# 7.37: Untitled Page 182

## Chapter 7

Figure 7.6. Production of aniline

oxide produced in the reaction remains in the reactor and it is later regenerated with hydrogen. The conversion is given by

 RC H NO

6

5

2

C  Conversion of C H NO

 0 . 80

6

5

2

( M

)

C6H5NO2 1

and the feed consists of 100 kg/h of an equimolar gaseous mixture of nitrobenzene and water. Determine the mole fraction of all components leaving the reactor. If the reactor is initially charged with 2000 kg of iron ( Fe ) , use Eq. 7-5 to determine the time required to consume all the iron. Assume that the reactor operates at a steady state until the iron is depleted.

7‐7. Vinyl chloride ( CH CHCl ) is produced in a fixed‐bed catalytic reactor 2

where a mixture of acetylene ( C H ) and hydrogen chloride ( HCl ) react over 2

2

in the presence of mercuric chloride supported on activated carbon. Assume that an equilibrium mixture leaves the reactor with the equilibrium relation given by y

A

K

 300

eq

y y

B

C

Here y , y and y are the mole fractions in the exit stream of vinyl chloride A

B

C

( CH CHCl ) , acetylene ( C H ) and hydrogen chloride ( HCl ) respectively.

2

2

2

Determine the excess of hydrogen chloride over the stoichiometric amount in order to achieve a conversion given by

 RC H

C  Conversion of C H

2 2

2

2

0 . 99

( M C

)

2H2 feed

7‐8. Carbon dioxide ( CO ) gas reacts over solid charcoal ( C ) to form carbon 2

monoxide in the so‐called Boudouard reaction illustrated in Figure 7.8. At 940 K

the equilibrium constant for the reaction of carbon  Material Balances for Complex Systems

341

Figure 7.8. Production of carbon monoxide

dioxide with carbon to produce carbon monoxide is given by

2

p

CO

K

 1 . 2 atm

(1)

eq

p CO2

A mixture of carbon dioxide and nitrogen is fed to a fixed bed reactor filled with charcoal at 940 K. The mole fraction of carbon dioxide entering the reactor is 0.60. Assuming that the exit stream is in equilibrium with the solid charcoal, compute the mole fraction of all components in the exit stream.

7‐9. Hydrogen cyanide is made by reacting methane with anhydrous ammonia in the so‐called Andrussov process illustrated in Figure 7.9. The equilibrium constant for this reaction at atmospheric pressure and 1300 K is given by 3

p

p

HCN

H

2

2

K

 380 atm

eq

p

p

CH4 NH3

A mixture of 50% by volume of methane and 50% anhydride ammonia is sent to a chemical reactor at atmospheric pressure and 1300 K. Assuming the output of the reactor is in equilibrium, what would be the composition of the mixture of gases leaving the reactor, in mole fractions?

Figure 7.9. Hydrogen cyanide production

7‐10. Teflon, tetrafluoroethylene ( C F ) is made by pyrolysis of gaseous 2 4

monocholorodifluoromethane ( CH Cl F ) in a reactor such as the one shown in 2

342