PYREG Biochar from bioso­lids proves a nega­tive global warming poten­tial by a factor of 10 compared to conven­tional fertilizer.

In a 2019 study by the German Federal Envi­ron­mental Agency, the result is that conven­tional ferti­lizer produc­tion in Germany emits about +1.2 kg CO₂ eq/kg P₂O₅. Further­more, phos­phate reco­very processes like preci­pi­ta­tion (in digested sludge or centrate) or sewage sludge ash also demons­trably cause CO₂ emissions.

In compa­rison to the global warming poten­tial (GWP) of these processes, PYREG biochar from bioso­lids has a nega­tive GWP of –4,01 kg CO₂ eq / kg P₂O₅. Conse­quently, the reco­very of phos­phate within the PYREG process and the final appli­ca­tion of the biochar contri­butes to fight global warming and reaching net zero.

In addi­tion to that the phos­phate reco­very rate of PYREG biochar from bioso­lids is nearly 80 %, which is in the range of other thermal treat­ments and far better than preci­pi­ta­tion processes with <40 % reco­very rate.

Sources:
UBA TEXTE 13/2019: Ökobi­lan­zi­eller Vergleich der P-Rück­ge­win­nung aus dem Abwas­ser­strom mit der Dünge­mit­tel­pro­duk­tion aus Rohphos­phaten unter Einbe­zie­hung von Umwelt­fol­ge­schäden und deren Vermei­dung, Forschungs­kenn­zahl 3716 31 330 0 UBA-FB 002759, ISSN 1862-480
Kratz, Schnug (2009): Zur Frage der Löslich­keit und Pflan­zen­ver­füg­bar­keit von Phos­phor in Dünge­mit­teln JOURNAL FÜR KULTUR­PFLANZEN, 61 (1). S. 2–8, 2009, ISSN 0027-7479 VERLAG EUGEN ULMER KG, STUTTGART
Koch, Bern­hard (2021): Gefäß­ver­such zur Phos­phor­ver­füg­bar­keit aus Klär­schlamm­re­cy­claten, Landes­be­trieb Land­wirt­schaft Hessen, DPP Forum 2021 Frankfurt
EVS 2019: Expe­ri­men­teller Nach­weis der Cadmi­um­ent­frach­tung während des Karbo­ni­sie­rungs­pro­zesses von Klärschlamm
Kuzyakov 2015: Biochar stabi­lity in soil: Meta-analysis of decom­po­si­tion and priming effects, GCB Bioen­ergy, DOI:10.1111/gcbb.12266
EBI White­pa­paper