Navegando por Autor "Camargos, Adonai Bruneli de"
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Item Enhancing biobased volatile fatty acids production from olive mill solid waste by optimization of pH and substrate to inoculum ratio.(2023) Fonseca, Yasmim Arantes da; Camargos, Adonai Bruneli de; Gomes, Gustavo Silva Magalhães; Lomar, Priscila Fregulia; Silva, Silvana de Queiroz; Gurgel, Leandro Vinícius Alves; Baeta, Bruno Eduardo LoboThe pH and substrate-to-inoculum ratio (S/I) are important parameters in the anaerobic fermentation of agroindustrial residues, and therefore the optimization of these two parameters is needed for a stable, efficient, and sustainable reactor operation. In this work, the parameters pH (5–9) and S/I (0.5–3 gVS gVS−1 ) were optimized to produce biobased volatile fatty acids (VFAs) from hydrothermally pretreated olive mill solid waste (HPOMSW). The response variables evaluated in the Doehlert design were total VFAs concentration (tVFAs) (mg L−1 ) and amounts (%) of isobutyric, butyric, isovaleric, and valeric acids on the VFAs profile. The pH was the variable that most influenced the mixed culture fermentation of HPOMSW, proving to be a key parameter in the process. Microbial community analyses of conditions 1 (S/I = 3 gVS gVS−1 and pH = 7) and 4 (S/I = 1.13 gVS gVS−1 and pH = 5) showed that Proteobacteria and Firmicutes accounted for more than 87% of the total microorganisms identified for both conditions. In addition, the second-order model best fitted the experimental data for the VFAs production at the desirable condition (S/I = 3 gVS gVS−1 and pH = 8).Item Influence of hydrothermal pretreatment conditions, typology of anaerobic digestion system, and microbial profile in the production of volatile fatty acids from olive mill solid waste.(2021) Fonseca, Yasmim Arantes da; Silva, Nayara Clarisse Soares; Camargos, Adonai Bruneli de; Silva, Silvana de Queiroz; Luna Wandurraga, Héctor Javier; Gurgel, Leandro Vinícius Alves; Baeta, Bruno Eduardo LoboThis study aimed to investigate the production of biobased volatile fatty acids (VFAs) from pretreated olive mill solid waste (OMSW). Three hydrothermal pretreatment (HP) conditions (D1: 125 oC, 53 min; D2: 161 oC, 62 min; D3: 191 oC, 83 min) were selected. The pretreated olive mill solid fraction (OMSF), pretreated olive mill liquid fraction (OMLF), and pretreated OMSW were evaluated as potential substrates for acidification in the anaerobic digestion (AD) in liquid (L-AD), semi-solid (Ss-AD), and solid (S-AD) phases. The best acidification efficiency (AE) observed in this study was 65%, for L-AD and HP condition D2 (161 oC, 62 min). However, the HP condition D2 applied to the Ss-AD provided a VFA concentration of 18218 mg L− 1 , about 6-fold higher than that observed in the L-AD system. Polyphenols changed the profile of VFAs, increasing the production of longer chain VFAs in the L-AD and S-AD systems. Also, the influence of the typology of the AD system and HP severity on the microbial community was evaluated. Proteobacteria and Firmicutes were the most representative phyla in acidogenic fermentation of OMSW substrates and the genera Enterobacter, Pseudomonas, Achromobacter, Clostridium, Ochrobactrum, and Peptoclostridium played an important role in the pretreated OMSW fermentation and, consequently, in the VFAs production profile.Item Pretreatment of sugarcane bagasse with dilute citric acid and enzymatic hydrolysis : use of black liquor and solid fraction for biogas production.(2022) Gomes, Michelle Garcia; Paranhos, Aline Gomes de Oliveira; Camargos, Adonai Bruneli de; Baeta, Bruno Eduardo Lobo; Baffi, Milla Alves; Gurgel, Leandro Vinícius Alves; Pasquini, DanielThis study evaluated the pretreatment of sugarcane bagasse (SCB) with dilute citric acid solution for biogas production. The black liquor (BL) from pretreatment and residual solid fraction (RSF) obtained after enzymatic hydrolysis were used as substrates for the biogas production. After saccharifications of the pretreated solid fractions performed with Cellic® CTec 3 cocktail, the highest concentration of total reducing sugars (TRS) was in the range of 10.7–184.8 g L−1 and the sugar yields were in the range of 3.5–88.8%. For BL, the contents of glucose, xylose, and arabinose were in the range of 1.9–8.9 g L−1, 4.0–24.7 g L−1, and 0.2–5.4 g L−1, respectively. Biogas production from BL and RSF resulted, respectively, in maximum values of 563.6 and 57.8 NmL gCOD−1, indicating the feasibility of using dilute citric acid pretreatment coupled to biogas production in biorefineries. Brief energy and economic assessment were carried out considering the energy balance (thermal energy generated by burning biogas - thermal energy spent in the pretreatment), as well as revenue from a possible sale of electricity generated in a combined heat and power system.Item Production of biogas and fermentable sugars from spent brewery grains : evaluation of one- and two-stage thermal pretreatment in an integrated biorefinery.