Mohamed Bechir Ben Hamida
This study focuses on simulating and optimizing cumene (isopropylbenzene) production via the alkylation of benzene with propylene using a beta zeolite catalyst. Two process configurations were evaluated: a conventional setup without a transalkylation reactor and an enhanced configuration incorporating a transalkylation unit to convert byproducts back into cumene. The process was modeled under steady-state conditions in Aspen HYSYS using plug flow reactors and the Peng–Robinson fluid package, with reaction kinetics derived from established literature on zeolite-catalyzed systems. Optimization studies examined the effects of reactor temperature, pressure, and the benzene-to-propylene molar ratio. Increasing the reactor temperature to 178 °C improved propylene conversion to 96.20%, while raising the pressure from 3540 kPa to 3600 kPa further enhanced it to 96.24%. By optimizing the benzene-to-propylene molar feed ratio to approximately 1.02:1 and increasing the fresh benzene feed to 138.5 kmol/h, cumene production reached 135.792 kmol/h while minimizing byproduct formation. Comparative analysis revealed that the configuration without a transalkylation reactor generated 4.171 kmol/h of diisopropylbenzene (DIPB) as waste, representing both economic loss and environmental concern due to its toxicity. In contrast, the integration of a transalkylation reactor enabled the conversion of DIPB into additional cumene, significantly improving process efficiency and sustainability. These findings demonstrate that optimizing reaction conditions and integrating a transalkylation step substantially enhances cumene yield and reduces waste, leading to a more viable and environmentally friendly industrial process.