*3.6. Profitability Parameters*

Considering the interest rate and money time value in the operating costs and total capital investment, discounted cash flow and the profitability parameters, i.e., profitability index, net return rate on investment, and payout period are calculated (Table 5) [33].


**Table 5.** The profitability parameters of four scenarios.

The payout period is the minimum time to get back the total capital investment. The minimum time is calculated for scenario 2 because of the lowest capital investment requirement and higher revenue. Net return rate is the ratio of the net present value and the present value (PV) of cumulative outflows. NRR of the two scenarios is positive, indicating the profitability of the two processes.

The relative profitability of processes was evaluated by the profitability index (PI), which is calculated by dividing the income value by the costs. The results (Table 5) show that both scenarios are profitable since the project is profitable when PI is greater than one. However, scenario 2 is more profitable, which is due to the production of higher amounts of ethanol.
