Application of Response Surface Methodology and Central Composite Rotatable Design for Modeling and Optimization of Catalyst Compositions in Ethanol Synthesis via CO Hydrogenation

Abstract

Abstract A statistical analysis about the effect of catalyst compositions on ethanol synthesis from CO hydrogenation was studied. The effect of Rh loading (0–3 wt.%), Fe loading (2–10 wt.%) and Mn loading (0.5–2.5 wt.%) of RhMnFe/γ-Al2O3 was studied through response surface methodology (RSM) combined with a central composite rotatable design (CCRD). A linear and a quadratic model were proposed to correlate the three variables to the two responses: CO conversion and ethanol selectivity. The predicted values for ethanol selectivity were in a good agreement with the experimental values, with R2 of 0.9779. The optimum conditions for achieving the maximum ethanol selectivity (27.8%) while limiting CO conversion at a moderate level (>20%) were as follows: Rh loading of 2.5 wt.%, Mn loading of 2.5 wt.% and Fe loading of 4 wt.%. Two representing catalysts were characterized by XRD, TPR and DRIFTS.