Partial oxidation of n-butane to maleic anhydride has been studied in a small scale recycle reactor immersed in a molten salt bath at atmospheric pressure between 410˚-510℃.
Catalysts containing oxide of vanadium & phosphorus were prepared using tetrahydrofuran as a reducing agent without support in the laboratory and were characterized. Catalyst prepared from $V_2O_5$ & $POCl_3$ using tetrahydrofuran was chosen for detailed investigation. The influence of variables, including reaction temperature & feed rate of the reactant, on conversion and product distribution was examined.
Based on the experimental kinetic data, an isothermal pellet model was proposed for the catalyst particle, and then with the isothermal catalyst pellet model being incorporated a steady-state simulation of a large scale fixed-bed reactor was carried out within practical range of operating variables.
A maximum yield of 39 mole percent for the large scale fixed-bed reactor is obtained in its steady-state simulation while a maximum yield of maleic anhydride obtained in a small scale recycle reactor was 33 mole percent.
A linearized low-order state-space model was developed for a large scale fixed-bed reactor and its dynamic behavior was observed through the desired state-space model for control analyses. The error in steady-state outlet conditions from a linear state-space model are negligible compared with those from a nonlinear model to a disturbance of 15˚K in the reactor wall temperature. Finally, the stability of the model was examined using the pole-zero information of the transfer function matrix calculated from the system matrix.