Design approach for the condensate from low-temperature shift in water-coal slurry gasification
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There are currently two different design approaches for the condensate from low-temperature shift in water-coal slurry gasification. 1. The low-temperature shift condensate can be used to feed the deoxygenator, or it can be used as makeup water for the high flash tower. 2. The low-temperature shift condensate enters the deaerator directly. Could everyone please help analyze these two designs to determine which one has more advantages in production?
We have both types. After removing the oxygen remover directly, the pH value of the system’s graywater increases; using a high-flash removal method yields better results
No matter where it goes, the ammonia nitrogen contained in the low-temperature condensate accumulates within the system, resulting in high ammonia nitrogen levels in the gray water. One advantage is that the situation is relatively better after flashing; if possible, this water should be sent to a wastewater treatment facility or the system should be modified so that the water can be directed elsewhere
Could we also consider sending it to another place? What about using it as coal grinding water in a direct gasification furnace? Also, what are the benefits of using high flash point?
The flash evaporation system can handle approximately 30 Nm3/h of ammonia nitrogen, and flash evaporation facilitates better separation of ammonia nitrogen. Coal grinding definitely won’t work; the temperature of this water is too high. The pressure upon direct entry into the gasifier is not sufficient; it’s the condensate from low-temperature shift reaction
There are two types of condensed liquid in the shift stripping tower system: one is the condensed liquid with low ammonia content that comes from the bottom of the tower, and the other is the condensed liquid with high ammonia content that comes from the top of the tower. At present, in our company, the former is sent directly to the high-pressure flasher, while the latter is sent to the coal mill as supplementary water for slurry preparation.