Loaded catalyst for propane dehydrogenation to propylene and preparation method thereof

Abstract

The invention aims to provide a loaded catalyst for propane dehydrogenation to propylene and a preparation method thereof. The catalyst consists of a Cr2O3 active component and a carrier material withhigh temperature sintering resistance, phase change resistance and high specific surface at high temperature. The chemical formula of the catalyst is yCr2O3 / MaOb.xAl2O3, y=10-30%, a=1-3, b=1-4; x=4-8, and the carrier material is metal doped aluminum oxide salt MaOb.xAl2O3. Precipitation technique, complexing technique, sol-gel technique or reverse micro-emulsion technique is employed to prepare the carrier material MaOb.xAl2O3 with high temperature sintering resistance, phase change resistance and high specific surface; impregnation process and solid phase ball mill mixing technique are adopted to prepare the yCr2O3 / MaOb.xAl2O3 loaded catalyst, y=10-30%, and the Cr2O3 active component precursor material adopts chromium nitrate, chromium acetate, chromium citrate, chromium acetylacetonateand other chromium-containing precursors. The synthesized loaded catalyst shows good catalytic activity in the reaction of direct dehydrogenation of alkane to prepare propylene, especially shows excellent sintering and phase change resistance, thus greatly improving 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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