A fluidized bed reactor for light olefin cracking and methanol to olefin

Abstract

The invention discloses a fluidized bed reactor for light olefin cracking or methanol to olefin, including a reactor, a pre-riser, etc.; the reactor includes two parts: a dense-phase fluidized-bed reactor and a dilute-phase conveying Or on the same axis, the pre-riser and the dilute phase transfer reactor are respectively located above and below the dense-phase fluidized bed reactor; the diameter of the pre-riser is smaller than the diameter of the dense-phase fluidized bed reactor, and the upper Partially extending into the dense-phase fluidized bed reactor; the upper port of the pre-riser pipe located in the dense-phase fluidized bed reactor is sealed, and the pipe wall of the pre-riser pipe extending into the dense-phase fluidized bed reactor Or, the upper end of the pre-riser pipe located in the dense phase fluidized bed reactor is an opening, and a baffle is arranged above the opening. The reactor improves the gas-solid contact efficiency, the degree of oil gas and catalyst back-mixing is small, and can greatly improve the conversion rate of light hydrocarbon cracking and methanol-to-olefin reaction and the selectivity of the target product small molecule olefin.

Description

technical field [0001] The invention relates to a fluidized bed reactor for light olefin cracking and methanol-to-olefin production, in particular to a dense-phase fluidized-bed reactor with high gas-solid contact efficiency for light olefin cracking and methanol-to-olefin production. Background technique [0002] Butene, pentene and hexene are very good raw materials for catalytic cracking to produce propylene or ethylene and propylene. The cracking of light olefins mentioned here refers to the catalytic cracking of butene, pentene and hexene. The target products of cracking can be Propylene, and also ethylene and propylene. [0003] The catalyst active components used in catalytic cracking are all acidic molecular sieves. The target products ethylene and propylene produced by the cracking of light olefins can easily undergo secondary reactions on acidic molecular sieve materials and be converted into low value-added products such as alkanes. Therefore, as a light olefin c...

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Problems solved by technology

[0007] However, if the riser reactor in the catalytic cracking process is used, the catalyst in it is in a state of dilute phase transport, and light olefins or methanol dispersed in molecular form cannot fully contact with the catalyst, so the conversion rate per pass is not high; if bubbling is used bed or turbulent bed, the back-mixing of catalyst and oil and gas is relatively serious, resulting in the secondary reaction of the target product small molecular olefins into low value-added products, and it is easy to form large bubbles or grooves in the dense phase section of these two types of fluidized beds flow phenomenon, thereby reducing the efficiency of gas-solid contact

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