Continuous synthesis by spray drying of highly stable mesoporous silica and silica–alumina catalysts using industrial raw materials

Nanostructured but amorphous mesoporous materials, such as MCM-41 and SBA-15, suffer from relatively weak hydrothermal stability, when compared to crystalline zeolites. This hinders their industrial application as a component to new generations of catalysts for fluidized catalytic cracking (FCC) of large molecules and other processes that require considerable stability in the presence of steam, but also a pore size larger than that of zeolites. Here, a method is introduced to synthesize mesoporous silica and silica–alumina that possess extraordinary steam stability when exposed to extremely adverse conditions, namely 100% steam at 788 oC for 20 h, which closely represent conditions in an industrial fluidized catalytic cracking (FCC) unit. These materials were prepared using industrial raw materials, as well as a non-ionic surfactant (P123) to control the porosity and the pore size. The method offers exciting opportunities for further industrial development as part of mesoporous zeolite composites; scalable quantities could be made using a continuous, industrial laboratory spray drier. Furthermore, the steamed samples showed good potential when their performance was tested in pulse cracking experiments using tri(iso-propyl)benzene (TiPB) and linear alkane (C12H26 and C14H30) probe molecules.