Coal blending issue
Thread Content
What is the difference between volatile matter on a dry basis and volatile matter on a dry ash-free basis in blended coal?
Dry basis: Removing moisture (including internal and external moisture) yields the dry basis; in English, it is referred to as “dry”, abbreviated as D. Dry ash-free basis: Removing both moisture (including internal and external moisture) and ash gives the dry ash-free basis, which is also known as the combustible basis; in English, it is called “dry, ash free”, abbreviated as DAF
For example: In 100 grams of coal, there is 10 grams of water, 9 grams of ash, 28 grams of volatile matter, 60 grams of fixed carbon. What is the amount of volatile matter on a dry basis for the other components? 28÷(100-10)×100%=31.1% What is the volatile matter on a dry, ash-free basis? 28÷(100-10-12)×100%=35.90%