Ok, thanks for checking in the new version as well.
It sounds like the input file is missing some boundary condition information. The keyword REAC occurs for inlet streams to a reactor and is the mole fraction of the reagent gases entering the reactor for an inlet stream or for the initial conditions in a closed system. For example, REAC fuel1 C2H2 0.5, would indicate that acetylene has a mole fraction of 0.5 for an inlet stream named fuel1. The sum of all the reactant mole fractions for a stream should equal one.
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