Catalyst Laboratory

Yuseong gu, South Korea

Catalyst Laboratory

Yuseong gu, South Korea
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Nguyen-Huy C.,University of Ulsan | Kweon H.,University of Ulsan | Kim H.,University of Ulsan | Kim D.K.,Catalyst Laboratory | And 3 more authors.
Applied Catalysis A: General | Year: 2012

In this study, red mud (RM) was used as a catalyst in slurry-phase hydrocracking of vacuum residue (VR) in batch system. Without RM, thermal cracking occurred and a lighter fraction and higher conversion was achieved than in the presence of catalyst. However, the catalytic cracking obviously inhibited both the coke formation and residue cracking reaction. We investigated the influence of reaction temperature, reaction time and RM concentration on VR conversion. Reaction temperature and time significantly improved the yield of naphtha, diesel and vacuum gas oil; unfortunately, they also increased the gas fraction, which is an undesirable product. Catalyst concentration negligibly affected the VR conversion while vacuum gas oil fraction in product distribution increased with catalyst concentration, indicating that the cracking reaction was suppressed in the presence of catalyst. Through the characterization of fresh and spent catalysts by diverse techniques, it has been determined that the crystalline iron oxide of RM transforms into pyrrhotite (Fe (x-1)Sx), an active phase for the hydrocracking reaction, due to presence of sulfur in VR. Our results show that RM is possibly self-activated during the reaction and the pretreatment step can be eliminated. © 2012 Elsevier B.V.


Nguyen-Huy C.,University of Ulsan | Pham V.H.,University of Ulsan | Kim D.K.,Catalyst Laboratory | Kim D.-W.,Catalyst Laboratory | And 4 more authors.
Applied Catalysis A: General | Year: 2013

To improve the catalytic performance of red mud (RM) for slurry-phase hydrocracking of vacuum residue, macro-mesoporosity was introduced into RM using polystyrene and Pluronic F-127 as co-templates in this study. The obtained macro-mesoporous red mud (Ma-RM) catalysts were characterized by nitrogen adsorption, X-ray diffraction, ammonia temperature-programmed desorption, scanning electron microscopy, and transition electron microscopy. Subsequently, they were applied to the slurry-phase hydrocracking of vacuum residue at 490 C for 2 h. Comparative reaction tests revealed that Ma-RM exhibited better catalytic behavior for the VR hydrocracking compared to activated RM without macropores. Ma-RM successfully suppressed coke formation and increased liquid yield in products distribution. The macroporous structure of Ma-RM was connected by mesopores containing active sites for hydrogenation. The presence of a macro-mesoporous structure enhanced hydrogenation over the catalysts due to better accessibility to the active sites for hydrogenation, which induced less coke and more liquid yield. © 2013 Elsevier B.V. All rights reserved.


Nguyen-Huy C.,University of Ulsan | Kim H.,University of Ulsan | Kweon H.,University of Ulsan | Kim D.K.,University of Ulsan | And 3 more authors.
Chemical Engineering and Technology | Year: 2013

A disposable iron-based catalyst, red mud, was modified by different dissolution-precipitation methods. The catalysts obtained were characterized by nitrogen adsorption, X-ray diffraction, scanning electron microscopy, and ammonia temperature-programmed desorption. They were tested for slurry-phase hydrocracking of vacuum residue in a batch reactor. The red-mud catalyst activated by phosphoric acid showed the highest catalytic activity since the activation by phosphoric acid resulted in the decrease in particle size which facilitated the transformation of red mud to the active sulfide form in the reaction. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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