Freisetzung von Vinylchlorid bei einem Eisenbahntransportunfall. Es traten in Folge bei mind. 328 Personen Gesundheitsstörungen in Form von Augen-, Haut- und Schleimhautreizungen und gastrointest. Beschwerden auf.
technologyComment of Mannheim process (RER): Production of sodium sulfate and HCl by the Mannheim process. This process can be summarized with the following overall stoechiometric reaction: 2 NaCl + H2SO4 → Na2SO4 + 2 HCl technologyComment of allyl chloride production, reaction of propylene and chlorine (RER): based on industry data in the US and Europe technologyComment of benzene chlorination (RER): Clorobenzenes are prepared by reaction of liquid benzene with gaseous chlorine in the presence of a catalyst at moderate temperature and atmospheric pressure. Hydrogen chloride is formed as a by-product. Generally, mixtures of isomers and compounds with varying degrees of chlorination are obtained, because any given chlorobenzene can be further chlorinated up to the stage of hexa-chlorobenzene. Because of the directing influence exerted by chlorine, the unfavoured products 1,3-dichlorobenzene, 1,3,5-trichlorobenzene and 1,2,3,5-tetrachlorobenzene are formed to only a small extent if at all. The velocity of chlorination for an individual chlorine compound depends on the compound's structure and, because of this, both the degree of chlorination and also the isomer ratio change continuously during the course of reaction. Sets of data on the composition of products from different reactions are only comparable if they refer to identical reaction conditions and materials having the same degree of chlorination. By altering the reaction conditions and changing the catalyst, one can vary the ratios of different chlorinated products within certain limits. Lewis acids (FeCl3, AlCl3, SbCl3, MnCl2, MoCl2, SnCl4, TiCl4) are used as principal catalysts. The usual catalyst employed in large scale production is ferric chloride, with or without the addition of sulfur compounds. The ratio of resulting chlorobenzenes to one another is also influenced by the benzene:chlorine ratio. For this reason, the highest selectivity is achieved in batch processes. If the same monochlorobenzene:dichlorobenzene ratio expected from a batch reactor is to result from continuous operation in a single-stage reactor, then a far lower degree of benzene conversion must be accepted as a consequence of the low benzene:chlorine ratio). The reaction is highly exothermic: C6H6 + Cl2 --> C6H5Cl + HCl ; delta H = -131.5 kJ/mol Unwanted heat of reaction can be dissipated either by circulating some of the reactor fluid through an external heat exchanger or by permitting evaporative cooling to occur at the boiling temperature. Circulation cooling has the advantage of enabling the reaction temperature to be varied in accordance with the requirements of a given situation. Evaporative cooling is more economical, however. Fractional distillation separates the products. Iron catalyst is removed with the distillation residue.Unreacted benzene is recycled to the reactor. technologyComment of hydrochloric acid production, from the reaction of hydrogen with chlorine (RER): HCl can be either directly prepared or generated as a by-product from a number of reactions. This dataset represents the production of HCl via the combustion of chlorine with hydrogen gas. The process involves burning hydrogen gas and chlorine in a gas combustion chamber, producing hydrogen chloride gas. The hydrogen chloride gas then passes through a cooler to an absorber where process water is introduced, producing aqueous hydrochloric acid. H2 + Cl2 -> 2 HCl (exothermic reaction) References: Althaus H.-J., Chudacoff M., Hischier R., Jungbluth N., Osses M. and Primas A. (2007) Life Cycle Inventories of Chemicals. ecoinvent report No. 8, v2.0. EMPA Dübendorf, Swiss Centre for Life Cycle Inventories, Dübendorf, CH. technologyComment of tetrafluoroethylene production (RER): The production of fluorochemicals and PTFE monomers can be summarized with the following chemical reactions (Cedergren et al. 2001): CaF2 + H2SO4 -> CaSO4 + 2HF (1) CH4 + 3Cl2 -> CHCl3 + 3HCl (2) CHCl3 + 2HF -> CHClF2 + 2HCl (3) 2 CHClF2 + heat -> CF2=CF2 + 2 HCl (4) This dataset represents the last reaction step (4). Parts of the production are carried out at high pressure and high temperature, 590 ºC – 900 ºC. The first reaction (1) takes place in the presence of heat and HSO3 - and steam. The inventory for the production of hydrogen fluoride can be found in the report (Jungbluth 2003a). Reaction (2) is used to produce trichloromethane. Reaction 3 for the production of chlorodifluoromethane takes place in the presence of a catalyst. The production of PTFE (4) takes place under high temperature pyrolysis conditions. Large amounts of hydrochloric acid (HCl) are generated as a couple product during the process and are sold as a 30% aqueous solution. A large number of other by-products and emissions is formed in the processes (benzene, dichloromethane, ethylene oxide, formaldehyde, R134a, and vinyl chloride) and small amounts of the highly toxic perfluoroisobutylene CF2=C(CF3)2. The by-products in the production of monomers can harm the processes of polymerisation. Because of this, the refinement of the production of monomers has to be very narrow. This makes the process complex and it contributes to a high cost for the PTFE-laminates. (Cedergren et al. 2001). References: Althaus H.-J., Chudacoff M., Hischier R., Jungbluth N., Osses M. and Primas A. (2007) Life Cycle Inventories of Chemicals. Final report ecoinvent data v2.0 No. 8. Swiss Centre for Life Cycle Inventories, Dübendorf, CH.
