Vad var motivationen för studien?
Lindeborgs gård har haft en pyrolysreaktor sedan hösten 2017. Det är en av de första gårdarna i Sverige med en sådan reaktor, med syfte att generera värme till byggnaderna och producera biokol. Vår fallstudie utfördes 2018-2019 och vid tidpunkten fanns det inte mycket data tillgänglig från reaktorn och vissa praktiska utmaningar upptäcktes, särskilt under varmare vinterdagar. Därför fokuserade denna studie på att kombinera livscykelanalys med simulering av de små reaktorerna i drift, på lokal nivå.
Azzi ES, Karltun E, Sundberg C (2021) Small-scale biochar production on Swedish farms: A model for estimating potential, variability, and environmental performance. Journal of Cleaner Production 280:124873. DOI: 10.1016/j.jclepro.2020.124873
Studien har presenterats vid en konferens och ett flertal workshops. Slides från presentationerna kan laddas ned nedan:
I studien modellerades systemet i Python, där brightway2 och ficus användes. Filerna finns tillgängliga på GitHub via P2_farm_biochar.
Titta på en presentation av artikeln.
Several small-scale pyrolysis plants have been installed on Swedish farms and uptake is increasing in the Nordic countries. Pyrolysis plants convert biomass to biochar for agricultural applications and syngas for heating applications. These projects are driven by ambitions of achieving carbon dioxide removal, reducing environmental impacts, and improving farm finances and resilience.
Before policy support for on-farm pyrolysis projects is implemented, a comprehensive environmental evaluation of these systems is needed. Here, a model was developed to jointly: (i) simulate operation of on-farm energy systems equipped with pyrolysis units; (ii) estimate biochar production potential and its variability under different energy demand situations and designs; and (iii) calculate life cycle environmental impacts. The model was applied to a case study farm in Sweden.
The farm’s heating system achieved net carbon dioxide removal through biochar carbon sequestration, but increased its impact in several other environmental categories, mainly due to increased biomass throughput. Proper dimensioning of heatconstrained systems is key to ensure optimal biochar production, as biochar production potential of the case farm was reduced under expected climate change in Sweden.
To improve the environmental footprint of future biochar systems, it is crucial that expected co-benefits from biochar use in agriculture are realised. The model developed here is available for application to other cases.
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