Accoe, Frederik

Ghekiere, Greet

Lebuf, Viooltje

Meers, Erik

Michels, Evi

Sigurnjak, Ivona

Tack, Filip

Vaneeckhaute, Céline

Ghent University Academic Bibliography

     Nutrient and energy recuperation from digestate  Ivona Sigurnjak1, Céline Vaneeckhaute1, Erik Meers1, Evi Michels1, Greet Ghekiere2, Frederik Accoe3, Viooltje Lebuf3, Filip Tack1   1 Laboratory of Analytical and Applied Ecochemistry, Faculty of Bioscience Engineering, Ghent, Belgium, www.ecochem.be  2 Provincial Research and Advice Centre for Agriculture and Horticulture (Inagro vzw), www.inagro.be 3 Flemish Coordination Centre for Manure Processing (VCM vzw), www.vcm-mestverwerking.be       Europe is facing with various environmental problems, among which increased dependency on fossil fuels and disturbing unbalance of nutrient redistribution, are focus points of Europe 2020 energy objectives. Therefore, solution  is needed, and possible solution will be provided by two European proojects, ARBOR (INTERREG IVB) and INEMAD (FP7). Both of this projects, are focused on the foster and accelerate use of biomass (e.g. energy crops, manure/digestate, VFG, …).   While ARBOR is aiming on improving the sourcing of biomass materials and efficiency of biomass conversion in North West Europe, INEMAD is trying to reconnect livestock and plant production on the European level, through improved nutrient and energy management. Special focus is on nutrient and energy recuperation from digestate. Efficient use of, biomass (i.e. manure/digestate) could lead to higher production of alternative fuels (i.e. biofuels) which would decrease the current increasing dependency on fossil fuels. At the same time effficient  use of  digestate  could offer a solution to phosphorus depletion and help nutrient- rich areas to manage their nutrient surplus through applying different nutrient recovery techniques.                              PARAMETER   AVERAGE VALUE  Dry matter  Decreases due to organic matter decrease. More cattle/pig slurry  lower DM-content  9% Total N Constant during digestion. More pig slurry  more N 5 kgN/ton (+m)3 kg N/ton (-m) Mineral N Increase due to organic N NH4+ More organic waste  lower share of NH4+ 44 –47% up to 82% (100% pig slurry) pH Increase due to decomposition volatile fatty acids. Less dependency on input streams. 8.3 Phosphate  content Constant during digestion. More pig slurry  more P 4 kg P2O5/ton (+m)3 kg P2O5/ton (-m) Heavy metals & impurities Constant. Can be problematic for Zn and Cu in pig slurry. Inactivation of weed seeds & pathogens depends on T & residence time -  TECHNIQUE   STARTING FROM  END-PRODUCT  Composting  SF digestate  P- fertilizer (compost), CO2, H2O + possible NH3 and GHG emissionss Thermal drying SF digestate or digestate P- fertilizer (solid fraction) or NPK- fertilizer (digestate), NH3 and condensate Pyrolysis Dried SF of digestate Biochar, biocrude oil and  syngas (mixture of CO2, CO, CH4, H2 and N2, as well as S-containing gases) + possible emissions of GHG  Gasification Dried SF of digestate Biochar  (P-fertiliser) and syngas (CO2, CO, CH4, H2 and N2) + possible  emissions of GHG Combustion  Dried SF of digestate P nutrient - rich ash, heat & power + possible emissions of GHG P-extraction Ashes/biochar/SF digestate Acid P-extract/CaHPO4 Acidair washer Air charged with NH3 (NH4)2SO4solution Reversed osmosis UF/MF/DAF-permeate RO-concentrate (NK-fertiliser) Forward osmosis UF/MF/DAF-permeate FO-concentrate (NK-fertiliser) Electrodialysis LFdigestate NK-fertiliser TMCS LF filtered on 10 μm NK-fertiliser P-precipitation (LF)digestate MgNH4PO4/MgKPO4/CaNH4PO4 NH3-stripping& acid air washer LFdigestate (NH4)2SO4 solution Biomass production  Diluted LF digestate Biomass  NUTRIENT AND ENERGY RECUPERATION FROM DIGESTATE FUTURE PERSPECTIVES :  REPLACEMENT OF MINERAL FERTILIZERS  WITHIN GREENHOUSE CROPS DIGESTATE CHARACTERISTICS END-PRODUCTS • Digestate = valuable by-product (together with biogas) of anaerobic digestion that contains the non-digested resilient organic fraction, water, micro- and macro- nutrients.  • Composition depends strongly on ingoing streams (digestate contains 80% less organic matter  than the ingoing streams)  • Organically bound N is released as NH4+  directly available for crop uptake  • Nutrient recovery techniques separate NPK from OM  • Result of mechanical separation  P nutrient-rich solid fraction and NK nutrient-rich liquid fraction  • Depending on the wanted end- product, different nutrient techniques are applied  result: end-product with a higher concentration of NPK than raw digestate  WHY RECOVER NUTRIENTS AND ENERGY?  Awareness of increasing artificial fertilizer use : • Energy consuming • Economical burden for farmer   • Experiment will start mid of May 2013, and last for 7 weeks   • Test plant (lettuce (Lactuca sativa) / bean (Phaseolus vulgaris) • Field experiment (greenhouses 2x 400 m2)  Replacement will be done by 4 type of products: (1)  Struvite (P) (2)  Liquid fraction of digestate (NK- fertilizer) (3)  Ammonium sulfate (air scrubbing or stripper) (4)  Urea (derived from pig urin) END-PRODUCT THAT CAN SUBSTITUTE ARTIFICIAL FERTILIZER  OR AS A FEEDSTOCK IN INDUSTRIAL PROCESSES Contact: ivona.sigurnjak@ugent.be 

Nutrient and energy recuperation from digestate

https://biblio.ugent.be/publication/3259050/file/3259055

Nutrient and energy recuperation from digestate

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