Advanced sulfur control concepts in hot gas desulfurization technology. Quarterly report, April 1--June 30, 1996

Technical Report · Thu May 01 04:00:00 EDT 1997

DOI:https://doi.org/10.2172/474845· OSTI ID:474845

Experimental effort during the past quarter was restricted to the fixed-bed reactor. Effort during April was devoted to the sulfidation and regeneration of cerium oxide. Sulfidation tests were plagued by over-sulfidation, i.e., the quantity of H{sub 2}S removed from the gas phase exceeded the stoichiometric amount associated with the conversion of CeO{sub 2} to Ce{sub 2}O{sub 2}S. This was initially attributed to the formation of Ce{sub 2}S{sub 3} which was found to be thermodynamically possible in the highly reducing feed gas. However, the addition of steam to the feed gas to prevent Ce{sub 2}S{sub 3} formation did not eliminate the over-sulfidation problem. Later tests indicated that the apparent over-sulfidation was due to reaction between H{sub 2}S and the walls of the reaction vessel. Apparently the alonizing treatment to passivate the reactor walls was either ineffective at the reaction conditions or had deteriorated with use to the point that protection was no longer viable. Limited Ce{sub 2}O{sub 2}S regeneration results, although very qualitative, were quite favorable. In one regeneration test in an O{sub 2}-N{sub 2} atmosphere, no SO{sub 2} or H{sub 2}S were detected by the chromatograph in the regeneration product. Significant amounts of total sulfur were detected, and the test had to be terminated prematurely when elemental sulfur caused the product line leading to the chromatograph to plug. Experimental tests during May and June examined the regeneration of FeS as a function of temperature, gas feed composition, and gas flow rate. Complete regeneration was achieved with as much as 75% of the sulfur liberated in elemental form. Low regeneration temperature and large ratios of H{sub 2}O to O{sub 2} in the feed gas promote the formation of elemental sulfur. A number of changes in the reactor system were made during the quarter, including improvements to the sulfur condenser and filters on the reactor product line leading to the gas chromatograph.

• Research Organization: Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Chemical Engineering
• Sponsoring Organization: USDOE Assistant Secretary for Fossil Energy, Washington, DC (United States)
• DOE Contract Number: AC21-94MC30012
• OSTI ID: 474845
• Report Number(s): DOE/MC/30012--5306; ON: DE97052342
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ADSORBENTS
CERIUM OXIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTORS
DESULFURIZATION
EXPERIMENTAL DATA
FLUE GAS
HOT GAS CLEANUP
HYDROGEN SULFIDES
PROGRESS REPORT
REGENERATION
REMOVAL
SULFIDATION