Hydrogen production by methanol cracking
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Our company has a methanol cracking hydrogen production system with a capacity of 1500 NM/hr. The process temperature in the conversion reactor is required to be 250°C. Currently, heat transfer oil furnaces are being phased out, so we want to use medium-pressure steam for heating; however, the steam available from external suppliers has a temperature of only 233°C. Does anyone among you have a solution for this issue?
In your case, it’s definitely not possible to use steam as the heating medium for the reactor and the vaporization superheater; steam at 233 degrees Celsius has a pressure of around 30 kgf, and the hot sides of the vaporization superheater and the reactor cannot withstand such high pressure
Heat transfer oil furnaces can use methanol as fuel; I have seen ones like that.
The temperature of 3.5MPa superheated steam is sufficient
It’s sufficient for the steam to be superheated slightly by the adjacent device
The steam temperature is too low; at least 40 kilograms are required to work properly. Superheated steam with low pressure may not be suitable either. The temperature drop of superheated steam does not provide much heat, mainly due to the large latent heat of condensation. Moreover, steam is used to heat the heat transfer oil, rather than being fed directly into the vaporizer and converter. I have used this type of equipment at Quanzhou Sinochem, where there was a methanol cracking unit designed by Sichuan Asia Union with a capacity of 3500 Nm3/h; it followed this same process, utilizing medium-pressure steam from power plants, with a pressure of around 40 kg. The performance is fairly good; however, care must be taken when starting the machine regarding the introduction of steam, as it’s very difficult to control the temperature rise of the heat transfer oil.
A higher degree of superheating for the steam should work, right?
Why should heat transfer oil furnaces be banned? Is it coal-fired? Just switch to gas, right? If the temperature of the low-pressure steam isn’t sufficient, don’t even think about it