(173c) A Kinetic Study of the Ethylene Oligomerization over a Nibea Catalyst
AIChE Annual Meeting
2018
2018 AIChE Annual Meeting
Catalysis and Reaction Engineering Division
Reaction Chemistry and Engineering I
Monday, October 29, 2018 - 1:12pm to 1:33pm
We suggest the Langmuir-Hinshelwood Hougen-Watson kinetic mechanism to study the ethylene oligomerization over the NiBEA catalyst. Additionally, we propose two distinct mechanisms. The first mechanism involves the reaction between two adsorbed ethylene species. On the other hand, the second mechanism considers that one of the ethylene species is adsorbed on the catalyst surface and the other one is in the gas phase. The latter mechanism is denominated Eley-Rideal. We performed the experiments on a packed bed reactor with a catalyst loading of 0.25 grams and a WHSV of 30.24 h-1. Prior to the kinetic data acquisition, we performed experiments to determine if the system was limited by diffusion mechanisms. Therefore, we performed oligomerization experiments at different temperatures ranging from 30 to 200 oC at fixed conditions. We used this data to calculate the activation energy and the pre-exponential factor of the Arrhenius equation. We found the activation energy and the pre-exponential to be equal to 11 kJ/mol and 182 g ethylene g catalyst-1 h-1, respectively. We approached the development of the kinetic model from two different perspectives. First, we developed a kinetic model based on the consumption of ethylene in the reaction system. Second, we used the rate of production of products ranging from C4 to C8 to develop the kinetic model. This model is able to predict not only the total ethylene consumed in the system but also the major products produced during the reaction. It is important to highlight that the product range listed is suitable to be used as gasoline additives.