A review of the evaluation of mesoporous ZSM-۵ catalyst application in themethanol to propylene process

Propylene is a highly adaptable material and can be considered a feedstock for a wide range of monomers,polymers, and intermediate and chemical products. The most important derivatives of propylene arepolypropylene, acrylonitrile, propylene oxide, phenol, exo alcohol, acrylic acid, and isopropyl alcohol. Most ofthese products are used in the automotive, construction, packaging, and electronics industries. Due to theincreasing demand for propylene and the reduction of crude oil reserves, new processes are needed to producehigh-performance propylene. The methanol to propylene process (MTP) is considered a promising alternativeroute for the production of high-performance propylene, as methanol can be produced using proven natural gasand coal technology on an industrial scale. Zeolite Socony Mobile-۵ (ZSM-۵) high silica zeolite is one of themost promising MTP catalysts due to its Mobile-Five (MFI) topology. However, due to the presence of uniformmicro-pores in its structure, it is still affected by severe coking, which leads to the deactivation of the catalyst.One way to solve this problem is to use a mesoporous ZSM-۵ catalyst. This type of catalyst has better masstransfer properties, which makes it more resistant to high coking and extends the life of the catalyst. Differentways to make mesopores in the structure of microporous zeolites, which is called "hierarchical zeolite synthesis,"have been suggested. These include the use of mesogenous templates in addition to the initial zeolite template,the use of a multi-functional template that makes micropores and mesopores in the structure of zeolite at the sametime, changes in synthesis methods without the use of a secondary template, and defects in the crystal lattice ofmicroporous zeolite by leaching reactions.

Keywords:

Mesoporous catalyst , methanol to propylene , ZSM-۵ , MFI structure