The Myriad of NOx Control Decisions were analyzed in the Hot Topic
Hour December Third
The Hot Topic Hour yesterday was a review and discussion of the many NOx control options which are available. The slide deck, which was sequenced and discussed, is a guide to the NOx information which appears in Power Plant Air Quality Decisions (PPAQS).
• PPAQS is a system for NOx decision makers. It is available to operators (coal, cement, WTE, refining, etc.) at no charge and by subscription to others.
• Subscribers are encouraged to submit additional case histories and analyses for inclusion in the system.
• The current information in the system is quickly accessed by decisive key words, e.g., application, contaminant, product, process, and company.
• McIlvaine is pursuing improved classifications in multiple languages e.g., consensus on catalyst cleaning, rejuvenation and regeneration as the three maintenance options.
• Every corporation has a corporate number to identify all facilities in multiple languages. This is very important for Chinese companies where confusion reigns.
The contents of the slide deck were presented in 5 segments
|
1. Overview |
2. Options |
3. Options |
4. Factors |
5. System |
|
Overview |
Hybrid SCR/SNCR |
HG aggressive |
HG Oxidation |
Urea -Ammonia |
|
Integration in System |
SNCR/SCR China |
HG moderate |
System factors |
Pumps |
|
Control Options |
SNCR/SCR – Fuel Tech |
Catalyst HT |
MHPS HG Cat |
NH3 CEMS
options |
|
Reaction principles |
ROFA + LoTOx |
HT Experience |
Fuel Mercury |
Extractive pluses |
|
DeNOx vs. SO3
|
Burners/SCR/SNCR |
Ceram Cat Mgmt. |
Fuel Chlorine |
Extractive-UV |
|
Catalyst Poisoning |
LoTOx - AECOM |
CoaLogix Mgmt. |
Chlorine impact |
In situ pluses |
|
SCR Basics |
Linde LoTOx |
HC vs. Plate |
Bromine/ |
In situ-UV |
|
Tail End SCR |
Peroxide |
Cat. Filter
|
Bromine impact |
Mixers-Sulzer |
|
GT Simple Cycle |
Optimization Benefits |
Top Kat |
Temperature impact |
Need input on ammonia
quality and options from Yara, Koch, etc. |
|
GT Simple
factors |
Optimization-EPRI |
Catalyst
distribution |
NH3 impact |
|
|
NOx
Regulations |
CO/NOx/LOI Invensys |
Catalytic filter
Systems |
Catalyst
condition |
|
|
More on regulations in
each country but lots in system already. |
Hg Cat Management |
Catalytic F.
Applications |
Layer selection |
|
|
SNOx |
The major options for NOx reduction are catalysts and chemicals either applied individually or in combination. However, combustion, fuel and other parameters are also important.
|
DeNOx decisively classified options for coal, cement,
incineration |
||
|
Option |
* |
Details |
|
SCR |
E |
Ammonia injection followed by a catalytic reactor |
|
|
A |
High
efficiency and accepted by regulatory authorities |
|
|
D |
Cost, catalyst plugging, space |
|
SNCR |
E |
Urea
injection in the furnace |
|
|
A |
Low
cost, low maintenance, space |
|
|
D |
Low
efficiency, ammonia slip |
|
Ozone |
E |
Ozone injection followed by scrubber |
|
|
A |
Little space if scrubber already in place |
|
|
D |
Ozone cost, efficiency |
|
Hydrogen |
E |
Chemical injection converts to NO2 followed by scrubbing |
|
|
A |
Low
capital cost if scrubber already in place |
|
|
D |
Chemical cost |
|
Catalytic |
E |
Fabric filter has embedded catalyst |
|
|
A |
Lower footprint with combination, lower capital and operating cost |
|
|
D |
Lack
of experience |
|
* E= explanation, A=advantages
D=disadvantages |
||
Dave Repp of Johnson Matthey explained the window between 550°F-650°F is where ammonium bisulfate is formed.