Modelagem, simulação e otimização do processo de desidratação catalítica do etanol a etileno em diferentes escalas

Abstract

Catalytic dehydration of ethanol is the key step in the sustainable production of the renewable ethylene value chain. In turn, obtaining a mathematical model to optimize the configuration of a reaction section is of great interest to the industry, allowing for the ideal design of larger plants and improvements in existing processes. In addition, an essential condition for reactor design is the knowledge of the relevant kinetic rates that must be applied in the process. Therefore, the present work proposes and develops 13 mechanistic kinetic models that seek agreement with experimental data on a laboratory scale for the main reactions. For this purpose, alumina was used as a catalyst, with its optimal calcination temperature equal to 500 °C, in addition to the required physical-chemical characteristics. In addition, a phenomenological model of a fixed bed reactor is presented, considering 18 reaction routes and 20 chemical species, as well as a model for catalytic deactivation, with ethanol, acetaldehyde and light olefins identified as the main precursors of coke formation. In turn, the model parameters were estimated from data from an industrial scale operation, after a statistical treatment procedure with filtering and reconciliation. In short, model validation was performed for different conditions and campaigns, with average deviations of less than 5% for the reactor temperature profiles and 10% for the main components. Finally, the concept of the proposed industrial process was simulated and evaluated economically, being optimized for different capacities, presenting an increase in revenue of US $ 2,064,625 per year under optimal operating conditions.