Catalytic distillation process for olefin production device

Abstract

The catalytic rectification method for olefin production includes setting catalytic reaction area in the pre-depropanizing column of the olefin producing apparatus; selectively hydrogenating C3- acetylene hydrocarbons and diene while separating C3, C3-, C4 and C4+ fractions; making top gaseous matter flow into gaseous hydrogenating reactor for further eliminating C3- acetylene hydrocarbons and diene; and feeding the cauldron liquid C4+ to the further separation area. The said method of the present invention can convert most of the C3- acetylene hydrocarbons and diene into corresponding olefin, reduce the hydrogen amount into the deeply freezing system, lower the power consumption, simplify technological process, reduce investment, raise the selectivity of catalytic hydrogenation and raise olefin yield, and has prolonged catalyst operating period, stable operation and no loss of butadiene.

Description

technical field [0001] The present invention relates to a method used in an olefin production unit, in particular to a method used in catalytic rectification and selective hydrogenation of C2 and C3 highly unsaturated hydrocarbon components in the hydrogenation process before depropanization before olefin production method. Background technique [0002] In the process of hydrocarbon cracking to olefins, a small amount of alkynes and dienes will be produced along with ethylene, propylene, and butene. These alkynes and diolefins will reduce the activity of the polymerization catalyst and deteriorate the physical properties of the polymer during the post-processing of olefins, especially during the polymerization of olefins, so they must be removed. In industry, catalytic selective hydrogenation and solvent absorption are usually used to remove alkynes and dienes in cracked gas. Due to the simple process of selective hydrogenation, less energy consumption, no environmental po...

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Problems solved by technology

The hydrogen used in the post-hydrogenation can be added as needed, which improves the hydrogenation selectivity, reduces the loss of the target product, and the quality of the hydrogenation product is stable, but its disadvantage is that the process of the separation system is relatively complicated. In order to obtain high-purity ethylene products , it is necessary to set up a second demethanizer or adopt the side discharge technology of the ethylene rectification tower

However, this process also hydrogenates diolefins with high industrial value such as butadiene in the feed, and the loss is relatively large

In addition, the catalyst loading method of this process adopts the CDTECH bundled structure, the catalyst is unevenly distributed, the utilization rate is not high, the local pressure drop of the bed is too large, the gas-liquid flow is not good, and the liquid distribution is uneven, which affects the reaction efficiency.

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