Problem 1-9 points CHE 4224 Chemical Engineering Design II Spring 2024 Homework #5 Due: Friday, 4/12/24 A demethanizer is the first tower in a natural gas processing plant and operates at high pressure and low temperature. The tower produces a residue gas as the top product and a Y-Grade NGL as the bottom product. Additionally, the tower has two side heat exchangers to help distribute the heat input and balance the vapor/liquid traffic in the column. The preliminary design indicates that the feed (439,930 lbm/hr, Cp,avg = 1.042 Btu/lbm °F) needs to be cooled from 80 °F to -56 °F. In order to minimize the capital and operating costs of the refrigeration system, we will use the following process streams to cool the feed. Tstart (°F) Tfinish (°F) Mass Flow Rate (lbm/hr) Cp,avg (Btu/lbm °F) Residue Gas -120 70 297,031 0.5785 Y-Grade NGL 55 70 142,899 0.6580 Side-Exchanger, Stream 1 -112 -82 197,402 0.6754 Side-Exchanger, Stream 2 -47 -6 202,695 0.4813 Using an approach temperature of 5 °F, construct the temperature interval (3 pts) and heat cascade (3 pts) diagrams. Determine the pinch point, the minimum utility requirements, and the minimum number of heat exchangers required (3 pts) You may neglect the effects of phase-change and two-phase flow and use the average heat capacities to calculate available heat.