Patent RU-2731380-C2 (RU)
Title: Integrated method of dehydration of c3-c4-hydrocarbons
Inventor: PRETS METYU T
IPC: B01J23/96
Filed: 2016-03-07
Granted: 2020-09-02
Abstract: FIELD: chemical or physical processes. 
     SUBSTANCE: disclosed is an integrated method of producing C3-C4 or C4-diolefin olefins, involving the following steps: (1) (a) contacting in a dehydrogenation reactor with a fluidised bed (i) a C3-C4 hydrocarbon feedstock and (ii) a catalyst stream comprising a catalyst, meeting requirements for group A or group B according to Geldart's classification; at weight ratio of catalyst flow to C3-C4-hydrocarbon material from 5 to 100; and wherein average contact time of said C3-C4-hydrocarbon feedstock with said catalyst stream is from 1 to 10 s and reaction temperature in said dehydrogenation reactor with fluidised bed ranges from 550 to 750 °C; and absolute pressure in said dehydrogenation reactor with fluidised bed at outlet of said reactor is from 6.0 to 44.7 pounds per square inch (from 41.4 to 308.2 kPa); under conditions providing formation of mixture of products of step (1) (a) containing target C3-C4-olefin or target C4-diolefin, hydrogen and unreacted C3-C4-hydrocarbon material; and depositing coke on said catalyst and at least partially deactivating said catalyst in such a way that it forms at least partially deactivated catalyst; and (b) transferring the mixture of products of step (1) (a) and said at least partially deactivated catalyst from said dehydrogenation reactor with a fluidised bed into a cyclone separation system, and under conditions where (i) said mixture of products of step (1) (a) and said at least partially deactivated catalyst remain in contact at reaction temperature and after transfer to said cyclone separation system during average time from 0 to less than 10 s, and (ii) said mixture of products of step (1) (a) is converted to produce a mixture of products of step (1) (b); and then said mixture of products of step (1) (b) and said at least partially deactivated catalyst are substantially separated from each other; (c) transfer of at least a portion of said at least partially deactivated catalyst into a regenerator vessel and heating said at least partially deactivated catalyst therein to a combustion temperature of 660 to 850 °C with coke combustion, deposited on said at least partially deactivated catalyst using heat generated by said coke firing as well as additional fuel, wherein during said heating is formed heated deactivated catalyst, having lower activity to dehydration of C3-C4-hydrocarbon raw material, than said at least partially deactivated catalyst, and (d) conditioning said additionally heated deactivated catalyst, including holding said heated additionally deactivated catalyst at temperature of at least 660 °C in oxygen-containing gas stream for more than 2 minutes, to obtain an oxygen-containing at least partially reactivated catalyst, having higher activity to dehydration of C3-C4-hydrocarbon raw material, than said at least partially deactivated catalyst; and (e) transferring said at least partially reactivated catalyst back to said fluidised bed dehydrogenation reactor; (2) transfer of mixture of products of step (1) (b) into compressor, wherein said mixture of products of step (1) (b) is compressed at least once to produce a mixture of products of step (2); as well as (3) transfer of mixture of products of step (2) to product extraction zone, wherein said mixture of products of step (2) is divided into recovered products containing at least one or more of the desired C3-C4-olefin or target C4-diolefin fractions. 
     EFFECT: using the method to increase power, reduce power consumption or both, so that an existing enterprise can operate more efficiently. 
     14 cl, 3 dwg