Assignment Questions

Q1. Using gas-phase NO oxidation reaction: NO(g) + 1⁄2 O2(g) = NO2(g) as an example demonstrates how the reaction conditions may be manipulated in order to achieve the highest possible NO conversion. Support your statement with relevant equations and/or calculated results when possible and your discussion should be focused on:

1. Reaction temperature;
2. reaction pressure;
3. feed composition;
4. others (single or multiple reactors, heating or cooling, feeding and/or removing of gaseous components to and from the reactor, and any other factors).

Please note that the discussion here should be based only on the information derived from the thermodynamic properties of the components and the reaction system involved (no reaction kinetics should be involved here).

Q2. A solid catalyst was developed which shows good activity and selectivity for NO oxidation in a temperature range between 100 and 500°C. Discuss, if NO oxidation reaction is to run as a continuous process in the presence of the solid catalyst, which type of reactor (MFR and PFR) and/or network of reactors (connected in series or parallel) you would choose, assuming the process is to be operated at steady-state and atmospheric pressure, and NO oxidation is the only reaction occurring in the reactor. Justify your choice.

Q3. Determine the maximum achievable NO conversion, if two adiabatic reactors connected in series and operated at atmospheric are used with the initial feed enters the first reactor at 100°C, and the exit stream from the first reactor can be cooled to 100°C before entering the second reactor.

The initial feed contains only NO and O2 at the reaction stoichiometric ratio. The conversion of NO reaches 95% of equilibrium conversion in both first and second reactors. The enthalpy of NO oxidation reaction may be taken as -58 [kJ/mol] and the heat capacity at a constant pressure of reaction mixtures before and after the reaction may be taken as 47 [J/(mol.K)], both values are based on per mol of NO.