Process for simultaneous removal of SO[sub 2] and NO[sub x] from gas streams

Patent · Tue Feb 03 00:00:00 EST 1987

OSTI ID:7260483

Rosenberg, H S

A process is described for simultaneous removal of SO[sub 2] and NO[sub x] from a gas stream that includes flowing the gas stream to a spray dryer and absorbing a portion of the SO[sub 2] content of the gas stream and a portion of the NO[sub x] content of the gas stream with ZnO by contacting the gas stream with a spray of an aqueous ZnO slurry; controlling the gas outlet temperature of the spray dryer to within the range of about a 0 to 125 F approach to the adiabatic saturation temperature; flowing the gas, unreacted ZnO and absorbed SO[sub 2] and NO[sub x] from the spray dryer to a fabric filter and collecting any solids therein and absorbing a portion of the SO[sub 2] remaining in the gas stream and a portion of the NO[sub x] remaining in the gas stream with ZnO; and controlling the ZnO content of the aqueous slurry so that sufficient unreacted ZnO is present in the solids collected in the fabric filter to react with SO[sub 2] and NO[sub x] as the gas passes through the fabric filter whereby the overall feed ratio of ZnO to SO[sub 2] plus NO[sub x] is about 1.0 to 4.0 moles of ZnO per of SO[sub 2] and about 0.5 to 2.0 moles of ZnO per mole of NO[sub x]. Particulates may be removed from the gas stream prior to treatment in the spray dryer. The process further allows regeneration of ZnO that has reacted to absorb SO[sub 2] and NO[sub x] from the gas stream and acid recovery. 4 figs.

• DOE Contract Number: AC22-83PC60264
• Assignee: Battelle Memorial Inst., Columbus, OH (United States)
• Patent Number(s): US 4640825; A
• Application Number: PPN: US 6-716290
• OSTI ID: 7260483
• Resource Relation: Patent File Date: 26 Mar 1985
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ADSORBENTS
REGENERATION
FLUE GAS
DENITRIFICATION
DESULFURIZATION
ADSORPTION
AIR POLLUTION CONTROL
FABRIC FILTERS
NITROGEN OXIDES
SPRAY DRYING
SULFUR DIOXIDE
ZINC OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CONTROL
DRYING
FILTERS
GASEOUS WASTES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL
SORPTION
SULFUR COMPOUNDS
SULFUR OXIDES
WASTES
ZINC COMPOUNDS
010800* - Coal
Lignite
& Peat- Waste Management