Molasses vs. juice: Maximizing biohydrogen production in sugarcane biorefineries to diversify renewable energy generation

Autor(es)

Fuess, Lucas Tadeu ; Zaiat, Marcelo ; Oller do Nascimento, Claudio Augusto

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF WATER PROCESS ENGINEERING; v. 37, p. 14-pg., 2020-10-01.

Resumo

Diversifying the portfolio of bioenergy-related products in sugarcane biorefineries is required to increase substrate conversion efficiency and market reach. The suitability of producing biohydrogen (bioH(2)) through the thermophilic dark fermentation of juice and molasses was assessed as an alternative to conventional sugarcane processing. The energetic potential of applying anaerobic digestion with phase separation to process molasses was also investigated. Molasses outperformed juice as substrate for continuous bioH(2) production due to a more balanced nutrient content, whilst nitrogen deficiency directly hindered juice fermentation. An optimal COD/N ratio (similar to 100) could maximize bioH(2) production from both juice and molasses. Continuous bioH(2) production from molasses fermentation was optimized at pH and organic loading rate values of 5.38 and 86 kg-COD m(-3) d(-1), which are consistent with acidogenic systems inoculated with sugarcane vinasse-derived consortia. Metabolite profiles suggested that capnophilic lactic fermentation coupled to lactate-based butyrate production were the primary conversion pathways. Bioenergy generation from molasses (bioH(2) + methane) exceeded that of vinasse by over 600 %, highlighting the relevance of anaerobic digestion as an efficient core processing step in the sucroenergetic industry. In particular, phase separation enhanced the total energy production by 13.1 % (604.30 vs. 683.76 MJ per ton of sugarcane) by maximizing the methane yield up to theoretical values. (AU)

• Processo FAPESP: 15/50684-9 - Sustainable gas pathways for Brazil: from microcosm to macrocosm
• Beneficiário: Reinaldo Giudici
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 17/00080-5 - Potencialização da produção de energia a partir da cana-de-açúcar em biorrefinarias de primeira geração: biodigestão como etapa central de conversão
• Beneficiário: Lucas Tadeu Fuess
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/06246-7 - Aplicação do conceito de biorrefinaria a estações de tratamento biológico de águas residuárias: o controle da poluição ambiental aliado à recuperação de matéria e energia
• Beneficiário: Marcelo Zaiat
• Modalidade de apoio: Auxílio à Pesquisa - Temático