Our revolutionary patent-pending plasma technology utilizes advanced plasma chemical processes to convert air and water into nitrate fertilizer. The breakthrough technology dramatically, 17x-360x, reduces the energy cost of electrically powered nitrogen fixation compared to other plasma-based systems, opening way to replacing the current hydrocarbon-based Haber-Bosch/Ostwald process.

With our technology, fertilizer production would become sustainable and completely decarbonized. Estimates show that production with our technology would be 4-6 times less capital-intensive per unit amount of the product than that with the current process, and the product cost would be about half of that produced with the current technology. Some of the savings could be passed on to the customers, making this an attractive value proposition. The production would be decentralized, with small regional or local plants producing fertilizers close to the farmers. Dependence on imported fertilizers and price volatility would also be mitigated or eliminated.

Why nitrogen?

Chemical compounds containing nitrogen are used extensively in fertilizers, explosives, cleaning agents, dyes, plastics, and pharmaceuticals. Fertilizers represent by far the largest market for nitrogen compounds: nitrogen fertilizers are absolutely essential for highly productive farming. Air is the source of nitrogen for fertilizers and other compounds, but atmospheric nitrogen itself is inert and not directly usable and thus has to be converted into forms that can be used by plants or are precursors for further chemical synthesis. Thus, nitrogen fixation is crucial because it converts atmospheric nitrogen, which is unusable by most organisms, into forms like ammonia, nitric acid and nitrates that plants can use to synthesize essential building blocks like proteins and nucleic acids.

Nitrogen fixation today

In the early 20th century, Fritz Haber (1918 Nobel Prize) demonstrated a catalytic process of ammonia synthesis from nitrogen and hydrogen at high pressure and temperature, and Carl Bosch (1931 Nobel Prize) developed it to industrial scale. Since then, the Haber-Bosch (HB) technology underpins the industrial production of ammonia – a precursor to all other nitrogen compounds, including fertilizers. Nitrogen for the HB process is taken from air, and hydrogen is produced from natural gas using steam reforming.

Production of nitric acid, a crucial component in the fertilizer industry, is done with the Ostwald process. It involves the catalytic oxidation of ammonia (made with the HB process) to produce nitric oxide, which is then further oxidized to nitrogen dioxide, and finally absorbed in water to form nitric acid.

The Haber-Bosch and Ostwald (HB+O) technology is highly efficient. However, it is not free from drawbacks:

· The process uses natural gas and produces more than 3% of total world CO2 emissions

· The production is very capital-intensive: a typical plant costs 1-2 billion dollars to build

· Small plants are non-viable economically

· Production requires location near natural gas sources and giant centralized facilities and distribution networks.

Therefore, the rising costs of traditional fertilizers and geopolitically driven volatility, together with environmental concerns and the growing demand for sustainable agriculture and industry create a demand for new technologies of nitrogen fixation and fertilizer production.

Why plasma?

Removing an electron from an atom or molecule (a process called ionization) creates an electron and ion pair. If all the atoms in a gas are ionized, a fully ionized plasma is thus created. Fully ionized plasmas exist at very high temperatures in stars or controlled fusion devices. If only a small fraction of atoms and molecules are ionized, a weakly ionized, low temperature plasma is formed. Such plasmas, for instance, those in fluorescent lights and arc welders, are generated by electric discharges and are powered by electrical energy. Weakly ionized plasmas possess very interesting and useful properties. Although the gas as a whole may be at low (e.g. ambient) temperature, the electrons that receive energy from an electric or electromagnetic field are typically hot, having a temperature of about 10,000 – 50,000 K. The energetic electrons collide with molecules and either bring them to higher energy states or break the molecules apart, producing chemically active species and initiating secondary reactions. This, together with collisions of plasma ions with plasma-bounding surfaces, is what underpins plasma technology of microchip fabrication, by far the largest and most important plasma application today.

Can low-temperature plasma chemistry be used for nitrogen fixation and offer a viable alternative to Haber-Bosch and Ostwald chemical technologies? Of particular interest is the possibility of using plasma to make nitric acid from air and water, which would eliminate the need for hydrocarbon feedstock and the accompanying CO2 emissions.

Attractive as plasma technology could be, and despite dozens of reported experimental studies, plasma production of nitric acid could not match the efficiency of the Haber-Bosch and Ostwald (HB+O) technology. That is, until now.

The breakthrough in plasma process efficiency

How efficient should the plasma synthesis of nitric acid be, given that it would have to compete not only with the HB+O technology but also with the electrolysis-driven Haber-Bosch and Ostwald (EHB+O) technology where hydrogen is obtained by electrolysis of water rather than by steam reforming of natural gas?

A recent techno-economic study (K.H.R. Rouwenhorst, F. Jardali, A. Bogaerts, and L. Lefferts, Energy Environ. Sci., 16, 6170, 2023) answered this question and found that in order for the plasma production of nitric acid to be competitive with the HB+O and with the EHB+O technologies, the plasma process has to have the energy consumption not exceeding 1 – 1.5 MJ/mol of HNO3, or 4.4 – 6.6 MWh per ton of HNO3. The specific energy consumption is thus the crucial make-or-break factor determining the viability and competitiveness of plasma technology.

In all reported studies of the plasma process where the product was HNO3 or its equivalent, NO3- (aq), the energy consumption was much higher than the required level: from about 12 to 250 MJ/mol of HNO3.

Our company has developed and demonstrated a patent-pending revolutionary plasma process of nitrate/nitric acid production from air and water. We built and tested a lab-scale prototype and showed the energy consumption below (i.e. better than) the required 1 – 1.5 MJ/mol of HNO3.