Acidogenesis of Pentose Liquor to Produce Biohydrogen and Organic Acids Integrated with 1G–2G Ethanol Production in Sugarcane Biorefineries
Guilherme Peixoto,
Gustavo Mockaitis,
Wojtyla Kmiecik Moreira,
Daniel Moureira Fontes Lima,
Marisa Aparecida de Lima,
Filipe Vasconcelos Ferreira,
Lucas Tadeu Fuess,
Igor Polikarpov,
Marcelo Zaiat
Affiliations
Guilherme Peixoto
Department of Engineering of Bioprocesses and Biotechnology, School of Pharmaceutical Sciences, São Paulo State University (UNESP), São Paulo 14800-903, SP, Brazil
Gustavo Mockaitis
Interdisciplinary Research Group On Biotechnology Applied to the Agriculture and the Environment (GBMA), School of Agricultural Engineering (FEAGRI), University of Campinas (UNICAMP), Av. Candido Rondon, 501–Cidade Universitária, São Paulo 13083-875, SP, Brazil
Wojtyla Kmiecik Moreira
Biological Processes Laboratory, São Carlos School of Engineering, University of São Paulo (EESC/USP), São Carlos 13563-120, SP, Brazil
Daniel Moureira Fontes Lima
Department of Civil Engineering, Federal University of Sergipe (UFS), São Cristóvão 49107-230, SE, Brazil
Marisa Aparecida de Lima
Molecular Biotechnology Group, São Carlos Physics Institute, University of São Paulo (IFSC/USP), São Carlos 13566-590, SP, Brazil
Filipe Vasconcelos Ferreira
Biological Processes Laboratory, São Carlos School of Engineering, University of São Paulo (EESC/USP), São Carlos 13563-120, SP, Brazil
Lucas Tadeu Fuess
Biological Processes Laboratory, São Carlos School of Engineering, University of São Paulo (EESC/USP), São Carlos 13563-120, SP, Brazil
Igor Polikarpov
Molecular Biotechnology Group, São Carlos Physics Institute, University of São Paulo (IFSC/USP), São Carlos 13566-590, SP, Brazil
Marcelo Zaiat
Biological Processes Laboratory, São Carlos School of Engineering, University of São Paulo (EESC/USP), São Carlos 13563-120, SP, Brazil
Second-generation (2G) ethanol production has been increasingly evaluated, and the use of sugarcane bagasse as feedstock has enabled the integration of this process with first-generation (1G) ethanol production from sugarcane. The pretreatment of bagasse generates pentose liquor as a by-product, which can be anaerobically processed to recover energy and value-added chemicals. The potential to produce biohydrogen and organic acids from pentose liquor was assessed using a mesophilic (25 °C) upflow anaerobic packed-bed bioreactor in this study. An average organic loading rate of 11.1 g COD·L−1·d−1 was applied in the reactor, resulting in a low biohydrogen production rate of 120 mL·L−1 d−1. Meanwhile, high lactate (38.6 g·d−1), acetate (31.4 g·d−1), propionate (50.1 g·d−1), and butyrate (50.3 g·d−1) production rates were concomitantly obtained. Preliminary analyses indicated that the full-scale application of this anaerobic acidogenic technology for hydrogen production in a medium-sized 2G ethanol distillery would have the potential to completely fuel 56 hydrogen-powered vehicles per day. An increase of 24.3% was estimated over the economic potential by means of chemical production, whereas an 8.1% increase was calculated if organic acids were converted into methane for cogeneration (806.73 MWh). In addition, 62.7 and 74.7% of excess organic matter from the 2G ethanol waste stream could be removed with the extraction of organic acid as chemical commodities or their utilization as a substrate for biomethane generation, respectively.