Claims
- 1. In a process of dehydrogenating para-ethyltoluene to selectively form para-methylstyrene comprising contacting the para-ethyltoluene under dehydrogenation reaction conditions with a catalyst composition comprising:
- (a) from about 30% to 60% by weight of iron oxide, calculated as ferric oxide;
- (b) from about 13% to 48% by weight of a potassium compound, calculated as potassium oxide; and
- (c) from about 0% to 5% by weight of a chromium compound, calculated as chromic oxide,
- the improvement comprising dehydrogenating the para-ethyltoluene with a catalyst composition comprising, in addition to the components (a), (b) and (c), a modifying component (d) capable of rendering the para-methylstyrene-containing dehydrogenation reaction effluent especially resistant to the subsequent formation of popcorn polymers when the dehydrogenation of para-ethyltoluene is conducted over the modified catalyst, the modifying component (d) being a bismuth compound present to the extent of from about 1% to 20% by weight of the catalyst composition, calculated as bismuth trioxide.
- 2. A process in accordance with claim 1 wherein said dehydrogenation conditions include a temperature of from about 500.degree. C. to 700.degree. C., and a liquid hourly space velocity of para-ethyltoluene of from about 0.3 to 3.
- 3. A process in accordance with claim 2 wherein
- (a) the iron oxide comprises from about 35% to 55% by weight of the catalyst composition;
- (b) the potassium compound comprises from about 27% to 41% by weight of the catalyst composition;
- (c) the chromium compound comprises from about 1% to 4% by weight of the catalyst composition; and
- (d) the bismuth compound comprises from about 2% to 15% by weight of the catalyst composition.
- 4. A process in accordance with claim 3 wherein para-ethyltoluene is contacted with the catalyst in the presence of steam and wherein the weight ratio of steam to para-ethyltoluene ranges from about 1:1 to 5:1.
- 5. A process in accordance with claim 4 wherein the catalyst composition is substantially free of clay material.
- 6. A process in accordance with claim 5 wherein the catalyst composition additionally comprises up to about 20% by weight of a binder/filler component selected from the group consisting of Portland cement, calcium aluminate, sawdust, carbon, wood flour, graphite, methylcellulose and mixtures thereof.
CROSS-REFERENCE TO RELATED APPLICATION
This is a divisional application of application Ser. No. 449,908, filed on Dec. 15, 1982, now U.S. Pat. No. 4,504,594.
US Referenced Citations (6)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0693822 |
Sep 1964 |
CAX |
1143510 |
Mar 1960 |
DEX |
WO8300687 |
Mar 1983 |
WOX |
0925792 |
May 1963 |
GBX |
Divisions (1)
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Number |
Date |
Country |
Parent |
449908 |
Dec 1982 |
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