Freezing in low-temperature methanol washing
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During the process of cooling the system after it is built, by using an propylene cooler to lower the temperature, will the exhaust gas scrubber freeze? Both our CO2 separation tower and H2S concentration tower require nitrogen to maintain pressure, and this nitrogen is released from the exhaust gas scrubber. Will freezing occur when the system temperature reaches -20 degrees? How should I proceed?
Freezing is possible, but the system temperature does not drop to -20 degrees until air is introduced. After heat exchange, the temperature of the exhaust gas entering the exhaust gas scrubber does not drop very low. Pay close attention: if the inlet temperature of the exhaust gas scrubber falls below zero degrees, you can avoid this by using a bypass to prevent the exhaust gas from entering the scrubber. However, this will result in the waste of a small amount of methanol! If your exhaust pipeline is equipped with a temperature control valve (a device that uses steam to regulate the temperature), then such problems wouldn’t occur!
It will not freeze; during the washing process, the absorption of gas is an exothermic process.
It does not freeze; it absorbs and releases heat. And it is controlled by a regulating valve
Freezing will occur, as what comes out of the system is \"dry gas\"; some moisture needs to be removed in the exhaust gas scrubber so that the vapor pressure of water at the temperature inside the tower is reached. In my opinion, if the goal is to maintain a low pressure in the system while operating the equipment, the amount of nitrogen used for gas lift can be adjusted accordingly, allowing the outlet temperature to remain above 0 degrees. (During normal operation, the temperature of the exhaust gas entering the system is 30 degrees, the temperature of the deionized water entering the system is 40 degrees, while the temperature at the outlet at the bottom of the tower is only 16 degrees; therefore, I think it’s possible to keep this temperature higher.) If the temperature cannot be controlled or if there are specific requirements regarding the amount of nitrogen, then venting through a bypass should be used, but it’s essential that the temperature of the exhaust gas leaving the heat exchanger remain above -11 degrees. (Normally, these pipelines are made of carbon steel, with a designed minimum temperature of -11 degrees; two interlocks will also be installed in this case.)
This issue should be taken into consideration during design; remember that a low-pressure steam pipeline is installed on the exhaust pipe line leading to the inlet of the exhaust gas scrubber. In my opinion, as long as the vehicle is driven properly, icing should not occur.
Freezing is possible, as during the water washing process the exhaust gases need to reach saturation; water must evaporate, which requires heat absorption, with no heat being released.
You must be Luchi’s craftsmanship! The design includes a low-pressure steam pipeline! ! ! ! !
In the Luchi process, a low-pressure steam pipeline is connected before the exhaust gases enter the scrubber tower; by adjusting the opening degree of the control valve on this steam pipeline, the temperature of the exhaust gases can be maintained above 0 degrees. Generally, the exhaust gas coming out of the regeneration tower passes through a heat exchanger before entering the exhaust gas scrubber, so its temperature is not too low.
Personally, I don’t think freezing will occur~! In winter, with heat tracing in use, freezing will occur as long as it is turned on
On the 8th floor, as you said, the Lurgi process. Freezing is possible, but it shouldn’t occur if the operations are done properly.