Coal Bed Methane Reservoir Engineering Book

[zeliustitan]

hi people..

i m kinda stuck with my CBM gas storage capacity calculation in adsorption isotherm

i was able to find out the gas content for every pressure steps but i have a problem

The langmuir equation related to gas storage capacity is

V= VL [ P / (PL +P)]

then i convert it into y = mx + c and became

P/V = (1/VL)*P + PL/VL

basically slope = m = 1/VL and interception is c = PL/VL

my problem is i got a negative slope.

My question is does this negative slope can represents Langmuir Volume? or it shouldnt be negative slope?

I m stuck here.. Hope anyone can help me.. thanks

[vinomarky]

I think your math is wrong somewhere, your equations are correct I believe.

I've uploaded a worked very simple example for you to look at;

[link Point to another website Only the registered members can access]
Where I've simply started with values of PL & VL, created a Langmuir curve, and then fitted that curve back to original PL & VL constants