technologyComment of air separation, cryogenic (RER): The main components of air are nitrogen and oxygen, but it also contains smaller amounts of water vapour, argon, carbon dioxide and very small amounts of other gases (e.g. noble gases). The purification and liquefaction of various components of air, in particular oxygen, nitrogen and argon, is an important industrial process, and it is called cryogenic air separation. Cryogenic distillation accounts for approximately 85% of nitrogen and over 95% of oxygen production. It is the preferred supply mode for high volume and high purity requirements (Praxair 2002). Cryogenic air separation is currently the most efficient and cost-effective technology for producing large quantities of oxygen, nitrogen, and argon as gaseous or liquid products (Smith & Klosek 2001). Besides the air needed as a resource the major input for the liquefying process is the electricity to compress the inlet air, which normally comprises 95% of the utility costs of a cryogenic air separation plant. In some plants the amount of processed air (in Nm3) can be up to 5 times larger than the derived liquid products (Cryogenmash 2001). In these plants, the waste gas stream is naturally also much larger (in order to obtain the mass balance). As output of the cryogenic air separation there are three products: liquid oxygen, liquid nitrogen and liquid crude argon. The assumed process includes no gaseous co-products. In reality gaseous products are also processed if there is a demand at the production site. The investigated cryogenic air separation process leads to liquid products in the following quality: - Liquid oxygen: min. 99.6 wt-% - Liquid nitrogen: min. 99.9995 wt-% - Liquid argon, crude: 96-98 wt-% An air pre-treatment section downstream of the air compression (0.7 MPa) and after cooling removes process contaminants, including water, carbon dioxide, and hydrocarbons. The air is then cooled to cryogenic temperatures and distilled into oxygen, nitrogen, and, optionally, argon streams. Alternate compressing and expanding the recycled air can liquefy most of it. Numerous configurations of heat exchange and distillation equipment can separate air into the required product streams. These process alternatives are selected based on the purity and number of product streams, required trade-offs between capital costs and power consumption, and the degree of integration between the air separate unit and other facility units. This process requires very complicated heat integration techniques because the only heat sink for cooling or condensation is another cryogenic stream in the process. Since the boiling point of argon is between that of oxygen and nitrogen, it acts as an impurity in the product streams. If argon were collected and separated from the oxygen product, an oxygen purity of less than 95% by volume would result (Barron & Randall 1985). On the other hand, if argon were collected with the nitrogen product, the purity of nitrogen would not exceed 98.7% by volume. To achieve higher purities of oxygen and nitrogen the elimination of argon is necessary. Commercial argon is the product of cryogenic air separation, where liquefaction and distillation processes are used to produce a low-purity crude argon product. Praxair (2002) Gases > Nitrogen > Production of Nitrogen. Praxair Technology Inc. 2002. Retrieved 16.01.2002 from http://www.praxair.com Smith A. R. and Klosek J. (2001) A Review of Air Separation Technologies and their Integration with Energy Conversion Processes. In: Fuel Processing Technology, 70(2), pp. 115-134. Barron and Randall F. (1985) Cryogenic Systems. 2 Edition. Oxford University Press, New York Cryogenmash (2001) KxAxApx Type Double-Pressure Air Separation Plants. Gen-eral Data. Cryogenic Industries, Moscow, Russia. Retrieved 16.01.2002 from http://www.cryogenmash.ru/production/vru/vru_kgag2_e.htm imageUrlTagReplaceb1f86554-243f-4c79-b3a2-e6a9efa3a7ef
technologyComment of iron ore beneficiation (IN): Milling and mechanical sorting. Average iron yield is 65% . The process so developed basically involves crushing, classification, processing of lumps, fines and slimes separately to produce concentrate suitable as lump and sinter fines and for pellet making. The quality is essentially defined as Fe contents, Level of SiO2 and Al2O3 contamination. The process aims at maximizing Fe recovery by subjecting the rejects/tailings generated from coarser size processing to fine size reduction and subsequent processing to recover iron values. technologyComment of iron ore beneficiation (RoW): Milling and mechanical sorting. Average iron yield is 84%. technologyComment of iron ore mine operation and beneficiation (CA-QC): Milling and mechanical sorting. Average iron yield is 75%. Specific data were collected on one of the two production site in Quebec. According to the documentation available, the technologies of the 2 mines seems similar. Uncertainity has been adjusted accordingly. technologyComment of niobium mine operation and beneficiation, from pyrochlore ore (BR, RoW): Open-pit mining is applied and hydraulic excavators are used to extract the ore with different grades, which is transported to stockpiles awaiting homogenization through earth-moving equipment in order to attain the same concentration. Conveyor belts (3.5 km) are utilized to transport the homogenized ore to the concentration unit. Initially, the ore passes through a jaw crusher and moves to the ball mills, where the pyrochlore grains (1 mm average diameter) are reduced to diameters less than 0.104 mm. In the ball mills, recycled water is added in order to i) granulate the concentrate and ii) remove the gas from the sintering unit. The granulated ore undergoes i) magnetic separation, where magnetite is removed and is sold as a coproduct and ii) desliming in order to remove fractions smaller than 5μm by utilizing cyclones. Then the ore enters the flotation process - last stage of the beneficiation process – where the pyrochlore particles come into contact with flotation chemicals (hydrochloric & fluorosilic acid, triethylamene and lime), thereby removing the solid fractions and producing pyrochlore concentrate and barite as a coproduct which is also sold. The produced concentrate contains 55% Nb2O5 and 11% water and moves to the sintering unit, via tubes or is transported in bags while the separated and unused minerals enter the tailings dam. In the sintering unit, the pyrochlore concentrate undergoes pelletizing, sintering, crushing and classification. These units not only accumulate the material but are also responsible for removing sulfur and water from the concentrate. Then the concentrate enters the dephosphorization unit, where phosphorus and lead are removed from the concentrate. The removal of sulphur and phosphorus have to be executed because of the local pyrochlore ore composition. Then the concentrate undergoes a carbothermic reduction by using charcoal and petroleum coke, producing a refined concentrate, 63% Nb2O5 and tailings with high lead content that are disposed in the tailings dam again. technologyComment of rare earth element mine operation and beneficiation, bastnaesite and monazite ore (CN-NM): Firstly, open pit, mining (drilling and blasting) is performed in order to obtain the iron ore and a minor quantity of rare earth ores (5−6 % rare earth oxide equivalent). Then, a two-step beneficiation process is applied to produce the REO concentrate. In the first step, ball milling and magnetic separation is used for the isolation of the iron ore. In the second step, the resulting REO tailing (containing monazite and bastnasite), is processed to get a 50% REO equivalent concentrate via flotation. technologyComment of rare earth oxides production, from rare earth oxide concentrate, 70% REO (CN-SC): This dataset refers to the separation (hydrochloric acid leaching) and refining (metallothermic reduction) process used in order to produce high-purity rare earth oxides (REO) from REO concentrate, 70% beneficiated. ''The concentrate is calcined at temperatures up to 600ºC to oxidize carbonaceous material. Then HCl leaching, alkaline treatment, and second HCl leaching is performed to produce a relatively pure rare earth chloride (95% REO). Hydrochloric acid leaching in Sichuan is capable of separating and recovering the majority of cerium oxide (CeO) in a short process. For this dataset, the entire quantity of Ce (50% cerium dioxide [CeO2]/REO) is assumed to be produced here as CeO2 with a grade of 98% REO. Foreground carbon dioxide CO2 emissions were calculated from chemical reactions of calcining beneficiated ores. Then metallothermic reduction produces the purest rare earth metals (99.99%) and is most common for heavy rare earths. The metals volatilize, are collected, and then condensed at temperatures of 300 to 400°C (Chinese Ministryof Environmental Protection 2009).'' Source: Lee, J. C. K., & Wen, Z. (2017). Rare Earths from Mines to Metals: Comparing Environmental Impacts from China's Main Production Pathways. Journal of Industrial Ecology, 21(5), 1277-1290. doi:10.1111/jiec.12491 technologyComment of scandium oxide production, from rare earth tailings (CN-NM): See general comment. technologyComment of vanadium-titanomagnetite mine operation and beneficiation (CN): Natural rutile resources are scarce in China. For that reason, the production of titanium stems from high-grade titanium slag, the production of which includes 2 processes: i) ore mining & dressing process and ii) titanium slag smelting process. During the ore mining and dressing process, ilmenite concentrate (47.82% TiO2) is produced through high-intensity magnetic separation of the middling ore, which is previously produced as a byproduct during the magnetic separation sub-process of the vanadium titano-magnetite ore. During the titanium slag smelting process, the produced ilmenite concentrate from the ore mining & dressing process is mixed with petroleum coke as the reducing agent and pitch as the bonding agent. Afterwards it enters the electric arc furnace, where it is smelted, separating iron from the ilmenite concentrate and obtaining high-grade titanium slag.
