Have just now come across your post. A few comments:
The statement "The objective of coal ultimate analysis is to determine the amount of fixed carbon....." should read "The objective of proximate analysis is.....".
Frankly, comparing coals on an air dried or dry basis is meaningless because thats never how coal is received or used. In fact comparing on such bases can be unintentionly deceptive.
I have some issues with the quoted reference.Essentially it is important to keep in mind that so-called volatile matter and fixed carbon are hypothetical terms."Volatile matter" is simply a number resulting from a very rigidly defined test procedure.A coal sample measured on the one hand in the USA will produce a different result to the same coal measured in the UK or Australia, simply because the countries use different test methods. Percent "fixed carbon" is simply 100-%moisture-%ash-%"volatile matter". There is no such thing as "fixed carbon"..( Re: IGC Dryden, The Efficient Use of Energy,p 571)
