Is steam added directly to the methanol dehydration tower?

Linde technology does not have this design, please introduce it in detail.

I think~~If the water separation tower has a steam pipeline during the original startup, you can add some steam appropriately when the temperature is difficult to control~ Adding steam can better control the temperature of the methanol water separation tower~ But you must consider how many kilograms of steam pipeline are used~ Will it affect the operating pressure of the tower?

In fact, under normal circumstances, if the methanol in the separated water exceeds the standard, you can also consider adding steam. Generally, low pressure steam of 1.5MPa is sufficient.

They are usually added during technical modifications. This steam line was added mainly because the load design of the reboiler was insufficient or the heat exchanger was blocked and scaled, which affected the heat transfer effect! The main benefit of this design is that it can quickly increase the tower temperature and maintain the liquid level of the water separation tower!

The key is to see whether the heat load design of the thermal reboiler can meet the production requirements. Directly adding steam can replace the heat load of the reboiler. The key is that the steam condensate is not properly recovered.

The main reason for adding direct steam is to: 1. Rapidly increase the temperature of the methanol-water separation tower ； 2. Add water to the tower to maintain the liquid level in the tower ；

This steam is generally called direct compensation steam. When the liquid level is established during startup, there are too many impurities at the bottom of the tower, the heat load is insufficient, and the liquid level at the bottom of the tower cannot be maintained, direct compensation steam can be used to solve the problem.

In our process flow, there is a stream of straight steam at the bottom of the methanol distillation tower of the Lurgi gasifier. It is mainly used for heating when the heat exchange effect of the reboiler is not good. No other uses have been seen:victory: :victory: Anyone who wants to have the same process can share it.

This steam needs to be added as long as the system is running. When starting up, the dehydration tower is generally empty, and the water content in the feed is not high, so it is difficult to establish the liquid level at the bottom of the dehydration tower. Therefore, adding steam can quickly establish the liquid level at the bottom of the dehydration tower and operate stably. When driving, the amount of steam added is generally relatively large. Adding steam during normal operation also replenishes water, because there are many impurities at the bottom of the dehydration tower, and the amount of water in the two feed streams of the regeneration tower and the methanol/water separation tank is not very large, so the opening of the discharge valve at the bottom of the dehydration tower is small. When the flow rate is slow, it is easy to block the pipes and valves. Adding steam is replenishing water, which increases the discharge volume and is less likely to cause blockage.

The methanol-water separation tower needs to control the ratio of methanol and water in the tower so that the temperature inside the tower will be normal. It turns out that some old plants did not have tail gas scrubbers and the water content in the water separation tower was not enough. After the technical transformation, direct supplementary steam was added, which not only saved steam but also adjusted the water content. Now the water content of the new plant can be adjusted without adding direct supplementary steam.

Will turning on the steam during normal operation cause the water content to rise?

Control the amount of supplementary steam and the amount of reflux methanol so that no one will exceed the standard! !

I found several people upstairs who were misleading others. Methanol dehydration tower does not directly add steam during normal production. By adjusting the steam volume of the reboiler, the methanol content in the tower water can be adjusted. If the methanol content is high, the reboiler load is not sufficient. Direct steam is generally added directly to the tower in emergencies or when boiling the tower. Although adding direct steam can improve the distillation effect, the energy consumption will also increase. In today's production enterprises, this kind of high energy consumption method must be avoided.

Does adding direct steam help save steam or is it a waste of steam?

Generally, there will be a direct steam supply line. When there is a lot of dirt at the bottom of the tower, or the reboiler steam is insufficient, or the water content in the system is low, steam will be replenished appropriately.

Directly adding steam is beneficial to stabilizing the temperature of the tower, especially when the water content in the system is high.