2(iii) CV of coke and tar can be calculated by Dulong formula.

  (iv) CV of coke-oven gas is the summation of heat of combustion values of all combustible components    in coke-oven gas as illustrated in Lecture 2.

Heat balance calculations can disclose

   (a) Distribution of heat energy in products and by-products.
   (b) Sensible heat available in products and by-products.
   (c) Heat losses can be determined from difference between heat output and heat input values.

Next lecture illustrates material balance calculations. The reader must revise the concept of calorific value and must also practice to calculate calorific value of solid and gaseous fuels   

References: 

O.P.Gupta: elements of fuels, furnaces and refractories