SU854267A3 - Method of catalytic cracking - Google Patents

Abstract

1387127 Chemical contact apparatus UNIVERSAL OIL PRODUCTS CO 2 May 1972 [3 May 1971] 20340/72 Heading B1F [Also in Division C5] A catalytic cracking in which both regenerated and unregenerated catalyst are recycled to the reactor riser (b) process comprises (a) cracking a feed stream (1) in contact with a mixture of regenerated catalyst and recycled used catalyst in a riser (6), (b) passing used catalyst, cracked products and any uncracked feed into a separation zone (8), (c) passing part of the used catalyst from the separation zone to a regeneration zone (9) where coke is removed from the catalyst, (d) passing regenerated catalyst from the regeneration zone to the riser (by line 18) to provide the regenerated catalyst for step (a), and (e) passing part of the used catalyst from the separation zone to the riser (by line 5) to provide the recycled used catalyst for a step (a), without mixing of the two catalyst streams outside the riser. As shown, the separation zone 8 includes a fluidized dense bed 16 in which further cracking takes place; both catalyst streams are stripped by gases from lines 19 and 20; and cracked products and spent regeneration gases are taken off by lines 10 and 11 through cyclone separators 12 and 13. Suitable catalysts are zirconia, silica, silica-alumina and zeolite.

Description

one

The invention relates to methods for the catalytic cracking of hydrocarbon feedstocks and can be used in a catalytic hydrogenation process for the production of fuel gases. .

The known method of catalytic cracking by contacting the hydrocarbon feedstock with a hot regenerated catalyst in a fluidized bed with obtaining the reaction products and coke, adsorbing coke on the catalyst, which is removed for regeneration, and returning the regenerated catcher to the contacting

The disadvantage of this method is increased catalyst consumption, which significantly reduces the efficiency of the process.

The purpose of the invention is to intensify the catalytic cracking process.

The goal is achieved by using a mixture of 25-75% by weight of catalyst containing 0.5-1.0% by weight of coke impurity as a regenerated catalyst.

The drawing shows the technological scheme of the installation, with which the method is realized.

The catalytic installation consists of a vertical one. over one hundred and connected

the reactor 2, the regenerator 3, the pipe 4 for supplying the regenerated catalyst connecting the regenerator 3 to the stand 1, and the pipeline 5 for circulating the catalyst that connects the reactor 2 to the bottom of the stand 1. The reactor 2 is a cylindrical Container containing a fluidized bed 6 of the capsizer and means 7 and 8 for separating the hydrocarbons from the incoming catalyst. The hydrocarbons purified from the catalyst are withdrawn from the reactor 2 via line 9. The separating means 7 can be made in the form of a cyclone with a pipe 10 immersed in the catalyst bed 6.

The circulation pipe 5 is provided with a spool 11, which controls the flow of the circulating catalyst. Pipe 5 has a pipe 12 for stripping the light ends, through which a gas stream is supplied. Pipeline 13 connects -: em reactor 2 to regenerator 3 and is equipped with a spool 14 for controlling the flow of catalyst from reactor 2 to regenerator 3. Pipe 15 provides gas to pipeline 13 to desorb hydrocarbons from the catalyst, which contains a cyclone 16 separating the regenerator 3, the catalyst from the fuel gas, which, in turn, is discharged through the pipe 17, the separated catalyst returns IB the lower part of the regenerator 3 through the pipe 18, immersed in a dense catalyst LAY 19. The catalyst return pipe 4 is provided with a spool 20 that regulates the supply of the regenerated catalyst to one hundred kilograms, the lower part of which is connected to the feed 21 of fresh or recycled hydrocarbon feedstock 21.

The catalytic cracking method is implemented as follows.

The incoming feedstock is evaporated and its vapors convert the catalyst in station 1 to a fluidized state. Lzlee couples with the catalyst enter the reactor 2, while passing through the layer 6 of the catalyst. At the same time, in the lower part of the effluent 1, the feedstock is in contact with the regenerated catechesizer coming from the pipeline 5. The heated catalyst evaporates the feedstock and the entire mixture of the starting material and the catalyst passes through hundred to 1 to the reactor 2. From the reactor 2, the catalyst enters via pipeline 13.c regenerator 3 for regeneration.

During catalytic cracking, the hydrocarbon on the catalyst is adsorbed as a coke impurity.

with a content of 0.01-0.4 wt.% and 0.51, 0 wt.%. Such a coke content on the catalyst is, respectively, in the regenerator and in the reactor, which then enters the lower part of the effluent 1 and mixes.

Using as a regenerated catalyst a mixture of 2575% by weight of catalyst with O, 01-0.4% by weight of coke impurity and 25-75% by weight of catalyst with 0.5-1.0% by weight of coke impurity allows significantly reduce catalyst losses and improve the heat balance of the cracking reaction, which generally intensifies the cracking process.

Claims (1)

Invention Formula The method of catalytic cracking by contacting the hydrocarbon feedstock with a hot regenerated catalyst in a fluidized bed to produce reaction products and coke, adsorbing coke on the catalyst, which leads to regeneration and returning the regenerated catalyst to contact, characterized in that, in order to intensify the process, A mixture of 25-75% by weight of a catalyst containing 0.01-0.4% by weight of coke impurity with 25-75% by weight of a catalyst containing 0.5-1.0% by weight of impurity is used as a regenerated catalyst. and coke. I. Information sources, taken into account in the examination 1, US Patent 3152084, cl. 208-78, publ. 06.10.64.