Advances in Commercial Scale Production of Bio-Based NPK Fertilisers from Waste Streams

Keywords: bio-based fertilisers, circular economy, recycling, nutrient recovery.

Turning waste into resources is key to a circular economy. The recovery of bio-waste is generating numerous possibilities to produce chemicals, fuels and valuable products. However, there are still technological and market challenges before achieving large-scale commercialisation of the developed products can be achieved. In this sense, the B-FERST project was born with the idea of developing a novel industrial process focused on establishing an innovative concept for the fertiliser industry through a new waste value chain based on nutrient recovery towards bio processes. This innovation, to be introduced into existing industrial processes is intended to replace part of the mineral raw material used currently by a biobased material with a complex matrix influence.

A number of factors have been identified as being the most important in influencing in the use of these new biowastes: quality, regulation, security, processing feasibility, logistics-availability, product stability, economic feasibility and carbon footprint.

A new versatile nutrient extraction process has been validated at pilot plant scale, and is currently being upscaled into a demonstration plant with 500 kg/h capacity at Fertiberia’s facilities in Huelva Plant (Spain). This process uses as raw material ashes produced in the combustion of sludges from Waste water treatment Plants, manure or slaughterhouses. It works in a closed circuit to be environmentally sustainable without generating liquid effluents. The designed reactor allows heat exchange that makes the application of energy to the process unnecessary.

Likewise, a new flexible coating demonstration plant is currently being built, using the results from the pilot plant scale, validating the application of biodegradable materials in the fertiliser’s surface, enhancing their agronomic efficiency.

The replacement of part of the conventional mineral raw materials with bio-based material as nutrient sources and Non-Microbial Plant Biostimulant (NMPB) or Microbial Plant Biostimulant (MPB) additives has been demonstrated in the pilot plant scale fertiliser manufacturing process.