MDEA Viscosity
MDEA Viscosity
(OP)
I've been looking for some data on MDEA viscosity at low temperatures. As of yet, the lowest temperature that I have found any data for is 32°F. I want some data so that I can show the need for steam tracing piping through which pure, or almost pure, MDEA flows. The ambient temperature can easily reach 0°F in the winter at this location, yet the client does not see the need for steam coils in the storage tank or for tracing the line and pump.
Does anyone know where I could find viscosity data for MDEA below 32°F?
Thanks.
Does anyone know where I could find viscosity data for MDEA below 32°F?
Thanks.





RE: MDEA Viscosity
My guess is that this stuff would be solid at 0F. Are you planning on installing a screw pump?
RE: MDEA Viscosity
BR&E TSweet only goes down to 32°F. HYSYS/AMSIM only goes down to 77°F, and it only does amine concentrations of 0 wt% - 50 wt%.
The freezing point of pure MDEA is -6°F, but it lowers considerably when water is added. At 60 wt% and 32°F, the viscosity is 65.4 cP. At 80 wt%, it's 337.7 cP.
It looks like I'll just have to try to make an educated guess based on what information I do have.
RE: MDEA Viscosity
Viscosity of MDEA : 101.0 cP @ 20 deg C.
33.8 cP @ 40 deg C.
RE: MDEA Viscosity
RE: MDEA Viscosity
u = AL exp BL/T
From two known values of viscosity constants AL and BL can be determined
BL = (T1 * T2 * ln(u1/u2))/(T2 - T1)
AL = u1/exp (BL/T1)
Where T is absolute temperature
Using the 2 points provide by pronab the viscosity at 0F comes out to about 1275 Cp I think.
RE: MDEA Viscosity
Thanks for the equation. Can you tell me where you found information on that? I checked the index of my Fluid Mechanics book from college, but couldn't find it there. Is this in Perry's?
RE: MDEA Viscosity
Flow Measurement Engineering Handbook by Richard W. Miller.
RE: MDEA Viscosity
Andrade corelations is used at low temperature , when
Tr~ 0.75 ( Reduced temperature = Tc/T). However I found constant AL and BL are : -5019.5 and 21.74 respectively. With this constant and @0 deg F(-17.77 Deg C) viscocity of MDEA coming 7.806 cP, which is not matching.I believe it is due to Tr>0.75(using 20 & 40 deg.C). I don't have the value of Tc for MDEA.
Freda can you help me how you calculate and get the MDEA viscosity @ 0 degF ( 1275 cP).
For Andrade corelations one can get it from PERRY Handbook;6th edition;p:3-281.
Regards to all.
Pronab Mistry.
RE: MDEA Viscosity
Anyway, using the BP chart that gives kinematic viscosity in cS vs temperature based on the relation loglog(v+0.8)=f(t) where v is in cS and t is absolute temperature, and taking published densities to convert cP to cS and viceversa, one gets 3000 cS at 0oF or 3210 cP. Same result was obtained by using ASTM D341 chart for petroleum products.