Kinetic Models Evaluation in Methanol Production for Improved Process Design

The work aimed to evaluate kinetic models of methanol synthesis for improved design of the process. Graaf’s and Kubota’s models were chosen based on their goodness of fit to the respective kinetic data. Polymath was used to fit published experimental data to these kinetic models and evaluate kinetic parameters. The statistical results from Polymath show that Graaf’s model fits to the data well when the partial pressure of CO₂ in the feed was low and to a reasonable extent when it was high with R² 0.83 and 0.52 respectively, with scattered residuals. Kubota’s model fits to the data well only when the partial pressure of CO₂ was high with R² 0.59 with scattered residuals but poorly fits when it was low with R² 0.106 (far from unity). The combined model was the best fit model and it described methanol synthesis kinetics most appropriately with R² 0.88 irrespective of CO₂ partial pressure range.