Inline monitoring helps fertilizer plants control concentration in real time

Fertilizer producers can use continuous inline concentration measurements to monitor process conditions and identify deviations before they affect product quality, assures German measurement technology supplier SensoTech. Its LiquiSonic system measures sonic velocity and temperature directly in process liquids to calculate concentration using product-specific calibration data.

The technology is intended for several stages of nitrogen fertilizer production, including ammonium nitrate neutralization and evaporation, urea concentration and the blending of urea ammonium nitrate (UAN) solutions. In urea production, continuous readings can help operators maintain target concentrations during evaporation while avoiding unnecessary energy use. In ammonium nitrate production, measurements can support control of the solution before downstream processes such as prilling or granulation.

For UAN solutions, which combine urea, ammonium nitrate, and water, SensoTech says it uses ultrasonic measurements alongside conductivity readings to monitor the mixture’s composition. The company says this can make changes visible during blending rather than after laboratory sample results become available.

The system can also be applied in ammonia and nitric acid synthesis and in phosphoric acid and phosphate fertilizer production, including superphosphate, monoammonium phosphate (MAP) and diammonium phosphate (DAP). Sensors can be installed in pipelines, vessels or reactors, or in a bypass, and readings can be sent to plant control systems through analog outputs or fieldbus interfaces.

Continuous measurement may help plants reduce off-spec batches, rework and manual sampling, while improving process control. SensoTech notes that laboratory analyses remain part of quality assurance and that economic benefits depend on the plant configuration and existing operating practices.