Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Conversion from mmcmd to mmscfd

Status
Not open for further replies.

wireline1

Chemical
Nov 20, 2010
1
Hi Guys,

Can anyone put me through a step by step calculation to converting gas volume from mmcmd(million cubic meter per day) to mmscfd(million standard cubic feet per day).
I seem to be getting a little confused when i am doing the conversion.
A spreadsheet will be much appreciated.

Cheers!!!!
 
Replies continue below

Recommended for you

Mass Flow Rate=density*volume flow rate=denstiy(stp)*std volume flow rate

That is all you need to know. Mass flow rate is not density dependent, but volume flow rate is. So to get from standard to actual you multiply Std flow rate times density(stp)/density(actual).

Once you have the volume flow rate at the pressure and temperature you need, cubic meters to cubic feet is trivial.

David
 
Before going through the steps, be sure you know exactly what you mean by the terms “cubic meter per day” (at what temperature and pressure?) and “standard” (there are literally hundreds of standards; what temperature and pressure do you regard as “standard”?). Then proceed with the following:

1. Multiply the MMcmd by the density of the gas at the related conditions. This gives you the mass of gas per day – in kg/day, lbs/day, etc.

2. Divide the gas mass rate by its molecular weight and you get the kg-mols or lb-mols per day.

3. You know that there are 22.414 liters/g-mol at 0 oC and 1.0 atmospheres, so you convert the above number to g-mols/day and divide by the molar volume and obtain the rate of gas in liters/day. Convert this into cubic meters per day at 0 oC and 1 atm. I assume that you mean this condition as “standard”.

There is another method:

Use the Equation of State for gas at two conditions:

P1V1 = Z1N1RT1
P2V2 = Z2 N2RT2

Condition 1 = Your first condition;
Condition 2 = Your so-called, “Standard” condition.

1. Convert the cubic meters/day to cubic feet per day at the condition 1;
2. Divide Equation 2 by Equation 1 and you get:

V2 = (Z2/Z1) (P1/P2) (T2/T1)

All temperatures and pressures should be in absolute units. If your condition 1 is close to atmospheric, the compressibilities (Z’s) can cancel out.

You can easily put the above steps into a spreadsheet format and use it repeatedly.
 

To wireline1,

Obviously, if both volumetric units refer to the same conditions for the same fluid, every cubic meter equals 35.314725 cuft.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor