Can acid pre-treatment enhance biohydrogen and biomethane production from grass silage in single-stage and two-stage fermentation processes?

Deng, Chen; Lin, Richen; Cheng, Jun; Murphy, Jerry D.

Can acid pre-treatment enhance biohydrogen and biomethane production from grass silage in single-stage and two-stage fermentation processes?

dc.contributor.author	Deng, Chen
dc.contributor.author	Lin, Richen
dc.contributor.author	Cheng, Jun
dc.contributor.author	Murphy, Jerry D.
dc.contributor.funder	Science Foundation Ireland	en
dc.contributor.funder	Horizon 2020	en
dc.contributor.funder	Environmental Protection Agency	en
dc.date.accessioned	2019-06-06T11:15:12Z
dc.date.available	2019-06-06T11:15:12Z
dc.date.issued	2019-05-23
dc.date.updated	2019-06-06T11:08:12Z
dc.description.abstract	Grass silage is an excellent feedstock for biofuel production, however, the recalcitrant cellulosic structure may limit its biodegradability. In this study, the effect of acid pre-treatment with mild thermal treatment conditions on biohydrogen and biomethane production from grass silage was assessed through single-stage (CH4) and two-stage (H2 + CH4) fermentation. Microstructural characterisation showed that pre-treatment significantly reduced the recalcitrance and enlarged the specific area of grass silage. The optimal pre-treatment with 2% H2SO4 at 135 °C for 15 min achieved a total reducing sugar yield of 333.79 mg/g volatile solid (VS) of grass silage. The pre-treated silage led to a hydrogen yield of 68.26 ml/g VS in the first stage hydrogen fermentation, a 3-fold increase compared to untreated silage. The production of volatile fatty acids accordingly increased by 29.2%. In the second stage anaerobic digestion, untreated silage achieved the highest biomethane yield of 392.84 ml/g VS, with a corresponding highest total energy conversion efficiency of 83.5%. Due to a lower biomethane yield, the pre-treated silage presented a decreased total energy efficiency of 68.4%. In comparison, single-stage anaerobic digestion showed lower energy conversion efficiencies of 49.7% and 54.2% for the pre-treated and untreated silage, respectively. Despite the slight decrease in CH4 yield, the pre-treatment led to decreased energy consumption for the operation of anaerobic digestion processes due to the shorter digestion duration.	en
dc.description.sponsorship	Science Foundation Ireland (16/SP/3829); Environmental Protection Agency (EPA 2018-RE-MS-13)	en
dc.description.status	Peer reviewed	en
dc.description.version	Accepted Version	en
dc.format.mimetype	application/pdf	en
dc.identifier.citation	Deng, C., Lin, R., Cheng, J. and Murphy, J. D. (2019) 'Can acid pre-treatment enhance biohydrogen and biomethane production from grass silage in single-stage and two-stage fermentation processes?', Energy Conversion and Management, 195, pp. 738-747. doi: 10.1016/j.enconman.2019.05.044	en
dc.identifier.doi	10.1016/j.enconman.2019.05.044	en
dc.identifier.endpage	747	en
dc.identifier.issn	0196-8904
dc.identifier.journaltitle	Energy Conversion and Management	en
dc.identifier.startpage	738	en
dc.identifier.uri	https://hdl.handle.net/10468/8025
dc.identifier.volume	195	en
dc.language.iso	en	en
dc.publisher	Elsevier Ltd.	en
dc.relation.project	info:eu-repo/grantAgreement/SFI/SFI Research Centres/12/RC/2302/IE/Marine Renewable Energy Ireland (MaREI) - The SFI Centre for Marine Renewable Energy Research/	en
dc.relation.project	info:eu-repo/grantAgreement/EC/H2020::MSCA-IF-EF-ST/797259/EU/Direct Interspecies Electron Transfer in advanced anaerobic digestion system for gaseous transport biofuel production/DIET	en
dc.relation.uri	http://www.sciencedirect.com/science/article/pii/S0196890419305990
dc.rights	© 2019, Elsevier Ltd. All rights reserved. This manuscript version is made available under the CC BY-NC-ND 4.0 license.	en
dc.rights.uri	https://creativecommons.org/licenses/by-nc-nd/4.0/	en
dc.subject	Grass silage	en
dc.subject	Acid pre-treatment	en
dc.subject	Dark fermentation	en
dc.subject	Anaerobic digestion	en
dc.subject	Biohydrogen	en
dc.subject	Biomethane	en
dc.title	Can acid pre-treatment enhance biohydrogen and biomethane production from grass silage in single-stage and two-stage fermentation processes?	en
dc.type	Article (peer-reviewed)	en