EDC is produced industrially by the chlorination of ethylene, either directly with chlorine or by using hydrogen chloride (HCl). In practice, both routes are carried out together, the HCl stems from the cracking of EDC to vinyl chloride. HCl from other processes can also be used. The major outlet is for the production of vinyl chloride monomer (VCM). There are both integrated EDC / VCM plants as well as stand-alone EDC plants. In 1997, European production of EDC was 9.4 million tons, according to (IPPC Chemicals, 2002). This makes it Europe’s most produced halogenated product. Global demand is expected to grow at roughly 6% per year in the short run, while future growth depends on the global demand for PVC. Major plants with capacities greater than 600’000 tons per year are located in Belgium, France, the Netherlands, Italy, Norway, the US, Canada, Brazil, Saudi Arabia, Japan and Taiwan. Available data from production sites often refer to the entire EDC/VCM chain and do not differentiate between the production lines. There is some information on stand-alone sites, however, and this data forms the basis for part of the inventory developed in this report. EDC can be produced by two routes, both involving the chlorination of ethylene. One route involves direct chlorination, the other is carried out with hydrochloric acid (HCl) and oxygen. In practice, both routes are carried out together. This study includes an average of the available literature data from both routes. EDC by direct chlorination of ethylene: C2H4 + Cl2 C2H4Cl2 Yield on ethylene 96-98% / on chlorine 98% Liquid chlorine and pure ethylene are reacted in the presence of a catalyst (ferric chloride). The chlorination reaction can be carried out at low or high temperature. In the low-temperature process takes place at 20 ºC – 70 ºC. The reaction is exothermic and heat exchangers are needed. The advantage of this process is that there are few by-products. The high-temperature process takes place at 100 ºC – 150 ºC. The heat generated is used to distill the EDC, which conserves energy. the reaction product consists of more than 99% EDC, the rest being chlorinated hydrocarbons that are removed with the light ends and then combusted or sold. EDC by direct chlorination of ethylene: C2H4 + Cl2 C2H4Cl2 Yield on ethylene 96-98% / on chlorine 98% Liquid chlorine and pure ethylene are reacted in the presence of a catalyst (ferric chloride). The chlorination reaction can be carried out at low or high temperature. In the low-temperature process takes place at 20 ºC – 70 ºC. The reaction is exothermic and heat exchangers are needed. The advantage of this process is that there are few by-products. The high-temperature process takes place at 100 ºC – 150 ºC. The heat generated is used to distill the EDC, which conserves energy. Tthe reaction product consists of more than 99% EDC, the rest being chlorinated hydrocarbons that are removed with the light ends and then combusted or sold. EDC by chlorination and oxychlorination: C2H4 + Cl2 C2H4Cl2 (1) C2H4 + 1/2 O2 + 2HCl C2H4Cl2 + H2O (2) Yield on ethylene 93-97% / on HCl 96-99% Pure ethylene and hydrogen chloride are heated and mixed with oxygen. The reaction occurs at 200 ºC – 300 ºC at 4-6 bar in the presence of a catalyst (cupric chloride). After reaction the gases are quenched