(2021) Camargos, Adonai Bruneli de; Fonseca, Yasmim Arantes da; Silva, Nayara Clarisse Soares; Barreto, Elisa da Silva; Herrera Adarme, Oscar Fernando; Paranhos, Aline Gomes de Oliveira; Gurgel, Leandro Vinícius Alves; Baeta, Bruno Eduardo LoboIn this study, the production of fermentable sugars and biogas from thermally pretreated brewer’s spent grains (BSGs) was investigated. There were two autohydrolysis conditions (C1-1S: 180 oC, 30 min, 5 mLH2O gBSG − 1 and C2- 1S: 180 oC, 60 min, 5 mLH2O gBSG − 1 ) which were evaluated, with and without a previous low severity pretreatment (80 oC, 10 min, 10 mLH2O gBSG − 1 ). The highest specific methane production (302.4 NLCH4 kgCOD − 1 ) and enzymatic hydrolysis yield (EHY of 98%, 50 FPU gBSG − 1 ) were obtained from the two-stage pretreatment, with the second stage operated at 180 ◦C for 60 min, 5 mLH2O gBSG − 1 . However, in the integrated process, the two-stage pre- treatment with the second stage performed at 180 ◦C for 30 min, and 5 mLH2O gBSG − 1 was the best condition to produce fermentable sugars from enzymatic hydrolysis of pretreated BSGs, using a lower enzyme loading (EHY of 93%, 25 FPU gBSG − 1 ). The burning of biogas produced from an anaerobic digestion of liquid fractions (hydroly- sates) generated after two-stage thermal pretreatment in a combined heat and power system can produce a net thermal energy of 1.71 MJ kgBSG dry basis − 1 and electrical energy of 0.392 kW h kgBSG dry basis − 1 .Item Valorização do bagaço de malte através do pré-tratamento hidrotérmico em uma ou duas etapas : perspectivas para a obtenção de biometano e açúcares fermentescíveis.(2019) Camargos, Adonai Bruneli de; Baeta, Bruno Eduardo Lobo; Gurgel, Leandro Vinícius Alves; Baeta, Bruno Eduardo Lobo; Gurgel, Leandro Vinícius Alves; Passos, Fabiana Lopes Del Rei; Brandão, Rogélio LopesO presente trabalho teve como objetivo principal comparar as produções de metano, advindas da digestão aneróbia dos hidrolisados obtidos a partir da autohidrólise do bagaço de malte bruto e do bagaço de malte submetido a um prétratamento preliminar de baixa severidade como etapa prévia. Considerando que a biomassa pode conter açúcares provenientes do processo de produção de cerveja, o tratamento preliminar objetivou a remoção desses açúcares para uma solução aquosa, que foi conduzida a avaliação de seu potencial de geração de metano. As frações sólidas resultantes do pré-tratamento da biomassa foram submetidas à hidrólise enzimática para a obtenção de açúcares fermentescíveis. Ferramentas estatísticas foram utilizadas para a definição de cenários favoráveis à obtenção de biometano e etanol celulósico. Um planejamento experimental Doehlert foi realizado, utilizando como variáveis independentes, os parâmetros operacionais da auto-hidrólise do bagaço de malte. Dessa forma, avaliou-se as remoções dos componentes da biomassa e os rendimentos da hidrólise enzimática a fim de otimizar o pré-tratamento do bagaço de malte. Foram estabelecidos dois cenários para a produção de biogás e um cenário para a obtenção de etanol. Em cada cenário definido foram realizados os prétratamentos do bagaço de malte bruto e do bagaço de malte tratado previamente em uma baixa severidade. Os resultados foram comparados para avaliar a viabilidade ou não do uso do pré-tratamento em duas etapas. Verificou-se que no cenário para a produção de etanol, a biomassa tratada em duas etapas apresentou uma maior acessibilidade enzimática. O maior rendimento da hidrólise enzimática (86%) e a maior produção de metano (302,4 NL.kg-1 bs) foram obtidos com a biomassa tratada em dois estágios no segundo cenário para a produção de biogás, na condição mais severa (180°C, 60 min, 5,5 mL.g-1). Porém, os maiores valores de recuperação energética foram obtidos com a biomassa tratada em uma única etapa nos dois cenários para a produção de biogás. A máxima recuperação de energia térmica (1,88 MJ.kg-1 bs) e energia elétrica (0,403 kWh.kg-1) foi obtida no primeiro cenário para a produção de biogás (180°C, 31 min, 5 mL.g-1).