Iron catalyst used in butadiene production through n-butylene oxidation dehydrogenation, and preparation method and application thereof

Abstract

The invention relates to an iron catalyst used in butadiene production through n-butylene oxidation dehydrogenation, and a preparation method and an application thereof. The catalyst comprises Fe as a main component, and a co-catalyst comprising Mg, Zn, and other elements. The catalyst is composed of, by mass, 48.80-60.53% of Fe, 0.01-18.00% of Mg, 0-15.00% of Zn, 0-5.00% of other elements, and balance of oxygen element. The catalyst is prepared with a precipitation method. The catalyst is applied in butadiene production through n-butylene oxidation dehydrogenation by using an adiabatic fixed bed. Application conditions comprise: adiabatic fixed bed material inlet temperature is 260.0-445.0 DEG C; molar ratio of inlet oxygen to n-butylene is 0.42-0.90; molar ratio of inlet water to n-butylene is 12.0-25.0; inlet n-butylene volume space velocity is 180-600h<-1>, and an adiabatic fixed bed material outlet temperature is 457.0-650.0 DEG C. Compared with prior arts, the catalyst provided by the invention is suitable for an adiabatic fixed bed, and has the advantages such as high butadiene selectivity, good catalyst reaction stability, and the like.

Description

technical field [0001] The invention relates to a catalyst, in particular to an iron catalyst used for producing butadiene by oxidative dehydrogenation of n-butene in an adiabatic fixed bed, as well as its preparation method and application. Background technique [0002] In recent years, the downstream industries of butadiene such as styrene-butadiene rubber, butadiene rubber, nitrile rubber, ABS resin, SBS thermoplastic elastomer and styrene-butadiene latex have developed rapidly, and the raw materials of butadiene are in short supply. The rise of shale gas chemical industry has caused a decline in the production of butadiene obtained through extraction methods, and the oxidative dehydrogenation of n-butene has become an effective way to obtain butadiene. [0003] The n-butene oxidative dehydrogenation reactor mainly includes fluidized bed and adiabatic fixed bed. [0004] The oxidative dehydrogenation of n-butene uses a fluidized bed as the reactor, which requires high ca...

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Problems solved by technology

[0004] The oxidative dehydrogenation of n-butene uses a fluidized bed as the reactor, which requires high catalyst strength and wear resistance. The catalyst powder brought out of the reaction system often blocks the post-treatment system, making it difficult to recover the catalyst. The disadvantage of the fluidized bed also involves operation. Complicated, the amplification effect is obvious

The fluidized bed catalyst disclosed in early Chinese patents CN1184705, CN1072110 and CN1033013 has the advantages of high catalytic activity and good butadiene selectivity, but the mechanical strength and wear resistance of the catalyst are low, and the catalyst is easy to pulverize and lose. Treatment system; Chinese patents CN102580749 and CN102716754 all attempt to prepare microsphere catalysts by spray drying method, on the basis of maintaining good performance of the catalyst, reduce the pulverization and loss of the catalyst in the fluidized state as far as possible, but it is still difficult to avoid catalyst powder Clogging and aftertreatment system clogging

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