A process for producing light olefins

Patent metadata

Field	Value
Publication number	US-2017313636-A1
Application number	US-201515520721-A
Country	US
Kind code	A1
Filing date	Oct 20, 2015
Priority date	Oct 20, 2014
Publication date	Nov 2, 2017
Grant date	—

Abstract

Disclosed is a process for producing light olefins. In the process for producing light olefins by continuously bringing an alkane feedstock and a catalyst into contact to subject to a dehydrogenation reaction, the reaction pressure P of the dehydrogenation reaction is made 0.6-2 MPa and the volume space velocity H of the dehydrogenation reaction is made 500-1000 h −1 . The light olefins production process of the present invention is simple and continuous in operation and has the characteristics of low investment, significant increase in yield of light olefins and high safety.

First claim

1 . A process for producing light olefins, wherein in the process for producing light olefins by continuously contacting an alkane feedstock and a catalyst to conduct a dehydrogenation reaction, the reaction pressure P of the dehydrogenation reaction is 0.4-6 MPa, preferably 0.4-3 MPa, more preferably 0.5-2 MPa, most preferably 0.6-2 MPa, the volume space velocity H of the dehydrogenation reaction is 100-5000 h −1 , preferably 200-2000 h −1 , most preferably 500-1000 h −1 .

2 . The process according to claim 1 , wherein during the dehydrogenation reaction, H and P satisfy a mathematical function of H=f(P), which is a strictly increasing function, wherein P (unit: MPa) is in the interval [0.4, 6.0], preferably in the interval [0.4, 3.0], more preferably in the interval [0.5, 2.0], most preferably in the interval [0.6, 2.0], H (unit: h −1 ) is in the interval [100, 5000], preferably in the interval [200, 2000], most preferably in the interval [500, 1000].

3 . The process according to claim 1 , comprising the following steps:
continuously contacting the alkane feedstock and the catalyst to conduct the dehydrogenation reaction to obtain a light olefins-rich hydrocarbon and a spent catalyst, transporting at least a part of the spent catalyst to the regeneration reaction to obtain a regenerated catalyst, and circulating at least a part of the regenerated catalyst to the dehydrogenation reaction, wherein the reaction pressure P of the dehydrogenation reaction is at least 0.3 MPa, preferably 0.5 MPa, 0.7 MPa, 0.9 MPa, 1.2 MPa or 2.0 MPa higher than the regeneration pressure of the regeneration reaction.

4 . The process according to claim 1 , wherein one or more reactors are used for the dehydrogenation reaction, and each independently selected from a fluidized bed reactor, a dense bed reactor, a riser reactor, an ebullated bed reactor and a combination thereof, preferably selected from a fluidized bed reactor, more preferably selected from a bubbling fluidized bed reactor or a turbulent fluidized bed reactor.

5 . The process according to claim 1 , wherein the alkane feedstock is selected from at least one of C2-C12 straight-chain or branched alkanes (preferably at least one of C2-C5 straight-chain or branched alkanes (more preferably at least one of propane and isobutane) or a mixture of C3-C12 hydrocarbons), or selected from at least one of natural gas condensate, natural gas liquid, catalytic cracking liquefied gas, oil field gas condensate, shale gas condensate, straight-run naphtha, shale oil light constituent, hydrogenated naphtha, coker gasoline and cracking gasoline.

6 . The process according to claim 1 , wherein the catalyst is selected from at least one of a dehydrogenation catalyst, a cracking catalyst and a dehydrogenation/cracking composite catalyst.

7 . The process according to claim 3 , wherein the reaction conditions of the regeneration reaction comprise: reaction temperature 550-750° C., preferably 600-700° C.; reaction pressure 0.1-0.5 MPa, preferably 0.1-0.3 MPa; spent catalyst residence time 5-60 minutes, preferably 6-20 minutes; oxygen-containing atmosphere, preferably air atmosphere or oxygen atmosphere.

8 . The process according to claim 3 , wherein the spent catalyst and/or the regenerated catalyst are withdrawn by separation through a filter.

9 . The process according to claim 3 , wherein the transporting and the circulating are performed via one or more (preferably one or two) lock hoppers ( 4 ).

10 . The process according to claim 1 , wherein with the proviso that the size and amount of the reactors for the dehydrogenation reaction are kept the same, the process enables to increase the output of light olefins by 50%, preferably 100%, more preferably 150%, 200%, 500% or 800%, most preferably 1000% or higher.

11 . The process according to claim 1 , further comprising a step of circulating an unconverted alkane feedstock to the dehydrogenation reaction.

12 . The process according to claim 1 , comprising the following steps:
continuously contacting a preheated alkane feedstock and a catalyst in the reactor to conduct the dehydrogenation reaction under a dehydrogenation condition to produce the light olefins-rich hydrocarbon and the coked spent catalyst; separating the hydrocarbon and the spent catalyst, introducing the separated hydrocarbon to a product separation-recovery system, and continuously withdrawing the spent catalyst from the reactor; transporting the spent catalyst withdrawn from the reactor to a spent catalyst receiver, then to a spent catalyst feeding tank via a lock hopper, then to a regenerator from the spent catalyst feeding tank, and regenerating the spent catalyst in an oxygen-containing atmosphere in the regenerator to produce a regenerated catalyst; continuously withdrawing the regenerated catalyst from the regenerator and transporting it to a regenerated catalyst receiver, then to a regenerated catalyst feeding tank via a lock hopper, and continuously transporting it back to the reactor from the regenerated catalyst feeding tank.

Assignees

• China Petroleum & Chem Corp
• Res Inst Petroleum Processing Sinopec

Inventors

• Wang Xin
• Yu Jingchuan
• Li Minggang
• Gong Jianhong
• Zong Baoning
• Xu Youhao

Classifications

• C07C2523/62

  with gallium, indium, thallium, germanium, tin or lead · CPC title

• C07C5/333

  Catalytic processes · CPC title

• C07C2529/00

  Catalysts comprising molecular sieves · CPC title

• C07C5/3337 Primary

  of the platinum group · CPC title

• C07C11/02

  Alkenes · CPC title