# Scenario-Based Techno-Economic Analysis of Steam Methane Reforming Process for Hydrogen Production
## 3 Results and Discussion
### Hydrogen Production Cost  
Figure 3 shows the costs and revenues of the six scenarios. The H\({}_{2}\) production cost, defined as the price of production at the breakeven point, is calculated using the discounted cash flow methodology presented in the NREL reports [37; 38] (see Tables S9-S14 in the Supplementary Materials for detailed discounted cash flows for Sc 1-6, respectively). H\({}_{2}\) production costs consist of feedstock costs, operating costs, capital depreciation, income taxes, and return on investment calculated by the formula [44]. Sc 5 includes CO\({}_{2}\) emission allowances, and Sc 6 includes CO\({}_{2}\) emission allowances, CO\({}_{2}\) capture cost, and sales credit.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **Sc 1** & **Sc 2** & **Sc 3** & **Sc 4** & **Sc 5** & **Sc 6** \\ \hline A100: Hydrogen production & 307,888 & 326,817 & 393,578 & 289,849 & 307,888 & 307,888 \\ A200: Steam production & 23,608 & 25,331 & 26,493 & 10,759 & 23,608 & 23,608 \\ A300: Hydrogen purification & 102,747 & 104,032 & 104,032 & 295,521 & 102,747 & 102,747 \\ A400: Feed intake & 12,347 & 11,842 & 12,210 & 11,827 & 12,347 & 12,347 \\ Total installed equipment costs & 446,590 & 468,021 & 536,312 & 607,956 & 446,590 & 446,590 \\ Total direct costs & 526,976 & 552,265 & 627,231 & 717,388 & 526,976 & 526,976 \\ Total indirect costs & 316,186 & 331,359 & 376,338 & 430,433 & 316,186 & 316,186 \\ Fixed capital investment & 843,162 & 883,624 & 1,003,569 & 1,147,821 & 843,162 & 843,162 \\ Total capital investment & 902,183 & 945,478 & 1,073,819 & 1,228,168 & 902,183 & 902,183 \\ \hline \multicolumn{8}{c}{**Operating Costs (S/y)**} \\ \hline  & **Sc 1** & **Sc 2** & **Sc 3** & **Sc 4** & **Sc 5** & **Sc 6** \\ \hline Feedstock & 121,977 & 121,860 & 120,588 & 119,368 & 121,977 & 121,977 \\ Ru–Ni/Al\({}_{2}\)O\({}_{3}\) catalyst & 462 & 438 & 438 & 420 & 462 & 462 \\ Cu/Fe\({}_{3}\)O\({}_{4}\)–Cr\({}_{2}\)O\({}_{3}\) catalyst & 513 & 665 & 879 & 478 & 513 & 513 \\ Adsorbent & 1776 & 1813 & 1813 & 1940 & 1776 & 1776 \\ Electricity & 6215 & 6391 & 6391 & 30,434 & 6215 & 6215 \\ Cooling water & 834 & 783 & 696 & 834 & 834 & 834 \\ Deionized water & 13,652 & 14,434 & 14,434 & 16,056 & 13,652 & 13,652 \\ CO\({}_{2}\) emission allowances & - & - & - & - & 40,632 & 40,632 \\ CO\({}_{2}\) capture & - & - & - & - & - & 88,270 \\ Fixed operating costs & 35,634 & 36,346 & 38,456 & 40,994 & 35,634 & 35,634 \\ Total operating costs & 181,063 & 182,730 & 183,695 & 210,524 & 221,696 & 273,397 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Capital and operating costs in six scenarios.  
As discussed in Section 3.1, the cost of H\({}_{2}\) production increases from Sc 1 to 2, 3, and 4 because of the use of a low-temperature WGS reactor, the addition of the low-temperature WGS reactor, and the low pressure in the reformer, respectively. In Sc 5, the CO\({}_{2}\) emission allowances are applied to 100% of the CO\({}_{2}\) generated from the burning of the tail gas, adding a cost of $0.25/kg-H\({}_{2}\). In Sc 6, the CO\({}_{2}\) emission allowances are applied to only 10% of CO\({}_{2}\), increasing the cost by $0.025/kg-H\({}_{2}\) because 90% of the generated CO\({}_{2}\) is captured. Among the six scenarios, Sc 6 shows the lowest H\({}_{2}\) production cost of $1.80/kg-H\({}_{2}\) mainly due to the additional revenue from the sale of captured CO\({}_{2}\), despite the additional production cost required for CO\({}_{2}\) capture. Therefore, the SMR process configuration in Sc 6 is economically optimal with CO\({}_{2}\) capture and sales.