following results: - isotopes considered in the evaluation: 18 - isotopes easy to be measured: 8 sr91, i131, i133, ru103, ru105, te132, i134, i135 - isotopes detectable: 6 zr95, y92, y 93, zr97, ba140, nd149 - isotopes not detectable or with interference: 4 y91, te127m, ce144, nd147. The fabrication of the measuring device is in progress and it is scheduled to be available when the mol 7c/6 experiment is being carried out.
Das Projekt "New composite DMFC anode with PEDOT as mixed conductor and catalyst support" wird vom Umweltbundesamt gefördert und von DECHEMA Forschungsinstitut Stiftung bürgerlichen Rechts durchgeführt. Project description: The direct methanol fuel cell (DMFC) as electrochemical power source has attracted attention due to its simple system design, low operating temperature, and convenient fuel storage and supply. Major limitations of the DMFC are related to the low power density, which is a consequence of the poor kinetics of the anode reaction, poisoning of the catalyst by reaction intermediates, and methanol crossover. Research efforts have to address improvements of the anode catalyst structure and the ion-exchanger membrane. This project aims at the development of a new type of membrane anode assembly PEM*/PEDOT/CAT based on the conducting polymer PEDOT (Poly(3,4-ethylene-dioxythiophene)) as catalyst support and a new type of proton-exchange membrane (PEM*) with reduced methanol permeability. As the catalyst (CAT) Pt and Pt-Ru will be utilised. The new proton exchange membranes are to be made of thermal-stable polymers of arylide, so that they can be used in fuel cells working at higher temperatures (Tianjin University, China). Conventional Pt/C cathodes will be used for manufacturing the membrane electrode assemblies (MEAs) to be tested in single cell experiments. The application of PEDOT as mixed electronic and ionic conductor is expected to improve the charge transfer kinetics and the transport of protons and electrons within the anode structure leading to a better utilisation of the noble metal catalyst.
Das Projekt "Simultane katalytische Reduktion von SO2 und NOx Mittels Ru-Katalysatoren als Beitrag zur Luftreinhaltung" wird vom Umweltbundesamt gefördert und von Universität Marburg, Fachbereich 14 Physikalische Chemie, Fachgebiet Kernchemie durchgeführt. Ein in Los Alamos (USA) vorgeschlagener neuer Ruthenium-Katalysator hat offenbar die Eigenschaft, unter Standbedingungen SO2 bei verhaeltnismaessig tiefen Temperaturen zu S zu reduzieren, gleichzeitig wird NOx zu N2 (bzw. N2O) reduziert. Die Reaktion verlaeuft bei 300 Grad C sehr glatt, bei tieferen Temperaturen (200 Grad C) koennte sie moeglicherweise auch noch mit hinreich. Geschwindigkeit ablaufen. Dieser Katalysator soll jetzt daraufhin ueberprueft werden, ob er auch in einem Durchflusssystem aehnlich guenstige Eigenschaften besitzt. Dabei ist die Standfestigkeit des Systems, der Einfluss von Katalysatorgiften (z.B. HC1) und die Abtrennung von Schwefel moeglichst im Gleichstrom mit dem Ballastgas zu untersuchen. Abschliessend soll festgestellt werden, ob und in welchem Umfang weitere Entwickl.- Arbeiten sinnvoll sind, um die industr. Anwendbarkeit dieses Katalysators genauer zu bestimmen. Alle Arbeiten werden von der Fa. Nukem begleitend mitgetragen
Das Projekt "Teilprojekt 4: Bleibatterien" wird vom Umweltbundesamt gefördert und von Johnson Controls Recycling GmbH durchgeführt. Das Projekt soll unter anderem die folgenden Materialen adressieren: Edelmetalle wie Gold, Silber und die Platingruppenmetalle* (Platin*, Palladium*, Rhodium*, Ruthenium* etc.), Indium*, Kobalt*, Lithium sowie Seltene Erden* wie z.B. Neodym*, Praseodym* und Dysprosium*. Die mit * gekennzeichneten Materialien sind in der Liste der EU Kommission zu kritischen Rohstoffen und überwiegend auch in den entsprechenden Listen der USA und Japan aufgeführt und somit klar strategischer Natur hinsichtlich Ihrer Bedeutung für Schlüsseltechnologien und des zugeordneten Versorgungsrisikos. JC ist in diesem Zusammenhang an den Synergie - Effekten der Sammlungsstrukturen in Verbindung mit der Rückholung von verbrauchten Blei-Säure Starterbatterien interessiert. Im Rahmen des Arbeitsplanes des Projektes ist Johnson Controls speziell in den Arbeitspaketen mit den Analysen, Planung, Schulung und Durchführung von Aktionen mit dem Verbundpartner eingebunden. Dabei bringt Johnson Controls das in Europa durch effektive Sammlungsstrukturen gewonnene Know How in die Projektgruppe ein.
