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Example 3
The test was conducted in accordance with the process flow shown in
The fraction comprising C4 olefin was fed to an oligomerization reactor for oligomerization, and the fraction comprising C12 olefin (with a C12 olefin content of 85.3 wt %) separated by a rectifying column was recycled to the riser reactor. The C12 olefin recycled to the riser reactor for further cracking accounted for 14.17 wt % of the total catalytic conversion feedstock. The operating conditions and product distribution are listed in Table 5.
The operation was substantially the same as in Example 3, except that the catalytic conversion product was split according to distillation range in the product separation device to obtain dry gas, liquefied gas, propylene, gasoline, diesel oil and slurry oil, and the recycling of the catalytic conversion product was not performed. The operating conditions and product distribution are listed in Table 5.
Example 2
The test was conducted using Feedstock oil B as the feedstock for catalytic conversion, on a composite reactor as shown in
The fraction comprising C4 olefin was fed to an oligomerization reactor for oligomerization, and the fraction comprising C12 olefin (with a C12 olefin content of 85.1 wt %) separated by a rectifying column was recycled to the dense phase bed unit. The C12 olefin introduced into the dense phase bed unit for further cracking accounted for 15.5 wt % of the total catalytic conversion feedstock. The operating conditions and product distribution are listed in Table 4.
The operation was substantially the same as in Example 2, except that the catalytic conversion product was separated and split to obtain dry gas, liquefied gas, propylene, gasoline, diesel oil and slurry oil, and the recycling of the catalytic conversion product was not performed. The operating conditions and product distribution are listed in Table 4.
Example 1
This example was conducted in accordance with the process flow shown in
The fraction comprising C4 olefin was fed to an oligomerization reactor for oligomerization, and the fraction comprising C12 olefin (with a C12 olefin content of 85.2 wt %) separated by a rectifying column was recycled to the second reaction zone 8; the light cycle oil fraction having a distillation range of 200-260° C. was recycled to the first reaction zone 9 for reuse, the FGO fraction having a distillation range >260° C. was subjected to a hydrotreatment under conditions including a hydrogen partial pressure of 18.0 MPa, a reaction temperature of 350° C., a hydrogen-to-oil volume ratio of 1500 and a volume space velocity of 1.5 h−1, and the hydrogenation product was recycled to the first reaction zone 9 for catalytic conversion reaction. The C12 olefin introduced in the second reaction zone 8 accounted for 18.9 wt % of the total catalytic conversion feedstock. The operating conditions and product distribution are listed in Table 3.
The operation was substantially the same as in Example 1, except that a conventional catalytic cracking catalyst D was used and the product was split as required in the conventional catalytic cracking process to obtain dry gas, liquefied gas, propylene, gasoline, diesel oil and slurry oil, and no recycle of the catalytic conversion product was carried out. The operating conditions and product distribution are listed in Table 3.
The operation was substantially the same as in Example 1, except that the separated C4 olefin-containing fraction (with a C4 olefin content of 85.7%) was fed to the oligomerization reactor for oligomerization, and the C8 olefin-containing fraction (with a C8 olefin content of 84.9 wt %) separated by the rectifying column was recycled to the second reaction zone, and the C8 olefin accounted for 18.8 wt % of the total catalytic conversion feedstock. The operating conditions and product distribution are listed in Table 3.
Example 4
The test was conducted using Feedstock oil C as a feedstock for catalytic conversion on a system of double riser reactors as shown in
The fraction comprising C4 olefin was fed to an oligomerization reactor 44 for oligomerization in accordance with the process flow shown in
As can be seen from a comparison of the results of the above examples and comparative examples, the process and system of the present application provides a higher propylene yield by oligomerizing C4 olefin to C12 olefin and recycling the resulting C12 olefin. In addition, the results in Table 3 also show that the catalytic conversion reaction of Example 1 can provide a lower alkane yield and a higher propylene yield by itself, as compared to Comparative Example 1, and the propylene yield can be further greatly increased by the oligomerization of C4 olefin and the recycle of C12 olefin.
The present application is illustrated in detail hereinabove with reference to preferred embodiments, but is not intended to be limited to those embodiments. Various modifications may be made following the inventive concept of the present application, and these modifications shall be within the scope of the present application.
It should be noted that the various technical features described in the above embodiments may be combined in any suitable manner without contradiction, and in order to avoid unnecessary repetition, various possible combinations are not described in the present application, but such combinations shall also be within the scope of the present application.
In addition, the various embodiments of the present application can be arbitrarily combined as long as the combination does not depart from the spirit of the present application, and such combined embodiments should be considered as the disclosure of the present application.
Example 2
Example 2 was conducted at a pilot plant having the first reactor configuration and characteristics of steam catalytic cracking reactor 180 illustrated in
The hydrocarbon feed comprised 20 wt. % naphtha preheated to from 93° C. to 205° C. and 80 wt. % vacuum gas oil heated to from 370° C. to 590° C. was passed to a fixed bed steam catalytic cracking reactor. The hydrocarbon feed was preheated and the preheated feed at 70° C. was introduced to the reactor at space velocity of 0.5 hourly (h−1) and steam was injected at space velocity of 1 hourly (h−1). The steam to oil volume ratio was 2 to 1. The steam catalytic cracking was carried out in the steam catalytic cracking reactor loaded with nano ZSM-5 zeolite bounded with 40 wt. % alumina binder. The catalyst was loaded into the steam catalytic cracking reactor forming a cylindrical catalyst bed arranged with a height of 4 units and diameter of 2 units. The catalyst loading height to diameter ratio was 2 to 1, for a ratio of height HC to inside diameter ID of 2. The inert carrier pre-heating zone of the steam catalytic cracking reactor was loaded with silica carbide. The inert carrier pre-heating loaded volume to catalyst loaded volume ratio was 2 to 1. The catalyst bed zone and the inert carrier pre-heating zone were operated at 575° C.
As shown in Table 4, the steam catalytic cracking process operated in the propylene-selective mode achieved high conversion. High yield of olefins 49 wt. % with a yield ratio of propylene/ethylene of 1.87 was obtained.