with water. The acid and water are removed, the gases are cooled and the organic layer is washed and dried. If air is used instead of oxygen, the reaction is easier to control. However, oxygen-based processes operate at lower temperatures, reducing vent gas volume. By-products are ethyl chloride, 1,1,2-trichloromethane and chloral (trichloroacetaldehyde). Thermal cracking of EDC: Thermal cracking of dry, pure EDC produces VCM and HCl. Often all the HCl generated in the cracking section is reused in producing EDC by oxychlorination. Plants that exhibit this characteristic and also do not export EDC are called “balanced”. The balanced process is the common process used as a Best Available Technology benchmark. C2H4 + Cl2 C2H4Cl2 (Chlorination of ethylene to EDC) C2H4Cl CH2CHCl + HCl (Cracking of EDC to form VCM) C2H4 + 1/2 O2 + 2HCl C2H4Cl2 + H2O (Oxychlorination route to EDC) Reference: IPPC Chemicals, 2002 European Commission, Directorate General, Joint Research Center, “Reference Document on Best Available Techniques in the Large Volume Organic Chemical Industry”, February 2002 Wells, 1999 G. Margaret Wells, “Handbook of Petrochemicals and Processes”, 2nd edition, Ashgate, 1999
The production of fluorochemicals and PTFE monomers can be summarized with the following chemical reactions (Cedergren et al. 2001): CaF2 + H2SO4 -> CaSO4 + 2HF (1) CH4 + 3Cl2 -> CHCl3 + 3HCl (2) CHCl3 + 2HF -> CHClF2 + 2HCl (3) 2 CHClF2 + heat -> CF2=CF2 + 2 HCl (4) This dataset represents the last reaction step (4). Parts of the production are carried out at high pressure and high temperature, 590 ºC – 900 ºC. The first reaction (1) takes place in the presence of heat and HSO3 - and steam. The inventory for the production of hydrogen fluoride can be found in the report (Jungbluth 2003a). Reaction (2) is used to produce trichloromethane. Reaction 3 for the production of chlorodifluoromethane takes place in the presence of a catalyst. The production of PTFE (4) takes place under high temperature pyrolysis conditions. Large amounts of hydrochloric acid (HCl) are generated as a couple product during the process and are sold as a 30% aqueous solution. A large number of other by-products and emissions is formed in the processes (benzene, dichloromethane, ethylene oxide, formaldehyde, R134a, and vinyl chloride) and small amounts of the highly toxic perfluoroisobutylene CF2=C(CF3)2. The by-products in the production of monomers can harm the processes of polymerisation. Because of this, the refinement of the production of monomers has to be very narrow. This makes the process complex and it contributes to a high cost for the PTFE-laminates. (Cedergren et al. 2001). References: Althaus H.-J., Chudacoff M., Hischier R., Jungbluth N., Osses M. and Primas A. (2007) Life Cycle Inventories of Chemicals. Final report ecoinvent data v2.0 No. 8. Swiss Centre for Life Cycle Inventories, Dübendorf, CH.
Das Projekt "Untersuchung zur quantitativen Erfassung der Belastung der Umwelt durch Vinylchlorid aus PVC" wird vom Umweltbundesamt gefördert und von Battelle-Institut e.V. durchgeführt. Quantitativer Erfassung des VC-Gehaltes in PVC-Roh- und Halberzeugnissen, sowie in PVC-Produkten aus dem In- und Ausland und quantitative Erfassung der Emissionssituation von VC bei der Lagerung und Verwendung dieser PVC-Teile.
