GRAPH BASED CAD MODULE FOR BINARY DISTILLATION COLUMN

Abstract

Graph based technique of computer aided design is a new approach of parametric studies of design of process equipments in order to find the most suiatble condition for the equipment design. Graph based technique of computer aided design of binary distillation column has been carried out. The effect of feed condition (temperature, pressure and molar flow rate) on the actual number of stages, optimal feed stage, condenser duty and reboiler duty was investigated. The effect of feed condition (temperature, pressure and molar flow rate) on the actual number of stages, optimal feed stage, condenser duty and reboiler duty were investigated. The effect of external reflux ratio on the actual number of stages, optimal feed stage, condenser duty and reboiler duty was also investigated. The most suitable feed condition obtained for the design of the binary distillation column are feed temperature of 30 oC, feed pressure of 101 .3 kPa and molar flow rate of 100 kmollhr. The external reflux ratio of 4 was obtained as the best value that gave minimum number of stages and reboiler duty. The equipment design shows that a sieve tray of 1m section diameter was obtained. The column has a sectional height of 4.3m and cross-sectional area of 0.79 m2• The design also shows that there is no flooding in the distillation column. The cost estimation was carried out using Hysys spreadsheet. The cost index used is the chemical engineering cost index of 2006. The cost estimation of the column shows that the total bare module cost of the tower, trays, condenser, reboiler and reflux accumulator at 2006 Chemical Engineering index is two hundred and seventy eight million nine hundred and eighty thousand naira (W 278,980,000). the total utility cost (condenser, cooling water, and