Where does NH3N in the water-coal slurry gasification system come from?
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What are the factors that affect the NH3N in the system?
The NH3N in the gasification system is generated as a result of NH3 produced by the gasification reaction.
Most of it is N gas from the pressure-taking balance tube, as well as NH3 accumulated from coal and system circulation.
As long as the ammonia nitrogen comes from the pyrolysis of coal itself, HCN can also react with H2 to be produced during this process; however, the yield of ammonia nitrogen from the reaction of nitrogen and hydrogen is very low. Factors affecting the ammonia nitrogen content in the system include coal type (nitrogen content in the coal; higher volatiles in lower-grade coal lead to higher ammonia nitrogen levels), system pressure and temperature, coal particle size, and the circulation rate of ammonia nitrogen in the system. Ammonia nitrogen is primarily generated in the gasification furnace; there is a significant amount of ammonia nitrogen in the high and low pressure condensates from the subsequent systems, as well as in the ammonia-containing wastewater. When ammonia-containing wastewater is recycled (with its temperature kept relatively low), the ammonia nitrogen level in the gasification system tends to worsen over time.
Ammonia nitrogen is primarily generated through reactions in the gasification furnace, and it is related to the purity of oxygen. In the post-system, both the condensed liquid and the ammonia-containing wastewater contain high levels of ammonia nitrogen. When ammonia-containing wastewater is recycled (with relatively low temperature control), the ammonia nitrogen level in the gasification system tends to worsen over time. Ammonia nitrogen also comes from the ammonia-containing wastewater supplied from the subsequent system.
Please share your opinions on how to reduce ammonia nitrogen in the system! I heard that Hualu Hengsheng handles this well, being able to keep the ammonia nitrogen level in the gasification system around 200 mg/m³? But I don’t know how they did it?
Ammonia is primarily produced through the carbonization of coal; under high temperature and pressure, the nitrogen in coal is essentially converted into ammonia.