Comparison of the application of pressure swing adsorption decarburization in urea production plants?
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It is said that pressure swing adsorption units have low power consumption in urea production; so compared to carbon adsorption, by how much is the power consumption actually lower? For example, when calculating the power consumption based on a production capacity of 120,000 standard cubic meters at 1.8 MPa, what is the difference? Can anyone help clarify this? ! Waiting! !
Providing a detailed answer to this question is somewhat complicated. When using urea, it is required that the CO2 emissions be at 0.2%, and the purity of CO2 is supposed to be over 95%; therefore, the standards are higher compared to other applications. The initial investment for this method is certainly higher than that of other carbon removal techniques, but the operating costs are likely to be lower. In this process, where the pressure is 2.0 MPA, unpowered carbon removal is generally used; aside from the use of some instrument air and electricity for the control system, there are no other energy consumption requirements, so there are essentially no operating costs
The decarburization of propylene carbonate is generally carried out at a pressure of 28 Kgf; the power consumption per ton of ammonia produced is around 110 kWh, with approximately 0.7 Kg of propylene carbonate being used (the current price of propylene carbonate is 10 yuan/Kg). Since the flash vapor carries away some hydrogen, the hydrogen yield is around 98–98.5%, yet the purity of the CO2 obtained is high. Pressure swing adsorption carbon removal can be performed either with or without power, but both processes can meet the requirements of the urea production process at a pressure of 18 Kgf. In the powered version (i.e., the vacuum-based process), the electricity consumption per ton of ammonia is around 50 kWh, there is also some water consumption, and the hydrogen yield is approximately 98.5%. The power consumption for producing one ton of ammonia without a drive system is around 6 kWh, but the investment required is slightly higher than that for systems with a drive system; the hydrogen yield is around 99.5%. The original poster can do the calculations themselves; in terms of consumption, pressure swing adsorption is definitely more cost-effective than carbon polymer, and moreover, carbon polymer requires increasing the pressure of CO2 in the feed gas from 18 to 28 Kgf, which increases the energy consumption of the compressors. The above are merely personal opinions; if there are any issues, I welcome everyone to discuss them.
Well said, very specific. The use of PSA for adsorption in urea applications is already quite widespread; it has low operating costs, and nowadays most systems employ pressure swing adsorption