Question

Which of the following is the correct condition for the efficient combustion of coal?

(a) Coal should be of high calorific value

(b) Intimate mixing of air with the combustible matter

(c) The ignition temperature should be high

(d) The volatile matter should be low

I have been asked this question in an interview for internship.

The doubt is from Efficiency of Combustion topic in portion Fuels and Combustion of Engineering Chemistry II

Answer 1

The correct answer is (b) Intimate mixing of air with the combustible matter

To elaborate: For efficient combustion, it is essential that the coal and its distillation products are brought into intimate contact with sufficient quantity of air to burn all combustible material. Also, sufficient time should be allowed to complete the combustion process.