×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Water and Hydrocarbon Dew Point temperature

Water and Hydrocarbon Dew Point temperature

Water and Hydrocarbon Dew Point temperature

(OP)
Can somebody tell me how to calculate Water and Hydrocarbon Dew Point Temperature of natural gas OR refinery fuel gas without help from any simulation?

RE: Water and Hydrocarbon Dew Point temperature

See GPSA Engineering Data Book.

RE: Water and Hydrocarbon Dew Point temperature

Handbook of chemical engg. calculations by Nicholas P Chopey..!

RE: Water and Hydrocarbon Dew Point temperature

set up the equations of e.g. Soave-Redlich-Kwong and solve them yourselv. Its not that hard - if you only have to do it for one state and have the pure component data.

Best regards

Morten

RE: Water and Hydrocarbon Dew Point temperature

Try this: Water in pounds/MMSCFD =(10^(3.5551-0.94283*LOG(absolute pressure)+0.01576*(Temperature F-31)))

RE: Water and Hydrocarbon Dew Point temperature

dcasto,
I've been looking for an equation like that one for several years. Do you have a reference for it?

When I plot the data from your equation on the same plot as data from the GPSA fig 20-3, the equation shows a family of semi-log straight lines (of course), but the GPSA data shows a distinct downward curve at higher temps.  Below 100F the match is outstanding.  By 150F the equation is 80% higher than GPSA, and at 200F it is over three times as large.

The GPSA data looks to be dead straight in the book, but picking points off it gives you a curve.  I've got three different versions of the GPSA plot (going back to the 1960's) from other sources and I got the same points from all three, and the three isobar's I picked points from gave me three parallel lines--all with a downward curve.

Now I'm really confused.

David

RE: Water and Hydrocarbon Dew Point temperature

David,

The equation is a form of the fugacity equation of partial pressure.  I got it from and O&GJ article years ago.  I've tried todo a linear regression using the GPA tables with the EXCEL.

Highlite the stuff below, then copy paste to and excel blank sheet to see all the cells.
  
SUMMARY OUTPUT            Constant    (1/t)^2    (1/t)^3    ln(p)    (ln (p))^2    (ln (p))^3    (ln(p/t))^2    (ln(p/t))^3
        ln( water ) =    13.29315     (4,261,306.00)     662,351,880     1.8362996    -0.36872304    0.01679344    0.1751796    -0.0086638038
Regression Statistics                                        
Multiple R    1                                    
R Square    1                                    
Adjusted R Square    1                                    
Standard Error    2.66844E-12                                    
Observations    14                                    

ANOVA                                        
    df    SS    MS    F    Significance F                    
Regression    7    62.71211606    8.958873722    1.25817E+24    4.56498E-72                    
Residual    6    4.27235E-23    7.12059E-24                            
Total    13    62.71211606                                
                                        
    Coefficients    Standard Error    t Stat    P-value    Lower 95%    Upper 95%    Lower 95.0%    Upper 95.0%        
Intercept    13.29315    4.078E-10    32597200865    5.62629E-62    13.29315    13.29315    13.29315    13.29315
X Variable 1    -4261306    5.00461E-05    -85147693311    1.7712E-64    -4261306    -4261306    -4261306    -4261306
X Variable 2    662351880    0.015687353    42222028294    1.19143E-62    662351879.9    662351880    662351879.9    662351880
X Variable 3    1.836299599    3.32517E-10    5522417297    2.37973E-57    1.836299599    1.8362996    1.836299599    1.8362996
X Variable 4    -0.36872304    9.70528E-11    -3799201784    2.24466E-56    -0.36872304    -0.36872304    -0.36872304    -0.36872304
X Variable 5    0.01679344    7.6343E-12    2199736334    5.95772E-55    0.01679344    0.01679344    0.01679344    0.01679344
X Variable 6    0.1751796    5.0335E-11    3480274334    3.79859E-56    0.1751796    0.1751796    0.1751796    0.1751796
X Variable 7    -0.008663804    8.15032E-12    -1063002241    4.67841E-53    -0.008663804    -0.008663804    -0.008663804    -0.008663804

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources