Life Cycle Assessment der alterungsbedingten Umweltverträglichkeit biogener Hydraulik-Schmierstoffe

Biogenic hydraulic fluids, based on synthetic esters (categorie: HEES), have an excellent environmental profile in the unused state, so that they are typically classified into water hazard class 1 or as "not hazardous to water". During storage at room temperature and tribological application, occurring chemical and toxicological changes take no account in the classification of lubricants until now. However, the ageing and oxidation stability gets increasing importance, since it determines the service life of lubricants in tribological systems in addition to the storage time. Since it always comes to direct and uncontrolled entries into the environment in case of accidents or hydraulic leaks, it is essential to assess whether there is an environmental hazard by waste oils. With an increased use of biogenic hydraulic fluids in environmentally sensitive areas, thus the need for an appropriate monitoring and assessment approach as part of a Life Cycle Assessment (LCA). The aquatic and miniaturised test procedures applied in this work with the Water Soluble Fraction (WSF) concept, allows a simple and quick screening of age-related ecotoxic potential of lubricants by oxidative processes and tribological application. For detection of genotoxic potential the umu-test is a suitable indicator test to detect geno- and cytotoxic effects by oxidative reactions. The determination of biodegradability is essential for the assessment of the environmental impact of hydraulic fluids. The optimised biodegradability test system “O2/CO2-Headspace Test” has proved itself as a suitable procedure for the investigation of biogenic lubricants within the scope of a LCA and shows therefore a comparable method of the required test procedures for the assignment of ecolabels. In addition, the combination of biological test procedures and chemical analysis allows a comprehensive investigation of effects and causes of age-related changes of hydraulic fluids after tribological application. The quantification of the metal content in used oils as well as the determination of the water soluble metal content allows a better interpretation and differentiation of age-related aquatic ecotoxicity. The additional characterisation of conditional-use changes in the ecological characteristics allows a comprehensive assessment and is still widely unknown, but an important aspect regard of LCA for biogenic hydraulic fluids. Such a methodical approach allows therefore the feedback of the desired product properties on the production method during chemical modification. The results of this study demonstrate that optimisation of the lubricant synthesis on the base of herbal reactants (high oleic sunflower oil) leads to successful reproducibility of synthetic esters and therefore also to an invariable environmental compatibility. The storage of basic synthetic esters and complicated ester mixtures leads to increasing toxicity with increasing temperature and storage time conditioned by oxidation. Besides, the age-related toxicity correlates with decreasing DOC-content of the WSF. The typical kinematic viscosity of 32 mm2/s for hydraulic fluids represents positive effects if stored at room temperature, since it causes a slower degredation by oxygen diffusion. The ageing behaviour of synthetic esters during tribological application is independent of their previous synthesis process or their storage, so that biogenic hydraulic fluids can still be used after previous storage in environmentally friendly hydraulic systems. The long term investigation in an environmentally friendly tribosystem leads in spite of metal entry to a decrease of eco- and genotoxic potential which was already available by storage at room temperature. In contrast, in a short period of use the metal content is correlated with the ecotoxicity, since the tribological load is in the foreground. Therefore the influence and change of the toxicity is dependent not exclusively on the metal content in the lubricant, but primarily on its age-related change due to usage.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2012

Author dc:creator

• Bressling, Jana

Contributors dc:contributor

• Dott, Wolfgang
• Hollert, Henner

• info:eu-repo/classification/ddc/570
• Umweltverträglichkeit
• Blauer Engel <Umweltzeichen>
• Umwelttoxizität
• Mutagenität
• Umweltbilanz
• Hydrauliköl
• Biowissenschaften, Biologie
• Lagerung
• Bioschmierstoffe
• Ölalterung
• Tribosystem
• Ökobilanz
• biolubricants
• Life Cycle Assessment
• oil ageing
• storage
• tribological system
• hydraulic fluid

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-124419%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:62946