Within the context of food processing the term "cold" can potentially engender misleading images of refrigeration requirements as a part of the plasma treatment.
The two features which distinguish NTP from other mature, industrially applied plasma technologies, is that they are 1) nonthermal and 2) operate at or near atmospheric pressure.
[25] Magnetohydrodynamic power generation, a direct energy conversion method from a hot gas in motion within a magnetic field was developed in the 1960s and 1970s with pulsed MHD generators known as shock tubes, using non-equilibrium plasmas seeded with alkali metal vapors (like caesium, to increase the limited electrical conductivity of gases) heated at a limited temperature of 2000 to 4000 kelvins (to protect walls from thermal erosion) but where electrons were heated at more than 10,000 kelvins.
[32] Studies conducted in wind tunnels involve most of the time low atmospheric pressure similar to an altitude of 20–50 km, typical of hypersonic flight, where the electrical conductivity of air is higher, hence non-thermal weakly ionized plasmas can be easily produced with a fewer energy expense.
Collisions between hot temperature electrons and cold gas molecules can lead to dissociation reactions and the subsequent formation of radicals.
Among the different application fields, there are ozone production[34] at a commercial level; pollution abatement, both solid (PM, VOC) and gaseous (SOx, NOx);[35] CO2 conversion[36] in fuels (methanol, syngas) or value added chemicals; nitrogen fixation; methanol synthesis; liquid fuels synthesis from lighter hydrocarbons (e.g. methane),[37] hydrogen production via hydrocarbons reforming[38] The coupling between the two different mechanisms can be done in two different ways: two-stage configuration, also called post-plasma catalysis (PPC) and one-stage configuration, also called in-plasma catalysis (IPC) or plasma enhanced catalysis (PEC).
As an example, the oxygen ground state atom O(3P) has a lifetime of about 14 μs[39] in a dry air atmospheric pressure plasma.