Study on Effective Radial Thermal Conductivity of Gas Flow through a Methanol Reactor

Abstract

The heat conduction performance of the methanol synthesis reactor is significant for the development of large-scale methanol production. The present work has measured the temperature distribution in the fixed bed at air volumetric flow rate 2.4-7 m 3 · h −1 , inlet air temperature 160-200°C and heating tube temperature 210-270°C. The effective radial thermal conductivity and effective wall heat transfer coefficient were derived based on the steadystate measurements and the two-dimensional heat transfer model. A correlation was proposed based on the experimental data, which related well the Nusselt number and the effective radial thermal conductivity to the particle Reynolds number ranging from 59.2 to 175.8. The heat transfer model combined with the correlation was used to calculate the temperature profiles. A comparison with the predicated temperature and the measurements was illustrated and the results showed that the predication agreed very well with the experimental results. All the absolute values of the relative errors were less than 10%, and the model was verified by experiments. Comparing the correlations of both this work with previously published showed that there are considerable discrepancies among them due to different experimental conditions. The influence of the particle Reynolds number on the temperature distribution inside the bed was also discussed and it was shown that improving particle Reynolds number contributed to enhance heat transfer in the fixed bed.

Validation of a Fixed Bed Reactor Model for Dimethyl Ether Synthesis Using Pilot-Scale Plant Data

“…(2) On the reactor tube, the radial temperature is negligible, as is the axial dispersion, due to the large ratio of catalyst bed length, the tube diameter, and catalyst particle diameter (the values are provided in Table 1) [35,36]. (3) The radial temperature is inappreciable in the catalyst pellets since its conductivity is sufficiently high to reduce the core and surface temperature difference [37].…”