Abstract:
The coking product distribution and composition of the various vacuum residues are very different because these vacuum residues come from various oil fields and refined ways. Properties of 17 vacuum residues, such as density, residue carbon (electric furnace method), ash, metallic content, SARA (saturate, aromatics, resins, asphaltene) fractions, are analyzed. Coking reactive tests of the vacuum residues are respectively appraised by using the tubular coking reactor. According to the stepwise regression analysis on 11 series of data, the physical and chemical properties of the vacuum residues, which significantly affect coking product distribution(such as the yield of coke, ≤200 ℃ light oil, >200 ℃ heavy oil, and gas, and the content of hydrogen and methane in gas), are determined and their regression indexes are fitted. A model, which can predict the product distribution of the delayed coking units, is established. The model is tested by predicting the coking product distribution of six vacuum residues with different properties, and all the relative errors are within the permitted limit of 5%. Compared with other models existed, this model can predict not only the yield of the coking gas, light oil, heavy oil, and coke, but also the content of hydrogen and methane in coking gas. This model can provide overall information on coking products distribution and optimized coking feedstock process.