Process & contact
https://www.sfi.ie/challenges/future-food-systems/SINFERT
Updated 7/2024
Input materials
Bone meal ash (BMA), fish bone meal ash (FBMA); apatite phosphate rock (APR), sewage sludge ash (SSA), chicken manure ash (CMA); struvite, vivianite and calcined vivianite (all tested).
Output products
Orthophosphoric acid; plant-available fully soluble inorganic fertilisers MAP, DAP.
Inorganic phosphates e.g. trisodium phosphate.
Triorganophosphates e.g. triethylphosphate; work is underway to produce triorganophosphines and triorganophosphine oxides that can otherwise only be accessed via white phosphorus.
Anhydrous metal chlorides e.g. CaCl2; FeCl3
Process description
Solid phosphate materials (particle size 25-100 um, 5-18%P w/w, 0-5% water w/w) are treated in a liquid phase system using a proprietary deoxychlorination (DOC) promoter, and a catalyst. The process generates a volatile phosphorus intermediate which is separated from the excess promoter via distillation at 60-100 °C. The chlorinated intermediate is treated with waterto obtain phosphoric acid and its derivatives, or with alcohols for phosphate esters. The chlorine is recovered as HCl and is cycled in the system. The core DOC process runs isothermally at a medium temperature (60-100°C) with possibility for heat from hydrolysis and etherification processes being recycled.
The process generates water-soluble solid byproduct/residue containing metal chlorides eg CaCl2 from apatite.
P recovery of 90%+ has been achieved in repeated batch lab tests on apatite; the target is 90% for vivianite, SSA, BMA and FBMA.
Heavy metals are retained in the solid slag as nonvolatile components.
Operating status
Laboratory gram scale. Scale up to 100-1000g is under way in the following stage of the project 2025-26.