Nonthermal plasmas are currently being studied as a green
alternative
to the Haber–Bosch process, which is, today, the dominant industrial
process allowing for the fixation of nitrogen and, as such, a fundamental
component for the production of nitrogen-based industrial fertilizers.
In this context, the gliding arc plasma (GAP) is considered a promising
choice among nonthermal plasma options. However, its stability is
still a key parameter to ensure industrial transfer of the technology.
Nowadays, the conventional approach to stabilize this plasma process
is to use external resistors. Although this indeed allows for an enhancement
of the plasma stability, very little is reported about how it impacts
the process efficiency, both in terms of NOx yield and energy cost. In this work, this question is specifically
addressed by studying a DC-powered GAP utilized for nitrogen fixation
into NOx at atmospheric pressure stabilized
by variable external resistors. Both the performance and the stability
of the plasma are reported as a function of the utilization of the
resistors. The results confirm that while the use of a resistor indeed
allows for a strong stabilization of the plasma without impacting
the NOx yield, especially at high plasma
current, it dramatically impacts the energy cost of the process, which
increases from 2.82 to 7.9 MJ/mol. As an alternative approach, we
demonstrate that the replacement of the resistor by an inductor is
promising since it allows for decent stabilization of the plasma,
while it does not affect either the energy cost of the process or
the NOx yield.