Evaluation of Spent Catalyst Structure Changes during Ethylbenzene Dehydrogenation in Different Technologies
Authors
Abstract:
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.
similar resources
The Effect of Addition of ppm-Order-Pd to Fe-K Catalyst on Dehydrogenation of Ethylbenzene
full text
Lanthanoid-free perovskite oxide catalyst for dehydrogenation of ethylbenzene working with redox mechanism
For the development of highly active and robust catalysts for dehydrogenation of ethylbenzene (EBDH) to produce styrene; an important monomer for polystyrene production, perovskite-type oxides were applied to the reaction. Controlling the mobility of lattice oxygen by changing the structure of Ba1 - x SrxFe y Mn1 - y O3 - δ (0 ≤ x ≤ 1, 0.2 ≤ y ≤ 0.8), perovskite catalyst showed higher activity ...
full textRole Of CO2 As a Soft Oxidant For Dehydrogenation of Ethylbenzene to Styrene over a High-Surface-Area Ceria Catalyst
Catalytic performance and the nature of surface adsorbates were investigated for high-surface-area ceria during the ethylbenzene oxidative dehydrogenation (ODH) reaction using CO2 as a soft oxidant. The high surface area ceria material was synthesized using a template-assisted method. The interactions among ethylbenzene, styrene, and CO2 on the surface of ceria and the role of CO2 for the ethyl...
full textHomogeneous Catalyst for Alkane Dehydrogenation
The removal of hydrogen from alkanes to give alkenes is an important commercial objective, as alkenes are widely used as organic feedstocks in industrial processes involving chemical synthesis and polymerisation. This reaction is, however, significantly endothermic, needing up to 30 kcal per mole, and normally occurring at temperatures exceeding 400°C in the presence of heterogeneous supported ...
full textPorous graphene-based material as an efficient metal free catalyst for the oxidative dehydrogenation of ethylbenzene to styrene.
Reduced porous graphene oxide as a metal free catalyst was selected for the oxidative dehydrogenation of ethylbenzene to styrene. It showed the best catalytic performance compared with other carbon materials (routinely reduced graphene oxide, graphite powder and oxidized carbon nanotubes) and commercial iron oxide.
full textevaluation of sadr eminence in safavid period
چکیده: یکی از دوره های مهم تاریخی ایران به لحاظ تأمین استقلال ملی مذهبی و حتی تأثیر آن بر فرهنگ و مذهب ایرانیان، دوره صفویه است. رسمیت دادن و رواج مذهب شیعه توسط شاه اسماعیل اول، یکی از مهمترین اقدامات این دولت محسوب می شود. بنابراین برای اجرای این سیاست، وی منصب صدارت را به عنوان منصبی مذهبی- حکو متی ایجاد کرد .این منصب از دوره ی تیموریان ایجاد شده بود ولی در اواخر این دوره اهمیت بیشتری یافت...
15 صفحه اولMy Resources
Journal title
volume 36 issue 1
pages 45- 57
publication date 2017-03-01
By following a journal you will be notified via email when a new issue of this journal is published.
Hosted on Doprax cloud platform doprax.com
copyright © 2015-2023