A kind of support catalyst of propane dehydrogenation to propylene and preparation method thereof

Abstract

The purpose of the present invention is to provide a propane dehydrogenation to propylene supported catalyst and its preparation method, the catalyst is composed of Cr 2 O 3 The active component is composed of a carrier material that resists sintering at high temperature, resists phase transformation and has a high specific surface at high temperature. Its chemical formula is: yCr 2 O 3 / M a O b ·xAl 2 O 3 , y=10~30%, a=1~3, b=1~4; x=4-8, the carrier material is metal-doped alumina salt M a O b ·xAl 2 O 3 . Precipitation method, complex method, sol-gel method or reverse microemulsion method to prepare high temperature anti-sintering, anti-phase transition and high temperature carrier material M with high specific surface a O b ·xAl 2 O 3 ; Preparation of yCr by dipping method and solid-phase ball milling mixing method 2 O 3 / M a O b ·xAl 2 O 3 Supported catalyst, y=10~30%Cr 2 O 3 The active component precursor materials are chromium-containing precursors such as chromium nitrate, chromium acetate, chromium citrate, and chromium acetylacetonate. The synthesized supported catalyst showed good catalytic activity in the direct dehydrogenation of alkane to propylene, especially the catalyst showed excellent anti-sintering and anti-phase transformation ability, which greatly improved the stability and service life of the catalyst.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a supported catalyst for propane dehydrogenation to propylene and a preparation method thereof. Background technique [0002] Propylene is an important organic petrochemical basic raw material second only to ethylene, and is widely used in the production of very important chemical products such as polypropylene, propylene oxide, and acrylic acid. In recent years, with the rapid increase in the demand for downstream derivatives of propylene, the supply gap of propylene resources has become increasingly apparent. [0003] At present, the vast majority of propylene comes from steam cracking and catalytic cracking in refineries. However, steam cracking is limited by the ratio of propane-ethane co-production, and catalytic cracking is restricted by the further production of high-octane gasoline from light hydrocarbons. Traditional The existing propylene production technol...

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Problems solved by technology

[0004] Precious metal platinum catalysts have high activity and stability in propane dehydrogenation, but they are expensive and prone to poisoning and deactivation; chromium catalysts are cheap and have relatively low requirements for impurities in raw materials, and the production of propylene by direct dehydrogenation of propane has been realized industrially In the process, Catofin, Linde, and FBD processes all use chromium-based catalysts

However, the carrier used in industrial chromium catalysts is active γ-Al 2 o 3 , the catalyst carrier is prone to sintering or crystal phase transformation to generate α-Al during the reaction and charcoal activation process 2 o 3 , thus leading to catalyst deactivation, therefore, active γ-Al 2 o 3 The anti-sintering and anti-phase change properties need to be further improved

[0005] The key to solving the above problems is to be able to prepare a new type of carrier material that is resistant to sintering at high temperature, resistant to phase change, and has a high specific surface area at high temperature, which fundamentally solves the problem of chromium-based catalysts in the direct dehydrogenation of propane to propylene. Problems with catalyst deactivation due to sintering or phase change

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