Abstract
In this work, stationary states in nonequilibrium plasmas of chemical
reactions that can produce hydrogen are explored, namely the water
splitting and water gas shift reactions. For both reactions, the
effluent from the reactor at long gas residence times in the plasma was
found to be independent of the influent speciation. In other words,
feeding the reactor either 0.1 H2O or 0.1H2+0.05O2 by mole produced the
same effluent composition, and similarly, feeding the reactor
0.1CO+0.1H2O produced nominally the same effluent as 0.1CO2+0.1H2. For
both reactions, the effluent from the plasma was found to be very far
from local equilibrium at the total pressure and background temperature
of the reactor. An important conclusion of this work is that special
attention must be paid to the recombination zone in plasma chemical
processes. The recombination zone tends to drive the gas composition
from plasma stationary states back towards local equilibrium.