Associated effects of storage and mechanical pre-treatments of microalgae biomass on biomethane yields in anaerobic digestion
- Author(s)
- M. R. Gruber-Brunhumer, J. Jerney, E. Zohar, M. Nussbaumer, C. Hieger, P. Bromberger, G. Bochmann, F. Jirsa, M. Schagerl, J. P. Obbard, W. Fuchs, B. Drosg
- Abstract
The pre-treatment of microalgae cell walls is known to be a key factor to enhance methane (CH
4) yields during anaerobic digestion. This study investigated the combined effects of two different biomass storage methods and physical pre-treatments on the anaerobic digestion for three different microalgae species. Acutodesmus obliquus, Chlorella vulgaris and Chlorella emersonii were cultivated in 80 L sleevebag photobioreactors (batch mode), and then subjected to different storage (cooling and freezing) and pre-treatment methods prior to anaerobic digestion using the biochemical methane potential (BMP) test. A. obliquus was selected to evaluate pre-treatment methods for further experimentation. Significantly higher CH
4 yields of cooled (4 °C) A. obliquus biomass were achieved through ultrasonication (+53% CH
4) and wet-milling (+51% CH
4). These methods were then applied in follow-up experiments to cooled (4 °C) biomass of C. emersonii and A. obliquus. Ultrasonication again led to significantly higher CH
4 yields for A. obliquus biomass (323 dm
3 kg
−1 CH
4 yield calculated at standard gas conditions of 273 K, and 101.5 kPa per unit volatile solids, +41% CH
4), and C. emersonii biomass (308 dm
3 kg
−1; +35% CH
4). In a third experiment series, frozen A. obliquus and C. vulgaris biomass were thawed prior to pre-treatment and BMP-testing. Among all BMP tests, the highest CH
4 yields were achieved with untreated, freeze-thawed C. vulgaris biomass (406 dm
3 kg
−1); pre-treatment did not enhance CH
4 yields for C. vulgaris, but for A. obliquus (ultrasonication +20%). Pre-treatment was more effective for cooled than freeze-thawed microalgal biomass and combined effects acted strain dependently.
- Organisation(s)
- Department of Inorganic Chemistry, Functional and Evolutionary Ecology
- External organisation(s)
- University of Natural Resources and Life Sciences, BIOENERGY 2020+ GmbH, University of Helsinki, Erber Future Business GmbH, Fachhochschule Wiener Neustadt, University of Johannesburg (UJ), Qatar University
- Journal
- Biomass & Bioenergy
- Volume
- 93
- Pages
- 259-268
- No. of pages
- 10
- ISSN
- 0961-9534
- DOI
- https://doi.org/10.1016/j.biombioe.2016.07.013
- Publication date
- 10-2016
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 104023 Environmental chemistry, 106020 Limnology, 106022 Microbiology
- Keywords
- ASJC Scopus subject areas
- Forestry, Waste Management and Disposal, Agronomy and Crop Science, Renewable Energy, Sustainability and the Environment
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/2127c2fa-4bd8-471f-8c0e-6d70637e13fa