PENFIX · Plasma efficient nitrogen fixation
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-10-01 → 2021-09-30
- EU contribution
- €178,320
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Plasma efficient nitrogen fixation
Artificial nitrogen fixation is a cornerstone of modern civilisation and sustains much of the world's growing population. The activity is, however, a large contributor to anthropogenic climate change. Plasma-based gas conversion using air and renewable electricity shows great potential for enabling a carbon-free alternative, addressing an important societal issue. Electrically powered plasma processes are considered as a promising alternative for delocalised fertilizer production, based on renewable energy, and more specifically for NOx production. To date, however, plasma designs for NF have not exceeded Haber-Bosch efficiencies. The overall objective of Plasma efficient nitrogen fixation ’PENFIX' is exploring the utility of atmospheric microwave (MW) plasma for nitric oxides (NOx) production using air and N2/O2 mixtures. Our project outcomes demonstrate energy-efficient NOx formation from air and N2/O2 mixtures. The electrode-free ignition possible with this approach is found to provide a significant advantage, given the reduced energy losses to the walls, which limits damage, especially at higher powers, with the key benefits of a prolonged reactor lifetime and no metal contamination (which is potentially detrimental to soil and ecosystems in agriculture applications). NOx production, via an enhanced Zeldovich mechanism, is found to scale efficiently with gas flow rate and power. For relatively high flow rates (i.e., 20 L/min), increasing MW power (up to 1 kW) leads to the highest NOx production (3.8%), as well as minimum energy cost (2 MJ/mol), giving the best cost-conversion metric for this work. This energy cost is the lowest reported up to now in literature for atmospheric pressure plasmas. The experiments are supported by chemical kinetics modeling, which reveals that the higher flow rate reduces the time available for the back reactions, explaining the better performance.
Data: CORDIS, © European Union
Project objective
Industrial scale nitrogen fixation (NF) via the Haber-Bosch process dominates artificial fertilizer production and at present, enables yield enhancements which nourish over 40 % of the world population. Owing to the exceptional stability of molecular nitrogen’s triple bond the Haber-Bosch process is an energy intensive chemical process which accounts for 1-2 % of the world's energy production, consumes 2-3 % of the global natural gas output and emits more than 300 million tonnes of CO2. In light of an increasing population (and fertilizer demand) coupled with an urgency to reduce CO2 emissions, efforts to find alternative technologies for NF that offer the potential of reduced energy usage while minimizing greenhouse gas emissions have accelerated. Electrically powered plasma processes are considered as a promising alternative for delocalized fertilizer production, based on renewable energy, and more specifically for NO production. To-date, however, plasma designs for NF have not exceeded Haber-Bosch efficiencies. Pulsed powered microwave (MW) generated plasma technology offers some promise in this regard. Pulsing of the discharge power enables strategies which direct energy to primarily heat electrons (’non-thermal’ conditions) providing a far more efficient pathway to molecular bond breakage (and resulting NO production) than thermal effects. Indeed, reports on pulsed powered MW discharges have indicated an opportunity to tune electron energies to maximize molecular vibrational excitation, identified as an optimal route for energy efficiency in NO production. In a novel advance, plasma efficient nitrogen fixation ’PENFIX', proposes to interrogate ’pulsed’ powered atmospheric microwave (MW) plasma for nitric oxide (NO) production using air. Novel reactor designs informed by validated modelling will be of particular focus. Diagnostic and modelling activities will elucidate the fundamental physics while addressing the challenges of future industrial scale deployment.
Original text from CORDIS.
Participants
- UNIVERSITEIT ANTWERPEN · AntwerpenCoordinatorBelgium
Links
- View on CORDIS
- DOI: 10.3030/838181
- https://www.uantwerpen.be/en/research-groups/plasmant/research/research-projects/
Data: CORDIS, © European Union