Catalytic cracking process of petroleum hydrocarbons

9 The process according to claim 1, wherein said tube-in-tube riser reactor is one having single conduit for feeding catalyst, which comprises mainly the following members:

• catalyst inlet conduit (1), inner tube (2), outer tube (3), confluence tube (4), pre-lifting distribution rings (5), (6) and (7) and feed nozzles (8) and (9);
• wherein inner tube (2) and outer tube (3) are coaxial, and the ratio of the cross-section area of the inner tube to the cross-section area of the annular space between the inner and outer tubes is 1:0.1-10;
• the lower end of the inner tube (2) is located at a place above the catalyst inlet, the inner tube has a length amounting to 10-70% of the total length of the reactor, one end of the confluence tube (4) is connected with the upper end of the outer tube (3), and the other end is connected with a gas/solid separation apparatus, the cross-section area ratio of the confluence tube (4) to the inner tube (2) is 1:0.2-0.8;
• the pre-lifting distribution rings (5), (6) and (7) are respectively located at the bottoms of the reactor, the inner tube and the outer tube.

21 A catalytic cracking process of petroleum hydrocarbons, comprising mainly the following steps:

• (1) sending a regenerated catalyst to the bottom of the tube-in-tube riser reactor via a catalyst conduit, which flows upwards under an action of a pre-lifting media, 20-80% by weight of the regenerated catalyst flowing into the inner tube, and the remaining part of the regenerated catalyst entering the annular space between the inner and outer tubes, which flows upward under an action of the pre-lifting media;
• (2) feeding a hydrocarbon feedstock to the inner tube of the reactor to contact the catalyst therein and form a oil-catalyst mixture, so that the reaction of the hydrocarbon feedstock is carried out under catalytic cracking reaction conditions to form a reaction stream which flows upward along vessel wall;
• (3) the reaction stream from the inner tube and the regenerated catalyst (stream) from the annular space flow together in the confluence tube, and making the reaction stream react continuously under catalytic cracking conditions;
• introducing the resulting reaction stream to a separation apparatus via the confluence tube, where a hydrocarbon product stream is separated from a spent catalyst;
• (4) separating the hydrocarbon product stream further into various products including gasoline, diesel oil and liquefied petroleum gas;
• stripping and regenerating the spent catalyst, and recycling the regenerated catalyst into the reactor for reuse.

The process according to claim 21, wherein said tube-in-tube riser reactor is one having single conduit for feeding catalyst and comprises mainly the following members:

• catalyst inlet conduit (1), inner tube (2), outer tube (3), confluence tube (4), pre-lifting distribution rings (5), (6) and (7), and feed nozzles (8) and (9), wherein, the inner tube (2) and the outer tube (3) are coaxial, and the ratio of the cross-section area of the inner tube to the cross-section area of the annular space between the inner and outer tubes is in the range 1:0.1-10;
• the lower end of the inner tube (2) is located at a place above the catalyst inlet;
• the inner tube has a length amounting to 10-70% of the total length of the reactor;
• one end of the confluence tube (4) is connected with the upper end of the outer tube (3), and the other end is connected to the gas/solid separation apparatus, the cross-section area ratio of the confluence tube (4) to the inner tube (2) is 1:0.2-0.8;
• the pre-lifting distribution rings (5), (6) and (7) are located at the bottoms of the reactor, the inner tube and the outer tube respectively.

The process according to claim 21, wherein said tube-in-tube riser reactor is one having two conduits for feeding catalyst and comprises mainly the following members:

• catalyst inlet conduits (21) and (22), inner tube (35), outer tube (36), confluence tube (38), pre-lifting distribution rings (31) and (33), and feed nozzles (32) and (34), wherein, the inner tube (35) and outer tube (36) are coaxial, the ratio of the cross-section area of the inner tube to the cross-section area of the annular space between the inner and outer tubes is 1:0.1-10;
• the catalyst inlet conduit (21) is connected with the lower end of the inner tube (35), the length of the inner tube is 10-70% of the total length of the reactor;
• the distance from the lower end of the outer tube (36) to the lower end of the inner tube (35) is 2-20% of the total length of the reactor, the catalyst inlet conduit (22) is connected with the lower end of the outer tube (36);
• one end of the confluence tube (38) is connected with the upper end of the outer tube (36), and the other end is connected with a gas/solid separation apparatus, the cross-section area ratio of the confluence tube (38) to the inner tube (35) is 1:0.2-0.8;
• the pre-lifting distribution rings (31) and (33) are located at the bottom of the inner tube and the bottom of the annular space between the inner and outer tubes respectively;
• feed nozzles (32) and (34) are located at the lower part of the inner tube and the lower part of the outer tube respectively.