Advances in the Conversion of Methanol to Light Olefins (MTO)

The global market of light olefins is expected to increase annually by 6.2% from 2022 to 2030, derived by the huge demands of the end-use industries. However, the process of light olefin production is well known through different industrial processes such as steam cracking, fluid catalytic cracking, catalytic dehydrogenation, and olefin metathesis. These processes have several disadvantages such as the huge consumption of energy, environmental impact, and variety of the products. Therefore, the methanol-to-olefins process emerged as a superior alternative, offering advantages over other processes. The MTO process is a selective process with efficient energy and has less environmental impact. Furthermore, methanol has multiple production routes that can be derived from different processes such as fossil fuels, biomass, pyrolysis, and wastes, which make the MTO process an important process for sustainable light olefins production. The MTO process requires zeolite-based catalysts, which can be synthesized in the labs or by modifying the naturally available zeolites. However, the physiochemical properties of zeolite and metal-based zeolites can be modified based on the targeted reaction conditions, type of reactor, and the required product distribution. Tuning the silica-to-aluminum ratio is one of the main factors to vary the catalytic selectivity of all products, especially propylene and ethylene. Likewise, the pore opening size has a great effect on the nature of product distribution. Other parameters such as large and medium scale pores such as BEA and MFI zeolites can be used for the selective process of aromatics production besides light olefins. The target of end-user industries determines the type and nature of zeolite that could be used in the process.