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Title: Mercury removal in utility wet scrubber using a chelating agent

Abstract

A method for capturing and reducing the mercury content of an industrial flue gas such as that produced in the combustion of a fossil fuel or solid waste adds a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) or other similar compounds like HEDTA, DTPA and/or NTA, to the flue gas being scrubbed in a wet scrubber used in the industrial process. The chelating agent prevents the reduction of oxidized mercury to elemental mercury, thereby increasing the mercury removal efficiency of the wet scrubber. Exemplary tests on inlet and outlet mercury concentration in an industrial flue gas were performed without and with EDTA addition. Without EDTA, mercury removal totaled 42%. With EDTA, mercury removal increased to 71%. The invention may be readily adapted to known wet scrubber systems and it specifically provides for the removal of unwanted mercury both by supplying S.sup.2- ions to convert Hg.sup.2+ ions into mercuric sulfide (HgS) and by supplying a chelating agent to sequester other ions, including but not limited to Fe.sup.2+ ions, which could otherwise induce the unwanted reduction of Hg.sup.2+ to the form, Hg.sup.0.

Inventors:
 [1]
  1. Louisville, OH
Issue Date:
Research Org.:
BABCOCK & WILCOX CO
OSTI Identifier:
874159
Patent Number(s):
6328939
Assignee:
McDermott Technology, Inc. (New Orleans, LA)
Patent Classifications (CPCs):
B - PERFORMING OPERATIONS B01 - PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL B01D - SEPARATION
DOE Contract Number:  
FC22-94PC94251
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
mercury; removal; utility; wet; scrubber; chelating; agent; method; capturing; reducing; content; industrial; flue; gas; produced; combustion; fossil; fuel; solid; waste; adds; ethylenediaminetetraacetic; acid; edta; similar; compounds; hedta; dtpa; andor; nta; scrubbed; process; prevents; reduction; oxidized; elemental; increasing; efficiency; exemplary; tests; inlet; outlet; concentration; performed; addition; totaled; 42; increased; 71; readily; adapted; systems; specifically; provides; unwanted; supplying; ssup2-; convert; hgsup2; mercuric; sulfide; hgs; sequester; including; limited; fesup2; otherwise; induce; form; hgsup0; flue gas; chelating agent; elemental mercury; wet scrubber; /423/

Citation Formats

Amrhein, Gerald T. Mercury removal in utility wet scrubber using a chelating agent. United States: N. p., 2001. Web.
Amrhein, Gerald T. Mercury removal in utility wet scrubber using a chelating agent. United States.
Amrhein, Gerald T. Mon . "Mercury removal in utility wet scrubber using a chelating agent". United States. https://www.osti.gov/servlets/purl/874159.
@article{osti_874159,
title = {Mercury removal in utility wet scrubber using a chelating agent},
author = {Amrhein, Gerald T},
abstractNote = {A method for capturing and reducing the mercury content of an industrial flue gas such as that produced in the combustion of a fossil fuel or solid waste adds a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) or other similar compounds like HEDTA, DTPA and/or NTA, to the flue gas being scrubbed in a wet scrubber used in the industrial process. The chelating agent prevents the reduction of oxidized mercury to elemental mercury, thereby increasing the mercury removal efficiency of the wet scrubber. Exemplary tests on inlet and outlet mercury concentration in an industrial flue gas were performed without and with EDTA addition. Without EDTA, mercury removal totaled 42%. With EDTA, mercury removal increased to 71%. The invention may be readily adapted to known wet scrubber systems and it specifically provides for the removal of unwanted mercury both by supplying S.sup.2- ions to convert Hg.sup.2+ ions into mercuric sulfide (HgS) and by supplying a chelating agent to sequester other ions, including but not limited to Fe.sup.2+ ions, which could otherwise induce the unwanted reduction of Hg.sup.2+ to the form, Hg.sup.0.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2001},
month = {Mon Jan 01 00:00:00 EST 2001}
}

Works referenced in this record:

Advanced Emissions Control Development Program
report, March 2001


Uptake of Elemental Mercury Vapors by Activated Carbons
journal, March 1996


Enhanced control of mercury emissions through modified speciation
report, July 1997


Advanced Emissions Control Development Program
report, October 1998