Das Projekt "Teilprojekt 1" wird vom Umweltbundesamt gefördert und von Stadtwerke Düsseldorf AG durchgeführt. Bei der Sanierung von Grundwaessern, die mit Chlorkohlenwasserstoffen und Aromaten verunreinigt sind, werden die zu entfernenden Schadstoffe durch Strippen aus der waessrigen in die Gasphase ueberfuehrt und nach Teilentfeuchtung der Stripperabluft an Aktivkohle absorbiert. Bei diesem Verfahren werden insbesondere bei Vorliegen der Abbauprodukte cis-Dichlorethen und Vinylchlorid erhebliche Mengen in die Atmosphaere ausgetragen. Ausserdem fuehrt die beladene Aktivkohle zu neuen Entsorgungsproblemen. In dem beantragten Vorhaben sollen deshalb Verfahren entwickelt werden, die eine weitestgehende Mineralisierung der Schadstoffe zum Ziel haben. Dazu werden folgende Konzepte parallel verfolgt: 1. Zerstoerung der Stoffe in der Gasphase durch Excimer-UV-Strahler (222 und 206 nm); 2. Zerstoerung der Stoffe in der Gasphase durch Elektronenbestrahlung; 3. Versuche mit der offenen Entladungsstrecke zur Zerstoerung der Stoffe in der Gasphase.
Das Projekt "Vinylchlorid-Messungen am Arbeitsplatz und in der Emission" wird vom Umweltbundesamt gefördert und von Landesanstalt für Umweltschutz Baden-Württemberg durchgeführt.
Das Projekt "Drei-Schluchten-Stausee am Yangtze - China - Teilprojekt 2: Mikrobieller Abbau" wird vom Umweltbundesamt gefördert und von DVGW Deutscher Verein des Gas- und Wasserfaches e.V. - Technisch-wissenschaftlicher Verein - Technologiezentrum Wasser (TZW) durchgeführt. Das Vorhaben soll zum Verständnis der Stoffaustauschprozesse zwischen Sediment und Wasserkörper und der mikrobiellen Umsetzungsprozesse beitragen. Mit dem beantragten Projekt soll ein verbessertes Prozessverständnis zu anaeroben und aeroben biologischen Abbauprozessen erreicht und eine Gefährdungsabschätzung und Prognose des Schadstoffverhaltens in Wasserkörper und Sediment ermöglicht werden, welches die Basis für die Entwicklung angepasster Management-Strategien bietet. Die Untersuchungen am TZW beinhalten ein analytisches Screening der Schadstoffe und Abbau-relevanter Begleitverbindungen (z.B. Huminstoffe) im Wasserkörper und zielen auf das Verständnis der mikrobiologischen Abbauprozesse. Bei den mikrobiologischen Untersuchungen wird besonderes Augenmerk auf Partikel-/Sediment-gebundenen Massentransfer gelegt, der zum Transport von Mikroorganismen und Partikeln zwischen unterschiedlichen Redoxbereichen führt. Als Modellsubstanzen sind z.B. aromatische Kohlenwasserstoffe (PAK, NSO-Heterozyklen) und halogenierte Verbindungen (z.B. PCP, Chlorethene) vorgesehen. Die Dynamik des Systems Schadstoff-Sediment-Abbau wird erfasst und der Einfluß wechselnder Redoxverhältnisse (aerob/anaerob) auf die Umsetzungsprozesse ermittelt. Zur Erfassung der mikrobiellen Besiedelung und Stoffwechselaktivität sollen Kulturverfahren (MPN) sowie insbesondere auch molekularbiologische Verfahren (PCR) weiterentwickelt und eingesetzt werden.
Das Projekt "Ausstieg aus der FCKW-Anwendung/VC-Kaelteanlage" wird vom Umweltbundesamt gefördert und von Buna Sow Leuna Olefinverbund, Werk Schkopau durchgeführt. Industrielle Kaelteanlagen, die vor dem Inkrafttreten der FCKW-Verbots-Verordnung in Betrieb genommen wurden, weisen eine durchschnittliche Leckagerate von ca 10 Prozent auf. Bei einer geschaetzten FCKW-Gesamtmenge von 5000 t in Altanlagen betragen damit die FCKW-Emissionen allein aus diesem Anwendungsbereich ca 5000 t/a. Neben Massnahmen zur Verminderung der Emissionen muss das Hauptaugenmerk deshalb auf die Umruestung solcher Anlagen auf FCKW-freie Alternativen liegen. Das Ziel dieses Vorhabens ist, das in der Kaelteanlage zur Erzeugung von Prozesskaelte (-34 Grad Celsius) fuer die Produktionsanlage fuer Vinylchlorid enthaltene FCKW R12 durch das Alternativkaeltemittel R 134a zu ersetzen. Die Kaelteanlage hat folgende Parameter: R12 -Grosskaelteanlage, 3 vierstufige Turboverdichter, 1,5 MW Kaelteleistung, R12-Fuellmenge 27 t und getrennter Aufstellort fuer Kompressoren und Verdampfer. Die Umstellung soll unter den Bedingungen einer kurzfristig stillgelegten Produktion erfolgen. Im einzelnen sind folgende Arbeitsschritte vorgesehen: Zustandsanalyse der Gesamtanlage und der Einzelkomponenten, Verdichtermodifikation und -wechsel, Anlagenkomponentenaustausch, Betriebsstoffaustausch (Kaeltemittel, Kaeltemaschinen), Entsorgung der gebrauchten Betriebsstoffmittel und Untersuchungen zum Leistungsverhalten der Anlage. Die Leistungsparameter der Anlage, wie zB der Energieverbrauch, werden im Rahmen eines Messprogramms verfolgt, um Aussagen ueber das Langzeitverhalten von umgeruesteten Altanlagen zu erhalten.
