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KR-102962447-B1 - FLUIDIZED-BED DEHYDROGENATION REACTOR AND METHOD

KR102962447B1KR 102962447 B1KR102962447 B1KR 102962447B1KR-102962447-B1

Abstract

The present invention relates to an apparatus and method for producing propylene by dehydrogenating propane using fluidized bed technology in which a chlorine dispersion device and a hydrogen reduction device are added downstream of a catalyst regenerator. According to the present invention, when a chlorine dispersion device and a hydrogen reduction device are added downstream of a catalyst regenerator, the bonding strength between the sintered catalyst metal and the support during the catalyst regeneration process is increased, and the catalyst dispersion and propylene yield can be maintained at an initial level.

Inventors

  • 조재한
  • 김원일
  • 염희철
  • 우재영
  • 이강현
  • 정기영
  • 정단비

Assignees

  • 효성화학 주식회사

Dates

Publication Date
20260508
Application Date
20230908

Claims (11)

  1. A fluidized bed dehydrogenation reactor in which the dehydrogenation reaction of a hydrocarbon stream proceeds using a dehydrogenation catalyst; A catalyst regenerator that regenerates an inactivated catalyst transferred from a fluidized bed dehydrogenation reactor of the previous stage; A chlorine dispersion device connected to the downstream end of the catalyst regenerator and supplying a dispersion gas mixed with chlorine and oxygen to the regenerated catalyst to disperse chlorine; and It includes a hydrogen reduction device connected to the downstream end of the chlorine dispersion device, which supplies hydrogen reducing gas to the chlorine-dispersed catalyst to reduce it to hydrogen and then recirculates it to a fluidized bed dehydrogenation reactor. A fluidized bed dehydrogenation device characterized by further installing a gas mixing prevention device between the chlorine dispersion device and the hydrogen reduction device to prevent combustion-supporting oxygen and combustible hydrogen from mixing with each other and to block hydrogen from flowing into the fluidized bed dehydrogenation reactor.
  2. A fluidized bed dehydrogenation device according to claim 1, characterized in that the chlorine dispersion device and the hydrogen reduction device are of the bubble-fluidized-bed type.
  3. A fluidized bed dehydrogenation device according to claim 1, characterized in that a sparger or dispersion plate is installed at the bottom of the chlorine dispersion device and the hydrogen reduction device to allow gas to be well dispersed and react with the entire catalyst.
  4. delete
  5. A fluidized bed dehydrogenation device according to claim 1, characterized in that the chlorine dispersion device and the hydrogen reduction device are configured such that gas is supplied to the bottom and discharged to the top, and the residence time is controlled by the height of the catalyst layer.
  6. A fluidized bed hydrocarbon dehydrogenation method comprising the step of contacting a hydrocarbon stream with a fluidized bed bed composed of a catalyst in a fluidized bed dehydrogenation reactor, removing an inert catalyst from the fluidized bed bed, regenerating the catalyst by a catalyst regenerator, and returning it to the fluidized bed bed, wherein the method A step of extracting the catalyst regenerated in a catalyst regenerator and dispersing the chlorine using a dispersion gas mixed with chlorine and oxygen; and A fluidized bed hydrocarbon dehydrogenation method characterized by including a hydrogen reduction step in which oxygen is removed by supplying a hydrogen reducing gas to a chlorine-dispersed catalyst.
  7. A fluidized bed hydrocarbon dehydrogenation method according to claim 6, characterized in that the chlorine dispersion step is performed within the range of a regeneration gas space velocity of 0.1 to 50 h⁻¹ , a chlorine concentration of 30 to 1000 ppm, an oxygen concentration of 3 to 21%, a treatment time of 3 to 60 minutes, and a temperature of 550 to 750℃.
  8. A fluidized bed hydrocarbon dehydrogenation method according to claim 6, characterized in that the hydrogen reduction step is carried out within the range of a reducing gas space velocity of 0.5 to 100 h⁻¹ , a processing time of 1 minute to 60 minutes, and a temperature of 550 to 750℃.
  9. A fluidized bed hydrocarbon dehydrogenation method according to claim 6, characterized in that the dehydrogenation reaction in the fluidized bed dehydrogenation reactor is carried out within the range of a catalyst ratio in the reactor of 0.5 to 10%, a propane gas flow rate of 0.5 to 8 m/s, a catalyst inlet temperature of 550 to 750℃, a propane gas inlet temperature of 500 to 700℃, a catalyst residence time of 3 to 60 seconds, a propane residence time of 1 to 30 seconds, and a reaction gas space velocity of 5 to 50 h⁻¹ .
  10. A fluidized bed hydrocarbon dehydrogenation method according to claim 6, characterized in that the catalyst regeneration is carried out within the range of a regeneration gas space velocity of 0.1 to 50 h⁻¹ , a processing time of 1 minute to 40 minutes, and a temperature of 550 to 750℃.
  11. A fluidized bed hydrocarbon dehydrogenation method according to claim 6, characterized in that the dehydrogenation catalyst is one type of Group VIII noble metal catalyst selected from the group consisting of platinum, palladium, iridium, rhodium, osmium, ruthenium, or a mixture thereof.