Within the frame of the comprehensive SPOC project (Subduction Processes off Chile) the SONNE cruises SO161 Leg 2 and 3 have been conducted between October 16th and November 29th, 2001, off central Chile between 28° and 44° S. In that period some 5,300 km were surveyed with multichannel seismic (MCS) reflection, magnetic, gravity, high-resolution bathymetric and echographic methods. In addition, approximately 3,900 km were surveyed with the same spectrum of methods but without MCS. The total number of 2D profiles was 48. Target was the variation of the subduction properties between the convergent oceanic Nazca and continental Southamerica plates and the different conditions that might influence the subduction process as there are: (1) age of the oceanic crust, (2) its structure and composition, (3) its sedimentary cover, (4) its thermal state, (5) the subduction angle and obliquity, and (6) the terrigenous sediment afflux from the continent. Furthermore, special focus was given to the subduction front, the subduction interface, the structure of the slope as well as to the forearc basin structure and history, and the general distribution of gas hydrate indicating bottom simulating reflectors (BSR's). The results are to be compared with previous studies of the Chilean active margin, e.g. CONDOR (SO 101 and 103) and CINCA (SO 104). The SPOC target area was subdivided into three sub-areas A,B and C. One area was chosen for a detailed survey by aid of a narrowly spaced grid and for a close link with a lot of partners. This area is characterized by a distinctly different margin type south of it is assumed. Moreover, the subducting portion of the aseismic Juan Fernandez Ridge is located in that area representing another important target of the survey. Advantageous conditions enabled the survey of an east-west profile south of Chiloé Island, providing a section through the submerged coastal Cordillera into the flooded longitudinal valley. Some results of Leg 2 and 3 are: In all areas A, B and C no subduction bulge (outer high) in the oceanic crust was visible perhaps due to the shortness of the profiles. The sedimentary cover of the oceanic crust is exceptionally thin, and the crustal thickness is generally quite "normal" with around 7 km derived from relatively weak Moho reflections. In area B a so far magnetically unmapped region was filled providing reliable ages of the oceanic crust, and suggesting that the Challenger Fracture Zone abruptly terminates west of the area of investigation. The survey in area C yielded valuable information on the trench morphology. The so far unique MCS profile south of Chiloé island shows a very wide trench and allows to extrapolate the general conditions encountered an area A southward to approximately 44° S. It can be stated that the situation is in sharp contrast to the basin structures detected by industry profiles further north in the Golfo de Corcovado.
With ballast water in ships, marine organisms are transported around the globe and to environments on which they may have adverse effects (e.g. displacement or even elimination of indigenous species). In order to prevent this world-wide distribution, the International Maritime Organisation (IMO) approved the ‘International Convention for the Control and Management of Ships' ballast water and sediments’ (Ballast Water Convention) in 2004. This convention aims at a management of ballast water to avoid the transfer of organisms around the world. Consequently, a variety of technologies have been developed to remove living organisms from ballast water before it is discharged into the environment. Subsequently, any toxic substance that has served as biocide in the process or was formed during the treatment will be released to the environment when the large amounts of ballast water are discharged. Hence, before ballast water treatment measures are approved by the competent authorities, an assessment of the potential isk for the environment needs to be carried out. Veröffentlicht in Texte | 34/2011.
