Methanol to Olefin MTO Process

The UOP/HYDRO MTO process converts methanol to light olefins. The process provides greater selectivity to ethylene and propylene versus C4+ byproducts. 

The ethylene and propylene are produced from a dimethylether (DME) intermediate in the MTO process. Some by-products such as butenes and other higher olefins are also produced. The MTO reaction is exothermic. The coke deposited on the catalyst can be removed by combustion with air in a catalyst regenerator system in order to prolong the active life of the catalyst. 

The UOP/Hydro MTO process utilizes the highly selective metalloaluminophosphate molecular sieve catalyst MTO-100, which is based on SAPO-34. The main olefin products are ethylene and propylene, but the catalyst is rapidly deactivated by aromatic coking. An alternative MTO catalyst is the medium-pore zeolite ZSM-5. In this case the main olefin product is propylene, and the deactivation of catalyst caused by aromatic coke is slow, but significant quantities of Cs+Zaromatic by-products are formed. 

In the UOP/Hydro MTO process unit, the methanol and recycled DME come into contact with the catalyst in the reactor and are converted into light olefins. Residence times are very short and the reactor operates in a stable steady-state in the vapor phase at temperatures between 350 and 600 °C, and pressures between 0.1 and 0.3 MPa. In the process, the catalyst is deactivated by coke accumulation, and a part of catalyst is transferred to the fluidized bed regenerator in order to restore its activity. 

Oxygenates in the reactor effluent are recovered and recycled. Pol5mier grade ethylene and propylene can be produeed from the reactor effluent by a series of purification steps. The results from an MTO demonstration plant show that the conversion of methanol is 100 %, selectivity to ethylene is above 40 %, and selectivity to propylene is close to 40 %. 

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A variation of this process is Mobil s methanol-to-olefins (MTO) process, in which up to 80% C2—olefins are produced over ZSM-5 of reduced acidity and at much higher temperatures. 

UOP/HYDRO Olefins Methanol Methanol to olefins (MTO) process uses fluidized-bed reactor and efficient product recovery system NA NA... 

Because the market for olefins currently greatly exceeds that for methanol production, olefin production could become an important new outlet for the potentially vast quantities of low-cost methanol. Methanol conversion produces a mixture of ethylene and propylene of various ratios or primarily propylene depending on the process. Currently, there are two processes for the production of propylene from methanol the first process is methanol to olefin (MTO) process, developed by UOP and Hydro,... 

Principal Characteristics. - Molecular sieves with pore openings of about 0.45 nm show very interesting shape-selectivity properties for the conversion of methanol to olefins (MTO process). The small-pore molecular sieves studied in the MTO process are chabazite, erionite, zeolite T, ZK-5, ZSM-34, zeolite A, SAPO-17, SAPO-34, and SAPO-44. All of them can sorb only straight chain molecules, e.g. primary alcohols and linear paraffins and olefins, but no branched isomers and aromatics the pore opening is smaller than the kinetic diameter of branched and aromatic molecules, but large enough to permit the access of linear molecules. 

Application The UOP/HYDRO Methanol-to-Olefins (MTO) Process produces ethylene and propylene from methanol derived from raw materials such as natural gas, coal, petroleum coke or biomass. 

In the context of the zeolite-catalyzed reactions of methanol-to-gasoline (MTG process) and methanol-to-olefins (MTO process), the activation of CH3OH on acid zeolite surfaces was particularly interesting. It was, for instance, studied in detail through the picosecond infrared technique (cf., e.g., [821]). 

Zhang K, Cheng Y, Li X Simulation of fluidized bed reactor form methanol to olefins (MTO) process, J Chem Eng Chin Univ 26 69—76, 2012. 

Wang W, Jiang Y, Hunger M. Mechanistic investigations of the methanol-to-olefin (MTO) process on acidic zeolite catalysts by in situ solid-state NMR spectroscopy. Catal Today 2006 113 102-14. 

The Mobil methanol-to-olefins (MTO) process may seem to be an abridged version of the MTG process, but the distribution of olefins is governed not only by the process conditions, but largely by the architecture of the zeolite, with ZSM-5 being the best option for the modification. In this case, smaller-pore zeolites (ZSM-34, SAPO-34) show excellent results so far as the olefins formed should not be transformed into gasoline. The latter zeolite-like material developed and commercialized by UOP jointly with Norsk Hydro provides the selectivities to ethylene and propylene above 85% at the 100% methanol conversion [113]. 

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