Development of centrifugal coating device to load CuZnZr/γ-Al2O3 catalyst on porous substrates for methanol steam reforming

Abstract

The porous foam material has been attracted to be used as the catalyst coating substrate for microreactors due to its generally excellent heat and mass transfer characteristics. Preparing uniform catalyst coating onto porous foam can increase the adhesion area between the coating and substrate to reduce spallation and extend the service life of microreactors. Herein, we developed a highly automatic centrifugal coating device to fabricate relatively uniform catalyst coating onto porous foam structures. The structural and hardware components of the automatic centrifugal coating device are introduced, and an active disturbance rejection control (ADRC) algorithm is adopted to accurately adjust the centrifugal speed with an error of <1 % to ensure the relative uniformity of catalyst coating. By using the developed device, the CuZnZr/γ-Al2O3 catalyst coating can be successfully loaded onto three types of foam substrates (Cu, α-SiC/α-Al2O3, α-Al2O3) with high relative uniformity. The spallation resistance was examined by thermal shock and high-speed steam scouring tests. After that, the porous foam substrate with coated catalyst was used in microreactors for methanol steam reforming, results showed that the conversion rate of CuZnZr/γ-Al2O3/Cu foam structured catalyst can reach 90.7 % and hydrogen flow rate is 296.18 mL/min at 300 °C. This study demonstrates our developed centrifugal coating device has the potential for industrial application of structured catalyst preparation.