There are 10 mol/s going into the reactor. 20% is Inert. So, 2 mol/s inert. That means 8 mol/s of H2 and N2. If they're STOICHIOMETRIC then that means a 3:1 ratio of H2 to N2. If 8 is broken down that means a 6:2 ratio of H2 to N2. So, 2 mol/s N2, at a 15% conversion: 2(.15) = .3 mols N2. But each MOL of N2 makes 2 MOL NH3. So .3(2) = .6. VOILA!
Hello, I am a frequent viewer of your screencasts. I have an interest in Chemical Engineering but I do not know where to start learning. I am a Mechanical Engineer, so I already have good knowledge of Thermo, Fluids and Heat. What is the best topic to start learning Chemical Engineeering?
Great question. I would start with Chemistry and then go to Material and Energy Balances. Thermo is different in Chemical Engineering, as there is much more, but you may be able to skim the beginning of that course. Check out the screencasts here: www.learncheme.com/screencasts
There are 10 mol/s of feed, which includes fresh and recycle. 20% of that is recycle. So, 10(.2) = 2 mol/s inert. That leaves 8 mol/s of H2 and N2. If these are STOICHIOMETRIC, then each mol N2 has 3 mol H2. That's a 3:1 ratio of H2 to N2. Apply a 3:1 breakdown on the 8 moles of feed, and you get 6:2. (6+2 = 8) So, it's 6 mol H2 and 2 mol N2.
Badly written problem. As written it does have an inert feed, a feed of 0 mol/s. Saying, halfway through, "Oh, there's inert gas, oops, add a 25% recycle" isn't what the problem says. As an instructor, I encourage you to remove this problem, or accept that the inert feed is "zero." All this is going to do is confuse students. Don't amend the problem.
Thanks for your comment. We believe this is a good problem because it demonstrates why a purge stream is needed and then calculates the fresh feed composition for a purge stream of 25%..
Hi, I would like to ask about the lesson regarding the number of moles. How did you get the 0.6 mols of the NH3?
There are 10 mol/s going into the reactor. 20% is Inert. So, 2 mol/s inert. That means 8 mol/s of H2 and N2. If they're STOICHIOMETRIC then that means a 3:1 ratio of H2 to N2. If 8 is broken down that means a 6:2 ratio of H2 to N2. So, 2 mol/s N2, at a 15% conversion: 2(.15) = .3 mols N2. But each MOL of N2 makes 2 MOL NH3. So .3(2) = .6. VOILA!
@@planomathandscience not answering the question. He asked about the 0.6 mol of ammonia that comes out as the product
Hello, I am a frequent viewer of your screencasts. I have an interest in Chemical Engineering but I do not know where to start learning. I am a Mechanical Engineer, so I already have good knowledge of Thermo, Fluids and Heat. What is the best topic to start learning Chemical Engineeering?
Great question. I would start with Chemistry and then go to Material and Energy Balances. Thermo is different in Chemical Engineering, as there is much more, but you may be able to skim the beginning of that course. Check out the screencasts here: www.learncheme.com/screencasts
How did you get 6 moles of H2 and 2 moles of N2?
There are 10 mol/s of feed, which includes fresh and recycle. 20% of that is recycle. So, 10(.2) = 2 mol/s inert. That leaves 8 mol/s of H2 and N2. If these are STOICHIOMETRIC, then each mol N2 has 3 mol H2. That's a 3:1 ratio of H2 to N2. Apply a 3:1 breakdown on the 8 moles of feed, and you get 6:2. (6+2 = 8)
So, it's 6 mol H2 and 2 mol N2.
Badly written problem. As written it does have an inert feed, a feed of 0 mol/s. Saying, halfway through, "Oh, there's inert gas, oops, add a 25% recycle" isn't what the problem says.
As an instructor, I encourage you to remove this problem, or accept that the inert feed is "zero." All this is going to do is confuse students. Don't amend the problem.
Thanks for your comment. We believe this is a good problem because it demonstrates why a purge stream is needed and then calculates the fresh feed composition for a purge stream of 25%..