How do you perform heat integration in a complex process?

Heat integration methodology: (1) Data extraction - identify all streams needing heating/cooling with temperatures, duties, and heat capacity flow rates. (2) Targeting - composite curves and grand composite curve determine minimum utilities at chosen delta_T_min. (3) Select delta_T_min - smaller gives more recovery but higher area; optimize based on economics. (4) Pinch analysis - identify pinch point, design above and below pinch separately. (5) Network design - match streams, design heat exchangers, consider practical constraints (control, safety, operation). (6) Utilities - place heaters above pinch, coolers below pinch. Tools: Aspen Energy Analyzer, SPRINT. Practical considerations: don't cross the pinch, avoid transferring heat across pinch, consider startup flexibility, and maintain some cross-exchangers for feed-effluent heat recovery.