Claims
- 1. A process for the conversion of petroleum hydrocarbon in the presence of catalyst particles in a fluidized phase in an essentially upflow or downflow tubular reaction zone, said process comprising the steps of:
- steam crackling of at least one fraction of light hydrocarbons, said light hydrocarbons including in excess of 10 mol % C.sub.3 and heavier hydrocarbons up to middle distillates calculated on a water-free basis, in a first upstream portion of said reaction zone; said steam cracking being carried out by contacting the light hydrocarbons and a quantity of steam equal to at least 20 percent by weight of the quantity of said light hydrocarbons in a fluidized bed of the catalyst particles; the temperature resulting from such contacting ranging from 650.degree. to 850.degree. C.;
- atomizing and injecting a heavy feedstock of at least one fraction of heavy hydrocarbons in a second portion of the reaction zone into the effluents from the first, upstream steam-cracking portion of said reaction zone, which effluents include the fluidized catalyst particles, in such a way that the temperature of the resulting mixture ranges from 560.degree. to 650.degree. C. and wherein said temperature on contact is sufficient to vaporized the heavy feedstock;
- immediately downstream of the injection and vaporization of said heavy feedstock in the second portion of the reaction zone, atomizing and injection into a third portion of the reaction zone a hydrocarbon fraction that is completely vaporizable under conditions existing at the exit of the reaction zone so as rapidly to reduce the mixture temperature to a more effective catalytic cracking temperature ranging from 475.degree. to 550.degree. C. in the resulting downstream portion of said reaction zone;
- thereafter, catalytically cracking at least said vaporized heavy hydrocarbons in said third, downstream portion of said reaction zone;
- ballistically separating spent catalyst particles emanating from said third, downstream catalytic cracking portion of said reaction zone;
- regenerating separated catalyst particles in at least one zone for combustion of the coke deposited on such particles; and
- recycling of the regenerated particles to the intake of the first, upstream cracking portion of said reaction zone.
- 2. The process of claim 1 wherein olefins including ethylene and propylene are obtained from the hydrocarbon-containing effluent;
- and the process further comprises subjecting the ethylene thus obtained to oligomerization to obtain an oligomerization product, and recycling the oligomerization product into the light hydrocarbons of the steam cracking step, so that the oligomerization product is selectively cracked into propylene, thereby enhancing the propylene yield of the process.
- 3. A process for the conversion of petroleum hydrocarbon in the presence of catalyst particles in a fluidized phase in an essentially upflow or downflow tubular reaction zone, said process comprising the steps of:
- steam cracking of at least one fraction of light hydrocarbons, in a first upstream portion of said reaction zone; said steam cracking being carried out by contacting the light hydrocarbons and a quantity of steam equal to at least 20 percent by weight of the quantity of said light hydrocarbons in a fluidized bed of the catalyst particles; the temperature resulting from such contacting ranging from 650.degree. to 850.degree. C.;
- atomizing and injecting a heavy feedstock of at least one fraction of heavy hydrocarbons in a second portion of the reaction zone into the effluents from the first, upstream steam-cracking portion of said reaction zone, which effluents include the fluidized catalyst particles, in such a way that the temperature of the resulting mixture ranges from 560.degree. to 650.degree. C. and wherein said temperature on contact is sufficient to vaporize the heavy feedstock;
- immediately downstream of the injection and vaporization of said heavy feedstock in the second portion of the reaction zone, atomizing and injection into a third portion of the reaction zone a hydrocarbon fraction that is completely vaporizable under conditions existing at the exit of the reaction zone so as rapidly to reduce the mixture temperature to a more effective catalytic cracking temperature ranging from 475.degree. to 550.degree. C. in the resulting downstream portion of said reaction zone;
- thereafter, catalytically cracking at least said vaporized heavy hydrocarbons in said third, downstream portion of said reaction zone;
- ballistically separating spent catalyst particles emanating from said third, downstream catalytic cracking portion of said reaction zone;
- regenerating separated catalyst particles in at least one zone for combustion of the coke deposited on such particles; and
- recycling of the regenerated particles to the intake of the first, upstream cracking portion of said reaction zone.
- 4. The process of claim 1 wherein the light feedstock contains up to about 50 mol % C.sub.3 and heavier hydrocarbons up to middle distillates.
Priority Claims (1)
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Date |
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87 18375 |
Dec 1987 |
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Parent Case Info
This application is a division of application Ser. No. 07/814,249, filed Dec. 23, 1991, U.S. Pat. No. 5,264,115, which is a continuation of application Ser. No. 07/542,803, filed Jun. 22, 1990, now abandoned, which in turn is a continuation of application Ser. No. 07/292,478, filed Dec. 30, 1988, now abandoned.
US Referenced Citations (18)
Foreign Referenced Citations (5)
Number |
Date |
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0012685 |
Jun 1980 |
EPX |
024971 |
Mar 1981 |
EPX |
0171460 |
Feb 1986 |
EPX |
0184517 |
Jun 1986 |
EPX |
0208609 |
Jan 1987 |
EPX |
Non-Patent Literature Citations (2)
Entry |
Wuither, Le Petrole-Raffinage et Genie, pp. 693-694 (including Table III-5.1) and pp. 697-699 (1965). |
TSCA definition of Middle Distillates (1979, 1983, 1986, 1988). |
Divisions (1)
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Date |
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814249 |
Dec 1991 |
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Continuations (2)
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542803 |
Jun 1990 |
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Parent |
292478 |
Dec 1988 |
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