Heat transfers H2SO4 making

Fig. 21.1. Heat transfer flowsheet for single contact, suliiir burning sulfuric acid plant. It is simpler than industrial plants, which nearly always have 4 catalyst beds rather than 3. The gaseous product is cool, SO3 rich gas, ready for H2SO4 making. The heat transfer product is superheated steam. All calculations in this chapter are based on this figure s feed gas composition and catalyst bed input gas temperatures. All bed pressures are 1.2 bar. The catalyst bed output gas temperatures are the intercept temperatures calculated in Sections 12.2, 15.2 and 16.3.

So, per kg-mole of 1 catalyst bed feed gas, 8.46 MJ must be removed from 721.1 K 3 catalyst bed exit gas to cool it to the specified 470 K H2SO4 making input gas temperature. The heat is, of course, transferred to water in Fig. 21.1 s economizer. 

Calculate the rate, MJ/hour, at which heat must be transferred from 3 catalyst bed exit gas to economizer water to obtain the above specified 470 K H2SO4 making gas. 100 000 Nm per hour of catalyst bed feed gas is entering the 1 catalyst bed. 

---