Description

Fluidized-bed dehydrogenation reactor and method The present invention relates to a fluidized bed dehydrogenation apparatus and method, and more specifically, to an apparatus and method for dehydrogenating hydrocarbons through fluidized bed technology. A conventional fluidized bed propane dehydrogenation process generally consists of a fluidized bed dehydrogenation reactor, a gas-catalyst separator, and a catalyst regenerator. Propane gas and the catalyst are injected together into the bottom of the reactor and flow upward along the reactor to undergo the dehydrogenation reaction. After the reaction is complete, the catalyst, separated from the gas in the gas-catalyst separator, flows into the catalyst regenerator located below. In the catalyst regenerator, air or oxygen is injected to burn off and remove coke from the catalyst surface. This coke removal process generates high heat as an exothermic reaction; in the fluidized bed propane dehydrogenation process, this heat is utilized as reaction heat to improve the energy efficiency of the process. The heat generated during the coke combustion removal process of a catalyst regenerator can induce sintering of the catalyst metal located on the surface of the catalyst support, thereby degrading the catalyst's performance. Catalytic metals that have combined with the oxygen injected for regeneration and become oxidized move within the support surface via mass transfer. This mass transfer occurs more readily at higher temperatures and oxygen concentrations. Catalytic metals moving across the support surface tend to clump together to form a more thermodynamically stable structure. When catalyst metals clump, the number of active sites where dehydrogenation actually takes place decreases, leading to a reduction in reactivity. While lowering the temperature or oxygen concentration during regeneration can reduce this sintering phenomenon, it may also leave coke unremoved within the catalyst, potentially degrading its performance. Fluidized bed technology is a technique that introduces solid particles together with a fluid (gas or liquid) to move as a single fluid. By fluidizing the catalyst (solid particles) for propane dehydrogenation to react with propane gas for a short period and circulating the process, it enables the securing of high propylene yields. During this process, coke is generated as a byproduct on the catalyst surface after the propane dehydrogenation reaction. Since coke blocks reaction active sites and reduces performance, a regeneration process is essential to remove the coke and restore the catalyst to its original state. In particular, in fluidized bed processes with short catalyst regeneration cycles, the design of the catalyst regenerator is a key technology. If catalyst regeneration is not performed properly, the rapid increase in coke leads to the irreversible deactivation of the catalyst, resulting in a sharp decrease in process yield. Figure 1 is a diagram of a fluidized bed dehydrogenation reactor according to the prior art. FIG. 2 is a schematic diagram illustrating a fluidized bed dehydrogenation apparatus of one embodiment of the present invention. FIG. 3 is an enlarged view of the chlorine dispersion device and the hydrogen reduction device of a fluidized bed dehydrogenation apparatus of one embodiment of the present invention. FIG. 4 is a schematic perspective view of a sparger installed in a chlorine dispersion device and a hydrogen reduction device of a fluidized bed dehydrogenation reactor according to one embodiment of the present invention. The present invention will be described in more detail below with reference to the attached drawings. Throughout the specification, the same reference numerals denote the same components. The drawing symbols represent a simplified schematic diagram of a dehydrogenation reactor according to the present invention, and only the main components are illustrated. Other heat exchangers, internal heaters, movable pipes for catalyst delivery, pumps, and other similar components have been omitted. Where in this specification it is stated that a component is "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to the other component, or that there may be other components in between. In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. In this document, the term "reactor" refers to a reaction apparatus in which a reaction gas comes into contact with a catalyst on a catalyst bed. Various ranges an