Stream-3 is a combination of stream-1 and stream-2 Moles of CO in stream-3 = mol
ID: 700139 • Letter: S
Question
Stream-3 is a combination of stream-1 and stream-2
Moles of CO in stream-3 = moles of CO in stream-1
120*0.18=x*0.3, x= moles of S1= 120*0.18/0.3=72 moles/s. Stream-1 contains 0.7 molesN2/mole. Moles of N2 in S-1= 72*0.7=50.4 and CO in S-1= 72-50.4= 21.6 mole/s
Stream-3 contains H2 coming from Stream-2,
Hence 120*0.32=x*0.8, x= moles of S-2 =48 moles/s. N2 contains 0.2 mol/mol of N2. Moles of N2 in S2=48*0.2= 9.6 moles/s, moles of H2= 48*0.8=38.4 moles/s
Stream-3 before reaction contains 21.6 mole/s of CO, 38.4 moles/s H2, and 50.4 moles/s of N2 from S-1 + 9.6 moles/s of N2 from S-2= 60 moles/s
The reaction is CO(g)+ 2H2(g)----->CH3OH(g), theoretical molar ratio of CO:H2= 1:2
Actual molar ratio of CO:H2 at S3 is 21.6:38.4= 1:1.8
So Hydrogen is the limiting reactant since required ratio is 1: 1.8 as against 1:2
Excess reactant is CO. Moles of CO used= 38.4/2= 19.2 moles of CO remaining = 21.6-19.2= 2.4 moles/s. % of excess reactant= 100*2.4/19.2 =12.5%
Since 60% of CO reacts, moles of CO reacted= 19.2*0.6=11.52 moles/s, moles of H2 used = 2*11.52=23.04 moles/s. Moles of CO remaining = 19.2-11.52=7.68 moles/s, H2= 38.4-23.04=15.36 mol/s and N2= 60 moles/s, since it does not participate in the reaction.
Explanation / Answer
3. (11%) The system below is used to make methanol (CHLO) from carbon monoxide and Composition data for streams 1, 2 and 3 are shown in the table, along with the flowrate of stream 3. hydrogen S1 CO + 2H2 CH4 mixer S4 S2 S1 S2S3 S4 a. First consider the mixing step only. Determine Stream mol / s mol CO/mol 0.30 0.00 0.18 mol H2/mo mol CH4O/mol 0.00 0.00 0.00 mol N2/mol the flowrates (mol/s) of streams 1 & 2 120 0.00 0.80 0.32 0.70 0.20 0.50 b. Which reactant is the limiting reactant? Whatis the percent excess for the other reactant? c. If 60.90 of the CO reacts, what will be the flow of each species in stream 4? moles CO/s moles H2/s moles CH40/s moles N2/s