Mechanistic Modeling of the Thermal Cracking of Decylbenzene. Application to the Prediction of Its Thermal Stability at Geological Temperatures
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- 作者：Valé ; rie Burklé ; -Vitzthum ; Raymond Michels ; Gé ; rard Scacchi ; and Paul-Marie Marquaire
- 刊名：Industrial & Engineering Chemistry Research
- 出版年：2003
- 出版时间：November 12, 2003
- 年：2003
- 卷：42
- 期：23
- 页码：5791 - 5808
- 全文大小：433K
- 年卷期：v.42,no.23(November 12, 2003)
- ISSN：1520-5045
文摘
Thermal cracking of decylbenzene is experimentally studied at 330 
C under 70 MPa for 10 hto 1 month, that is, up to 20% of conversion. A detailed kinetic model consisting of 946 free-radical reactions and 1 molecular reaction is developed to describe the results. The formation ofmain products, namely, toluene, ethylbenzene, nonene, nonane, and octane, is correctly describedby the model. The global activation energy is equal to 66 kcal·mol-1. The molecular reaction,that is, the retroen reaction, is of great importance: it explains the major part of toluene andnonene formation at 330 C. At 400 C this reaction becomes negligible but at 200 C it ispredominant. Its activation energy is about 54 kcal·mol-1 and is confirmed by experimentalmeasurements. The mechanistic kinetic model is applied to the prediction of the thermal stabilityof decylbenzene at temperatures usually encountered in petroleum sedimentary basins (T <250 C). At such temperatures, the main reactive pathway, controlled by the retroen reaction,leads to the formation of toluene. Such conclusion is not intuitive in the geochemistry field andsuggests that long-chain alkylbenzenes may inhibit rather than accelerate the cracking of alkanesin natural hydrocarbon mixtures.
C under 70 MPa for 10 hto 1 month, that is, up to 20% of conversion. A detailed kinetic model consisting of 946 free-radical reactions and 1 molecular reaction is developed to describe the results. The formation ofmain products, namely, toluene, ethylbenzene, nonene, nonane, and octane, is correctly describedby the model. The global activation energy is equal to 66 kcal·mol-1. The molecular reaction,that is, the retroen reaction, is of great importance: it explains the major part of toluene andnonene formation at 330 C. At 400 C this reaction becomes negligible but at 200 C it ispredominant. Its activation energy is about 54 kcal·mol-1 and is confirmed by experimentalmeasurements. The mechanistic kinetic model is applied to the prediction of the thermal stabilityof decylbenzene at temperatures usually encountered in petroleum sedimentary basins (T <250 C). At such temperatures, the main reactive pathway, controlled by the retroen reaction,leads to the formation of toluene. Such conclusion is not intuitive in the geochemistry field andsuggests that long-chain alkylbenzenes may inhibit rather than accelerate the cracking of alkanesin natural hydrocarbon mixtures.