muhsinider

I have a few questions about how act2 calculates e-pH diagrams. 1- I had a similar question/problem with Fact database before about OH[-] ion reference state?. Does act2 use gas or aqueous state as a reference for OH[-]?. Also what reference state does act2 use for carbonate and bicarbonate? 2- I attached the pourbaix diagram for ethanol with this message. However, I could not get the same diagram when I use the "fact" database. Am I missing something about the activity of ionic species? I make my calculations using excel but I use 1 for activity of all ionic, gas and liquid species. In attached file I have E vs A+B*pH equations and they differ a little from act2 results. 3- I am trying to calculate E-pH diagram for ethanol, methane, CO2, HCO3[-], CO3[-2] etc. ? I cannot get the equilibrium between ethanol methane and the other 3 at the same time? what is the problem? I used the organic materials database but I could not get that. I had to suppress carbon from database but when I have both CH4 and C2H5OH the diagram does not show ethanol. When I suppress CH4 then it shows ethanol. Does that mean there is no equilibrium between ethanol and methane at all? I need help with that. My diagram is attached to this e-mail. I appreciate any help or comments. best wishes, Dr. Muhsin IDER Usak University ethanol pourbaix.xlsx

Hello Brian, Thanks for your help. I was able to plot E=pH diagram involving HCO3-, CH4. CO3-- and CO2. I have another problem with reading and constructing the data. My purpose is actually to see all the reactions in the same E-pH diagram if possible. By doing that I want to get a better understanding of ethanol decomposition mechanisms with respect to E and pH. I actually calculated all the reaction Gibbs energies given in the table. ​The most favorable reaction in terms of Gibbs energy is C2H5OH(l) + 4OH[-](aq) D CH4(g) + CO2(g) + 3H2O(l) +4e- I can not get this equilibrium line with the module. Am I doing something wrong? Is it metastable? ​the other most favorable reactions are as follows: 1- C2H5OH(l) + H2O(l) + 4KOH(s) D 6H2(g) + 2K2CO3(s) 2- C2H5OH(l) + 2 OH[-](aq) D 2CO2(g) + 4H2(g) +2e- 3- C2H5OH(l)+ 2OH[-](aq) D CH4(g)+ CO2(g)+ H2O(l) + H2(g)+2 e- My problem is how I can show the equilibrium line between ethanol and CH4, CO2, H2 together. For example the reaction number 3 above. How can I represent the equilibrium line in he diagram for reaction 3. I mean according to E=pH diagram the right side of the equilibrium line must be the zone where CH4, CO2, H2 are stable and the other side must be ethanol. Similarly for number 2 above. I can not get ethanol equilibrium with CO2 and H2 together. ​ Thanks for any help diagrams are in attached file. best wishes. Muhsin IDER diagrams.docx

I need to check e-ph diagram for ethanol. I calculated many reactions in excel myself and I want to check it with the software. But I dont know how to use the software effectively. I guess it is becuse I am new with the software. I actually calculated many reactions involving C2H5OH(l), CH4(gas), CO2(gas), H2(gas), O2(gas), CO3[-2][aq], HCO3-[aq], H+ and OH-. Can I obtain e-pH diagram of ethanol and also methanol with all those ionic species.where to start. I appreciate any help. SOme of the reactions are as follows; 25 ºC and 1 atm E0(V)= -DG0/nF DG0rx,298.15 (J/[mol) 1. 6H2(g) + 2HCO3[-] (aq) D C2H5OH(l) + 3H2O(l) + 2OH[-](aq) -27267, -29455 Ref[2] 2. 6H2(g) + 2CO3[-2] (aq) DC2H5OH(l) + H2O(l) + 4OH[-](aq) 14704, 12426 Ref[2] 3. 2H2(g) + CO3[-2] (aq) + CH4(g) D C2H5OH(l) + 2OH[-](aq) 89365 4. CH4(g) + CO2(g) + 3/2H2(g) + e-D C2H5OH(l) + OH[-] (aq) -1.1734 113216 5. CH4(g) + CO2(g)+ 3H2O(l) +4e-D C2H5OH(l) + 4OH[-](aq) -0.9146 352982 6. CH4(g) + CO2(g) + 2H2(g) + 1/2O2(g) + 2e- D C2H5OH(l) + 2OH[-](aq) 0.2283 -44055 7. CO2(g)+ 1/2O2(g) + 2e-D CO3[-2] (aq) 0.6914 -133420 8. CO2(g)+ 3H2(g) + 2e-D CH4(g) + 2OH[-](aq) -0.1508 29090.445847686129100 9. 2CO2(g) + 4H2(g) + 2e-D C2H5OH(l) + 2 OH[-](aq) -0.7374 142297 10. 2CH4(g) + 1.5O2(g) + 2e- D C2H5OH(l) + 2OH[-] (aq) 2.009 -387678 11. CH4(g) + CO2(g) + H2O(l) + H2(g) + 2e- D C2H5OH(l) + 2OH[-](aq) -1.0009 193144 12. CO2(g) + CH4(g) + 3H2(g) + 3/2O2(g) + 4e-D C2H5OH(l) + 4OH[-](aq) 0.9291 -358578 13. 2CO3[-2] (aq) + 16H+ + 12e-D C2H5OH(l) + H2O(l) 0.1977 -305244