Thursday, November 18, 2010

Thanks, I’m Just Browsing

“The high-ceilinged rooms, the little balconies, alcoves, nooks and angles all suggest sanctuary, escape, creature comfort. The reader, the scholar, the browser, the borrower is king.” -- David McCord (American Poet and Writer, 1897-1997)

Not for nothing are apps like Internet Explorer called “browsers”. Here are a few items I found during a recent browsing expedition. I wasn’t looking for them specifically, but they interested me enough to post them for your consideration.

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Catalysis Today
[PDF]
Catalysts for ultra deep hydrodesulfurization and/or aromatics ...
File Format: PDF/Adobe Acrobat - Quick View
by Y YOSHIMURA - Related articles
In developing the ultra deep hydrodesulfurization (HDS) catalysts, lots of efforts ... development in the catalyst preparation technology to produce and ...
Source: www.kfupm.edu.sa/catsymp/Symp%2017th/08YOSHIMURA.pdf
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[PDF]
Spectroscopic and Kinetic Studies of Hydrodenitrogenation and Hydrodesulfurization over Supported Nickel Phosphide (Ni2P)
Travis Matthew Gott (2008)
Dissertation submitted to the faculty of Virginia Polytechnic Institute and State
necessitates catalysts that are ~ 7 times more active than existing catalysts [1]. For these
reasons a new generation of hydrotreating catalysts are needed. Several studies have
shown that a new class of materials, transition metal phosphides, are highly active under
conditions of deep HDS in the presence of nitrogen compounds and have the potential of
being the next generation of hydrotreating catalysts [6].

The review by Song [1] comprehensively covers various process options for
removal of sulfur including standard hydroprocessing, but also alternative and emerging
processes such as catalytic distillation, reactive adsorption, polar molecule adsorption,
selective adsorption, selective extraction, selective alkylation, membrane separation, and
caustic extraction. In addition to these there is also biodesulfurization, oxidative
desulfurization and ultrasound-assisted oxidative desulfurization [40]. These methods
will be covered briefly.
Source: http://scholar.lib.vt.edu/theses/available/etd-11112008-42534/unrestricted/TGottDissertation_Revised.pdf
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Article in Press, Corrected Proof
Catalyst development for ultra-deep hydrodesulfurization (HDS) of dibenzothiophenes. I: Effects of Ni promotion in molybdenum-based catalysts
Qiang Gao(a), Thomas N.K. Ofosu(a), Shu-Guo Ma(a), Vasileios G. Komvokis(a), Christopher T. Williams(a) and Koichi Segaw(a) (kohichi@cec.sc.edu)
(a) Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208-4101, United States
Available online 5 November 2010.
Abstract
A strong synergistic effect of nickel and molybdenum was observed for hydrodesulfurization (HDS) of dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) over highly active Ni-MoS2/γ-Al2O3 catalysts. The surface of the most active catalyst in this study was composed by Ni:Mo = 1:3, which was determined by XPS results. In addition, catalytic behavior indicates the presence of two different adsorption models accounting for the DDS (direct desulfurization) and the HYD (hydrogenation) pathways. The structure of the NiMoS active phase appears to be identical regardless of Ni/(Ni + Mo) ratio. The reaction sequence of the DDS pathways is DBT > 4-MDBT > 4,6-DMDBT due to the steric hindrance of methyl groups located adjacent to the sulfur atom of DBT, which prevents σ-bonding of the sulfur to the active site within the NiMoS phase. The reaction rates of HYD pathways are independent of the number of methyl groups, suggesting that the alkyl groups do not interfere the π-adsorption of DBTs on the active sites.
Keywords: Hydrodesulfurization (HDS); Ni promoter; MoS2 catalyst; Dibenzothiophene (DBT); X-ray photoelectron spectroscopy (XPS)
Source: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFG-51D5RN1-3&_user=10&_coverDate=11%2F05%2F2010&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1546433393&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=066bc3d0e28e4e4a96931758afac87dc&searchtype=a
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Remember to browse the Desulfurization Blog (http://www.desulf.blogspot.com/) for tips and tricks on maximizing online research effectiveness in your area of expertise

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