A kind of propane dehydrogenation catalyst and preparation method thereof

Abstract

The invention discloses a propane dehydrogenation catalyst and a preparation method thereof. Chromium compound oxide is used as an active component, is mixed with a high-performance thermal carrier, is added with an adhesive and a modifying element, and then is mixed and kneaded, subjected to band extrusion, dried and roasted to prepare the catalyst. The propane dehydrogenation catalyst comprisesthe following components in percentages by mass: 55-80% of the chromium compound oxide, 10-30% of the high-performance thermal carrier, 0.1-10.0% of a modifying element and the balance of the adhesive. The dispersity of chromium on the carrier is improved by synthesizing the chromium compound oxide, and the effective utilization rate of the active component and the conversion rate of the raw material propane are increased effectively; by metal modification treatment, the activity and selectivity of the catalyst are improved, and then, the yield of propylene is increased; by high-temperature water vapor treatment, the acid content and the acid strength of the surface of the carrier are greatly reduced, and the coking and olefin cracking reaction of the catalyst is relived effectively; and by addition of the high-performance thermal carrier, the catalyst utilization efficiency is improved effectively, and the production load of the device is increased.

Description

Technical field [0001] The invention relates to a low-carbon alkane dehydrogenation catalyst and a preparation method thereof, in particular to a catalyst for the catalytic dehydrogenation of propane to propylene and a preparation method thereof. Background technique [0002] Propylene is an important chemical raw material, widely used in the production of chemical products such as polypropylene, acrylic acid, propylene oxide and acrylonitrile. Propylene in my country is mainly derived from the co-production or by-products of naphtha cracking and catalytic cracking. However, as the consumption of propylene increases year by year, traditional propylene production can no longer meet the demand. Therefore, the technology of propane dehydrogenation to propylene is developing rapidly. Become the third largest source of propylene after methanol to olefins. [0003] For chromium-based propane dehydrogenation catalysts, since the prior art mostly adopts the impregnation method to support t...

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Problems solved by technology

my country's propylene mainly comes from co-production or by-products of naphtha cracking and catalytic cracking processes. However, with the increase in propylene consumption year by year, the traditional propylene production can no longer meet the demand. Therefore, the technology of propane dehydrogenation to propylene is developing rapidly. Become the third largest source of propylene after methanol to olefins

[0003] For chromium-based propane dehydrogenation catalysts, since the prior art mostly uses the impregnation method to load the active components on the alumina carrier, this method affects the loading and dispersion of the active components on the alumina carrier, reducing the active component. The effective utilization rate of the catalyst affects the reactivity and selectivity of the catalyst; the existence of a large number of acid centers on the alumina leads to the rapid coking of the catalyst and the cracking of olefins

For this reason, catalysts are often modified with basic metals or their oxides to reduce the amount of carrier acid, but this modification causes a strong interaction between basic oxides and chromium oxide, thereby inhibiting the dehydrogenation activity, resulting in High valent chromium cannot be completely reduced and the selectivity of olefins is reduced

Propane dehydrogenation is a strong endothermic reaction. As the reaction progresses, the temperature of the catalyst bed drops rapidly, which leads to frequent switching between reaction and regeneration, which reduces the catalyst processing capacity and reduces the production load of the device.

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