Influence of Evaporation Behaviour of Liquid Fuels on the Tendency to Coking on Wetted Surfaces
The main objective of the investigations was to identify differences between fuels with different deposition potential. Purely thermal data such as the temperature-dependent heat capacity during evaporation and general physico-chemical parameters did not show any significant differences between different fuel oils. The evaporation behaviour of the considered fuels has been experimentally investigated within the project using two common evaporation concepts (fleece evaporation, spray evaporation). In the investigations, a fuel oil with high deposition potential produced larger quantities of (poly)aromatic compounds during evaporation compared to a fuel oil with lower deposition potential. The characterisation of the fuel oils by two-dimensional gas chromatography showed a comparable result and additionally revealed that the fuel oil with the higher deposition potential contains more long-chain alkanes. In addition to the deliberate generation of deposits, the project also investigated regeneration strategies for the subsequent removal of the resulting deposits.
It was shown that, depending on the fuel used, complete regeneration, i.e. complete decomposition of the deposits, is possible at temperatures between 300 °C and 540 °C. In this context, a model to describe the evaporation of multi-component fuels was developed and verified within the project. The QDM can therefore well represent the evaporation behaviour of fuel oils and represents a suitable method for modelling the evaporation behaviour of multi-component fuels.
The IGF project (18675 BG) of the research association DGMK Deutsche Wissenschaftliche Gesellschaft für Erdöl, Erdgas und Kohle e.V., Überseering 40, 22297 Hamburg was funded via the AiF within the framework of the programme for the funding of Industrial Collective Research (IGF) by the Federal Ministry for Economic Affairs and Energy on the basis of a resolution of the German Bundestag.