Question

On what basis does the grading of coals is done in India for coals containing high moisture?

(a) On the basis of its calorific value

(b) On the basis of its volatile matter

(c) On the basis of its ignition temperature

(d) On the basis of its ash content and moisture

The question was asked by my college professor while I was bunking the class.

My doubt stems from Coal in section Fuels and Combustion of Engineering Chemistry II

Answer 1

The correct answer is (d) On the basis of its ash content and moisture

Best explanation: For coals containing low moisture content, the grading is done by the calculation of percentile of moisture whereas for high moisture content, both ash and moisture content are taken into consideration. It is not done on the basis of its calorific value.