Das Projekt "Vergleich des Stoffwechsels von Tetrachlorethylen in Ratten und Menschen: ein Versuch zur verbesserten Bestimmung der Risiken einer Tetrachlorethylenexposition fuer den Menschen" wird vom Umweltbundesamt gefördert und von Universität Würzburg, Institut für Pharmakologie und Toxikologie durchgeführt. Tetrachloroethylene (TETRA) is a widely used solvent and, due to its volatility and resistance to degradation, a widely distributed environmental contaminant. TETRA shows only low acute toxicity, but was found to be tumorigenic in rodents causing liver tumors in mice and kidney tumors in male rats. The chronic toxicity of TETRA is due to bioactivation reactions. Two different bioactivation pathways of TETRA have been elucidated. TETRA is oxidized by cytochrome P-450 or conjugated with glutathione by glutathione S-transferases. Oxalic acid and trichloroacetic acid are stable metabolites formed by oxidation with cytochrome P450 and represents the major urinary metabolite of TETRA in rats and in humans. Reduction of trichloroacetic acid yields trichloroethanol, which may be excreted by glucuronic acid conjugation and has been identified as urinary metabolite in rats. The bioactivation mechanisms likely responsible for TETRA nephrotoxicity, which may also be involved in renal tumor formation in rats have been elucidated. The formation of S-(1,2,2-trichlorovinyl)glutathione (TCVG) in the liver is catalysed by glutathione S- transferases. TCVG is excreted with bile and further metabolized by gamma-glutamyltransferase and dipeptidases to S- (1 ,2,2-trichlorovinyl)-L-cysteine (TCVC), which is acetylated after reabsorption to give N acetyl-S-(1,2,2-trichloro- vinyl)-L-cysteine (N-Ac-TCVC). This S-conjugate is accumulated in the kidney and may be excreted in the urine. N- Ac-TCVC is a metabolite of TETRA found in rats. No information on the biosynthesis and excretion of S-conjugates in TETRA metabolism in humans in vivo is available; one study in in vitro subcellular fractions of one human liver failed to demonstrate the formation of TCVG. TCVC is mutagenic in several strains of Salmonella typhimurium induces unscheduled DNA-synthesis in cultured renal cells and is toxic to rat kidney cells. It is cleaved by cysteine conjugate beta-lyase, which is present in human renal epithelial cells, to yield pyruvate, ammonia, and dichlorothio- ketene. Dichlorothioketene is presumed to be the ultimate metabolite responsible for the mutagenic and nephro- toxic effects of TETRA by reaction with macromolecules. To obtain information about the formation of mercapturic acids and its relevancy for his use as biomarker for TETRA exposure, controlled exposures of humans and rats were planned. The formation and excretion of N-Ac-TCVC, trichloroacetic acid, trichloroethanol and dichloroacetic acid was quantified after exposure of rats and humans to 10, 20 and 40 ppm TETRA for 6 h by inhalation to simulate occupational exposure. The concentrations used were lower than the limit for occupational TETRA exposure in the German MAK-list. Experiments under the same exposure conditions with male and female rats permit a comparison on the relative excretion of these metabolites in humans and rats and are thus a basis for risk comparisons. The result of these studies will be published in