Experimental Prediction of the Amount of Asphaltene of Bitumen and Hydrocarbon Systems of Samples of an Iranian Refinary

Production of petroleum bitumen involves a heavy investment in high technology equipment and a commitment to quality control at all stages of manufacture, blending and distribution. The chemical composition of the bitumen has a significant effect on its viscoelastic properties and hence on its performance as road paving material in asphalts. The exact chemical composition of bitumen is dependent on the chemical complexity of the original crude petroleum and the manufacturing process. Bitumen is constituted by a complex mixture of two main components including asphaltenes and malthenes. The ratio of asphaltenes to the other components (aromatics, paraffins and resins) has a significant effect on viscoelastic properties of bitumens and hence on their performance on road paving binders. In this work, the composition of asphaltenic compounds of different bitumen samples from crude oil distillation process was measured using three different methods. The first method, ASTM D3279-97, is an standard method to measure weight percent of normal heptane insoluble compounds. Therefore, it can be used to determine the asphalts with or without mineral materials. The second method is based on extraction of the bitumen sample using normal heptane followed by a second extraction process with toluene. Each stage of the process takes 24 hrs. Using this method it would be possible to measure malthens, asphaltenes and other mineral and inorganic compounds insoluble in n-heptane. The ASTM D6560-00 was used as the third method to measure not only the asphaltene compounds but also other inorganic compounds and minerals insoluble in n-heptane. The results using the first and second method show that beside asphaltene other solid particles are also existed in the tested bitumen samples. Using the third method enables us to confirm the existence of the other solid particles as it has been indicted by the previous tests.

Experimental Prediction of the Amount of Asphaltene of Bitumen and Hydrocarbon Systems of Samples of an Iranian Refinary Keywords:

Asphalt , Asphaltene , Bitumen , Solid Particles , Maltenes , Resins