Surfactants are a major component of many detergents and household cleansers, and therefore, they also reach surface waters to a certain extent. In order to estimate the resulting environmental risk, two surfactant groups (i.e., LAS and AES) were determined by target analysis in 33 wastewater samples from German sewage treatment plants. Additionally, several other surfactants and their degradation products were measured by non-target analysis. Despite a high removal rate in the treatment process (more than 99% for LAS and AES), average concentrations of 14.4 μg/L and 0.6 μg/L, respectively, were measured in the effluent - due to the very large amounts used. Although neither of the two target surfactants nor any of the non-target analytes has exceeded their respective limit values, effects of background level from all surfactants together cannot be excluded. Therefore, the Federal Environment Agency recommends to further monitor the occurrence of this group of compounds and recommends to reduce at least the use of LAS in the future. Veröffentlicht in Texte | 108/2019.
Digitaler Produktpass kann bei Wiederverwertung von Faserverbundwerkstoffen helfen In Deutschland gibt es ca. 480.000 Sportboote*, eine Million Kanus, 10.000 Motorsegler und Segelflugzeuge sowie 8.000 motorisierte Leichtflugzeuge, die vorrangig zu privaten Zwecken genutzt werden. Am Ende der Nutzungsdauer werden die Gegenstände jedoch bislang nicht sachgerecht recycelt, da etablierte Verfahren der Abfallwirtschaft meist ungeeignet sind und Kapazitäten für die notwendige individualisierte Aufbereitung fehlen. Dirk Messner, Präsident des Umweltbundesamtes (UBA), betont: „Im Bereich der Faserverbundwerkstoffe fehlen derzeit noch Konzepte zur Wiederaufbereitung. Wertstoffe gehen verloren. Mithilfe des digitalen Produktpasses können wir zu einem weitaus besseren Recycling dieser Stoffe kommen.“ Zu diesem Ergebnis kommt auch eine neue Studie im Auftrag des Umweltbundesamtes (UBA-Text 93/2023). Sportboote und Leichtflugzeuge sowie bestimmte Freizeitgeräte, wie Fahrräder, Skier und Musikinstrumente, enthalten Faserverbundwerkstoffe (FVW). Sie sind oftmals langlebig, werthaltig und als Abfälle prädestiniert für die Vorbereitung zur Wiederverwendung oder das Recycling. Eine strukturierte Aufbereitung gilt jedoch derzeit noch als unwirtschaftlich und erfolgt deshalb nicht. Der digitale Produktpass könnte hier Abhilfe schaffen. Eine Einführung eines solchen digitalen Produktpasses mit seinen individualisierten und für Reparatur, Wiederverwendung und Recycling zweckgerichteten Informationen könnte die Kreislaufwirtschaft fördern und Ressourcen schonen. Er könnte zudem die Herausforderung bewältigen, die vergleichsweise geringe Anzahl von gelegentlich anfallenden Altprodukten wenigen, aber hoch spezialisierten Demontageanlagen zuzuführen. Generell liegt in der Digitalisierung ein großes Potential für das Recycling. Neben der Bereitstellung von praktischen Informationen für den Betrieb, die Wartung und das Recycling erlaubt der Produktpass auch die Mengenstromerfassung und Stoffstromlenkung. Logistische Optimierungsaufgaben sind lösbar, Kommunikation über weite Strecken gelingt und systematische Netzwerkanalysen decken Barrieren auf. Die Möglichkeiten für die Abfallwirtschaft sind bei Weitem noch nicht alle erschlossen. Der digitale Produktpass ist ein Datensatz, der die Komponenten, Materialien und chemischen Substanzen oder auch Informationen zu Reparierbarkeit, Ersatzteilen oder fachgerechter Entsorgung für ein Produkt zusammenfasst. Die Daten stammen aus allen Phasen des Produktlebenszyklus und können in all diesen Phasen für verschiedene Zwecke genutzt werden (Design, Herstellung, Nutzung, Entsorgung). Die Strukturierung umweltrelevanter Daten in einem standardisierten, vergleichbaren Format ermöglicht allen Akteuren in der Wertschöpfungs- und Lieferkette, gemeinsam auf eine Kreislaufwirtschaft hinzuarbeiten. * Anmerkung: In der ursprünglichen Version hieß es "ca. 580.000 Sportboote". Es sind aber nur 480.000 Boote. Wir haben die Zahl entsprechend korrigiert. (26.06.2023)
