Fabrication of Microspheres by Nano-TS-1 Crystals via a Spray-Forming Process: From Screening to Scale-up.

The spray-forming process of the nano-titanium silicalite (TS-1) zeolite was investigated and optimized in the lab in order to obtain materials with microsphere morphology and superior catalytic activity in cyclohexanone ammoximation on the industrial scale. The effects of spray-forming parameters, such as the state of the TS-1 raw material, load ratio, solid content, binder content, and calcination temperature, on the physicochemical and catalytic properties of TS-1 microspheres were investigated in detail. It was interesting to find that the shape of the spray-forming sample formed by wet powders was more intact than the sample formed by dried powders. Furthermore, the spray-forming process was successfully scaled up to a large spray device (LGZ-1000) according to the similarity principle of load ratio, and the shape of the TS-1 microspheres was as perfect as the spray-forming samples in the lab. The similarity principle of the load ratio for the spray-forming of titanium silicate was established and verified for the first time. The spray-forming TS-1 microspheres produced in the industry were used in cyclohexanone ammoximation, and ketone conversion and oxime selectivity were as high as 99.9 and 99.4%, respectively.