Reducing energy cost of in situ nitrogen fixation in water using an arc-DBD combination

Abstract

In this study, a sustainable air plasma-based nitrogen fixation into reactive nitrogen species in water (e.g. nitrate and nitrite) is presented, which mimics the lightning-based nitrogen fixation that occurs in nature. We report a hybrid plasma system that combines a dielectric barrier discharge (DBD) reactor (as an efficient ozone source) and an arc plasma reactor (as an efficient NO x source). This hybrid plasma system completely converts gaseous NO x and O 3 into NO −x in water with almost zero emissions (NO x and O 3 ). Gaseous outlets, in-liquid species, and electrical parameters were investigated. The energy cost for nitrate production via a single-pass reaction was extremely reduced to 8 MJ mol −1 , which enhanced the applicability of the direct one-step nitrogen fixation into NO −x in water for distributed fertilizer production to decrease the dependence on the Haber-Bosh process toward sustainable agricultural development.

Plasma-assisted nitrogen fixation: the effect of water presence

“…In addition, even at these conditions, NO 2 − can be effectively transferred to NO 3 − , introducing an additional oxidation step in the production chain as, for instance, done elsewhere. 53…”

“…In addition, even at these conditions, NO 2 − can be effectively transferred to NO 3 − , introducing an additional oxidation step in the production chain as, for instance, done elsewhere. 53 In summary, the liquid phase analysis has shown that a significant portion of the N-containing species generated in the plasma indeed dissolve in the liquid phase forming mainly NO 2…”

At-Field and On-Demand Nitrogenous Fertilizer Synthesis

“…28,40 Using the energy consumption of 8 MJ mol −1 reported, 28 generating 0.0016 mol rN in water would require ∼59,000 MJ ha −1 annually. In more realistic fertigation scenarios, fertilizer can be periodically generated at a high rate, such as the generation rate of 0.11 mol L −1 during 5 min reported in Dinh et al, 28 and then stored and distributed in its aqueous form when power is not readily available. 21 The company Nitricity utilized an ARPA system in order to fertigate 18.6 m 2 of tomato crops and was able to supply fertilizer at a maximum annual rate of 224 kg N ha −1 , 55 demonstrating the feasibility of ARPA systems to be used on the commercial scale.…”

An atmospheric pressure glow discharge in air stabilized by a magnetic field and its application on nitrogen fixation

“…Therefore, atmospheric pressure plasma has better application prospects in gas catalytic conversion but the energy cost needs to be further reduced to about 0.7 MJ mol −1 to be a highly competitive alternative. [23] So far, a variety of atmospheric pressure plasma sources, such as gliding arc (GA) discharge, [15,16,[24][25][26][27][28][29][30][31][32] microwave (MW) discharge, [33,34] dielectric barrier discharge (DBD), [36,37] spark discharge, [38] glow discharge, [38,39] and so on, have been developed and used in gas catalytic conversion. In addition, the nitrogen fixation effect and energy cost of these plasma sources have also been evaluating by many researchers.…”