## 3 Results and Discussion
### Cost and Economic Parameters  
Investment performance measurement was conducted using several economic analyses, including the calculation of NPV, IRR, PBP and ROI. The calculations were performed using SuperPro Designer(r) v9.0 with several assumptions employed, based on the particulars of the Indonesian industry context, such as the number of holidays in a year, the labour price, the price of raw materials and the risk-free rate. This section presents the estimation of the total capital investment cost (TCI), the annual operating cost (AOC) and the unit production cost of the hand-sanitiser product. The project is assumed to have a lifetime of 10 years and an annual operating time of 330 days (11 months). The depreciation of the capital investment was calculated using the straight-line method for a period of 10 years and a salvage value equal to 5% of the initial cost. The TCI of the plant was estimated according to the equipment purchase cost (EPC) following a well-established engineering methodology described in detail in the literature [42]. The equipment sizes were calculated using the simulation tool, based on the mass and energy balances. The EPC was estimated according to information from vendors, literature sources, and the SuperPro Designer(r) v9.0 equipment cost database. The total investment was estimated at $645,000; the breakdown of the TCI is presented in Table 5 below.  
Figure 5: The relationship between fermentation time and flow rate of bioethanol, glucose and yeast leaving fermenter simulated by SuperPro Designer(r). v9.0.  
The calculation of the annual operating cost (AOC) was conducted to determine the influence of operating components on the product cost. The calculated AOC for this plant was $305,000; its breakdown is summarised in Figure 6. As shown in Figure 6, the largest percentage of the AOC is facility-dependent costs, which consist of capital depreciation, maintenance, insurance and overheads [43]. This can be explained, as the high value of the TCI and the relatively short lifetime of the plant lead to higher annual depreciation. The second highest cost contributor is utilities, which consist of standard electrical power, steam (low pressure and high pressure), and a large amount of cooling and chilled water, with a total annual utility cost of $95,749. The highest contributor to the utility cost is electricity, at $58,807 annually, or more than 61% of the utility cost. This is a result of the long period of fermentation that leads to high electricity consumption for processes such as agitation and temperature control. Raw materials, despite the low price of OPEFB, contribute to 22% of the AOC. The breakdown of raw material and utility costs can be seen in Table 6. \begin{table}
\begin{tabular}{l l} \hline \hline
**Total Plant Direct Cost (TPDC)** & \\ \hline
1. Equipment purchase cost & 101,000 \\
2. Installation & 33,000 \\
3. Process piping & 35,000 \\
4. Instrumentation & 41,000 \\
5. Insulation & 3000 \\
6. Electrical & 10,000 \\
7. Buildings & 46,000 \\
8. Yard improvement & 15,000 \\
9. Auxiliary facilities & 41,000 \\ TPDC & 325,000 \\ \hline
**Total Plant Indirect Cost (TPIC)** & \\ \hline
10. Engineering & 81,000 \\
11. Construction & 114,000 \\ TPIC & 195,000 \\ \hline
**Total Plant Cost (TPC = TPDC + TPIC)** & \\ \hline TPC & 520,000 \\ \hline
**Contractor’s Fee and Contingency (CFC)** & \\ \hline
12. Contractor’s Fee & 26,000 \\
13. Contingency & 52,000 \\ CFC & 78,000 \\ \hline
**Direct Fixed Capital Cost (DFC = TPC + CFC)** & \\ \hline DFC & 598,000 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Fixed capital estimate summary (2020 prices in $).  
Figure 6: Annual operating cost breakdown.  
One of the reasons why this project could be economically beneficial is the low cost of labour in Indonesia. The actual minimum wage of labour in Indonesia varies depending on location. In this study, we used the highest value of minimum wage in Indonesia for labour and blue-collar jobs, which is about $0.9/labour-h.