Anaerobic Biological Treatment of Vinasse for Environmental Compliance and Methane Production

Abstract

The energy crisis resulted in increasing awareness that alternative sources of energy should be considered. During this time, Brazil implemented ethanol production from sugarcane as biofuel. However, during this process, large amounts of residues are generated, such as vinasse. This residue can be treated anaerobically to generate methane as a source of bioenergy with the use of sequencing batch reactors operated with immobilized biomass (AnSBBR). In this work, tests were conducted in an AnSBBR laboratory-scale reactor, and the main results regarding the kinetic model fitting and performance of substrate consumption (83 %), methane content in the biogas (77 %), applied organic load (5.54 g COD L(-1) day(-1)), methane productivity (973 N-mL CH4 L(-1) day(-1)), and yield (9.47 mol CH4 kg COD(-1)) show that AnSBBR is a promising technological alternative. After tests conducted in a laboratory-scale reactor, an industrial reactor was scaled and was also operated in a sequencing batch with immobilized biomass (AnSBBR) for the anaerobic treatment of vinasse with the goal of generating methane and environmental suitability to further disposal in soil. The calculations were performed based on data from a sugar and alcohol plant located in São Paulo, Brazil. This study proposes to the operation of the industrial scale reactor was the association of four AnSBBR (each one with a volume of 15849 m(3)) operating in parallel (with a feeding and discharge time of 4 h and a reaction time of 8 h), with the goal of adapting the treatment system from a discontinuous operation to a continuous operation. In this industrial scenario, the methane production was estimated at 1.65 × 10(6) mol CH4 day(-1), and the energy was approximately 17 MW, increasing the possible energy recovery contained in sugarcane from 93 to 96 %.

Optimal Design of a Co2 Removal Section for a Biogas-Based Oxidative Coupling of Methane Process

“…The OCM process using the biogas feed is entirely modeled in the software Aspen Plus v10. The biogas feed stream has a flow of 2,200 Nm 3 /h with approximately 70% CH4 and 30% CO2 as in (Albanez, et al 2016). This gas stream is fed to the reaction section, wherein methane reacts with oxygen at around 750 °C temperature to form ethylene and water.…”

THERMOPHILIC BIOMETHANE PRODUCTION BY VINASSE IN AN AnSBBR: START-UP STRATEGY AND PERFORMANCE OPTIMIZATION

“…The anaerobic sequencing batch biofilm reactor containing immobilized biomass used in this work was the same as that of Albanez et al (2016). The AnSBBR (Figure 1) was operated in batch and fed-batch mode, at 55 ºC, controlled by a water jacket, of which the temperature was regulated by an ultrathermostatic bath.…”

“…[ (a) Reactor BIOFLO III (New Brunswick Scientific Co.) with 6 L capacity; 2 -basket containing support material with immobilized biomass (c = 18.0 cm; d = 7.0 cm); 3 -Influent; 4 -Feed pump; 5 -Effluent; 6 -Discharge pump; 7 -Biogas outlet; 8 -Mechanical agitation; 9 -Temperature control system (ultrathermostatic bath)]. Adapted from Albanez et al (2016) 17 g.L -1 of total volatile solids. The inert support used to immobilize the biomass consisted of polyurethane foam cubes (1 cm edges).…”

Produção de metano em AnSBBR tratando soro em condição termofílica

“…Quando maior a concentração de acetato, maior produção de metano via rota acetoclástica, sendo, entretanto, necessário o conhecimento do limite metabólico do reator em assimilar a matéria orgânica disponibilizada na alimentação para manter a estabilidade do sistema (BEZERRA et al, 2009). Na literatura atual, é cada vez mais comum a utilização desta configuração de reator na produção de metano ou hidrogênio pela viabilização da produção de bioenergia gerada a partir do tratamento de diversas águas residuárias, como vinhaça, soro, esgoto doméstico, efluente da produção de biodiesel e efluentes industriais ou até para remoção de sulfatos (SARTI et al, 2008;BEZERRA et al, 2009BEZERRA et al, e 2011OLIVEIRA et al, 2009;RODRIGUES et al, 2011;LOVATO et al, 2012;ALBANEZ et al, 2016a;LIMA et al, 2016).…”

“…AVT (mgHAc.L -1 ) 587 ± 99 ( 14 ) 632 ± 187 ( 14 ) AT (mgCaCO 3 .L -1 ) 3868 ± 713 ( 14 ) 4776 ± 349 ( 14 ) AP (mgCaCO 3 .L -1 ) 899 ± 199 ( 14 ) 3649 ± 323 ( 14 ) AI (mgCaCO 3 .L -1 ) 3386 ± 667 ( 14 ) 1128 ± 163 ( 14 ) AB (mgCaCO 3 .L -1 ) 3868 ± 719 ( 14 ) 4327 ± 356 ( 14 ) ST (mg.L -1 ) 15537 ± 711 ( 6 ) 6279 ± 320 ( 6 ) SVT (mg.L -1 ) 9624 ± 511 ( 6 ) 1488 ± 239 ( 6 ) SST (mg.L -1 ) 328 ± 57 ( 6 ) 164 ± 56 ( 6 ) SSV (mg.L -1 ) 247 ± 39 ( 6 ) 146 ± 52 ( 6 ) Para se realizar a comparação entre os resultados descritos na literatura e a do presente projeto, foi utilizado no cálculo da recuperação energética os volumes de produção obtidos nos trabalhos de Albanez et al (2016a), Albuquerque (2017) e Almeida et al (2017), que foi de 7753,3 m³.d -1 de vinhaça, mas mantendo-se a concentração de 20.000 mgDQO.L -1 adotada para o soro.…”