Scaling up of 3D printed and Ni/Al2O3 coated reactors for CO2 methanation

This study presents innovative Ni/alumina coated structured metal supports manufactured by 3D-printing technique. Ni/alumina catalysts with nickel loading of 12 wt% were synthesized by a conventional impregnation method using two different alumina powders. It was proven that the agglomerated active metal particles affect the catalytic performance of the catalysts. 3D printed metal supports were coated with Ni/alumina catalysts and subsequently tested in single tube reactors over a range of reaction conditions. Methane productivity was compared for the structured catalysts in two different experimental set-ups: in a small lab scale reactor and a mini-pilot scale reactor. In the purpose-built, mini-pilot scale reactor with stacked catalyst structures, methane productivity of 256 mmol g(Ni)(-1) h(-1) was achieved, which was 3 times higher than that in the lab-scale reactor. The structured catalyst showed high stability for 80 h time-on-stream. The optimal reaction conditions - temperature, pressure and flow rate - were investigated and implemented. Fresh and spent catalysts were characterized by N-2 adsorption, XPS, TPR, SEM and TGA.