Fluidized bed reactor used for light olefin cracking and Methanol To Olefin (MTO)

Abstract

The invention discloses a fluidized bed reactor used for light olefin cracking and Methanol To Olefin (MTO), which comprises a reactor and a pre-riser; the reactor comprises a dense phase fluidized bed reactor and a dilute phase conveying reactor which are positioned at same axis, the pre-riser and the dilute phase conveying reactor are respectively positioned at upper part and lower part of the dense phase fluidized bed reactor; diameter of the pre-riser is smaller than diameter of the dense phase fluidized bed reactor, the upper part of the pre-riser extends into the dense phase fluidized bed reactor; an upper end port of the pre-riser in the dense phase fluidized bed reactor is sealed, and a perforate is provided on the tube wall of the pre-riser in the dense phase fluidized bed reactor; or the perforate is provided on the upper end of the pre-riser in the dense phase fluidized bed reactor, and a baffle plate is arranged over the perforate. The reactor is capable of increasing gas-solid contact efficiency, the backmixing degree of oil gas and a catalyst is less, and conversion rate of one way of the light olefin cracking and Methanol To Olefin (MTO) reactions can be greatly improved, and the target product micromolecule olefin selectivity can be greatly improved.

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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