Chemistry of inorganic compounds – Modifying or removing component of normally gaseous mixture – Nitrogen or nitrogenous component
Patent
1999-07-26
2000-11-14
Griffin, Steven P.
Chemistry of inorganic compounds
Modifying or removing component of normally gaseous mixture
Nitrogen or nitrogenous component
423235, B01J 800, C01B 2100
Patent
active
061466050
ABSTRACT:
In many situations where the maximum NOx reduction capabilities of conventional SCR systems are not necessary, and alternative SNCR systems may not economically provide desired NOx reduction, a staged SCR/SNCR system is believed to be the most appropriate solution available. By means of the present invention, a system has been developed for delivering NOx reduction agents from a common urea feedstock, when it appropriate to use combined NOx treatment stages (i.e. SNCR within the boiler followed by in-duct SCR and/or catalyzed air preheater elements). For the SNCR stage, the urea from the common feedstock is diluted prior to injection into the boiler and, for the SCR stage, the urea from the common feedstock is used to produce ammonia using hydrolysis. Urea solution which is not converted to ammonia in the SCR phase, is used for dilution of the solution being delivered to the SNCR system.
REFERENCES:
patent: 4220635 (1980-09-01), Schell
patent: 4302431 (1981-11-01), Atsukawa et al.
patent: 4602673 (1986-07-01), Michelfelder et al.
patent: 4978514 (1990-12-01), Hofmann et al.
patent: 4981660 (1991-01-01), Leach
patent: 5057293 (1991-10-01), Epperly et al.
patent: 5139754 (1992-08-01), Luftglass et al.
patent: 5233934 (1993-08-01), Krigmont et al.
patent: 5240688 (1993-08-01), von Harpe et al.
patent: 5252308 (1993-10-01), Young
patent: 5281403 (1994-01-01), Jones
patent: 5286467 (1994-02-01), Sun et al.
patent: 5399325 (1995-03-01), von Harpe et al.
patent: 5510092 (1996-04-01), Monsour et al.
patent: 5543123 (1996-08-01), Hofmann et al.
patent: 5853683 (1998-12-01), Gibbons et al.
Huhmann et al., "Evaluation of Retrofitted Post Combustion No.sub.x Control Technology on a Wet Bottom, Coal Fired Utility Boiler," May 15-16 1997, 19 pages, Symposium.
Johnson et al., "Combination of SNCR and SCR NO.sub.x Emission Control Systems. Synergetic Effects and Customer Benefits," Dec. 4-6, 1996, 26 pages, Symposium.
Wallace et al., "Selective Catalytic Reduction Performance Project at Public Services Electric and Gas Company's Mercer Generating Station, Unit No. 2," Symposium, Spring 1995, 22 pages.
Wahlco, "Staged NO.sub.x Reduction System," brochure, 1997, 6 pages, Santa Ana, California.
Fuel Tech, "NO.sub.x OUT Cascade", brochure, 1999, 3 pages, Batavia, Illinois.
Siemens, "SINO.sub.x Catalysts: The Best Solution for Nitrogen-Oxide Reduction ", brochure, 10 pages, Germany.
BASF, "BASF DeNO.sub.x Catalysts," brochure, 19 pages, Germany.
Griffin Steven P.
Hera, LLC
Medina Maribel
Sandler Howard E.
LandOfFree
Combined SCR/SNCR process does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Combined SCR/SNCR process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Combined SCR/SNCR process will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2062192