Meta-analysis on the potential to substitute mineral fertilizers by biobased fertilizers derived from agro-residues

Hongzhen Luo, Ivona Sigurnjak, Marcella Fernandes de Souza, Evi Michels, Erik MeersDepartment of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University, Belgium

Introduction

European demand on N, P and K fertilizer for 2020 is forecasted toreach 16.5 Mt, 4.4 Mt and 4.7 Mt, respectively[1].

Between 2 and 5 Mt of N and 0.6 Mt of P from waste streams are notbeing recovered for agricultural use[2].

Agro-processing can serve as a third pillar to reconnect nutrient andcarbon flows between crop production and animal husbandry. (Fig. 1)

Current work:

1) Collection of current existing and future promising techniques fromfarmers and agri-business research, operational groups and newpilot cases.

2) Selection of the submitted techniques for further investigation.

Selection of submitted showcases

Acknowledgement

The research is done as a part of the Nutri2Cycle project that receivesfunding from the European Union’s Horizon 2020 FrameworkProgramme for Research and Innovation under Grant Agreement no.773682. For more information, please seeWebsite: https://www.biorefine.eu/projects/nutri2cycle

@Nutri2Cycle @Biorefine Cluster

Fig. 1. Triangle model for reconnecting nutrient and carbon flows between conventional agro-pillars

FEEDSTOCK: Cattle and rabbit manure.

PROCESSING: The farm's cattlemanure is transferred intocompost using rabbit liquidmanure to get a stabilized andhygienized product, including amonitoring system on manureevolution.

PRODUCT: Compost as an organicsoil improver.

FEEDSTOCK: livestock slurry.

PROCESSING: Ammonia is releasedfrom water solution at reducedboiling point temperature whenvacuum is applied in an enclosedreactor. Energy cost is reduced as aresult of the lower heatingrequirement and the gas-phaseammonia mass transfer is boosted.

PRODUCT: An ammonia water thatcan be reused as a fertilizer.

FEEDSTOCK: Animal bone.

PROCESSING: Recover P and refineC though a purposely designed andspecific carbonization system withzero emission performance withinterlinked wide range of BIO-NPK-Cformulations.

PRODUCT: Animal Bone Char Bio-Phosphate granulate with specificmaterial and surface characteristics.

FEEDSTOCK: Pig manure.

PROCESSING: Pig manure firstgoes through the anaerobicdigestion; the digestate is thenseparated, the thick fraction isdried to 90% dry matter forfurther processing to organicfertilizer pellets, and the fluidfraction is concentrated by theevaporation unit.

PRODUCT: Recovered N and Korganic fertilizer concentrates.

Monitored composting

Source: CA17

Bio-Phosphate

Pellet and Evaporation

Source: TERRA Source: ZLTO

Vacuum stripping

Source: IRTA

Plasma technology

Struvite crystallization

Source: EBA

Source: UMIL

FEEDSTOCK: Manure or biogas digestate.

PROCESSING: The plasma unitfixates nitrogen from air by splittingthe N2 and O2 molecules into atomsto form nitrogen oxides, which areabsorbed into liquid manure orbiogas digestate and combinedwith free ammonia to formammonium nitrate.

PRODUCT: Ammonium nitrate fertilizer.

FEEDSTOCK: Liquid fraction ofdigestate and seawater bittern.

PROCESSING: Liquid fraction ofdigestate is used as ammoniumand magnesium source andseawater bittern as magnesiumsource to produce struvite in anairlift reactor with a continuousair flux to create internal recycleflow.

PRODUCT: Struvite as a slow-released fertilizer.

Reference:[1] FAO (Food and Agriculture Organization Of The United Nations), 2017.World fertilizer trends and outlook to 2020: Summary Report- Rome.[2] Buckwell, A. and Nadeu, E., 2016. Nutrient recovery and reuse (NRR) inEuropean agriculture. A Review of the Issues, Opportunities, and Actions.