Energy balance and environment cleanliness

Let me illustrate how energy balance can lead to environment cleanliness. Consider coke making technology. The details are discussed in lecture 27.

As discussed in lecture 26, coke is an important source of chemical and thermal energy in integrated steel plants producing steel from iron ore. In fact 1 ton of steel would require around 940 kg coal (Assuming coke consumption is 500 kg/ton of hot metal), thus 10,000 tons of steel would require 6600 tons of coke (assuming 0.75 ton of steel is produced from 1ton hot metal). For annual production of few million tons of steel, Coke requirement would be very high. Let us consider coke-coke conversion materials and heat balance. Material balance has already been discussed in lecture 27.

Consider heat balance of a by-product coke oven. The details  of heat balance calculations can be seen in video lecture 40 on materials and heat balance. Heat balance is given for 1000kg coal.

Heat input



(It is assumed that 40% of coke oven gas of calorific value  is used to produce heat in coke oven)

Analysis of heat output

Calorific values of coke, tar and coke oven gas can be utilized by combustion. Sensible heat in coke is notutilized since coke is wet quenched on wet quenching all sensible heat  coke is lost. In addition to this loss, air born coked us emissions 50kg/ton coke are produced. Also huge water is required say around  coke. The contaminants in water are discharged in environment.