1. The problem statement, all variables and given/known data If you are allowed to make changes of column pressure and temperature, stream preheating or cooling temperature, please propose a process change that can significantly reduce the energy consumption at DTmin of 10°C. The modified process should maintain the product quality and production rate unchanged. Utility Information Low pressure steam (LP, 140°C) = 0.03 $/kWh = 240 $/kW-Yr Medium pressure steam (MP, 170°C) = 0.05 $/kWh = 400 $/kW-Yr High pressure steam (HP, 200°C) = 0.07 $/kWh = 560 $/kW-Yr Hot Oil (HO, supply 450°C – return ≥ 300°C) = 0.15 $/kWh= 1200 $/kW-Yr Electricity = 0.1 $/kWh = 800 $/kW-Yr Cooling water (CW, 30°C) = 0.005 $/kWh = 40 $/kW-Yr Chilled Water (ChW, 5°C) = 0.05 $/kWh = 400 $/kW-Yr Refrigeration (R-10, -10°C) = 0.1 $/kWh = 800 $/kW-Yr (R-50, -50°C) = 0.3 $/kWh = 2400 $/kW-Yr (R-100, -100°C) = 1 $/kWh = 8000 $/kW-Yr (R-200, -200°C) = 5 $/kWh = 40000 $/kW-Yr 2. Relevant equations 3. The attempt at a solution This is my converged aspen simulation of a process to produce acetone (AC) from isopropyl alcohol (IP). I used a heat exchanger simulation software and here are my streams Basically just inputting the heat duties of all the units. I just do a heat curve analysis and when the heat capacity changes I add a separate cooler, which is why there are blank rows in "Name", because the specific heat capacity is assumed to be constant only in one phase. This is my composite curve This is my heat exchanger network I'm wondering what I could do to improve the efficiency of this process? Or at least places I could start looking and what I should look for.