For the economic analysis, three elements including product
selling income, feed cost, and utility cost were taken into account.
It is well accepted that the selection of less expensive
utilities will enhance the profitability of a plant. Therefore, it is
necessary to differentiate different utilities based on both the
heat capacities and the market prices. In the current study,
water was selected if the stream is to be cooled down above
40 C. Natural gas was chosen for heating, and electricity was
used for both chilling below 40 C and compressor work.