Is it feasible to burn ammonia in a furnace?
Thread Content
This post was last edited by liaifeng on 2018-8-3 at 22:28. In the acid water stripping process using a single tower for pressure boosting, can the ammonia gas extracted from the side stream be directed to a burner for combustion in order to reduce gas consumption? What are the advantages and disadvantages of this approach? Let’s discuss it
It can be fed into a sulfur production furnace designed for ammonia combustion. It cannot be led to the exhaust gas incinerator; the low temperature makes it impossible to burn ammonia.
The temperature in the exhaust furnace is low, preventing the combustion of ammonia; this makes it easy for ammonium salts to form, which can lead to blockages in the chimney.
The combustion of ammonia does not result in the formation of nitrogen alone; in the nitric acid industry, ammonia is burned at temperatures of 800–900 degrees, and as a result, not only nitrogen but also nitrogen oxides are produced. To convert all of the ammonia into nitrogen, a catalyst is required. Therefore, ordinary incinerators cannot be used for burning ammonia, as this could lead to the release of large amounts of nitrogen oxides, which are also pollutants.
The original poster has quite forward-thinking ideas! It would be best if ammonia could be treated separately, but only under the required conditions!
In some special cases, such as when the acid gas load is very low or during shutdown periods, it is entirely feasible to send a small amount of clean acid gas to the incinerator for burning (but in such cases some modifications to the burner are necessary). But it is absolutely unacceptable to feed ammonia into a furnace for combustion. Since the temperature in incinerators is usually only around 700°C, the consequences of such a temperature are predictable.
The incinerator in our company’s sulfur plant is designed for ammonia combustion (ammonia is not fed into the reaction furnace); the temperature is controlled at 1250 degrees when ammonia is being burned, and at 800 degrees when no ammonia is burned.
It seems that the Petrochemical Plant of Shengli Oilfield burns ammonia in incinerators. I don’t know what the specific situation is. If environmental considerations are not taken into account, it’s okay; but if high environmental standards are required, I think it’s not very feasible!
If the burning temperature reaches 1250 degrees, will nitrogen or nitrogen oxides be formed in the end?
Burning ammonia requires meeting two conditions； 1. The temperature reaches over 1250 degrees. 2. The residence time of ammonia in the furnace is 2.5 s. Ammonia combustion generates a large amount of heat, which should be made use of effectively for preheating and recovery.