Continuous production of biohythane from hydrothermal liquefied cornstalk biomass via two-stage high-rate anaerobic reactors
Open Access
- 21 November 2016
- journal article
- research article
- Published by Springer Science and Business Media LLC in Biotechnology for Biofuels
- Vol. 9 (1), 1-15
- https://doi.org/10.1186/s13068-016-0666-z
Abstract
Biohythane production via two-stage fermentation is a promising direction for sustainable energy recovery from lignocellulosic biomass. However, the utilization of lignocellulosic biomass suffers from specific natural recalcitrance. Hydrothermal liquefaction (HTL) is an emerging technology for the liquefaction of biomass, but there are still several challenges for the coupling of HTL and two-stage fermentation. One particular challenge is the limited efficiency of fermentation reactors at a high solid content of the treated feedstock. Another is the conversion of potential inhibitors during fermentation. Here, we report a novel strategy for the continuous production of biohythane from cornstalk through the integration of HTL and two-stage fermentation. Cornstalk was converted to solid and liquid via HTL, and the resulting liquid could be subsequently fed into the two-stage fermentation systems. The systems consisted of two typical high-rate reactors: an upflow anaerobic sludge blanket (UASB) and a packed bed reactor (PBR). The liquid could be efficiently converted into biohythane via the UASB and PBR with a high density of microbes at a high organic loading rate. Biohydrogen production decreased from 2.34 L/L/day in UASB (1.01 L/L/day in PBR) to 0 L/L/day as the organic loading rate (OLR) of the HTL liquid products increased to 16 g/L/day. The methane production rate achieved a value of 2.53 (UASB) and 2.54 L/L/day (PBR), respectively. The energy and carbon recovery of the integrated HTL and biohythane fermentation system reached up to 79.0 and 67.7%, respectively. The fermentation inhibitors, i.e., 5-hydroxymethyl furfural (41.4–41.9% of the initial quantity detected) and furfural (74.7–85.0% of the initial quantity detected), were degraded during hydrogen fermentation. Compared with single-stage fermentation, the methane process during two-stage fermentation had a more efficient methane production rate, acetogenesis, and COD removal. The microbial distribution via Illumina MiSeq sequencing clarified that the biohydrogen process in the two-stage systems functioned not only for biohydrogen production, but also for the degradation of potential inhibitors. The higher distribution of the detoxification family Clostridiaceae, Bacillaceae, and Pseudomonadaceae was found in the biohydrogen process. In addition, a higher distribution of acetate-oxidizing bacteria (Spirochaetaceae) was observed in the biomethane process of the two-stage systems, revealing improved acetogenesis accompanied with an efficient conversion of acetate. Biohythane production could be a promising process for the recovery of energy and degradation of organic compounds from hydrothermal liquefied biomass. The two-stage process not only contributed to the improved quality of the gas fuels but also strengthened the biotransformation process, which resulted from the function of detoxification during biohydrogen production and enhanced acetogenesis during biomethane production.Keywords
Funding Information
- National Natural Science Foundation of China (5151101167;U1562107)
- the National Key Technology Support Program of China (2014BAD02B03)
- Beijing Youth Top-notch Talent Support Project (2015000026833ZK10)
This publication has 73 references indexed in Scilit:
- Distribution and abundance of Spirochaetes in full-scale anaerobic digestersBioresource Technology, 2013
- Specific inhibition of biohydrogen-producing Clostridium sp. after dilute-acid pretreatment of sunflower stalksInternational Journal of Hydrogen Energy, 2013
- Bacterial bioaugmentation for improving methane and hydrogen production from microalgaeBiotechnology for Biofuels, 2013
- Lignocellulosic Materials Into Biohydrogen and Biomethane: Impact of Structural Features and PretreatmentCritical Reviews in Environmental Science and Technology, 2013
- Description of Christensenella minuta gen. nov., sp. nov., isolated from human faeces, which forms a distinct branch in the order Clostridiales, and proposal of Christensenellaceae fam. nov.International Journal of Systematic and Evolutionary Microbiology, 2012
- Feasibility of biohydrogen production from Gelidium amansiiInternational Journal of Hydrogen Energy, 2011
- Composition and hydrothermal pretreatment and enzymatic saccharification performance of grasses and legumes from a mixed-species prairieBiotechnology for Biofuels, 2011
- Complete genome sequence of Syntrophothermus lipocalidus type strain (TGB-C1T)Standards in Genomic Sciences, 2010
- Methane production from organic acids obtained by supercritical water treatment of Japanese beechJournal of Wood Science, 2009
- Global survey of diversity among environmental saltwater BacteriovoracaceaeEnvironmental Microbiology, 2007