Evaluation of Spent Catalyst Structure Changes during Ethylbenzene Dehydrogenation in Different Technologies
Ethylbenzene (EB) dehydrogenation to styrene (SM) on an industrial scale is generally performed using classic and SMART (Styrene Monomer Advanced Reheat Technology) technologies. In the current study, spent catalysts structural changes through classic and SMART technologies were investigated and com...
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| Format: | Article |
| Language: | English |
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Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR
2017-03-01
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| Series: | Iranian Journal of Chemistry & Chemical Engineering |
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| Online Access: | http://www.ijcce.ac.ir/article_25190_a3c0d6edfa5cab2fbefece94b4943843.pdf |
| _version_ | 1828945841121918976 |
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| author | Amir Naser Haghlesan Reza Alizadeh Esmail Fatehifar |
| author_facet | Amir Naser Haghlesan Reza Alizadeh Esmail Fatehifar |
| author_sort | Amir Naser Haghlesan |
| collection | DOAJ |
| description | Ethylbenzene (EB) dehydrogenation to styrene (SM) on an industrial scale is generally performed using classic and SMART (Styrene Monomer Advanced Reheat Technology) technologies. In the current study, spent catalysts structural changes through classic and SMART technologies were investigated and compared with the fresh catalyst. For this purpose, XRF, XRD, SEM-EDX, FT-IR, BET and crushing strength analysis were employed. It was found that styrene production via SMART technology with 40% potassium loss is led to more catalyst deactivation than the classic ones (26%). Due to pore mouth blocking by coke formation, the average pore radius in both classic and SMART spent catalysts is reduced about 33% and 53% compared to the fresh ones, respectively. SEM analysis showed that potassium migration mechanism is related to the temperature gradient in the classic spent catalysts and chemical vapour transportation in the SMART spent catalysts. Comparative evaluation of the catalysts performance indicated that the SMART spent catalyst with about 72% activity loss is more deactivated than the classic ones (61%).The large drop of styrene yield (72-74%) of SMART spent catalyst revealed that the activity is more depending on the pore mouth size, rather than the specific surface area. However, in situ steam injection redistributed migrated potassium and increased the selectivity of the classic spent catalyst, but it was led to more potassium migration and catalyst deactivation in the SMART spent ones. According to this study, styrene production and industrial unit design based on SMART technology not recommended strongly. |
| first_indexed | 2024-12-14T05:00:24Z |
| format | Article |
| id | doaj.art-b6e72b36985342f0ad6cce2e16e73662 |
| institution | Directory Open Access Journal |
| issn | 1021-9986 1021-9986 |
| language | English |
| last_indexed | 2024-12-14T05:00:24Z |
| publishDate | 2017-03-01 |
| publisher | Iranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECR |
| record_format | Article |
| series | Iranian Journal of Chemistry & Chemical Engineering |
| spelling | doaj.art-b6e72b36985342f0ad6cce2e16e736622022-12-21T23:16:15ZengIranian Institute of Research and Development in Chemical Industries (IRDCI)-ACECRIranian Journal of Chemistry & Chemical Engineering1021-99861021-99862017-03-01361455725190Evaluation of Spent Catalyst Structure Changes during Ethylbenzene Dehydrogenation in Different TechnologiesAmir Naser Haghlesan0Reza Alizadeh1Esmail Fatehifar2Faculty of Chemical Engineering, Sahand University of Technology, PO Box 51335/1996, Tabriz, I.R. IRANEnvironmental Engineering Research Center (EERC), Sahand University of Technology, Sahand New Town, Tabriz, Iranr.alizadeh@sut.ac.irEthylbenzene (EB) dehydrogenation to styrene (SM) on an industrial scale is generally performed using classic and SMART (Styrene Monomer Advanced Reheat Technology) technologies. In the current study, spent catalysts structural changes through classic and SMART technologies were investigated and compared with the fresh catalyst. For this purpose, XRF, XRD, SEM-EDX, FT-IR, BET and crushing strength analysis were employed. It was found that styrene production via SMART technology with 40% potassium loss is led to more catalyst deactivation than the classic ones (26%). Due to pore mouth blocking by coke formation, the average pore radius in both classic and SMART spent catalysts is reduced about 33% and 53% compared to the fresh ones, respectively. SEM analysis showed that potassium migration mechanism is related to the temperature gradient in the classic spent catalysts and chemical vapour transportation in the SMART spent catalysts. Comparative evaluation of the catalysts performance indicated that the SMART spent catalyst with about 72% activity loss is more deactivated than the classic ones (61%).The large drop of styrene yield (72-74%) of SMART spent catalyst revealed that the activity is more depending on the pore mouth size, rather than the specific surface area. However, in situ steam injection redistributed migrated potassium and increased the selectivity of the classic spent catalyst, but it was led to more potassium migration and catalyst deactivation in the SMART spent ones. According to this study, styrene production and industrial unit design based on SMART technology not recommended strongly.http://www.ijcce.ac.ir/article_25190_a3c0d6edfa5cab2fbefece94b4943843.pdfcatalyst deactivationethylbenzene dehydrogenationsmart technologystyrene |
| spellingShingle | Amir Naser Haghlesan Reza Alizadeh Esmail Fatehifar Evaluation of Spent Catalyst Structure Changes during Ethylbenzene Dehydrogenation in Different Technologies Iranian Journal of Chemistry & Chemical Engineering catalyst deactivation ethylbenzene dehydrogenation smart technology styrene |
| title | Evaluation of Spent Catalyst Structure Changes during Ethylbenzene Dehydrogenation in Different Technologies |
| title_full | Evaluation of Spent Catalyst Structure Changes during Ethylbenzene Dehydrogenation in Different Technologies |
| title_fullStr | Evaluation of Spent Catalyst Structure Changes during Ethylbenzene Dehydrogenation in Different Technologies |
| title_full_unstemmed | Evaluation of Spent Catalyst Structure Changes during Ethylbenzene Dehydrogenation in Different Technologies |
| title_short | Evaluation of Spent Catalyst Structure Changes during Ethylbenzene Dehydrogenation in Different Technologies |
| title_sort | evaluation of spent catalyst structure changes during ethylbenzene dehydrogenation in different technologies |
| topic | catalyst deactivation ethylbenzene dehydrogenation smart technology styrene |
| url | http://www.ijcce.ac.ir/article_25190_a3c0d6edfa5cab2fbefece94b4943843.pdf |
| work_keys_str_mv | AT amirnaserhaghlesan evaluationofspentcatalyststructurechangesduringethylbenzenedehydrogenationindifferenttechnologies AT rezaalizadeh evaluationofspentcatalyststructurechangesduringethylbenzenedehydrogenationindifferenttechnologies AT esmailfatehifar evaluationofspentcatalyststructurechangesduringethylbenzenedehydrogenationindifferenttechnologies |