You do get 9.58# of ash/100# of coal and 5.49#of water and .59# of
The btu figure they give is the dry ash free coal 14876 btu - only the
ash 14876 x 0.0958 = -1425 = 13451 btu/#.
You may also see a MAF amount which also takes out the moisture and
the ash, Moisture Ash Free btu.
Most stokers cannot get much of the volatiles to burn because of no
secondary air for combustion,so a portion of these are also useless.
So if the 14876 btu coal has the ash 1425btu,water 817btu,sulfer 88btu,
volatiles 649btu subtracted, you get 11897btu/#.This is the actual heat
value of this coal,maybe a little more if some of the volatiles combust.
Here is the WIKI for coal and has many definitions and added info on
all types of coal from the mine to the burning.