Low-carbon alkane chemical chain oxydehydrogenation to olefin technology

Abstract

The invention relates to a design of low-carbon alkane (C2-C5) chemical chain oxydehydrogenation to olefin technology. A catalyst adopted by the technology is a novel bifunctional catalyst, a metallicoxide with an oxygen-carrying function is used as an oxygen carrier to provide lattice oxygen for oxidative dehydrogenation, and a metal active ingredient with a dehydrogenation function is loaded onthe metallic oxide. According to the technology, a fixed bed, a circulating fluidized bed or a moving bed can be taken as a reactor, in the oxidative dehydrogenation process, the metal active ingredient can be taken as a dehydrogenation active center, the reaction of dehydrogenation of alkane to olefin is taken place in the reactor, the lattice oxygen carried by the oxygen carrier can be selectively reacted with H2 generated in the dehydrogenation to oxidize the H2 to steam, when the reaction is completed, the catalyst losing the lattice oxygen is oxidized and regenerated in the air to supplement the lattice oxygen while carbon deposit is removed, and the reactivity of the catalyst is recovered. Compared with a traditional technology, in situ oxidation is conducted on the H2 generated inthe dehydrogenation to greatly improve percent conversion of the alkane and olefin yield, demands of catalytic reaction and catalyst regeneration can be met simultaneously, the dehydrogenation can beconducted at a lower temperature, the oxidized and regenerated catalyst carries a large amount of heat which can be provided for the dehydrogenation to achieve an operation of self-heating in the dehydrogenation process, and energy consumption can be greatly reduced by means of the designs.

Description

technical field [0001] The invention relates to the technical field of catalytic dehydrogenation, in particular to a process for producing olefins by chemical chain oxidative dehydrogenation of low-carbon alkanes. Background technique [0002] In recent years, the demand for low-carbon olefins in the petrochemical industry has been increasing, and the traditional naphtha cracking and catalytic cracking processes to obtain low-carbon olefins can no longer meet market demand. Therefore, seeking reasonable and efficient olefin production methods has become a national and global The urgent need of petrochemical enterprises. The technology of catalytic dehydrogenation of low-carbon alkanes to olefins has attracted much attention. The successful development of low-carbon alkane dehydrogenation to olefins technology can not only improve the utilization rate of oil and gas resources, but also produce high value-added low-carbon olefin products. The development of this technology An...

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Problems solved by technology

[0003] Patents CN 107428636 A, JP 2010-90083 A describe a method for producing butadiene by oxidative dehydrogenation of n-butene. Both methods use a mixed feed of n-butene and oxygen, and simultaneously feed a large amount of inert gas such as nitrogen to avoid explosion hazards , this feeding method requires a large amount of high-cost concentrated nitrogen as a protective gas

At the same time, in an oxygen atmosphere, hydrocarbons are prone to various side reactions at high temperatures, such as deep oxidation reactions or the formation of various high-boiling sediment components, which not only leads to a significant drop in olefin selectivity, but also cools and separates the products after the reaction. High cost

[0004] It can be seen that the common problems in the current oxidative dehydrogenation process mainly include: the feeding process requires a high-energy-consuming air compressor; the oxidative dehydrogenation reaction path is complex, and the performance requirements of the catalyst are high; The equipment is complicated, the operation consumes a lot of energy, and there are safety hazards in the dehydrogenation reaction of oxygen-containing raw materials; a variety of complex side reactions occur in alkanes and alkenes, resulting in local hot spots in the reactor, and the selectivity of target products is greatly reduced

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