Some correlation questions. 1

[dbecker]

Hello.

Has anyone ever heard of Lucas in Reid, Prausnitz and Poling? I don't have the book, if someone does have this book; can you tell me exactly what this correlation or method is entails?

Also, who has a a good explanation of the Chen correlation. I was googling it and did not find much.

I also need the actual Chen correlation itself, sorry I cannot find these formulas; I don't have the right books.

Thank you!

 

[Latexman]

My 3rd Ed. has no Lucas in the index.

The Chen correlation was designed to estimate enthalpy of vaporization using vapor pressure data and eliminating the acentric factor. It averages ~ 2% error overall. It's real good for sat'd and unsat'd hydrocarbons (0.4-1.2% error). Not so good for alcohols and oxides (4-5 % error).

[Δ]H_vb=RT_cT_br(3.978T_br-3.938+1.555ln(P_c))/(1.07-T_br)

[Δ]H_vb=[Δ]H_v at the normal boiling point in cal/g-mol
R=gas constant, 1.987 cal/g-mol K
T_c=critical temperature in K
T_br=reduced normal boiling point (T_b/T_c)
P_c=critical pressure in atm

Good luck,
Latexman

 

[dbecker]

Thanks Latexman!!!!!!!!!!!!

 

[dbecker]

I am being told that the Lucas correlation is a very linear relationship between viscosity and pressure of an incompressible fluid.

I do not know the relation of viscosity and pressure of water for instance, does someone happen to know this?

 

[Latexman]

I checked my 5th Ed. at home. While there is no Lucas in the Index, it is in section 9-9 titled "Effect of high pressure on liquid viscosity" on page 9.55. It's kind of complicated and lengthy and there's an example that shows how to use it. It'd be best if you could get your hands on the book.

Good luck,
Latexman

 

[dbecker]

Thanks again Latexman... I will get a copy of this book.