Water Content in Natural Gas
Water Content in Natural Gas
(OP)
Hello Experts,
I am doing simulation for a TEG Dehydration package using HYSYS. I have the natural gas composition which is saturated at 42.3 Deg Celsius @ 36 bar (a). In the composition I could not find the H2O content.
Is there a way to find how much water present in the given composition? Composition of natural gas is attached here.
Please help in finding the water content in the natural gas.
Kind Regards,
Berbie
I am doing simulation for a TEG Dehydration package using HYSYS. I have the natural gas composition which is saturated at 42.3 Deg Celsius @ 36 bar (a). In the composition I could not find the H2O content.
Is there a way to find how much water present in the given composition? Composition of natural gas is attached here.
Please help in finding the water content in the natural gas.
Kind Regards,
Berbie





RE: Water Content in Natural Gas
David
RE: Water Content in Natural Gas
Another good resource is GPSA databook where you can find water content of natural gases.
http://antwrp.gsfc.nasa.gov/apod/astropix.html
RE: Water Content in Natural Gas
When calculating equilibrium points my software (Prode) permits to specify the fraction (in this case 0.000..1 fraction) for a specified component, this is useful in these cases, perhaps your simulator has a equivalent procedure.
RE: Water Content in Natural Gas
I don't understand, why they have not provided the water content in the natural gas. They have given the composition for all other components except water.
RE: Water Content in Natural Gas
I suppose you should correct this for the compressibility, but that will be a small change. From this manual estimation you can work out how much water you need to add to use EmmanuelTop's trick, and then HYSYS will work out the water content using whatever model you have specified.
Katmar Software - Engineering & Risk Analysis Software
http://katmarsoftware.com
"An undefined problem has an infinite number of solutions"
RE: Water Content in Natural Gas
Another possibility is using the chart in the GPSA Engineering Data Book. It is based on the McKetta-Wehe method published in 1958. This has been put into a computer program at the University pf Tulsa.
RE: Water Content in Natural Gas
RE: Water Content in Natural Gas
Following are the steps I followed in HYSYS,
1) Used PR as fluid package.
2) Added two streams one without water (with given natural gas flowrate) and one with pure water(added maximum flowrate).Both streams operating at 42.3°C and 26 bara.
3) Used 2-phase separator to separate the phases. Now the separated gas is saturated but the temperature got decreased.
4) I used 'ADJUST' to change the 'Water Stream' temperature to get 42.3°C.
Is it right???
RE: Water Content in Natural Gas
RE: Water Content in Natural Gas
The real point is that with PRSV and standard mixing rules (unless you spend time to fit BIPs) you must be prepared to accept a certain error in VLE.
I have a different software (Prode Properties) which instead of Stryjek Vera extension has the three parameters TWU (three parameter per each component), still there are (little) errors for water possibly because of van der Waals rules (water is a polar component), if I set different mixing rules (Huron Vidal or Wong Sandler) and custom BIPs the errors are much lower.
You should be very careful to select the proper thermodynamic options in your software, PRSV can fit reasonably well the vapor pressure of many pure components but still produce unreliable VLE results.
RE: Water Content in Natural Gas
I agree with Paolopemi, you must be prudent to evaluate water contents in natural gas with PRSV , you can get unreliable results.
RE: Water Content in Natural Gas
Best regards
Morteb
RE: Water Content in Natural Gas
http://antwrp.gsfc.nasa.gov/apod/astropix.html