We are recycling nitrogen from waste water
EasyMining's patented process enables it to chemically extract and purify nitrogen from waste water. This is unique as purification currently takes place using biological methods. The innovation will now be demonstrated in a project, RE-Fertilize, with the support of the EU's LIFE programme. The new circular solution makes it possible for water purification plants to also extract nitrogen in the process and use it as fertilizer, which in turn reduces emissions of greenhouse gases.
Up to now, water with a high nitrogen content, such as waste water, has been purified biologically using bacteria that separate nitrogen from water – a process which is both costly and sensitive to disruption. The biological process also entails emissions of nitrous oxide, a powerful greenhouse gas which has an impact on the climate that is 300 times greater than carbon dioxide.
Instead, EasyMining has developed a technique to purify waste water through chemical deposition of the nitrogen. In the process, which is patented, the water is treated with an adsorbent that deposits the nitrogen in crystals which can then be separated from the waste water. The nitrogen is extracted from the crystals and becomes a fertilizer while the adsorbent is reused. Nitrogen fertilizer can be used in agriculture, where nitrogen is one of the most important nutrients. This reduces the need to produce new nitrogen fertilizer with methods that are energy-intensive. Agriculture's carbon footprint can thereby be reduced.
"When sewage works use our method, they are reducing their emissions of nitrogen compounds into nearby water, thus reducing their carbon climate footprint and at a lower cost. Through recovering nitrogen, which is a valuable nutrient, they are making a real contribution to the circular economy," says Jan Svärd, CEO of EasyMining.
Traditional methods of purifying nitrogen usually release the nitrogen back into the air - instead of recycling it. Adsorbents which crystallise the nitrogen in EasyMining's process are not released, but are rather reused. The method can be used with all kinds of waste water that contains nitrogen in the form of ammonium. Besides purification plants for waste water and leachate from landfill, potential applications are treatment of fertilizer as well as liquids from biogas plants.
"Up to now, manufacture of nitrogen fertilizer has been associated with energy consumption and climate emissions. EasyMining's chemical process means that we are moving away from that and can capture both the nitrogen and the adsorbent. We also utilise the nitrogen, which becomes fertilizer, and the adsorbent is circulated back into the process. This chemical deposition process is also easier to control, in comparison with the biological process, and we can extract a high concentration of nitrogen," says Patrik Enfält, business developer at EasyMining.
Removing nitrogen from sewage water
In Sweden, towns of at least 10,000 people along large portions of the coast are required to remove nitrogen from their sewage water. In order to combat eutrophication, the levels of nitrogen allowed in water passing from a treatment facility are subject to regulation. The nitrogen removal methods most commonly used today focus only on reducing nitrogen in release water, not on capturing the nutrient for use as an agricultural fertilizer component.
The method is being commercialised
EasyMining has been received about SEK 19 million from the EU's LIFE programme (LIFE18 ENV/SE/000265) for its innovation within nitrogen extraction to demonstrate the patented method on a large scale. The project, ”RE-Fertilize”, is a partnership between EasyMining, Denmark's largest waste purification company BIOFOS, Lantmännen and Ragn-Sells. The first phase of the project will entail construction of pilot plants that will be in operation during 2021, and the plan is that the process will be ready for full commersialisation in three years.