How is process simulation software used in process design?

Process simulation software (Aspen Plus, HYSYS, PRO/II) performs rigorous material and energy balances. Usage in design: conceptual design (flow scheme development, option screening), basic engineering (equipment sizing, operating conditions optimization), detailed engineering (design case verification, control philosophy), and operation (troubleshooting, debottlenecking). Key capabilities: thermodynamic property calculation, unit operation models, reaction kinetics, economic evaluation, and optimization. Best practices: validate against plant data, document assumptions, use appropriate thermodynamic models, and maintain model revision control. Simulation output feeds into equipment sizing, P&ID development, and safety studies.