Mass Balance in the Haber Process

reactor conditions

temperature

600

pressure

100

reactor feed flow rate

10

Consider the high-pressure synthesis of ammonia (

1.5

H

2

+0.5

N

2

⇋

NH

3

), known as the Haber process. We use the Peng–Robinson equation of state and the reaction-coordinate method to compute the extent of reaction,

ξ

in moles of

NH

3

per unit time (e.g., hours), for user-set values of the reactor temperature

T

in degrees Kelvin and pressure

P

in bars. This Demonstration carries out the mass balance around the reactor and splitter in order to compute the amount of ammonia produced when chemical equilibrium is reached in the reactor and in the recycle stream. We assume that: (1) the splitter separates the product (i.e., ammonia) perfectly from the reactants (i.e., nitrogen and hydrogen); and (2) the fresh feed contains stoichiometric amounts of nitrogen and hydrogen. As expected from Le Chatelier's principle, the amount of ammonia produced is greater at low temperatures and high pressures.