|
Abstract
|
In ethylbenzene dehydrogenation process, the produced coke is the main source of catalyst deactivation, dete-rioration of stainless steel piping (carburization) and the flow pass plugging. The novelty of this work is determination, ranking and modeling of influencing factors and their interactions on the rate of coke formation in ethylbenzene dehydrogenation process including independent parameters such as styrene and toluene con-centrations, surface temperature, the reactor shape factor and steam to ethylbenzene (St/EB) weight ratio. A laboratory setup was used to investigate the effect of above listed parameters and the response surface meth-odology (RSM) was used to analyze the experiments and optimize the parameters. The ANOVA results illustrated that the model is significant and able to predict coke. The p-values for all parameters are less than 0.05, indi-cating these parameters are effective factors on coke formation. The results revealed that by increasing styrene and toluene concentrations and surface temperature, the rate of coke formation increases. In such circumstances, surface temperature showed maximum effect due to the increase of cracking reactions and the production of coke precursors such as stilbene, anthracene etc. On the other hand, the effect of St/EB weight ratio on the rate of coke formation is inverse. The results obtained from SEM/EDS analysis showed the filamentous coke forms on the surface of 304 H austenitic steel.
|