Capillary Sensor with Fluorescence Reading of Effects of Diesel and Biodiesel Fuel Degradation in Storage

摘要

There are many standards set by national organizations and fuel producers to test and guarantee the quality of diesel fuel and its stability under storage conditions. The diesel fuel stability is related with the fuel composition that evolved to the modern fuels from the historical ones. The stability of modern diesel fuel is mainly due to the reduction of the oxidation processes, the result of the presence of unsaturated components and components with oxygen as organic components and cetane index improvers. The simple characteristic of serious degradation of diesel fuel is the appearance of resins and sediments. Traditional techniques for measuring fuel stability, like the rancimat methods, are relatively complex. On the user side, fast and low-cost sensing of the degradation of diesel and biodiesel fuel is important. The present paper concentrates on the construction of the capillary sensor which enables the examination of the presence of resin and degradation of the most widely used cetane improver (2-ethyl hexyl nitrate) in one arrangement. Results of a development of a sensor working on the principle of fluorescence excited in a disposable capillary cell with high power light emitted diodes are presented. We discuss the principle of the sensor's operation, the construction of the sensor, and the experimental results of testing diesel fuels instability.