Claims
- 1. In a process for the dehydrogenation of 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% of a chromium compound, calculated as chromic oxide,
- the improvement comprising contacting the para-ethyltoluene with a catalyst composition additionally comprising a modifying component (d) being capable of enhancing the preferential formation of para-methylstyrene and 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) comprising about 1% to 15% by weight of the catalyst composition of a calcium compound, calculated as calcium oxide, and about 1% to 20% by weight of the catalyst composition of a bismuth compound, 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 for 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;
- d. the calcium compound comprises from about 2% to 10% by weight of the catalyst composition; and
- e. 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 said 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 said catalyst composition is substantially free of clay material.
- 6. A process in accordance with claim 2 wherein said catalyst composition additionally contains 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.
- 7. In a process for the dehydrogenation of ethylbenzene to selectively form styrene, comprising contacting the ethylbenzene 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 contacting the ethylbenzene with a catalyst composition additionally comprising a modifying component (d) comprising about 1% to 15% by weight of the catalyst composition of a calcium compound, calculated as calcium oxide, and about 1% to 20% by weight of the catalyst composition of a bismuth compound, calculated as bismuth trioxide.
- 8. A process in accordance with claim 7 wherein said dehydrogenation conditions include a temperature of from about 500.degree. C. to 700.degree. C., and a liquid hourly space velocity for ethylbenzene of from about 0.3 to 3.
- 9. A process in accordance with claim 8 wherein
- a. the iron oxide comprises from about 35% to 55% by weight of the composition;
- b. the potassium compound comprises from about 27% to 41% by weight of the composition;
- c. the chromium compound comprises from about 1% to 4% by weight of the composition;
- d. the calcium compound comprises from about 2% to 10% by weight of the composition; and
- e. the bismuth compound comprises from about 2% to 15% by weight of the composition.
- 10. A process in accordance with claim 9 wherein ethylbenzene is contacted with said catalyst in the presence of steam and wherein the weight ratio of steam to ethylbenzene ranges from about 1:1 to 5:1.
- 11. A process in accordance with claim 10 wherein said catalyst composition is substantially free of clay material.
- 12. A process in accordance with claim 9 wherein said catalyst composition additionally contains up to about 20% by weight of a binder/filler component selected from the group consisting of portland cememt, calcium aluminate, sawdust, carbon, wood flour, graphite, methylcellulose and mixtures thereof.
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a divisional application of application Ser. No. 449,911, filed Dec. 15, 1982.
US Referenced Citations (11)
Foreign Referenced Citations (3)
Number |
Date |
Country |
693822 |
Sep 1964 |
CAX |
8300687 |
Mar 1983 |
WOX |
925792 |
May 1963 |
GBX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
449911 |
Dec 1982 |
|