In today's post, I test the proposition that the results are independent of the reaction network, provided the network includes the necessary species.
Network 1 in the figure below is the network previously used. In the last reaction, nitric acid is formed by hydrolysis of NO2. In Network 2, that reaction now uses N2O4.
Network 2 Equilibrium Coefficients
Network 2 Temperature Survey
The results shown below are identical to those obtained with Network 1. Thus, the network change didn't affect the equilibrium results.
In a previous post, I asked why the HNO3 increased with increasing temperature when it's equilibrium coefficient indicated HNO3 should decrease. The answer: the NO2 <-> N2O4 equilibrium K declines at a faster rate with increasing temperature than the nitric acid production reaction. Thus, in the competition for NO2, the nitric acid reaction becomes more favored as temperature increases. By using Network 2, we see in the equilibrium plot that the new nitric acid reaction, R2, shifts to greater HNO3 production as temperature increases. We still have the decline in production of N2O4 to take into account, but at least we can see a possibility that HNO3 might increase with temperature.
I am perplexed
Not one reader submitted their answer to my question regarding HNO3 formation as a function of temperature. This suggests to me that everyone is afraid to make a mistake. That is not the best way to learn. We learn from our mistakes. And its better to make mistakes where the consequences are zero, than when the stakes are high, like a billion dollar plant, or a suspension bridge. I wonder if professors are noticing a lack of classroom participation these days, or is it just the blog format that inhibits two-way communication? Oops, there's another question that probably won't get answered.
Risk taking in the blog
I too am taking risks as I write this blog. When I start a series such as the FCC tracer study or this NOx absorber model, I learn as I proceed. I don't have all of the programs written prior to the start of the series. Thus, I sometimes have to make a correction, which I report.
For the absorber model, there is still much work to be done on the vapor-liquid thermodynamics. I will report some progress in that area in the next post.