Two-level Full Factorial Design for Selectivity Modeling and Studying Simultaneous Effects of Temperature and Ethanol Concentration in Methanol Dehydration Reaction

Using surface analysis, simultaneous effects of temperature (260-380ºC) and ethanol concentration (0-1%) on dimethyl ether (DME) selectivity, yields of hydrocarbon and DME, and methanol conversion were investigated in methanol dehydration reaction over γ-Al2O3 catalyst. Methanol conversion and yield of hydrocarbon/DME were found to be significantly affected by temperature and the temperature-ethanol concentration interactions. In addition, DME selectivity and yield of DME were found to be influenced by the process temperature, and ethanol concentration as well as their interactions. BET surface area measurement and scanning electron microscopy technique (SEM) confirmed that the catalyst deactivation was intensified at higher temperatures by increasing ethanol concentration. Using statistical regression, a mathematical model was developed, and then validated, to describe simultaneous effects of temperature and feedstock ethanol concentration on DME selectivity. Although the model was statistically significant, curvature was not significant. Therefore, a two-level full factorial design of experiment approach was followed as a promising strategy for DME selectivity modeling and interpretation of data in this work.