98/01163 Thermal cracking of coal residues: kinetics of asphaltene decomposition: Martinez, M. T. et al. Fuel, 1997, 76, (9), 871–877
- Publisher
- Elsevier Science
- Year
- 1998
- Weight
- 188 KB
- Volume
- 39
- Category
- Article
- ISSN
- 0140-6701
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✦ Synopsis
Thermal cracking was performed on an asphaltene residue from a synthetic crude obtained by coal liquefaction. The kinetics of formation of oil + gas and coke from conversion of the asphaltene fraction were determined. The authors propose a three-lump model, taking into account the parallel reactions for oil + gas and coke formation. Conversion data fitted secondorder kinetics throughout for asphaltene conversion and oil + gas and coke formation. Delplot analysis indicated that under the most severe experimental conditions, asphaltenes and oils participated in secondary cokeforming reactions which are not included in the model. The highest activation energy was that for asphaltene conversion, in a range of 63.94 to 86.13 kJ mol-'. The highest asphaltene conversion, 55.9 wt%, was obtained at 475°C and 40 min reaction time. At short reaction times, the asphaltene fraction converted to coke was much less than that converted to oil, whereas at long reaction times this trend was reversed. The oil from the products showed lower aromaticity and higher H/C and N/C ratios than the oil from the feed.