In choosing between an adiabatic or isothermal reactor, pressure was varied in the adiabatic reactor while holding the temperature of the feed constant, and temperature was varied in the isothermal reactor while holding its pressure constant. This is close to the point of intersection of the product flow line and the purity line, analogous to the point of equilibrium between supply and demand in economics. Pressure of 100 bar represented the best trade-off between the amount of NH3 produced in the product stream and the purity of the product stream. This pressure was chosen as the constant operating pressure of the isothermal Gibbs reactor. This temperature has the same implications as the pressure of 100 bar did for the adiabatic Gibbs reactor.
Adiabatic reactors are more common in industry.
It does not require temperature regulation. Peng-Robinson is well suited for use with gas and hydrocarbon processing and refining. The remaining pieces of the process flow diagram included two multistage compressors, a heat exchanger, and a flash vessel. The first compressor was modeled as an ideal three stage compressor and increased the pressure of the input feed stream to 100 bar before entering the reactor. The flash vessel was also operated at -30 oC and had a pressure drop of 5 bar.