Plasma treatment of liquid organic substrate is a new method for reducing ammonia and GHG emissions while simultaneously increasing the nitrogen content of organic waste, such as livestock slurry or digestate.

WHAT GOES IN

A liquid stream of organic waste, like livestock slurry, feeds into the unit from existing slurry infrastructure and before it reaches end storage. Ideally the slurry has had the solids separated or filtered out before treatment to ensure a smooth flow. The N2 Unit is versatile meaning it accepts nearly all forms of slurry providing they are liquid based.

WHAT COMES OUT

After plasma treatment the amount of plant available nitrogen in the slurry is doubled and stabilised, preventing losses under storage and application. This means that the plants will get more nitrogen. The treatment has also stopped the methane emissions from the slurry, and almost removed the odour. The organic carbon content and other important crop nutrients (P, K, Mg, Ca, S) are retained in the fertiliser. Even though the pH is lowered, there is no net soil-acidifying effect of enriched slurry or digestate. The organic waste is changed into a Nitrogen Enriched Organic fertiliser (NEO), which can improve the sustainability of food production. You can read more about NEO and the process by downloading our factsheet.

• Improve Nitrogen Use Efficiency (NUE)
• Higher yield from treated compared to untreated slurry or digestate
• Improved farm carbon footprint
• Less losses of nitrogen from the farm cycle
• Reduced manure smell from storage and application

WHAT HAPPENS IN THE PROCESS

The N2 Unit uses electricity and air to stop emissions and provide additional nitrogen. The process comprises two steps, plasma and then absorption. In the plasma step, nitrogen is fixed from the air using electricity, splitting nitrogen (N2) and oxygen (O2) molecules into N and O atoms which form nitrogen oxides. In the absorption step, the nitrogen oxides are then absorbed into livestock slurry or digestate.

The nitrogen oxides enrich the substrate with nitrate and nitrites; this stabilizes the ammonium and prevents its loss as ammonia (NH3), and it also eliminates methane loss in both storage and on field application. Meanwhile the organic-N content of the substrate is retained, meaning it can still provide long-term soil health benefits as untreated slurry and digestates already do.

Nitrogen is, and has always been, a vital nutrient to help feed the planet, and you can read more about the history of nitrogen and fertilisers here.

N2 plasma units are connected to the N2 Cloud system, a digital environment where production data is stored, analysed and can be provided to permissioned stakeholders who may want to quantify the value’s each unit brings. The N2 Cloud also enables remote maintenance, service and support, providing plasma engineers with oversight to optimise each unit’s performance and advise engineers on the ground.