Climate impact and energy return of reed canary grass or tall fescue on marginal land for biogas

Sammanfattning

Emerging fuels, such as biogas, can be produced from grasses. However, in order not to compete with food production, use of marginal land is preferred. This study compares three systems for biogas production on poorly drained fields in northern Sweden. In the first scenario, reed canary grass (RCG) (Phalaris arundinacea L.) first harvest is used for biogas production while its second, delayed, spring harvest is used for briquette production. In the second and third scenarios, RCG and tall fescue (TF) (Lolium arundinacea Schreb.) respectively were harvested twice per year for biogas production. Energy return on investment (EROI) was highest for RCG to biogas and briquettes, 8.5, while RCG to biogas gave 7.8 and TF to biogas 8.3. The higher EROI for TF to biogas compared to RCG to biogas is caused by a higher specific methane production per kg organic matter. Net climate impact was lowest for RCG to biogas, 6.9 g CO2 eq. MJ–1 energy output, and highest for TF to biogas, 7.6 g CO2 eq. MJ–1. This was largely due to longer duration of the RCG swards (10 years) than TF swards (3 years). All systems had quite similar climate impact and EROI so farmers can choose the system most suitable for their conditions.

Nyckelord

life cycle analysis; biogas; briquettes; reed canary grass; tall fescue

Publicerad i

Grassland Science in Europe
2024, volym: 29, sidor: 816-818
Titel: Proceedings of the 30th General Meeting of the European Grassland Federation Leeuwarden, the Netherlands 9-13 June 2024
Utgivare: European Grassland Federation (EGF)

Konferens

the 30th General Meeting of the European Grassland Federation Leeuwarden, 2024, 9-13 June, Leeuwarden, the Netherlands

SLU författare

• Palmborg, Cecilia

  • Institutionen för växtproduktionsekologi, Sveriges lantbruksuniversitet
    

• Cristescu, Carmen

  • Institutionen för skogens biomaterial och teknologi, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Förnyelsebar bioenergi

Publikationens identifierare

• eISBN: 978-90-903-8494-8

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/131407