Optimizing a methanol reactor in Aspen Plus

Using a Langmuir-Hinshelwood-Hougen-Watson kinetics, an industrial methanol reactor in a GCC-based plant was modeled in Aspen Plus®. The model parameters were adjusted to reduce the error as determined by deviation from thermodynamic equilibrium; the average error in composition was reduced by 88% for methanol. The optimization was carried out in four ways, in which flow rates and temperatures were manipulated within their physical limits. The case that was most successful in optimizing the methanol production involved controlling the flow rate and temperature of the main feed to the reactor, as well as those of the quenches. Methanol production increased by 3.99%, which represents a methanol mole percentage of 4.87% at the outlet, compared to the original case at 4.67%.