Digitally manufactured air plasma-on-water reactor for nitrate production

Abstract

The sustainable production of food to support the increasing world population is one of humanity’s most pressing challenges. Plasma activated water (PAW), produced using renewable energy, can help fulfil plants’ needs in sustainable agriculture approaches. The design, implementation, and characterization of a digitally manufactured air Plasma-On-Water Reactor (POWR) for the synthesis of nitrate as green nitrogen fertilizer is presented. The interaction of air plasma-generated reactive oxygen and nitrogen species with water produces nitrate (NO3-) and related species, which are the main nitrogen-containing nutrients for plants. The mild conditions of the operation of the POWR opens the possibility to use plastics, particularly through digital manufacturing strategies such as 3D-printing, for its fabrication. A pin-to-plate reactor configuration powered by high-voltage alternating power is chosen due to its simplicity and efficacy. A computational thermal-fluid model is used to evaluate the design and attain expected operational characteristics. The experimental characterization of the POWR encompassed design and operation parameters, namely electrode water spacing, air flow rat- e, and voltage level. A machine learning approach is implemented to extract and quantify characteristic features of the plasma-water interaction, such plasma volume and plasma-water interface area. Experimental results revealed that the nitrate production rate varies linearly with dimensionless plasma volume. The design, fabrication, and characterization methods presented can be adapted to other POWRs and help enable on-demand nitrogen fertilizer production at low environmental and economic cost.

Estimation of total forces of jets on liquid interfaces using image processing methods

“…Typical devices include plasma in a liquid and atmospheric-pressure plasma jets in contact with liquid. They are widely used in advanced oxidation processing [5][6][7][8][9], nanoparticle synthesis [10][11][12][13], plasma medicine and water treatment [14][15][16][17][18][19][20][21]. To ascertain physical and chemical processes occurring in plasma-liquid reactors, Liu et al investigated the plasma jet dynamics above the gas-liquid interface * Author to whom any correspondence should be addressed.…”

A double‐mode planar argon plume produced by varying the distance from an atmospheric pressure plasma jet

“…Without the need for a vacuum chamber, atmospheric pressure non-equilibrium plasmas are very attractive for applications [1], such as ozone generation [2], methane conversion [3], material synthesis [4], surface modification [5], water treatment [6], and plasma medicine [7,8] etc.…”

Using transfer-learning-based algorithms as data reduction strategies for volatile organic compounds classification using plasma spectroscopy

“…Machine learning (ML) has become increasingly popular in recent years across a variety of fields [8], including the analysis of images [9,10], videos [11], and spectra [12][13][14][15][16][17][18]. The features in the data can be successfully extracted using ML algorithms [19], and the extracted features can be used for regression [6,[20][21][22][23][24], classification [25,26], and error detection.…”