System pressure difference of 6.5 MPa, 30 tons/year water-coal slurry conversion system
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What is the system pressure difference of the 6.5 MPa, 30 tons/year water-coal slurry conversion system? The system pressure difference I calculated is very small, but some people say that the pressure difference in the light conversion furnace alone is already 0.15 MPa? Is it a bit too large? The calculation should be around 2500 mmH2O, right? I hope those who know about system pressure differences can offer some help! Let’s express thanks first!
Our entire system is at 0.27 Mpa； A partial transformation is used. After coming out of the water separator and passing through a heat exchanger, the pressure drop before exiting the converter is only 0.05 Mpa! You can refer to these data! 【It’s amazing that you design things on your own】
It can’t be that low; in actual production, the pressure drop during conversion should be less than 0.3 MPa
Our factory produces methanol, and partial shift is required; therefore, only one low-pressure shift reactor is installed, and an axial-radial design is used!
For the gasification of water-coal slurry to produce methanol, a shift reactor can be used. The pressure drop in the shift system is related to the catalyst chosen; it is recommended that you ask the catalyst manufacturer to design it for you – they should be able to provide data on the pressure drop
A pressure difference of 0.15 MPa is not considered high; any pressure difference below 0.3 MPa is not considered high either. The higher the system pressure, the greater the resulting pressure difference.
From the gas-liquid separator where the carbonated gas enters the shift zone to the last separator after the shift process, for a synthetic ammonia plant with a gasification pressure of 6.5 MPA and an output of 300,000 tons per year, the designed pressure drop for this shift system should be around 0.6 MPA. Of course, this is a design value; in normal operation, it may vary due to the load on the system and the condition of the catalysts used. This pressure drop includes the resistance loss caused by the catalysts, as well as that resulting from pipes, equipment, and valves.
For 6.5 MPa conversion, in some conversion scenarios, the bed resistance of the wide-temperature conversion catalysts we provide is less than 0.05 MPa; it should be even lower in the case of axial radial reactors. If referring to the entire transformation system, the pressure drop should include the catalyst bed resistance and the pipeline resistance. This post was last edited by dongchuancheng on 2009-3-25 11:28.]
The SCV value of the valve needs to be taken into account; in fact, the pressure difference is not solely related to the equipment, as the pressure drop across the valve is also an aspect that cannot be ignored.
What are the negative consequences of poor performance of a heat exchanger?
Generally, it’s around 0.3 MPA; the pressure difference in the converter should be less than 0.11 MPA
The pressure drop associated with the conversion process should refer to the pressure drop across the entire conversion section, that is, the pressure difference between the process gas entering the conversion system and the gas after it passes through this section. What everyone has mentioned here relates to the pressure drop in the conversion furnace; generally, the designed pressure drop for such furnaces is no more than 0.15 MPa. For an entire conversion unit of the scale mentioned by the original poster, the overall pressure difference is usually not greater than 0.3 MPa (including bed resistance, equipment resistance, pipeline resistance, and valve resistance). If this value exceeds 0.3 MPa, there is likely a problem somewhere in the system.
There are mainly three aspects to adjusting the pressure difference across the entire system: 1. Adjusting the pressure difference in the converter; if an axial radial converter is used, this pressure difference can be kept below 0.04 MPa. 2. The pressure difference between the desalinated water heater and the reformate cooler; the main reason for this large pressure difference is the possible formation of ammonium salt crystals in the outlet pipeline. 3. Crystallization in the outlet pipeline of the condensate stripping tower results in a high pressure difference in that tower.