Preserving sugarcane trash for year-round biogas production: effects of additives on ensiling properties and methane potential
Paper
Paper/Presentation Title | Preserving sugarcane trash for year-round biogas production: effects of additives on ensiling properties and methane potential |
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Presentation Type | Paper |
Authors | Janke, L. (Author), McCabe, B.K. (Author), Hill, A. (Author), Lee, S. (Author), Harris, P. (Author), Marchuk, S. (Author) and Baillie, C. (Author) |
Journal or Proceedings Title | Proceedings of the 41st Annual Conference of the Australian Society of Sugar Cane Technologists (ASSCT 2019) |
ERA Conference ID | 50305 |
Number of Pages | 9 |
Year | 2019 |
Place of Publication | Mackay, Australia |
ISBN | 9781510889682 |
Web Address (URL) of Paper | http://www.proceedings.com/49613.html |
Conference/Event | 41st Annual Conference of the Australian Society of Sugar Cane Technologists (ASSCT 2019) |
Australian Society of Sugar Cane Technologists Conference | |
Event Details | 41st Annual Conference of the Australian Society of Sugar Cane Technologists (ASSCT 2019) Event Date 30 Apr 2019 to end of 03 May 2019 Event Location Toowoomba, Australia |
Event Details | Australian Society of Sugar Cane Technologists Conference ASSCT |
Abstract | Sugarcane trash (SCT) composed of tops, and dry and green leaves represents the non-millable fractions of cane that is usually left to decay on the fields for soil protection after mechanized harvesting. The fractional recovery of this material for biogas production can potentially result in generation of renewable energy without negatively influencing soil quality, since digestate from the anaerobic digestion process can be used as a soil conditioner. However, as the length of the sugarcane harvesting season is around 6 months per year, strategies for biomass preservation that allow SCT to be used as a substrate throughout the entire year are required. Therefore, the present study aimed to optimize the ensiling of SCT using a commercial lactic acid bacterial (LAB) inoculant to promote lactic acid (LA) fermentation with the addition of molasses to increase the content of biodegradable sugars. The ensiling experiments were conducted in laboratory-scale silo-bags under anoxic conditions with the following additives applied to the sugarcane biomass: SCTctr (no additives); SCTmol (addition of molasses); SCTmol+lab (addition of molasses and lactic acid bacteria); and SCSctr (sugarcane stalks without additives). The experiment was run for 70 days and the following parameters were analyzed at days 0, 5, 15 and 70: total and volatile solids, total volatile fatty acids, LA, ammonium-nitrogen, pH and solubilized chemical oxygen demand (COD). Biochemical methane potential (BMP) tests were performed with fresh and ensiled material at day 70 to assess energy losses/gains due to ensiling. In general, the results showed a decrease in pH from 5.7-5.9 to 3.8-4.2 for all SCT treatments during the ensiling period. The rationale behind pH reduction lies in the increase in lactic acid concentration from 1.0-1.4 % DM (dry matter) up to 3.0 % DM in the SCTmol + lab treatment. SCSctr showed a marked increase in lactic acid (from zero to 3.7 % DM) resulting in the lowest observed pH of 3.7 among all treatments. The ensiling process increased methane yields by 17%, 39%, 17% and 79% for SCSctr, SCTctr, SCTmol and SCTmol+lab, respectively. Thus, ensiling of sugarcane is not only a suitable way for wet biomass preservation but also an effective method to improve the digestibility of sugarcane residues for biogas production. |
Keywords | Sugarcane stalks, pretreatment, lactic acid bacteria, molasses, anaerobic digestion, biochemical methane potential testing |
ANZSRC Field of Research 2020 | 300210. Sustainable agricultural development |
400499. Chemical engineering not elsewhere classified | |
Byline Affiliations | DBFZ German Biomass Research Centre, Germany |
Centre for Agricultural Engineering | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q5464/preserving-sugarcane-trash-for-year-round-biogas-production-effects-of-additives-on-ensiling-properties-and-methane-potential
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