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Title: Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases

Abstract

A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.

Inventors:
 [1]
  1. Bethel Park, PA
Issue Date:
Research Org.:
Pittsburgh Energy Technology Center
OSTI Identifier:
866005
Patent Number(s):
4615780
Assignee:
United States of America as represented by United States (Washington, DC)
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; removing; oxides; sulfur; nitrogen; exhaust; gases; continuous; combustion; regeneration; absorbent; gas; cleaned; particulates; hcl; water; scrub; prior; contact; liquid; aqueous; solution; bisulfite; sulfite; metal; chelate; iron; zinc; aminopolycarboxylic; acid; following; spent; subjected; electrodialysis; transfer; sulfuric; splitting; hydroxide; hydrogen; migration; equalize; electrical; charge; stack; alternate; layers; anion; selective; bipolar; membranes; removed; air; stripping; elevated; temperature; regenerated; returned; removal; liquid absorbent; nitrogen oxide; electrical charge; sulfur oxide; sulfur oxides; alternate layers; acid solution; nitrogen oxides; exhaust gases; aqueous solution; elevated temperature; sulfuric acid; combustion gases; carboxylic acid; combustion gas; exhaust gas; metal chelate; splitting water; removing oxide; removing oxides; continuous method; aminopolycarboxylic acid; /204/423/

Citation Formats

Walker, Richard J. Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases. United States: N. p., 1986. Web.
Walker, Richard J. Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases. United States.
Walker, Richard J. Wed . "Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases". United States. https://www.osti.gov/servlets/purl/866005.
@article{osti_866005,
title = {Method of removing oxides of sulfur and oxides of nitrogen from exhaust gases},
author = {Walker, Richard J},
abstractNote = {A continuous method is presented for removing both oxides of sulfur and oxides of nitrogen from combustion or exhaust gases with the regeneration of the absorbent. Exhaust gas is cleaned of particulates and HCl by a water scrub prior to contact with a liquid absorbent that includes an aqueous solution of bisulfite and sulfite ions along with a metal chelate, such as, an iron or zinc aminopolycarboxylic acid. Following contact with the combustion gases the spent absorbent is subjected to electrodialysis to transfer bisulfite ions into a sulfuric acid solution while splitting water with hydroxide and hydrogen ion migration to equalize electrical charge. The electrodialysis stack includes alternate layers of anion selective and bipolar membranes. Oxides of nitrogen are removed from the liquid absorbent by air stripping at an elevated temperature and the regenerated liquid absorbent is returned to contact with exhaust gases for removal of sulfur oxides and nitrogen oxides.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1986},
month = {1}
}

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