Investigation of properties of diesel water mixtures with and without emulsifier by terahertz spectroscopy

Çınar, Zühra
Additives such as alcohol, water are used in petroleum products for different purposes. Aim of the thesis is to determine water content in diesel water mixtures in THz region. The samples with and without emulsifier were analyzed in THz region. Besides, different kinds of oils (olive oil, sunflower oil, frying oil and engine grease #10) were measured in THz region because mixed of oils can be used instead of regular diesel. For this reason, we aimed to show distinguishability of regular diesel and mixed fuel. Then, FTIR spectrum of all diesel water mixtures and oils were collected in order to compare THz results. Meaningful results were obtained for diesel water mixtures by using both techniques. It has been shown that THz-TDS and FTIR are complementary techniques. However, FTIR was not a suitable technique for oils measurements because no marker could be seen to distinguish oils. On the other hand, THz-TDS was an effective technique because it enabled us to calculate refractive indexes of oils. When oils’ refractive indexes were compared, the differences between them could be seen clearly. These results gave a hint to us about distinguishability of diesel and mixed fuel by THz-TDS.