Phosphorus Recovery from Incinerated Sewage Sludge using the Improved Hard Process

Phosphorus Recovery from Incinerated Sewage Sludge using the Improved Hard Process

Bhavish Patel1, Rudolf Struis1, Mohamed Tariq1, Albert Schuler1, Tanja Schaaf2, Ludwig Harmann2, Christian Ludwig1

1Paul Scherrer Institute, General Energy Research Department, Laboratory for Energy and Materials Cycles, CH-5232 Villingen PSI, Switzerland; 2Outotec GmbH & Co. KG Ludwig-Erhard-Strasse 21, D-61440 Oberursel, Germany

Increasing global population and food consumption is causing unprecedented demand for crops. To maintain current and future yields, the application of fertilizers for crop cultivation is of utmost importance, and one such element enabling this is Phosphorus. Not available synthetically, phosphorus is applied to the soil for crop uptake, however substantial losses to the environment result in undesirable consequences. As a finite natural resource and to maintain global food security, the recovery of such element is of utmost importance, either at source, or downstream. Incinerated sewage sludge offers such opportunity, where an estimated 20% of applied phosphorus could be found. In this investigation, we present our initial characterisation data to make the case for phosphorus recovery from incinerated sewage sludge ash using a thermal process, namely the Improved Hard Process. Additionally, we will also provide a comparison of the feedstock with Moroccan sourced phosphate ore.