## 4 Case Studies and Process Description
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Stream** & **Units** & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** \\ \hline \(\dot{m}\) & kg/s & 43.89 & 43.91 & 71.35 & 56.75 & 45.39 & 116.75 & 92.59 & 403.90 \\ \(t\) & \({}^{\circ}\)C & 15.00 & 132.92 & 551.78 & 1157.35 & 550.00 & 1210.13 & 1168.38 & 231.80 \\ \(p\) & bar & 10.00 & 38.35 & 37.80 & 39.30 & 30.00 & 31.00 & 30.00 & 3.00 \\ \(x_{H_{2}}\) & \% (mole) & 0.00 & 0.00 & 0.00 & 0.00 & 0.00 & 55.26 & 62.10 & 0.00 \\ \(x_{CO}\) & \% (mole) & 0.00 & 0.00 & 0.66 & 0.00 & 0.00 & 25.49 & 32.16 & 0.00 \\ \(x_{CO_{1}}\) & \% (mole) & 0.70 & 0.72 & 0.45 & 0.00 & 0.00 & 2.69 & 0.73 & 0.00 \\ \(x_{CH_{4}}\) & \% (mole) & 94.90 & 94.86 & 62.08 & 0.00 & 0.00 & 0.00 & 0.01 & 0.00 \\ \(x_{H_{0}O}\) & \% (mole) & 0.00 & 0.02 & 35.83 & 1.00 & 0.00 & 16.10 & 4.49 & 0.00 \\ \(x_{CH_{3}OH}\) & \% (mole) & 0.00 & 0.00 & 0.00 & 0.00 & 0.00 & 0.00 & 0.00 & 0.00 \\ \(e\) & MJ/kg & 49.66 & 49.87 & 31.62 & 2.60 & 0.61 & 18.68 & 22.87 & 0.16 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Stream data of the methanol plant with steam–methane and autothermal reforming in serial configuration (Case II). Figure 4: Process flow sheet of the methanol plant with steam-methane and autothermal reforming in serial configuration (Case II). Case III uses the parallel reforming configuration that is shown in the flow sheet in Figure 5. Since the reaction in the DMR (R-04) favors high conversion rates at low pressure, the entire reforming unit needs to be operated at two different pressure levels. This requires the additional compressors CM-01 and CM-02 for the DMR (R-04) and the SMR (R-05) process line. Both reactors are designed as tubular gas-heated reformers to transfer heat from the combustion gases (stream 9) to the tubes. Due to the high heat demand of the reforming unit, a purge ratio of 0.2 (stream 14 in Table 5) is selected to keep the fuel consumption (stream 8) in a moderate range. However, large, steam-turbine-driven compressors CM-03 and CM-04 are required to feed air to the combustion chamber R-06. A stream of 60 kg/s CO\({}_{2}\) is fed as reforming agent to the DMR to result in methane slip below 1 mole-%. The syngas from R-04 contains a high fraction of CO\({}_{2}\), which is lowered by blending the product with syngas from the SMR unit. The composition of the synthesis inlet flow (stream 12) is slightly deficient in H\({}_{2}\) (H\({}_{2}\)/CO-ratio = 1.88) and rich in CO\({}_{2}\), which reduces the reactivity and \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Stream** & **Units** & **9** & **10** & **11** & **12** & **13** & **14** & **15** & **16** \\ \hline \(\dot{m}\) & kg/s & 429.16 & 320.66 & 320.66 & 25.26 & 71.35 & 2.86 & 55.08 & 429.16 \\ \(t\) & \({}^{\circ}\)C & 1155.90 & 241.75 & 38.00 & 38.00 & 551.78 & 96.74 & 70.96 & 276.81 \\ \(p\) & bar & 2.50 & 49.00 & 45.00 & 45.00 & 37.80 & 3.00 & 1.30 & 1.20 \\ \(x_{H_{2}}\) & \% (mole) & 0.00 & 60.54 & 53.50 & 59.35 & 0.00 & 0.00 & 0.00 & 0.00 \\ \(x_{\rm CO}\) & \% (mole) & 0.00 & 34.55 & 31.88 & 35.35 & 0.66 & 0.00 & 0.00 & 0.00 \\ \(x_{\rm CO_{2}}\) & \% (mole) & 4.99 & 1.87 & 2.14 & 2.30 & 0.45 & 0.00 & 0.00 & 4.99 \\ \(x_{CH_{4}}\) & \% (mole) & 0.00 & 0.03 & 0.04 & 0.04 & 62.08 & 0.00 & 0.00 & 0.00 \\ \(x_{H_{0}O}\) & \% (mole) & 7.90 & 0.00 & 0.07 & 0.00 & 35.83 & 14.11 & 0.00 & 7.90 \\ \(x_{CH_{0}OH}\) & \% (mole) & 0.00 & 1.37 & 10.44 & 0.81 & 0.00 & 85.89 & 99.99 & 0.00 \\ \(e\) & MJ/kg & 0.92 & 20.40 & 19.93 & 19.35 & 0.03 & 20.56 & 22.43 & 0.13 \\ \hline \end{tabular}
\end{table} 
Table 4: _Cont._  
Figure 5: Process flow sheet of the methanol plant with parallel steam-methane and dry reforming (Case III). the conversion rates of the reactants. The effluent from reactor R-07 contains 9.4 mole-% methanol. The relatively high purge ratio causes a low RTFR of 1.78.