Transformation of crystallization in the stripping gas line
Thread Content
In existing powder coal gasification or coal slurry gasification processes, a stripping gas is used to remove substances such as CO2, H2S, and NH3 from the condensate resulting from the shift reaction. The main problems associated with this stripping gas are corrosion and crystallization. It is generally believed that maintaining a temperature above 75°C can prevent crystallization; however, calculations using the multi-phase diagram of the CO2-NH3-H2O system show that crystallization should not occur. Some manufacturers maintain a temperature of 70°C and still do not experience crystallization, but in our plants, where the temperature is kept at 80–90°C, crystallization does occur sometimes. How can this be explained? Without considering the superheating of the stripping gas, what temperature is generally used to control the stripping gas?
Has the crystal been analyzed to find out what it is?
Which location’s temperature should be kept at 80°C? Is there a flowchart available? Let’s take a look