Highly accurate correlating method for phase equilibrium data, and phase equilibrium calculation method

Patent metadata

Field	Value
Publication number	US-9852241-B2
Application number	US-201214348439-A
Country	US
Kind code	B2
Filing date	Sep 25, 2012
Priority date	Sep 29, 2011
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A method for precisely predicting phase equilibrium from existing phase equilibrium data on the basis of a wide range of phase equilibrium data including binary vapor-liquid equilibrium data; a method or apparatus for designing or controlling a component separator or a refiner using the prediction method; and a program for designing this design or control apparatus. Binary phase equilibrium measurement data is used to calculate an index of proximity ratio to critical points and infinite dilution pressure gradients. The obtained index is correlated with the infinite dilution pressure gradients to newly calculate infinite dilution activity coefficients from the respective index to infinite dilution pressure gradients correlations. The obtained infinite dilution activity coefficients values are used to predict phase equilibrium. Thus, the obtained values are used to design or control a component separator or a refiner, such as a distillation column.

First claim

The invention claimed is:

1. A method for controlling a separator or a refiner, comprising:
recording existing binary phase equilibrium data;
implementing a computer-based method for predicting binary phase equilibrium data comprising:
 by using binary phase equilibrium measurement data, calculating an index X of proximity ratio to critical points according to

X
=

p

1
⁢
s

+

p

2
⁢
s

P

c
⁢

⁢
1

+

p

2
⁢
s

,

and calculating infinite dilution pressure gradients Y 1 and Y 2 according to:

Y
1

=

γ
1
∞

⁢

p

1
⁢
s

-

p

2
⁢

⁢
s

P

c
⁢

⁢
1

-

p

2
⁢
s

⁢

⁢
and
⁢

⁢

Y
2

=

p

1
⁢
s

-

γ
2
∞

⁢

p

2
⁢
s

P

c
⁢

⁢
1

-

p

2
⁢
s

,

wherein P c1 represents a critical pressure of a lighter component in a binary system, p 1s and p 2s represent vapor pressures of components 1 and 2, respectively, at a temperature T, and γ i ∞ and γ 2 ∞ represent infinite dilution activity coefficients of components 1 and 2 in a liquid phase, respectively;
 correlating the obtained index X of proximity ratio to critical points with the infinite dilution pressure gradients Y 1 and Y 2 and calculating infinite dilution activity coefficients γ 1 ∞ and γ 2 ∞ or binary parameters A and B from the X-Y 1 correlation and the X-Y 2 correlation, respectively, the binary parameters A and B being given by A=ln γ 1 ∞ and B=ln γ 2 ∞ ; and
 evaluating thermodynamic consistency of the X-Y 1 and X-Y 2 correlation data according to

H
=



β

e
⁢

⁢
x
⁢

⁢
p

-

β

ca
⁢

⁢
l

β

ca
⁢

⁢
l



using values of β exp and β cal obtained by incorporating values of binary parameters A and B into the following equation

β
=

F



B

Assignees

• Univ Tokyo Metropolitan

Inventors

• Kato Satoru

Classifications

• B01D11/0484

  Controlling means · CPC title

• B01D9/0063

  Control or regulation (control per se G05) · CPC title

• B01D3/32 Primary

  Other features of fractionating columns {; Constructional details of fractionating columns not provided for in groups B01D3/16 - B01D3/30} · CPC title

• B01D3/42 Primary

  Regulation; Control · CPC title

• G06F30/20

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title