Fuel Consumption Reduction and Energy Efficiency Enhancement in Allyl Chloride Production through Heat Recovery and Steam Integration Strategies

Abstract

Allyl chloride production via high temperature propylene chlorination (HTPC) is a strongly exothermic process operating at 420–510 °C and generating substantial recoverable thermal energy in the reactor effluent. In conventional configurations, a significant portion of this high-grade heat is dissipated, while external fuel combustion and steam utilities are required to maintain reactor inlet temperature and downstream heating. This study proposes a systematic heat integration strategy that simultaneously utilizes reactor effluent heat for feed preheating and internal steam generation, providing a more effective approach to reduce overall energy demand. Process simulations were performed using Aspen HYSYS based on rigorous mass and energy balances to evaluate both base and modified configurations, employing the Cubic-Plus-Association (CPA) equation of state due to its improved accuracy in representing non-ideal mixtures containing polar and associating components commonly found in chlorination systems. In the integrated design, reactor effluent heat was utilized to preheat the propylene feed to 200 °C and to generate 6 bar saturated steam for internal process heating. The results show a furnace duty reduction of 5.38 × 10⁶ kJ/h (≈26.3%), corresponding to fuel savings of 228.27 kg/h (≈26.3%) and a carbon dioxide (CO₂) emission reduction of 626.20 kg/h (≈26.3%). Additionally, 1.3943 × 10⁷ kJ/h of thermal energy was recovered. The economic evaluation, based on reduced natural gas consumption and elimination of external steam requirements, indicates significant operational cost savings and practical feasibility for industrial implementation.