Publikationsserver der RWTH Aachen University
Prozessorientierte Untersuchungen zur Schmierstoffsynthese basierend auf Ölsäuremethylester und Glycerintrioleat
Abstract
dc:descriptionThe aim of this work, which was part of collaborative research centre 442 was the synthesis of two lubricants with special focus on optimized application requirement and batch comparability in a 25-l-batch production. On one hand a low viscosity lubricant based on technical grade oleic acid methyl ester with the main component HISM, on the other hand a high viscosity one based on glycerintrioleate with the main component HIGTS was synthesized. Both lubricants were synthesized in a two-step reaction via epoxidation of the double bond and ring opening via alcoholysis afterwards. With this modification the fatty acid esters were stabilized against air-aging and their viscosity was raised. Further on many side reactions were minimized and the main components HISM and HIGTS were abuzz in each lubricant system. For lubricant characterization analytical methods as e. g. GC were developed and used to determine conversions, selectivity and kinetic values (chapter 3.4). With developing an alkaline decomposition reaction according to the DGF-Einheitsmethoden [47] the HIGTS lubricant (high temperature GC) was converted into the lower boiling HISM-system and both systems were directly comparable. Further more inline ATR IR spectroscopy was used to monitor the reaction progress. With a small failure in measurement between 1 and 5% the method delivered a high data density at each point of reaction progress. As a lubricant specification and quality control typical oil-values as e. g. viscosity, neutralization-, saponification- and iodine numbers were determined. In lab scale different reaction setups (order of reactants, stirring speed…) were tested to study the influence of mass transport limitation during the epoxidation. The variation of hydrogen peroxide concentration led to heavy losses in conversion. However the major reaction influence was monitored with temperature variation for both epoxidation and alcoholysis (rising temperature > 60°C caused DHSM production). For the alcoholysis reaction the influence of catalyst mass as well as different catalyst systems were tested in conversion and selectivity. Best results were obtained with Amberlyst 15 and the similar Dowex Marathon C catalyst. With the collected expertises in lab scale the 25-l-pilot plant was optimized. An automated and computer controlled reaction procedure minimized unwanted side reactions (over-night stand still times) and also raised batch reproducibility. With a special catalyst cleaning process using scCO2 and vacuum drying afterwards the catalyst could be recycled at least three times in reaction without any remarkable losses in selectivity and conversion. But with recycling the catalyst it starts to leach H2SO4 and aryl-sulphuric acid groups in the lubricant that decreased biodegradability and even caused toxicity against algae. This problem was fixed with integrating a steam stripping unit into the pilot plant. Finally optimizing the pilot plant not only led to a successful batch reproducibility and comparability but also a biodegradable production rout with e. g. small solvent amounts could be developed. Further more the optimized production process with methyl esters based on animal waste could be assigned on methyl esters based on rape seed (inapplicable for application requirement because of high unsaturated fatty acid grades, a weak anti air-aging behavior and contents of antioxidants; compare chapter 3.5.6). The high grade of synthesis optimization and batch reproducibility in this work was not only reached by process optimization. Further more multidisciplinary feedback of other CRC 442 Project partners with their research topics (e. g. changing biodegradability during synthesis optimization; TP A4; TP A6) led to the high grade of reproducibility in synthesis and characterizing the lubricants.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2008
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Eichholz, Sven
- Contributors dc:contributor
-
- Liauw, Marcel
Subjects
dc:subject × 9Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger