Heat associated with gas from the hydrolysis tower to the desorption tower
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Question: In the carbon dioxide stripping process for desorbing hydrolysis, what is the steam pressure and temperature used to supply heat to the gas leaving the hydrolysis tower and going to the desorption tower? Is it okay without heating, as long as there is insulation? Operating temperature of the hydrolysis tower: 210°C, operating pressure: 2.4 MPa (max). The system steam can be used for heat tracing at 2.4 MPa and 357°C, or at 0.35 MPa and 148°C.
Since the concentrations of ammonia and CO2 in the gas phase of the hydrolysis tower are not high, and the length of the pipelines leading to the desorption tower is also short, we use low-pressure steam tracing for insulation.
I fully agree with the opinion from the second floor; the ammonia and CO2 levels in the gas phase of the hydrolysis tower are relatively low, so the possibility of crystallization is minimal. In fact, insulation is sufficient.
Ammonium methylate tends to form in the gas phase of the hydrolysis tower, and the purpose of heating is to reduce its formation. ----– Prevent further corrosion.
Based on the hydrolysis parameters provided by the poster, the outlet gas temperature should be around 180°C; the thermal energy of the hydrolyzed gas phase still needs to be utilized in the desorption tower – for gas stripping in that tower. As long as good heat preservation is maintained, there is no need to require insulation for the accompanying pipes. A thermometer can be used to check; if a temperature of 130°C can be maintained at the inlet to the desorption tower, then insulation for the surrounding pipes is not necessary. Otherwise, energy is wasted again, which goes against the original design intent.
It seems that whether the pipeline is insulated or heated depends on preventing crystallization and providing heat energy for the overhead tower of the distillation column. I am asking everyone about this issue because I have seen two design options: one uses low-pressure steam for heating ； One is medium-pressure steam tracing; I’d like to see how people handle it in practice.
I’m sorry, but I’d like to express a different opinion. The application involves medium-pressure steam at 0.8 MPa for heating; if low-pressure steam is used, the large temperature difference between the inside and outside of the pipes prevents effective insulation (185°C on the inside, while if there is low-pressure steam at 0.35 MPa, the temperature on the outside is 143°C). In the gas phase of the hydrolysis tower, condensation easily occurs, forming ammonium methylate. Moreover, the slow flow rate of the fluid within the gas-phase pipes exacerbates corrosion. This post was last edited by 1025199692 on 2009-2-22 22:45.]
8 kilograms of steam for heating – is it a southern company or a northern company? Regardless of the heating method used, the likelihood of crystallization during normal production is very low