Methanol Injection Delivery Pressure

[Eric Lindof]

Hallo,

I work in a gas plant and we are trying to put in a methanol injection unit. It should be a stockunit (nothing fancy). I have contracted it out to a vendor but I have some questions. I have calculated the hydrate formation temperature and methanol injection rates. But the vendor spec sheet is asking for some other information.

1)What pressure should the pump deliver the methanol (into the pipeline)? The pipeline operating pressure? Also, what is:
2)Maximum input pressure
3)Maximum output pressure
4)Maximum input flow
5)Maximum output flow

Any and all help isappreciated. Thank you.

 

[LittleInch]

Well most of these are not easy to say from here but see below

1)What pressure should the pump deliver the methanol (into the pipeline)? The pipeline operating pressure?
Yes the methanol will inject into the gas line and hence the pipeline pressure is the minimum pressure the pump needs to achieve

Also, what is:
2)Maximum input pressure - maximum head of methanol into your pump from your methanol tank if an atmospheric tank or delivery pressure if a booster pump is being used or if you're pulling it from a lower pressure methanol supply.

3)Maximum output pressure
Highest input pressure plus your frictional and head losses from pump to gas pipeline

4)Maximum input flow
Errr maximum flow of methanol

5)Maximum output flow
Don't understand why this will be any different to max input

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[georgeverghese]

Max injection pressure will depend on the max built up backpressure permitted on the pipeline, which is usually the setting of the high set pipeline pressure controller. This controller is typically used to ramp down the supply of gas from all sources into the pipeline ( booster compressors or gas wells etc). Check your PID and talk to the plant operations / process controls engineer.