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US 3,965,206 AGranted
Production of stilbene and styrene
AssigneeMonsanto Company
InventorsPhillip D. Montgomery, Richard N. Moore, Walter R. Knox
Life of this patent
Estimating the term…
Abstract
Toluene and toluene derivatives are dehydrocoupled to stilbene and stilbene derivatives in a vapor phase reaction in the presence of a metal oxide. The stilbene products are purified of by-product polar impurities. The purified stilbene can be catalytically reacted in the vapor phase with ethylene to produce styrene.
Claims23
A process for producing stilbene and stilbene derivatives free of polar impurities from toluene and toluene derivatives as the starting hydrocarbon which comprises:
- a. effecting dehydrocoupling of toluene and toluene derivatives in the vapor phase in the presence of a solid metal oxide selected from the group consisting of the oxides of lead, cadmium and bismuth and mixtures thereof at a temperature in the range of from about 500.degree.C to about 650.degree.C,
- b. separating the dehydrocoupling effluent by distillation to provide a stilbene fraction,
- c. treating said stilbene fraction to remove polar impurities by either (1) passing it through a bed of an absorbent material capable of adsorbing polar impurities at a temperature in the range of from 75.degree. to 200.degree.C and at such a rate to provide a contact time of the stilbene and absorbent material of from 0.1 second to 15 minutes, or (2) intimately contacting it with a chemical treating agent selected from the group consisting of alkali metals, alkyl aluminums, aluminum alkoxides, Grignard reagents, metal hydrides, phenyllithium and disodium stilbene, or (3) distilling it to remove all compounds boiling below 128.degree.C, and cooling the distillation residue to effect crystallization;
- and
- d. recovering said stilbene fraction substantially free of polar impurities.
2 more elements
The process of producing styrene from toluene as the starting hydrocarbon which comprises:
- a. effecting dehydrocoupling of toluene in the vapor phase in the presence of PbO at a temperature in the range of 500.degree. to 650.degree.C,
- b. separating the dehydrocoupling effluent by distillation to provide a liquid stilbene fraction,
- c. treating said stilbene fraction to remove polar impurities therefrom by either (1) passing it through a bed of an adsorbent material capable of adsorbing polar impurities at a temperature in the range of from 75.degree. to 200.degree.C and at such a rate to provide a contact time of the stilbene and adsorbent material of from 0.1 second to 15 minutes, or (2) intimately contacting it with a chemical treating agent selected from the group consisting of alkali metals, alkyl aluminums, aluminum alkoxides, Grignard reagents, metal hydrides, phenyllithium and disodium stilbene, or (3) distilling it to remove all compounds boiling below 128.degree.C, and cooling the distillation residue to effect crystallization;
- d. recovering said stilbene fraction substantially free of polar impurities,
- e. effecting reaction of said recovered stilbene fraction in the vapor phase with ethylene in the presence of a disproportionation catalyst at a temperature in the range from 350.degree. to 500.degree.C, and
- f. separating and recovering styrene from the catalytic reaction.
3 more elements
Dependencies are inferred from the claim text.