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Title: Microbial reduction of SO{sub 2} and NO{sub x} as a means of by- product recovery/disposal from regenerable processes for the desulfurization of flue gas. Technical progress report, June 11, 1992--September 11, 1992

Based on the work described simultaneous SO{sub 2}/No{sub x} removal from flue gas based on direct contact of the gas with SRB and T. denitrificans co-cultures or cultures-in-series has been eliminated as a viable process concept at this time. The technical reasons are as follows: (1) NO inhibition of SO{sub 2} reduction by D. desulfuricans - Although the NO concentrations used in the experiments described above are somewhat higher than that found in a typical flue gas, it is quite possible that at lower NO concentrations (or partial pressures) the inhibiting effects will simply take longer to become apparent. (2) Nitrate suppression of NO removal - As noted previously, the cultivation of T. denitrificans in a microbial flue gas treatment system (either one or two stages) would require sulfide-limiting conditions. Therefore, the electron acceptor must be in excess, requiring nitrate in the T. denitrificans process culture. As shown in experiments described above, nitrate significantly suppresses the removal of NO from a feed gas making simultaneous SO{sub 2}/NO{sub x} removal impractical by microbial means. (3) O{sub 2} inhibition of SO{sub 2} and NO reduction - It has been demonstrated that D. desulfuricans working cultures are tolerant of up to 1.7% O{submore » 2} in the feed gas. However, further increases in the O{sub 2} partial pressure in the feed gas resulted in O{sub 2} inhibition of SO{sub 2} reduction. These inhibiting levels of O{sub 2} are comparable to those concentrations found in flue gases (3). Therefore, in any process in which raw flue gas contacts a D. desulfuricans culture marginal stability at best can be expected.« less
Authors:
Publication Date:
OSTI Identifier:
10109692
Report Number(s):
DOE/PC/90096--T4
ON: DE93006002
DOE Contract Number:
FG22-90PC90096
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: [1992]
Research Org:
Tulsa Univ., OK (United States). Center for Environmental Research and Technology
Sponsoring Org:
USDOE, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
20 FOSSIL-FUELED POWER PLANTS; 01 COAL, LIGNITE, AND PEAT; 59 BASIC BIOLOGICAL SCIENCES; FLUE GAS; DESULFURIZATION; DENITRIFICATION; FEASIBILITY STUDIES; DESULFOVIBRIO; CULTURE MEDIA; SULFUR DIOXIDE; BIOCONVERSION; NITROUS OXIDE; THIOBACILLUS FERROXIDANS; PROGRESS REPORT; BIOTECHNOLOGY; FOSSIL-FUEL POWER PLANTS; BIOREACTORS; SULFATE-REDUCING BACTERIA; MOLASSES; SEWAGE 200202; 014000; 550700; NOXIOUS GAS AND PARTICULATE EMISSIONS; COMBUSTION; MICROBIOLOGY