Question

How can we calculate the calorific value of coal using proximate analysis?

(a) By using Seyler’s formulae

(b) By using Dulong’s formula

(c) By using Davies formulae

(d) By using Nakamura’s formulae

I have been asked this question in an online interview.

This key question is from Coal in portion Fuels and Combustion of Engineering Chemistry II

Answer 1

Correct option is (d) By using Nakamura’s formulae

Easy explanation: The proximate analysis of the coal depends on moisture, ash content, volatile matter and fixed carbon. The Nakamura’s formulae is as follows-

       CV = a [V – (%Ash/10)] + 140.4 C

Here a depends on the percentile of volatile matter.