Complex Chemical equilibrium codes (CEA, PEP, SPP, TDK, RPA)

[ballistic_tom]

The subject codes use minimization of Gibbs energy to determine equilibrium composition given reactants and pressure. The literature (decades old NASA docs: SP-273, RP-1311, etc.) describes the process for setting up the matrices to solve for the correction factors needed for each iteration (toward minimizing Gibbs) but I'm absolutely lost on how to arrive at the required temperature. Other refs (NWC TP 6037, pg17) suggest that iterations on temp from system enthalpy (starting from adiabatic temp) are performed but I'm at a loss on where to start this process. Thanks in advance for any feedback.

 

[georgeverghese]

For the natural gas steam reforming / shift gas set of reactions, I got this done in the early 1980s' on the computer with info that was published in the nickel catalyst supplier's technical data brochure. The aim was to get the temp approach to equilibrium for the reactor exit stream. There was a search algorithm I had implemented in this program, details of which are in the 6th edn of Perry (I dont remember the method name now). Details on the method for Gibbs energy minimisation for an example set of reactions (steam reforming in this example) are on pages 4-31 to 4-33 in the 7th edn of Perry Chem Engg Handbook (chapter on thermodynamics).
What reactions are you dealing with? Is there a catalyst supplier tech databook for this set of reactions?