Can the low-temperature nitrogen be directed to the hydrogen sulfide concentration tower as a cooling source for the methanol washing system during its initial startup, after liquid nitrogen is accumulated in the cooling tank?
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After liquid nitrogen cooling tank accumulation occurs, if the methanol washing system is now started, can the low-temperature nitrogen from the liquid nitrogen cooling and synthesis gas pipeline be diverted to the hydrogen sulfide concentration tower as a cooling source for the initial startup of the methanol washing system, in order to reduce the startup time of this system?
As long as it remains within the temperature range allowed by the device, it should be fine; generally, a temperature difference of more than 50 degrees is not permitted
The cooling rate in low-temperature methanol washing is generally no more than 2 degrees per hour. Also, the liquefaction temperature of liquid nitrogen is -196 at standard pressure, while the freezing point of pure methanol is -97. Think about what the consequences of going through with it would be
Upstairs! ! The poster is asking whether it is possible to use the low-temperature nitrogen from the liquid nitrogen cooling pipeline of the synthesis gas pipeline as a cooling source for the initial startup of the methanol washing system in the hydrogen sulfide concentration tower; this has nothing to do with liquid nitrogen, and I think it is possible. But since I don’t have the ability to perform an energy balance and am not sure whether it’s cost-effective, I’m not clear about it; please ask an expert to provide an answer
I think it’s a bit difficult. When you send low-temperature nitrogen from the cold syngas stream to the methanol wash unit, wouldn’t there be a large temperature difference across the end faces of the plate-fin heat exchangers in that cold box? Can the heat exchanger handle it?
If it is low-temperature nitrogen, it can certainly be added to the hydrogen sulfide concentration tower; however, such amount of cooling capacity is far from sufficient to meet the cooling needs required for starting up the system. The idea itself is correct, but generally factories do not use this approach. I’m not very familiar with this either, so I hope someone else can provide a detailed explanation.
Reply to 4# hcaxuzheng: I would like to ask what is the temperature of the low-temperature nitrogen used for liquid nitrogen washing?
Reply to 7# z880347730 - around -67 degrees
Low temperatures are favorable for absorption but unfavorable for resolution. It will also increase the load on the regeneration tower. My humble opinion