Das Projekt "Teilvorhaben 3" wird vom Umweltbundesamt gefördert und von Technische Universität Dresden, Fachrichtung Chemie und Lebensmittelchemie, Professur für Anorganische Chemie 1 durchgeführt. Die Hauptzielsetzung des Projektes ist die stoffliche Nutzung von CO2 als Kohlenstoffbaustein für chemische Zwischenprodukte, die (i) sich wirtschaftlich darstellen lässt, (ii) effizient ist im Sinne der gesamten CO2- und Energiebilanz und (iii) ein großes Reduktionspotential an kohlenstämmigem CO2 bietet. Für eine wirtschaftliche und ökologisch nachhaltige stoffliche CO2-Nutzung sind regenerativ verursachte Schwankungen im Energieangebot attraktiv. Bisher ist die chemische Produktion auf ein konstantes Energieangebot ausgerichtet und optimiert. Daher müssen hier neue Modelle des Zusammenwirkens von Energiewirtschaft und Chemieindustrie entwickelt werden. Einerseits werden energieseitig stoffliche und elektrische Speicher benötigt. Andererseits gibt es in der chemischen Industrie starke Bestrebungen hin zu energieeffizienten Prozessen, die modular und flexibel sind. Schwerpunkt der TU ist die Entwicklung von Katalysatoren. Dabei werden Trägerkatalysatoren durch Precursor- und Fällungsmethoden hergestellt. Im Mittelpunkt stehen Synthesemethoden, welche eine Verkapselung von Edelmetallen wie Pd, Pt, Ir, Rh, Ru etc. mittels Mikroemulsionstechnik ermöglichen. Um die Stabilität und Aktivität der Katalysatoren zu erhöhen, werden Oxide der seltenen Erden eingesetzt. Die Katalysatoren werden zunächst in kleinen Mengen als Pulver synthetisiert. Für weiterführende Untersuchungen werden zudem Beschichtungsmethoden für keramische Träger entwickelt.
Das Projekt "Teilprojekt: CF04_2.4 Skalierung der Synthese von katalytisch aktiven Kathodenmaterialien und Elektroden" wird vom Umweltbundesamt gefördert und von Leibniz-Institut für Katalyse e.V. an der Universität Rostock durchgeführt. Im Rahmen des Verbundvorhabens CF04_2 zur Entwicklung von Kleinserien für MEAs für die SSAS - Solid State Ammoniak Synthese stellt das Ziel des Teilvorhabens CF04_2.4 die Skalierung der Synthese von katalytisch aktiven Kathodenmaterialien und Elektroden für die SSAS Kleinserie dar. Das Verbundvorhaben CF04_2 befasst sich mit dem Bau von tubularen Modulen zur elektrochemischen Synthese von Ammoniak basierend auf keramischen Dünnschichtmembranen. Dazu soll auf die zuvor im CF04 Projekt entwickelten dünnschichtbasierten Membran-Elektroden-Einheiten für die dezentrale Synthese von Ammoniak mittels Festkörper-Ammoniaksynthese (SSAS) zurückgegriffen werden. Bis zu fünf einzelne Zellen sollen nunmehr zu einem tubularen SSAS Modul verschaltet werden. Dazu müssen die Syntheseverfahren aus dem Vorgängerprojekt hochskaliert werden. Zur Umsetzung des Teilvorhabens CF04_2.4 wird das im Vorgängerprojekt entwickelte Material mit der höchsten katalytischen Aktivität hinsichtlich der Einsparung des teuren Edelmetalls Ruthenium optimiert und in der Synthese hochskaliert sowie auf tubularen Trägern mittels Ultraschallsprüh-Verfahrens aufgebracht.