KINETICS OF Mn-BASED SORBENTS FOR HOT COAL GAS DESULFURIZATION

Technical Report · Sun Jun 15 04:00:00 EDT 1997

DOI:https://doi.org/10.2172/7547· OSTI ID:7547

SADECKI, K A; HEPWORTH, M T

Manganese-based sorbents have been investigated for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases. Four formulations of Mn-based sorbents were tested in an ambient-pressure fixed-bed reactor to determine steady state H₂S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. In previous reports, the sulfidation and regeneration results from cyclic testing done at 550 and 600 °C were presented. Manganese-based sorbents with molar ratios > 1:1 Mn:Substrate were effective in reducing the H₂S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent at 600 °C. Regeneration tests determined that loaded pellets can be essentially completely regenerated in air/steam mixture at 750 °C with minimal sulfate formation. In this report, the performance of the leading formulation (designated C6-2) was investigated for high temperature removal of H₂S from simulated coal-derived fuel gas under varying sorbent induration temperature, reaction temperature, and superficial gas velocity. Sulfidation experiments were performed in an ambient pressure fixed-bed reactor between 500 °C and 600 °C. Four tests were conducted with each test consisting of four cycles of sulfidation and regeneration. Results showed that the induration temperature of the sorbent and the reaction temperature greatly affected the H₂S removal capacity of the sorbent while the superficial gas velocity between 1090 and 1635 cm/min had minimal affect on the sorbent's breakthrough capacity. Sorbent also showed 30 to 53% loss of its strength over four cycles of sulfidation and regeneration. The former being sorbent indurated at 1115 °C and the prior being sorbent indurated at 1100 °C.

• Research Organization: Federal Energy Technology Center (FETC), Morgantown, WV, and Pittsburgh, PA
• Sponsoring Organization: USDOE
• DOE Contract Number: FG22-94PC94212
• OSTI ID: 7547
• Report Number(s): DE-FG22-94PC94212--10; ON: DE00007547
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
Adsorbents
Chemical Reaction Kinetics
Coal Gas
Desulfurization
Manganese