As discussed in Example 6.7, toluene (left(mathrm{C}_{7} mathrm{H}_{8} ight)) is to be converted thermally to benzene (left(mathrm{C}_{6}

As discussed in Example 6.7, toluene \(\left(\mathrm{C}_{7} \mathrm{H}_{8}\right)\) is to be converted thermally to benzene \(\left(\mathrm{C}_{6} \mathrm{H}_{6}\right)\) in a hydrodealkylation reactor. The main reaction is \(\mathrm{C}_{7} \mathrm{H}_{8}+\) \(\mathrm{H}_{2} \rightarrow \mathrm{C}_{6} \mathrm{H}_{6}+\mathrm{CH}_{4}\). An unavoidable side reaction occurs that produces biphenyl: \(2 \mathrm{C}_{6} \mathrm{H}_{6} \rightarrow \mathrm{C}_{12} \mathrm{H}_{10}+\mathrm{H}_{2}\).

The reactor section of the process is shown in Figure 7.31 as are the conditions for the feed and two recycle streams. The flow rate of the quench stream should be such that the reactor effluent is quenched to \(1,150^{\circ} \mathrm{F}\). Conversion of toluene in the reactor is \(75 \mathrm{~mol} \%\). Two mole percent of the benzene present after the first reaction occurs is converted to biphenyl. Use a process simulator to perform material and energy balances with the Soave-Redlich-Kwong equation of state (RK-SOAVE option in ASPEN PLUS).

Figure 7.31:-

Data From Example 6.7:-

Figure 6.12:-

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Species Flow Rates (lbmol/hr) Feed Recycle Gas Recycle H 0 0 2,045.9 CHA 0 0 3,020.8 CH (benzene) 0 3.4 42.8 CHg (toluene) 274.2 82.5 5.3 CH10 (biphenyl) 0 1.0 0 Feed 75F, 569 psia Vapor Gas Recycle Product 121F 569 psia Recycle 250F, 569 psia 1,200F U-50 AP = 5 psi 100F FLASH U=60 AP=5 psi DRUM 120F CW 90F 1,000F. FURNACE AP = 70 psi 1,150F 1,268F REACTOR QUENCH PUMP AP=0 psi Liquid Product Figure 7.31 Reactor section of the toluene hydrodealkylation process.