After the methanol washing unit is started up properly, where does the methanol consumption mainly occur?
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After the methanol washing unit is started up properly, where does the methanol consumption mainly occur?
Methanol losses caused by various types of entrained gases and leaks
The greatest loss of methanol occurs in the flash vapor of the pre-washing and regeneration system where contaminated methanol is pre-washed
There are mainly the following aspects； First: Syngas entrainment ； Second: Tail gas entrainment in the hydrogen sulfide concentration tower ； Third: Carbon dioxide entrainment in the carbon dioxide product tower (not always present) ； Fourth: Entrainment of hydrogen sulfide acidic gas ； Fifth: entrainment of wastewater. In fact, the main loss is not wastewater; if the process is properly adjusted, the amount of wastewater lost will be very small. One point I would like to mention is not to overlook the entrainment of syngas and exhaust gases. Although there is a scrubber tower for exhaust gases. Both of these have a large volume. Dissipation accounts for a significant proportion of the total loss.
Our company consumes 80 to 100 tons per month. Is this normal? We are currently using the Lurgi process; in the old factory, I used to consume only a little over 20 tons per month. I talked about this with the manager, and he said I’m young and lack experience. I wonder if it’s true that I do lack experience
Hehe! This has nothing to do with age; it is related to theory and practical experience. As for the consumption in your unit, I’m not aware of what your production capacity is, and that consumption level is quite high. Take a look at the size of your design – it should be around 60 Kg/h. However, for newly commissioned facilities, high consumption is inevitable, as all parameters are still in the process of being determined.
Does the stripping gas used for methanol regeneration also consume some methanol? Moreover, it’s impossible to recover all the methanol used during the maintenance of pumps and equipment!
Point 4# has already been explained in detail; I’ll add more: Additionally, some methanol is carried away by the V2V3 flash vapor； So, to summarize, the areas where significant methanol consumption occurs in low-temperature methanol washing are: 1. The purified gas at the top of Tower T1 ； 2. Off-gases from the hydrogen sulfide concentration tower ； 3. Carbon dioxide in the carbon dioxide desorption tower ； 4. Remove sulfur to recover acidic gas or vent it ； 5. Wastewater from the bottom of T5 tower ； 6. The flash vapor from the V2V3 flash tank.