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Title: Ultrasound-promoted chemical desulfurization of Illinois coals

Technical Report ·
OSTI ID:5304417

Ultrasound can increase the rates of chemical reactions by many orders of magnitude at conditions much less severe than if the process were conducted without ultrasound. IGT proposed this work to promote chemical reactions that remove organic sulfur from coal using ultrasound at relatively mild conditions. Two model compounds (dibenzyl sulfide (DBS) and dibenzothiophene (DBT)) impregnated on a carbon substrate, and two coals from the Illinois Basin Coal Sample Program were used for this study. A number of agents, oxidizing chemicals and hydroperoxide precursors, were employed to react with organically bound sulfur in a variety of media. Desulfurization tests were conducted in a low-intensity ultrasonic bath unit and a high-intensity bench-scale ultrasonic unit. Results showed that DBS can be partially decomposed under milder conditions than those required for DBT. Hydrogen peroxide (H{sub 2}O{sub 2}) and tert-butyl hydroperoxide (TBPO) in acetic acid solution were the most effective for oxidation of DBS and DBT. Mo(CO){sub 6} catalyst was effective for oxidative desulfurization of the C-DBS and C-DBT model coals. Ultrasonic irradiation appears to promote the oxidative reactions of DBS and DBT through its kinetic effect of transporting oxidants onto the DBS and DBT sites on the carbon substrate. Increasing the reactor pressure to 100 psig did not affect the overall DBT conversion. However, hydroperoxide precursors, such as tetralin and decalin (used neat) under 100 psig oxygen converted a small amount of DBT to DBT sulfoxide. A limited number of tests were conducted with IBC-101 coal using H{sub 2}O{sub 2} and TBPO in acetic acid. About 60% of the pyritic sulfur or 20% total sulfur was removed. 8 refs., 1 fig., 5 tabs.

Research Organization:
Institute of Gas Technology, Chicago, IL (United States)
Sponsoring Organization:
USDOE; USDOE, Washington, DC (United States)
DOE Contract Number:
FG22-90PC90176
OSTI ID:
5304417
Report Number(s):
DOE/PC/90176-T41; ON: DE91018305
Country of Publication:
United States
Language:
English