Coal GCV

Too many TLAs:

http://www.acronymfinder.com/TPH.html

http://www.acronymfinder.com/TPD.html

http://www.acronymfinder.com/ADB.html

http://www.acronymfinder.com/ARB.html

http://www.acronymfinder.com/GCV.html

WTF.

You need to use the dry weight basis GCV of said coal, instead of paying for the water content. You do not seem to have control over this asset, due to weather exposure.

I can assure you the moisture content contributes nothing to the heating value of the fuel, but it does suck heat out of the burn to remove it as fed to the boiler.

Do you have fuel pre-heating equipment?

I feel for you, in sorting this out. I have heard of situations where the coal is paid for by the tonnage based on the lower heating value. My personal opinion of this practice is a dim one, since the numbers are all over the board, depending on the water content.

It depends how your purchasing department buys your coal, how they evaluate its price, how you analyze it, and how your boiler burns it.

The GCV (Gross Calorific Value) for high moisture content coal, peat, lignite, etc., can be determined on either the ARB (As Received Basis) or the ADB (Air Dried Basis). The ADB should always be higher since the moisture that has been absorbed during shipping and handling is removed prior to testing, while the ARB includes that water that doesn't contribute to the heating value of the fuel as mined.

Which would you rather pay for, a ton of coal that is 50% or 20% water? The price depends upon the contract specs, while you're stuck with the poorer performance and process retuning necessary that comes with varying moisture content.

Thanks for saying precisely, and clearly what I was stumbling over.