Environmental Footprint of Thermo-Chemical Phosphate Recycling

Three phosphate fertilizers from fossil and secondary starting materials have been assessed for their accumulated environmental footprint. Fertiliser types have been selected for their similarity in terms of phosphate and secondary nutrient concentrations and small waste flows, although significant and unavoidable differences in terms of phosphate solubility remain. Input data were taken from literature and from process simulations in Aspen Plus and HSC Chemistry, being based on evaluations of plants in operation or under construction. It was tested and confirmed that HSC Chemistry data can be directly exported to GaBi as an LCA evaluation tool. The paper shows in two cases a positive energy balance and a rather low environmental footprint of all three assessed processes.