Factors affecting nitrogen oxides in sulfur flue gas
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This post was last edited by liaifeng on 2018-9-1 at 18:17. My flue gas nitrogen oxide levels are generally around 20-30 mg/m3. The operation of the facility has been relatively stable recently, but the nitrogen oxide levels fluctuate between 20-100 mg/m3; I’m not sure why. No adjustments or parameters that seem to be related to this have been identified for now. May I ask, what are the factors that affect nitrogen oxides?
The nitrogen oxides levels in sulfur-containing flue gas are relatively low, ranging between 8 and 12 mg/m3; let’s first check the table
Although nitrogen oxides are not an evaluation indicator, I have also been paying attention to the trends in this value recently! I’m not sure if you’ve noticed the impact of the air flow ratio in the three stages of the incinerator, or more specifically in the first two stages, on nitrogen compounds. I spent a whole day observing yesterday and indeed found that there is an impact, but the degree of variation isn’t as significant as yours.
The table has been verified and compared; it is accurate. I’m now wondering if it’s due to unstable solvent absorption, with amines being carried into the incinerator, causing this problem?
Do you mean that the amine solution was brought into the incinerator? This possibility is probably low, after all, the temperature of the absorption system can’t be that high! It is recommended that you adjust the ratio of the air supply in the first two stages of the incinerator: increase the air supply for the first stage, reduce it for the second stage, and ensure the appropriate oxygen level in the third stage!
1. I’m wondering that if the absorption is unstable, for example if there’s a tendency to form bubbles, could it be that more amine in the form of saturated water gets carried away with the exhaust gases? 2. Just to confirm, when adjusting the air flow in the incinerator to reduce NOX, should the air flow be reduced slightly in order to create a combustion environment with low temperature and limited oxygen?
1. Don’t you do rich-lean liquid analysis here? 2. From our trials here, increasing the airflow significantly led to a notable reduction in nitrogen oxides emitted! You can give it a try!
Thank you! Which parameters are analyzed for the rich liquid? We regularly analyze H2S and CO2 in the rich liquid; as for these two components, what is related to NOX? The NOX levels have been quite low lately, between 10 and 40; I’m reluctant to make any changes. . . A few days ago, the wind speed was reduced for 5 or 6 hours; indeed, there was a upward trend, so the wind speed was increased again. But at that time, NOX levels fluctuated quite a lot. I suspect it was just a coincidence; if not, then what you said is correct.
Why did nitrogen oxides decrease when the wind was strong?
In practice, nitrogen oxides are also related to the temperature of the exhaust gas incinerator. And the temperature of the exhaust gas incinerator is related to sulfur production in the previous system. The temperature in the exhaust gas incinerator is high, so the levels of nitrogen oxides are also relatively high.
The acid gas contains ammonia, and the temperature in the combustion furnace is low, preventing the ammonia from being burned