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A Novel, Green Technology for the Production of Aromatic Thiol from Aromatic Sulfonyl Chloride

The hydrogenation of aromatic sulfonyl chloride to produce aromatic thiol is an
important industrial reaction. The aromatic thiol is a critical intermediate in the
production of many pharmaceuticals as well as several agrochemicals. Density
Functional Theory (DFT), a quantum mechanical method, was used to investigate the
new aromatic thiol production technology at the molecular level in aspects including
reaction species adsorption and transition state determination. Plant design methods and
economic analysis were performed to determine the economic feasibility of the new
technology in the current specialty chemicals market.
The quantum mechanical calculations showed that the molecules adsorbed to three
simulated (100) Pd catalyst surfaces will preferentially move to configurations that are
favorable for reaction progression. The calculations also show that the proposed reaction
sequence by DuPont is the most feasible option despite the investigation into an
alternative sequence that arose from molecular observations during calculations.
Predicted activation energies (Ea) were in the range of 6.88 ? 38.1 kcal/mol which is comparable to the 14.58 kcal/mol determined experimentally by DuPont, and the
differences between experimental and simulated values are easily explained.
Plant design calculations show that a semi-batch reactor plant can easily produce 2MM
lb of thiol/year, giving the owner of the plant an immediate 18% market share in the
worldwide market of benzenethiol. Economic analysis shows that a grassroots plant
construction is not currently an economically feasible option for corporate investment
unless a source of cheap, skilled labor can be found in addition to a means of a 25%
discount on certain raw material feed stocks. However, if both of these requirements can
be fulfilled then new plant construction will have a payback time of 3.71 years based on
the price of benzenethiol in the summer of 2007, $2.27/lb thiol.

Identiferoai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2008-05-15
Date16 January 2010
CreatorsAtkinson, Bradley R.
ContributorsAnthony, Rayford G.
Source SetsTexas A and M University
Languageen_US
Detected LanguageEnglish
TypeBook, Thesis, Electronic Dissertation
Formatapplication/pdf

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