Table 4.

Computational outputs from the PSO for the base case (Two interval).

	[Recycle amount (kg/s), Bottom operating pressure of deethanizer (MPaa), Bottom operating pressure of debutanizer (MPaa)]
	First Interval [12–45, 0.45–0.85, 0.5–0.7]
	Execution number
	1	2	3	4	5
Optimum recycled flowrate (kg/s)	12	12	12	12	12
Optimum bottom operating pressure for deethanizer(MPaa)	0.85	0.85	0.85	0.85	0.85
Optimum bottom operating pressure for debutanizer (MPaa)	0.50	0.50	0.50	0.50	0.50
TAC (1000 USD/year)	1132.90	1132.92	1132.95	1132.90	1132.98
CPU time (s)	973	978	1026	950	1000
Function evaluations	690	690	690	690	690

	Second Interval [3.2–12, 0.8–0.85, 0.5–0.7]
	Execution number
	1	2	3	4	5
Optimum recycled flowrate (kg/s)	3.2	3.2	3.2	3.2	3.2
Optimum bottom operating pressure for deethanizer (MPaa)	0.85	0.85	0.85	0.85	0.85
Optimum bottom operating pressure for debutanizer (MPaa)	0.50	0.50	0.50	0.50	0.50
TAC (1000 USD/year)	821.420	821.465	821.452	821.420	821.420
CPU time (s)	493	480	490	490	490
Function evaluations	660	660	660	660	660