perational and biochemical aspects of co-digestion (co-AD) from sugarcane vinasse, filter cake, and deacetylation liquo

Author(s)

Volpi, Maria Paula C. ^{[1, 2]} ; Ferraz Junior, Antonio Djalma N. ^[3] ; Franco, Telma T. ^[4] ; Moraes, Bruna S. ^[1]

Affiliation

^[1] Univ Campinas NIPE UNICAMP, Interdisciplinary Ctr Energy Planning, R Cora Coralina 330, Cidade Univ, BR-13083896 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Sch Agr Engn FEAGRI, Interdisciplinary Res Grp Biotechnol Appl Agr & E, Av Candido Rondon 501, Cidade Univ, BR-13083875 Campinas, SP - Brazil

^[3] Imperial Coll London, Ctr Environm Policy, Exhibit Rd, London SW7 1NA - England

^[4] Univ Campinas FEQ UNICAMP, Chem Engn Sch, Av Albert Einstein 500, BR-13083852 Campinas, SP - Brazil

• Document type: Journal article
• Source: Applied Microbiology and Biotechnology; v. 105, n. 23 OCT 2021.
• Web of Science Citations: 0

Abstract

This work performed co-AD from the vinasse and filter cake (from 1G ethanol production) and deacetylation liquor (from the pretreatment of sugarcane straw for 2G ethanol production) in a semi-Continuous Stirred Tank Reactor (s-CSTR) aiming to provide optimum operational parameters for continuous CH4 production. Using filter cake as co-substrate may allow the reactor to operate throughout the year, as it is available in the sugarcane off-season, unlike vinasse. A comparison was made from the microbial community of the seed sludge and the reactor sludge when CH4 production stabilized. Lactate, butyrate, and propionate fermentation routes were denoted at the start-up of the s-CSTR, characterizing the acidogenic phase: the oxidation-reduction potential (ORP) values ranged from -800 to -100 mV. Once the methanogenesis was initiated, alkalizing addition was no longer needed as its demand by the microorganisms was supplied by the alkali characteristics of the deacetylation liquor. The gradual increase of the applied organic load rates (OLR) allowed stabilization of the methanogenesis from 3.20 g(VS) L-1 day(-1): the highest CH4 yield (230 mL(N)CH(4) g(VS)(-1)) and average organic matter removal efficiency (83% +/- 13) was achieved at ORL of 4.16 g(VS) L-1 day(-1). The microbial community changed along with the reactor operation, presenting different metabolic routes mainly due to the used lignocellulosic substrates. Bacteria from the syntrophic acetate oxidation (SAO) process coupled to hydrogenotrophic methanogenesis were predominant (similar to 90% Methanoculleus) during the CH4 production stability. The overall results are useful as preliminary drivers in terms of visualizing the co-AD process in a sugarcane biorefinery integrated to scale. (AU)

• FAPESP's process: 18/09893-1 - Biogas production integrated to the concept of lignocellulosic biomass: operational aspects and use of nanoparticles
• Grantee: Maria Paula Cardeal Volpi
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/16438-3 - Biogas production in integrated 1st and 2nd generation sugarcane biorrefineries: fundamentals and operational aspects of the process
• Grantee: Bruna de Souza Moraes
• Support Opportunities: Regular Research Grants
• FAPESP's process: 15/50612-8 - An integrated approach to explore a novel paradigm for biofuel production from lignocellulosic feedstocks
• Grantee: Telma Teixeira Franco
• Support Opportunities: Research Projects - Thematic Grants