POWER-TO-P

The Power-to-P technology has disruptive potential. When successful, it will significantly impact the tradi-tional fertilizer supply chain by electrifying and decentralizing the current natural gas dependent heavy industry of phosphoric acid production. It will also cut phosphate rock import to Europe dramatically, cre-ate a new industry in Denmark and Europe, and enable increased growth in bio-sourced energy.
The European fertilizer industry relies heavily on import of phosphate rock and in some cases phosphoric acid (PA) from outside of Europe. Phosphate rock is converted to PA and PA to fertilizer. Natural gas and other fossil fuels are the dominant energy sources in the large-scale PA industry. Power-to-P offers an alternative high-volume route to PA where natural gas/fossil fuels are effectively substituted by green power and phosphate rock by renewable waste sources of phosphorus.
At the same time, biogas is a growing substitute for natural gas in the overall energy mix. Biogas is typically produced from a variety of biomass wastes such as wastewater sewage sludge, organic waste from agri-culture and organic municipal solid waste. Digestion residues contain P in high concentrations, and P being a necessary fertilizer in agriculture, it has been common practice to disperse residues in fields. However, this is increasingly problematic for sewage sludge residues due to pollutants, and e.g. Germany is phasing in a move away from dispersal to incineration with demands of 80% P recovery from ashes. A dosage limit on P that can be added to fields is also challenging dispersal of residues from biogas digestion of certain biowastes from food and agriculture. For this reason and for reasons of gas output optimization, this part of the biogas sector is therefore considering incineration of residues with high-temperature heat recovery for the biogas process, where residues are dried with excess low-temperature heat from digestion to leave a P-rich ash, where P must be converted to PA to re-enter the cycle in a controllable way. Power-to-P does the latter thus improving biogas OPEX, increasing biogas output and enabling growth in the biogas sector.