Aufgrund der hohen Tierbesatzdichte in einigen Regionen Europas und Deutschlands kommt es in diesen Regionen zu hohen Nährstoffüberschüssen, die vor Ort pflanzenbaulich nicht mehr sinnvoll zu nutzen sind und deren Ausbringung mit der Entstehung von Belastungen für die Ressourcen des Naturschutzes und des menschlichen Wohlbefindens verbunden ist. Dem gegenüber stehen Ackerbauregionen, in denen kaum Wirtschaftsdünger anfällt und in denen die notwendigen Nährstoffe über mineralische Düngemittel eingebracht werden. Neben der Flächenbindung der Tierhaltung könnte die Aufbereitung und der Transport des Wirtschaftsdüngers in Nährstoffmangel-Regionen zu einer besseren Verteilung und dem Recycling der anfallenden Nährstoffe beitragen. Es existieren eine Reihe von Aufbereitungsverfahren, die bisher kaum zum Einsatz kommen, da die geltenden Auflagen zur Ausbringung von Nährstoffen als nicht strikt genug angesehen werden können und darüber hinaus die ökonomischen Rahmenbedingungen der Aufbereitung und des Transportes einen wirtschaftlichen Einsatz der Techniken nicht erlauben. Der vorliegende Bericht greift das Thema der Wirtschaftsdüngeraufbereitung wieder auf und stellt die technischen Möglichkeiten der Aufbereitung sowie die ökonomischen Rahmenbedingungen des Einsatzes der Techniken dar. Darüber hinaus werden die politischen und ökonomischen Rahmenbedingungen und deren notwendige Weiterentwicklung betrachtet. So kann der Einsatz der Aufbereitung und des Transportes von Wirtschaftsdüngern unter veränderten Rahmenbedingungen durchaus wirtschaftlich erscheinen. Zu beachten ist jedoch, dass der Einsatz der entsprechenden Technik mit Trade Offs verbunden ist, die im Rahmen dieses Projektes nicht abschließend bewertet werden können. Veröffentlicht in Texte | 80/2015.
Although there is a considerable potential for the recycling of technical plastics from ELV and WEEE in Germany, the status is deficient and targeted measures are needed to develop appropriate capacities. The report provides a comprehensive status quo analysis on the legal framework, material requirements, a description of the most relevant types of plastics as well as interfering and polluting substances during recycling, a detailed account of the use of plastics in electrical and electronic equipment as well as in vehicles, and a detailed description of the existing process chains for the treatment of plastics from the two waste streams. In addition, lab-scale experiments were carried out in which promising approaches were tested. Against this background, separation and recycling strategies were derived and measures and recommendations for action were developed for political as well as economic actors. Veröffentlicht in Texte | 25/2024.
Die europäischen Umweltstandards für die Intensivhaltung wurden als ‚Beste verfügbare Techniken‘ (BVT) im BVT-Merkblatt (IRPP BREF , 2017) beschrieben. Die BVT-Nr. 19 in den BVT-Schlussfolgerungen (EU) 2017/302 der Kommission vom 15. Februar 2017 betrifft die Aufbereitung von Wirtschaftsdüngern. Ziel des Vorhabens war die Bewertung von Aufbereitungstechniken von Gülle und Gärresten. Der Bericht umfasst eine Klassifikation aller Aufbereitungstechniken aus sieben europäischen Ländern mit bedeutender Intensivtierhaltung. Für eine umweltentlastende Anwendung von Aufbereitungsanlagen sind regionale N- und P-Bilanzierungen erforderlich, damit die Anlagen einen Betrag zur Nährstoffreduzierung leisten. Der Bericht beinhaltet praktikable Ansätze zur Beurteilung der Nährstoffüberhänge, besonders in Gebieten mit hoher Viehbesatzdichte. Es wird gezeigt, wie eine nachhaltig verträgliche Nährstoffversorgung erreicht werden kann. Veröffentlicht in Texte | 109/2021.
The report analyzes, by looking back at existing compliance systems in the EU, Alberta, Australia, Colombia and Japan, the conditions under which offsets can add value to the compliance system without undermining its environmental integrity. The compliance system’s climate ambition as well as the efficiency of the institutions, processes and infrastructure that are used for the generation and crediting of offsets are seen as essential conditions for offsets to uphold environmental integrity and add value to a compliance system, to climate action and to sustainable development. Veröffentlicht in Climate Change | 58/2021.
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