Green biomass to biogas – A study on anaerobic digestion of residue grass

Scientific paper - Original scientific paper

• Author: Robert Bedoić
• Author: Lidija Čuček
• Author: Boris Ćosić
• Author: Damjan Krajnc
• Author: Goran Smoljanić
• Author: Zdravko Kravanja
• Author: Davor Ljubas
• Author: Tomislav Pukšec
• Author: Neven Duić
• Author's institution: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; (Department of Energy, Power and Environmental Engineering); (Power Engineering and Energy Management Chair)
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract (english)

Sustainable management in the biogas production via anaerobic digestion process intents the use of
alternative biomass sources that are not competitive with food production. The aim of this study is to
investigate the application of the abundant-quantity residue in more sustainable production of heat and
electricity along with the production of the digested substrate as a fertiliser. The study has been divided
into several sequential steps. First, the grass samples have been collected at the following locations:
uncultivated land, river embankment and highway verge. The greatest grass yield has been determined
for the riverbank grass, with an average value of 19 t/ha of fresh mass and 2.6 t/ha of dry mass. Next, the
chemical characterisation of the collected residue grass and the laboratory batch mono and co-digestion
tests with maize silage and cattle slurry have been conducted. The results show that all grass samples
have satisfying digestive parameters (C/N ratio between 16.6:1 to 22.8:1) with the low presence of
impurities, which makes them suitable for biogas production. The following biochemical methane potential in mono-digestion of residue grass has been recorded: uncultivated land (0.275 Nm3 /kgTS),riverbank (0.192 Nm3/kgTS) and highway verge (0.255 Nm3/kgTS). The control of the process has been
improved in co-digestion tests, by avoiding acidification in the first days of the operation. The estimation
of kinetic parameters in mathematical modelling has shown that the degradation of residue grass shows
some different parameters compared to the previous study. The model results for the gas phase show
some small deviations compared to the experimental data. Based on the life cycle analysis results it can
be concluded that there are perspectives in the use of residual grass compared to maize silage in the
production of heat and electricity, especially in the improvement of ecosystem quality.

• Keywords (english): Anaerobic digestion; Green biomass; Residue grass; Biogas; ADM1 model; LCA analysis
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Journal of Cleaner Production
• Numbering: vol. 213, p. 700, 709
• p-ISSN: 0959-6526
• e-ISSN: 1879-1786
• URN:NBN: urn:nbn:hr:235:387046
• Publication: 2019
• Type of resource: Text
• Access conditions: Open access
• Created on: 2024-06-03 14:36:30