The ethylene plant combines styrene extraction with aromatic extraction, while the pyrolysis gasoline hydrogenation process is integrated as well
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The last edit to this post was made by lvhongtaosg on 2019-6-19 at 10:59. Is this the process: styrene extraction, followed by hydroprocessing of the pyrolysis gasoline, and then aromatic extraction?
The task of the hydroprocessing unit for pyrolysis gasoline is to remove C5S and C9+ compounds from the pyrolysis gasoline coming from the ethylene unit. The remaining C6–C8 fraction is subjected to secondary hydroprocessing and then used as the output of the two-stage hydroprocessing process; it is sent to the aromatics extraction unit as a raw material for aromatics extraction. C5S and C9+ compounds are discharged as by-products outside the plant. C6~C8 from the reforming unit are the main target products, while C6~C8 from the ethylene unit are by-products. The contents of each component vary.
The task of the hydroprocessing unit for pyrolysis gasoline is to remove C5S and C9+ compounds from the pyrolysis gasoline coming from the ethylene unit. The remaining C6–C8 fraction is subjected to secondary hydroprocessing and then used as the output of the two-stage hydroprocessing process; it is sent to the aromatics extraction unit as a raw material for aromatics extraction. C5S and C9+ compounds are discharged as by-products outside the plant. The C6-7 of ethylene consists mainly of cycloalkanes, while the C6-7 of reformed hydrocarbons consists mainly of alkanes.
What if it’s extracted with styrene? Is the C8 fraction sent for styrene extraction, and then are the C6/C7 fractions mixed with the extracted C8 before being hydrogenated, followed by aromatics extraction? Is this the process? Why is hydrogenation at both ends required?
Hello, the C8 fraction obtained from Tower C8 is subjected to styrene extraction. Among the olefins present in C8, aside from phenylacetylene and styrene, is the content of other olefins significant? Will it affect styrene extraction?
As long as phenylacetylene is hydrogenated to styrene, other olefins do not affect the extraction of styrene
In addition to styrene and phenylacetylene, the C8 fraction also contains large amounts of mixed xylene (o-xylene, m-xylene, p-xylene, and ethylbenzene). These components do not affect the extraction of styrene; after being separated at the top of the extraction distillation tower, they are sent to the reactor system of the pyrolysis gasoline hydrogenation unit.
Pygase has C567 extracted via aromatics stripping. The remaining C8.9 is sent to the styrene extraction unit. Escape from C9. In C8, pa hydrogenation is carried out using a solvent to remove sm. Then, SM decolorization is carried out, followed by distillation, to obtain styrene of quality above the specified standard. The remaining C8 is returned to Fangchou’s hydrogenation unit.
Okay, understood. Thank you~ Getting ready