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Title: Direct catalytic decomposition of nitric oxide. Final report

Abstract

This project investigated a suitable catalyst system for the direct NO decomposition for post-combustion NO{sub x} control. The studied process does not use a reductant, such as ammonia in the case of Selective Catalytic Reduction (SCR) process for catalytic reduction of NO{sub x} to nitrogen. This is a simplified process basically involving passing the flue gas through a catalytic converter, thus avoiding problems generally associated with the commercial SCR process, namely high operating cost, ammonia slip, and potential N{sub 2}O emissions. The main results from this research project are summarized in the following: Cu-ZSM-5 and M/Cu-ZSM-5 were synthesized by incorporating metal cations into ZSM-5 zeolite supports by optimized ion exchange procedures. It was found that (1) the catalytic activity of Cu-ZSM-5 only increased with copper loading when the Cu-ZSM-5 was prepared in an aqueous copper acetate solution with pH lower than 5.74; (2) high pH of the solution led not only to ion-exchanged Cu{sup 2+}, but also copper deposition on the zeolite surface forming inactive CuO particles as identified by STEM/EDX and XRD; (3) the sequence of metal ion exchange first, followed by copper ion exchange to synthesize M/Cu-ZSM-5, where M represents any metal ion but copper, was important formore » the cocation to show promotion effects; and (4) air-calcination of M-ZSM was effective in keeping M cations in the zeolite during subsequent copper ion exchange. Positive alkaline and rare earth metal cocation effects on the Cu-ZSM-5 were identified in oxygen-containing gas mixtures in the high temperature region (450--600C). Cerium ion promoted the Cu-ZSM-5 activity in the low temperature range (< 450C) in oxygen-free gas mixture, while alkaline earth and transition metal cocations improved the NO conversion to N{sub 2} in high temperature region.« less

Authors:
; ;
Publication Date:
Research Org.:
Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
111932
Report Number(s):
DOE/PC/91293-T5
ON: DE95017760
DOE Contract Number:  
FG22-91PC91293
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 15 Jun 1995
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; 20 FOSSIL-FUELED POWER PLANTS; 54 ENVIRONMENTAL SCIENCES; FLUE GAS; DENITRIFICATION; NITRIC OXIDE; SELECTIVE CATALYTIC REDUCTION; COPPER; CATALYTIC EFFECTS; ZEOLITES; CERIUM; DECOMPOSITION; PROGRESS REPORT; EXPERIMENTAL DATA

Citation Formats

Flytzani-Stephanopoulos, M, Sarofim, A F, and Zhang, Yanping. Direct catalytic decomposition of nitric oxide. Final report. United States: N. p., 1995. Web. doi:10.2172/111932.
Flytzani-Stephanopoulos, M, Sarofim, A F, & Zhang, Yanping. Direct catalytic decomposition of nitric oxide. Final report. United States. doi:10.2172/111932.
Flytzani-Stephanopoulos, M, Sarofim, A F, and Zhang, Yanping. Thu . "Direct catalytic decomposition of nitric oxide. Final report". United States. doi:10.2172/111932. https://www.osti.gov/servlets/purl/111932.
@article{osti_111932,
title = {Direct catalytic decomposition of nitric oxide. Final report},
author = {Flytzani-Stephanopoulos, M and Sarofim, A F and Zhang, Yanping},
abstractNote = {This project investigated a suitable catalyst system for the direct NO decomposition for post-combustion NO{sub x} control. The studied process does not use a reductant, such as ammonia in the case of Selective Catalytic Reduction (SCR) process for catalytic reduction of NO{sub x} to nitrogen. This is a simplified process basically involving passing the flue gas through a catalytic converter, thus avoiding problems generally associated with the commercial SCR process, namely high operating cost, ammonia slip, and potential N{sub 2}O emissions. The main results from this research project are summarized in the following: Cu-ZSM-5 and M/Cu-ZSM-5 were synthesized by incorporating metal cations into ZSM-5 zeolite supports by optimized ion exchange procedures. It was found that (1) the catalytic activity of Cu-ZSM-5 only increased with copper loading when the Cu-ZSM-5 was prepared in an aqueous copper acetate solution with pH lower than 5.74; (2) high pH of the solution led not only to ion-exchanged Cu{sup 2+}, but also copper deposition on the zeolite surface forming inactive CuO particles as identified by STEM/EDX and XRD; (3) the sequence of metal ion exchange first, followed by copper ion exchange to synthesize M/Cu-ZSM-5, where M represents any metal ion but copper, was important for the cocation to show promotion effects; and (4) air-calcination of M-ZSM was effective in keeping M cations in the zeolite during subsequent copper ion exchange. Positive alkaline and rare earth metal cocation effects on the Cu-ZSM-5 were identified in oxygen-containing gas mixtures in the high temperature region (450--600C). Cerium ion promoted the Cu-ZSM-5 activity in the low temperature range (< 450C) in oxygen-free gas mixture, while alkaline earth and transition metal cocations improved the NO conversion to N{sub 2} in high temperature region.},
doi = {10.2172/111932},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {6}
}