Plasma Agricultural Nitrogen Fixation Using Clean Energies: New Attempt of Promoting PV Absorption in Rural Areas

Abstract

In recent years, a large number of countries have connected and distributed photovoltaics in remote rural areas, aiming to promote the use of clean energy in rural areas. The solar energy that is not used in time needs to be discarded, resulting in a large amount of wasted energy. Rural areas are closely related to agricultural production, and solar energy can be used for agricultural nitrogen fixation to supplement the nitrogen needed by crops and effectively use the upcoming waste of solar energy. A photovoltaic-driven plasma reactor for nitrogen fixation in agriculture was designed in this study. The air inlet and outlet holes are arranged above and below the reactor to facilitate air entry and directly interact with the gliding arc generated at the bottom of the electrode to achieve atmospheric nitrogen fixation in agriculture. The characteristics of gliding arc development in the process of nitrogen fixation in agriculture were studied experimentally. There are two discharge modes of the gliding arc discharge: one is steady arc gliding mode (A-G Mode), and the other is breakdown gliding mode (B-G Mode). By collecting discharge signals, different discharge modes of gliding arc discharge were analyzed, and the effect of the air flow rate on the discharge period and discharge mode ratio distribution is discussed. The effects of the air flow rate on the yield, specific energy input, and energy consumption in plasma agriculture were studied. The experimental results show that with an increase in the air flow rate, the B-G mode takes up a larger proportion and the gliding arc discharge period is shortened. However, the higher the proportion of the B-G mode, the more unfavorable the production of nitrogen oxides. Although the nitrogen oxides generated by the system are not particularly excellent compared with the Haber-Bosch ammonia process (H-B process), the access to distributed photovoltaic roofs in rural and remote areas can effectively use available resources like water, air, and solar, and avoid energy waste in areas where wind and solar are abandoned.