Process for manufacturing olefins
AssigneeMobil Oil Corporation
InventorsClarence D. Chang, William H. Lang
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Abstract
A lower alcohol and/or ether feed is selectively converted to a mixture of light olefins, including ethylene and propylene, by catalytic contact of the feed, for example methanol or dimethyl ether, at subatmospheric partial pressure, with certain crystalline aluminosilicate zeolite catalysts exemplified by HZSM-5.
Claims19
In a method for converting a feed to light olefins, said feed comprising one or more compounds selected from the group consisting of the lower monohydric alcohols with up to four carbon atoms and their simple and mixed ether derivatives, said method comprising:
- passing said feed at a space velocity of about 1.0 to about 50 L.H.S.V. over a catalyst contained in a reaction zone, said catalyst comprising a crystalline aluminosilicate zeolite having a constraint index of 1.0 to 12.0, a silica to alumina ratio of at least about 12 and a dried crystal density in the hydrogen form of not substantially less than about 1.6 grams per cubic centimeter, with the temperature in said reaction zone at about 500.degree. F. to about 1000.degree. F.;
- withdrawing from said reaction zone an effluent comprising a conjunct mixture of light olefins, paraffin hydrocarbons and aromatic hydrocarbons;
- and segregating said light olefins from said effluent;
- the improvement, whereby increasing the selectivity for said light olefins, which comprises:
- passing said feed over said catalyst at subatmospheric inlet partial pressure of said feed, referred to alcohols, of about 0.1 p.s.i.a. to about 12 p.s.i.a.
In a method for converting methanol to light olefins comprising ethylene, propylene and butenes, said method comprising:
- passing said methanol at a space velocity of about 1.0 to about 50 L.H.S.V. over a catalyst contained in a reaction zone, said catalyst comprising a crystalline aluminosilicate zeolite having a constraint index of 1.0 to 12.0, a silica to alumina ratio of at least about 12 and a dried crystal density in the hydrogen form of not substantially less than about 1.6 grams per cubic centimeter, with the temperature in said reaction zone at about 500.degree. F. to about 1000.degree. F.;
- withdrawing from said reaction zone an effluent comprising said light olefins mixed with paraffin hydrocarbons and aromatic hydrocarbons;
- and segregating said light olefins from said effluent;
- the improvement, whereby increasing the selectivity for said light olefins, which comprises:
- passing said methanol over said catalyst at subatmospheric inlet partial pressure of methanol of about 0.1 p.s.i.a. to about 12 p.s.i.a.
Dependencies are inferred from the claim text.