Belgium develops technology to turn ammonia emissions into nitrogen fertilizers

Belgian engineers have developed the Circlair system, which captures ammonia from the air at livestock facilities and converts it into ammonium nitrate, a valuable nitrogen fertilizer. The technology simultaneously reduces harmful emissions from livestock production and enables nitrogen to be recycled for agricultural use.

Unlike conventional scrubbers, which use sulfuric acid to capture ammonia and produce ammonium sulfate, Circlair uses nitric acid. This process produces a concentrated ammonium nitrate solution that can be used as a liquid nitrogen fertilizer.

Another major advantage of the technology is its significantly lower water consumption. The system uses up to 10 times less water than conventional air scrubbers, while the salt concentration in the resulting solution can reach 60% by weight. According to the developers, the product can be comparable to commercial liquid nitrogen fertilizers.

A demonstration unit is already operating at KU Leuven’s TRANSfarm experimental farm in Belgium, where it treats air from a pig facility housing 300–700 piglets. An algorithm developed by KU Leuven continuously monitors pH levels and ammonia volumes, automatically adjusting acid supply and water circulation, reducing water consumption by up to 90%.

The developers next plan to integrate a plasma reactor capable of producing nitric acid directly from air. This could reduce dependence on purchased acid and make the technology more self-sufficient, turning emissions from livestock facilities into a source of fertilizer for crop production.

Tags: Belgium, nitrogen fertilizers