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Reboiler flow calculation amine scrubber

Reboiler flow calculation amine scrubber

Reboiler flow calculation amine scrubber

(OP)
First of all: I'm sorry if there is already a thread regarding this.

I'm working on a design for a amine scrubber using MDEA. The purpose is to remove about 582 kg/h of CO2 from a CO2/CH4 gas flow. I calculated that I would need 480 kW for my reboiler capacity. Based on a reflux of 1.25 (about 300 kg of H2O). Can anyone confirm that this is correct?

The plan is to use 50% amine with 50% (demi)water. Because of the layout I cannot use a thermosyphon type of reboiler (to complicated piping / not enough height). Instead I'm planning to use a regular plate type heat exchanger for my reboiler with forced circulation (pump). The top of the plates will be below the minimal level in the sump/stripper.

From different literature / internet I understood that in the reboiler about 15-20% evaporation occurs?

Can anyone help to determine how much the flow rate for this pump should be (based on 15-20 % evaporation in heat exchanger).

Thanks ahead. PS: I'm new at this site

RE: Reboiler flow calculation amine scrubber

We need a lot more info to comment on this unusual design.  Can you provide amine circ rate?  What about contactor pressure and temp, treated gas specs, regen pressure, heat medium, etc.?

RE: Reboiler flow calculation amine scrubber

its closer to 730 kW.

There are plenty of pump around direct fired reboilers in operation which is similar to what you are proposing.

so, pick 16.66% evaporation, that means that for every pound (kg) vaporized 5 pounds do no get vaporized.  That means you need to circulate 6 times as much as needed.  Since you need 2,500,000 BTU/hr and it takes about 1000 btu/lb to vaporize, that means you need 2500 lb/hr times 6 or 15,000 lb per hour and at 9 lb/gallon, that is 30 GPM. you'll be circulating 32 gpm of a 50% solution of MDEA.

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