Methanol-to-olefin

Methanol to light alkenes in favor of methanol to aromahcs is another example of a reaction that is governed by product shape selechvity effects [13]. While aromatics are formed within the cavities of CHA and ERI framework types, as the reaction mechanism would require, aromatics would be trapped within the 8-MR charmel systems. With medium-pore size MFl aromatics are indeed observed as products, but the carbon number is limited to 10 (durene). Bulkier aromatics are observed with MOR and BEA. 

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Fig. 9. Methanol-to-olefins (MTO) and Mobil olefins-to-gasohne (MOGD) and distillate process schematic.

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. 

T. Inui, "Stmcture-Reactivity Relationship in Methanol to Olefin Conversion on Various Microporous Crystalline Catalysts," paper presented at... 

MTO [Methanol to olefins] A catalytic process for converting methanol to olefins, mainly propylenes and butenes. Developed by Mobil Research Development Corporation and first demonstrated in 1985. Another version of this process was developed by UOP and Norsk Hydro and has been ran at a demonstration unit at Porsgrunn, Norway, since June 1995. It is based on fluidized bed technology using a SAPO molecular sieve catalyst. It converts 80 percent of the carbon in the feed to ethylene and propylene. 

L.o 18-21 The conversion of methanol to olefins is an intermediate step in the conversion of methanol to... 

Barger, P. Methanol to Olefins (MTO) and Beyond. Catalytic Science Series, 2002, 3(Zeo-lites for Cleaner Technologies), 239-260. 

Most of the commercial zeolite catalyzed processes occur either through acid catalysis fluid catalytic cracking (FCC), aromatic alkylation, methanol to olefins (MTO),... 

Most of the catalytic interest in the AlP04-based molecular sieves have centered on the SAPOs which have weak to moderate Bronsted acidity, and two have been commerciahzed SAPO-11 in lube oil dewaxing by Ghevron and SAPO-34 in methanol-to-olefins conversion by UOP/Norsk Hydro. Spurred on by the success of TS-1 in oxidation catalysis, there is renewed interest in Ti, Co, V, Mn and Cr substituted AlP04-based materials, for a review of recent developments in the AlP04-based molecular sieves see [35]. 

M., Mukai, S.R., Kawase, M., and Hashimoto, K. (2003) Methanol to olefins using ZSM-5 zeolite catalyst membrane reactor. Chem. Eng. Sci.,... 

S. B., and Seo, G. (2008) Effects of cage shape and size of 8-membered ring molecular sieves on their deactivation in methanol-to-olefin (MTO) reactions. Appl. Catal. A, 339, 36-44. 

Marcus, D.M., McLachlan, K.A., Wildman, M.A., Ehresmann, P.W., and Haw, ).F. (2006) Experimental evidence from H/D exchange smdies for the failure of direct C-C coupling mechanisms in the methanol-to-olefin process catalyzed by HSAPO-34. Angew. Chem. Int. Ed., 45, 3133-3136. 

J.F. (2004) Theoretical smdy of the methylbenzane side-chain hydrocarbon pool mechanism in methanol to olefin catalysis. /. Am. Chem. Soc., 126, 2991-3001. 

Methylbenzene chemistry on zeolite h-beta multiple insights into methanol-to-olefin catalysis. /. Phys. Chem. B, 106, 2294-2303. 

HSAPO-34 during methanol-to-olefin catalysis ex situ characterization after cryogenic grinding. Catal. Lett., 76, 89-94. 

Haw, J.F. and Marcus, D. (2005) Well-defined (supra) molecular structures in zeolite methanol-to-olefin catalysis. Top. Catal, 34, 41 8. 

J. F., Nicholas, J.B., Heneghan, C., Methybenzenes Are the Organic Reaction Centers for Methanol-to-Olefin Catalysis on HSAPO-34, p. 10725-10727, Copyright 2000 American Chemical Society... 

Methanol to Olefins and Aromatics 525 Table 15.2 Comparison of SAPO-34 and SSZ-13 (chabazite) catalysts for MTO. 

Chen and co-workers have studied the role of coke deposition in the conversion of methanol to olefins over SAPO-34 [111]. They found that the coke formed from oxygenates promoted olefin formation while the coke formed from olefins had only a deactivating effect The yield of olefins during the MTO reaction was found to go through a maximum as a function of both time and amount of coke. Coke was found to reduce the DME dilfusivity, which enhances the formation of olefins, particularly ethylene. The ethylene to propylene ratio increased with intracrystal-line coke content, regardless of the nature of the coke. 

Lewis, J.M.O. (1988) Methanol to olefins process using silicoalumino-phosphate molecular sieve catalysts, in Catalysis 1987 (ed. J.W. Ward), Elsevier, Amsterdam, p. 199. 

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