Temperature rise issue in methanol synthesis tower
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Our facility features a shell-and-tube synthesis tower with a length of 3,600 mm, as well as a methanol production plant that uses 100,000 tons of coke oven gas per day. However, the boiler used is one with a capacity of 25 tons per hour and equipped with a superheater; it has not yet been put into operation. I would like to ask everyone: can 25 tons per hour of superheated steam meet the heating requirements of the synthesis tower? What if the temperature doesn’t rise by then? Note: 1. We no longer have large boilers. 2. There is no more high-pressure steam. 3. Fresh gas flow rate into the synthesis tower: 58,600; recycle gas flow rate: 323,000.
What is the steam pressure there? Especially the temperature – it’s fine if it’s over 200 degrees. In our synthesis tower, we start adding fresh gas gradually once the temperature reaches 170 degrees
It’s 25 kilograms of superheated steam, but the boiler room is about 300 meters away from the synthesis tower; I’m concerned about pressure and temperature drops, so I worry that the temperature won’t be able to rise enough
25 kilograms of superheat should not be a problem; saturated steam at 25 degrees should suffice, and it’s definitely better if there’s a superheat of 50 degrees
25 kilograms of saturated steam is only at 224 degrees; even with a superheat of 50 degrees, the temperature remains around 270 degrees. However, these temperatures and pressures correspond to those at the boiler – what I mean is that the actual temperatures and pressures in the synthesis tower are not that high. How can the temperature be maintained in the later stages of heating?
There’s absolutely no problem; feel free to use it without hesitation. Our situation is similar to yours, and the temperature increase is progressing smoothly, so there’s nothing to worry about
25 kilograms of superheat should not be a problem; saturated steam at 25 degrees should suffice, and it’s definitely better if there’s a superheat of 50 degrees
A certain heating curve should be followed
It is a bit low, but it will definitely rise; the rate of increase slows down towards the end. In abnormal situations, there needs to be sufficient steam volume. Experience is crucial when raising the temperature – I have discussed this in other posts, which you can refer to. Have a lightning strike; as long as there’s enough steam while driving, that’s fine.
As long as a pressure of 25 bar is maintained, it will work. It doesn’t matter whether it’s superheated or not, because it remains saturated after passing through the ejector.
No problem; even if the temperature of the gas entering the tower reaches over 210°C in later stages, a reaction should still occur.
No problem. The temperature of saturated steam at 2.5 MPa is 224 degrees; superheated steam would be even better. In our company, there is a pressure drop of 0.3 MPa over a distance of 500 meters from the boiler to the methanol pipeline, resulting in a temperature decrease of around 30 degrees