CSG/CBM -Ash and Moisture lab interpretations

[terrya]

Hi guys,

Most of the time in CSG/CBM we would have 2 sets of ash/moist data coming from both proximate analysis & adsorption analysis. The difference between both numbers are normally small but sometimes can be big. What's ur take in it? Should we use data from adsorption rather than proximate?

[ruhtra]

Hi Terrya,

you need to check on what basis of ash/moisture has been done. In general ash/moisture will be on air dried basis whereas ash/ moisture will be done at equilibrium moisture basis.

Hope this help.

Arthur

[ruhtra]

Hi Terrya,

you need to check on what basis of ash/moisture has been done. In general ash/moisture will be on air dried basis whereas ash/ moisture will be done at equilibrium moisture basis.

Hope this help.

Arthur

[terrya]

Hi Terrya,

you need to check on what basis of ash/moisture has been done. In general ash/moisture will be on air dried basis whereas ash/ moisture will be done at equilibrium moisture basis.

Hope this help.

Arthur

Hi Arthur,

Yes I understand the difference of both but my question is that which one is more accurate? One needed for Reservoir condition and the other one is not.

[ruhtra]

the EQM would be the most accurate as it run at 96-97% humidity..but if your reservoir temp is too high then your void volume will change during the analysis. pls note eqm is done at 30 oC

[terrya]

the EQM would be the most accurate as it run at 96-97% humidity..but if your reservoir temp is too high then your void volume will change during the analysis. pls note eqm is done at 30 oC

Hi Rutha,

Many thanks for your reply. Yes, I would thought that the case. Most of the time I see a differences around 10% uncertainty range comparison between ash from proximate and adsorption analysis and some even bigger.

[ruhtra]

No problem.

I have seen a lot of uncertainty in adsorption isotherm especially when it run at high temp. In Australia, people still running deep coal at high temp about 120-200 oC but still report in EQM which is run at 30 oC. By the time the test is completed the void volume would change a lot which is also shown on langmuir linear plot.

[ruhtra]

No problem.

I have seen a lot of uncertainty in adsorption isotherm especially when it run at high temp. In Australia, people still running deep coal at high temp about 120-200 oC but still report in EQM which is run at 30 oC. By the time the test is completed the void volume would change a lot which is also shown on langmuir linear plot.

[terrya]

No problem.

I have seen a lot of uncertainty in adsorption isotherm especially when it run at high temp. In Australia, people still running deep coal at high temp about 120-200 oC but still report in EQM which is run at 30 oC. By the time the test is completed the void volume would change a lot which is also shown on langmuir linear plot.

Just wondering, what impact it has on the Langmuir? I would reckon, will be minimal because it just account for max 10% of the total coal capability to contain gas

[terrya]

No problem.

I have seen a lot of uncertainty in adsorption isotherm especially when it run at high temp. In Australia, people still running deep coal at high temp about 120-200 oC but still report in EQM which is run at 30 oC. By the time the test is completed the void volume would change a lot which is also shown on langmuir linear plot.

Just wondering, what impact it has on the Langmuir? I would reckon, will be minimal because it just account for max 10% of the total coal capability to contain gas.