**3. Results and Discussion**

#### *3.1. Model Validation*

Table 2 shows results of the grid independence study using EC conversion as the most sensitive key variable. When the grid size exceeds 10,000, the EC conversions remain unchanged for both adiabatic and heat-exchange reactor models with sphere/cylinder catalysts. Therefore, the following work was carried out with a grid size of 10,000.

To validate the established multi-scale reactor and chemical kinetics model, we compared the model predictions with pilot plant data. The EC hydrogenation pilot reactor was operated at a production capacity of 1000 talcohol/a and had steadily run for over 72 h to allow collection of all reaction products. The structure and working conditions of the pilot reactor are shown in Table 3. Simulations were conducted with the same parameter settings as the pilot reactor, including the reactor geometry, operating conditions and catalyst properties. Figure 3 shows the mass flow rates of the converted EC and the produced EG, MeOH and by-products measured in pilot plant run and those predicted by our model. The model predictions are in quantitative agreement with the pilot plant data with relative

errors for both the converted EC and the produced EG < 5%. The amount of produced MeOH is underestimated by ~20%, which is accompanied by an overestimated amount of by-products. The reason is suspected to be incomplete measurement of the volatile MeOH in bench-scale experiments used for deriving the kinetics parameters. Nonetheless, the multi-scale reactor model is reliable in predicting the generic reaction performance of EC hydrogenation in industrial reactors and will be used to explore the operational behaviors of different types of tubular reactors.


**Table 2.** Dependence of EC conversion on grid sizes in simulation.

**Table 3.** Structure and working conditions of the pilot reactor for EC hydrogenation.


**Figure 3.** Comparison between pilot plant and simulation data for EC hydrogenation in the conduction oil-cooled multi-tubular reactor.
