Reasons for increased imported ammonia
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This post was last edited by Chemical Gas Purification on 2010-11-16 at 11:50. In our company’s 1200mm synthesis system, temperatures have been dropping since October 20th. The ammonia pressure in the syngas has decreased from 0.22–0.24 MPa in September to 0.18–0.20 MPa now; the temperature of the ammonia coolant has dropped from -11 to -12 degrees Celsius in September to -12 to -14 degrees Celsius currently. Meanwhile, the concentration of ammonia in the feedstream has increased from 2.208%–2.32% to 2.45–2.59%, after which it stabilized and stopped rising further. The methane content in the synthesis system has also decreased from 13.2% to 11.8%. Does this decrease in methane levels affect the amount of ammonia in the feedstream? If I increase system methane to the original level of 13.2%, can the imported ammonia level be reduced to 2.2%? If there is a leak in the cold exchanger tubes, and gas with a high ammonia content leaks into the synthesis tower – where the ammonia content is low – causing cross-ventilation between the gas and the cold exchanger packing, will the ammonia content at the inlet definitely exceed 3.0% or even more? And will the leakage get worse as time goes by? The ammonia level can be controlled; oil contamination blockages and the efficiency of ammonia separation can be addressed through thermal cleaning. Temperature issues need not be considered. Could experts help analyze what exactly is causing this problem? Does a 2.59% content of imported ammonia affect production? Thank you
Methane causes significant damage to the catalysts in the synthesis tower; our facility has almost no methane content before it enters the synthesis tower. I wonder what the original poster’s craftsmanship is like? To facilitate discussion among everyone.
In the synthetic system, the pressure of gaseous ammonia decreases and the temperature of ammonia cooling drops, while the ammonia content at the inlet of the synthesis tower increases. There are two reasons for this: first, leaks in the heat exchange tubes used for cooling and heating; second, leaks in the packing materials used in the cooling, heating, and ammonia separation units.
Reply to 2# sean816: What process do you use? Is there no methane in the gas fed into the synthesis tower? (Then isn’t it present in the recycled gas either?) ) So it means synthesis was done without releasing air, right? It is worth discussing.*