Small scale Birkeland Eyde reactors

Pochari Technologies is developing gliding arc plasma reactors based on the 120-year-old Birkeland Eyde process. Efficiencies are estimated to be 10 kwh/kg NOx based on non-thermal gliding ac plasma instead of 20 kw/kg NO2 using thermal plasma generated by the Birkeland Eyde electrodes.
With micro-nitric acid reactors, farmers can produce their own fertilizer without carbon emissions cost-effectively.

Photovoltaic technology has witnessed tremendous improvements in cost reduction in large part imputable to the dramatic decrease in the cost of polysilicon, from over $400/kg in 2008 to as little as $10kg in 2019. Modern photovoltaic systems wholesaling on Chinese marketplaces such as Alibaba sell for as little as $0.18/watt from RISEN ENERGY CO., LTD for monocrystalline architecture. Much as hydropower enabled the viability of the Birkeland-Eyde process in the early 20th century, modern-day photovoltaic technology with LCOE’s of under 2 cents/kWh opens up a world of opportunities for the electrification of ammonia production and other energy-intensive chemical resources.Degradation rates are typically around 15% for 20 years, or around 0.8% per anum. That means a 1 kW system will produce 84% of its original power output after two decades.Panel type: 275-280/330-335W Multi-Module Price per watt (USD): 0.28 High, 0.175 Low, 0.185 Average.The average price for 350-watt panels is 18.5 cents per watt.The second major cost input is the DC/AC converter. Using data from Alibaba, numerous products were sampled. The most cost-competitive DC/AC rectifiers were ones used for solar-powered well water pumps. 7.5 kW units were priced around $250, yielding a price per kilowatt of $34.The Levelized Cost of Energy (LCOE) is determined by the irradiance available much more so than it is by slight differences in the panel module costs. A solar array in Scotland (880 kWh/kWp/yr) won’t be nearly as cheap as one in Chile (2300 kWh/kWp/yr), or in Los Vegas (1900 kWh/kWp/yr). Using this data, we can estimate the cost of producing NH3 in a high irradiance region such as Los Vegas using a 300 kW unit producing 609,000 kWh per year. The size of the farm would include 15,000 square feet of panels. A 50 kW PV system at B-E efficiency levels translates into about 11 kW installed electrical capacity, although since PV output is cyclical, power is only produced from sun-rise to sun-set, so most of the power is concentrated during a short window. To get around this limitation, the power can be broken down into multiple smaller reactors that can each be switched on to adjust to the rising and falling power output.

Potential system cost. Bare Panel system: $9,250 Invertor: $1700 Wiring: $500 Metallic frame: Not included (insignificant) Land: Not included (assumed to be already owned)

Total: $11,500Price per kWh for one year: $0.12 Price per kWh for 20 years: $0.0071

Price per ton-HNO3 at original B-E efficiency: $108Price per ton-HNO3 at improved non-thermal plasma efficiency: $80Prevailing U.S market price of HNO3: $350-400.CAPEX cost of reactor:

The main CAPEX of the reactor system is the electrical transformer. I recently purchased two 3.5 kW transformer cores for $65/each, not including $300 in shipping. These cores weigh 16 kg each and are made of ferrosilicon alloy. The power density is 0.22 kw/kg. Adding the cost of enameled wire, I bought 10 meters of 1.2 mm transformer wire for $6 on Aliexpress. If the work is done yourself and the products purchased from Chinese marketplaces, what would otherwise be an expensive item if procured conventionally from a specialized supplier is in actuality a cheap item. Therefore, A 10 kW transformer is potentially a very cheap component. What about the electrodes? For the non-thermal design, the plasma reactor consists of two knife-shaped electrodes. To maximize conversion efficiency, the volume of air exposed to the plasma must be maximized, the reactors are thus more efficient at smaller scales. Rather than a cylindrical design where 4 or more electrodes are arranged in a circular pattern, two are placed inside a thin flat box with quartz covering the top of the electrode. The free air space is thus minimal and most of the air that passes through is exposed to the plasma flame. This completes the reactor, all that is left is the absorption system. Arguably, the absorption system is the most complicated and potentially costly. Plasma synthesis of NOx was demonstrated to be 3x more efficient in the kHz range than in the 50-60 Hz range. What this means is we can use the DC current from the solar panels directly to the rectifier to produce the necessary high-frequency AC power needed for the plasma module. The cost of a 1 kW rectifier PCB circuit module outputting 20 kHz is $30. The rectifier outputs 400 volts, so a high-frequency ferrite core can then be used to increase the voltage to around 10-15 kV, voltage above ten kV is unnecessary. The main disadvantage of the non-thermal plasma is the power density. While the original Birkeland Eyde furnaces used highly intense thermal plasma discs stabilized by electromagnets, non-thermal gliding arc discharges (GAD) suffer from lower power densities despite noticeably higher efficiencies. This is due to the difference in activation mechanisms. While the thermal process takes advantage of the non-linear thermal Zeldovich mechanism, whereby high-temperature breaks down the diatomic nitrogen and oxygen, create N-O radicals which immediately form, non-thermal plasma employs the electron excitation principle for activation.

“Nitric acid is one of the most important inorganic acids and it is used in the
production of fertilizers, dyestuffs, and resins. Further applications are stainless steel pickling and metal etching. About three-fourths of the nitric acid produced is used in the fertilizer industry, mainly for the production of ammonium nitrate, ammonium phosphates, and compound fertilizers. The nitric acid needed in the fertilizer industry is usually diluted nitric
acid with a concentration of 50-70%. For most other applications, such as
nitration reactions, 90-100% nitric acid is used”

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