Investigation of hydrodynamics in high solid anaerobic digestion by particle image velocimetry and computational fluid dynamics: Role of mixing on flow field and dead zone reduction

Hu, Yuying; Zheng, Xiaohuan; Zhang, Shihao; Ye, Wenjie; Wu, Jing; Poncin, Souhila; Li, Huai Z.

doi:10.1016/j.biortech.2020.124130

Cited by 16 publications

(8 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mechanical mixing and air supply with gas are two efficient methods to improve substrate agitation and provides suitable heat and mass transfer during the anaerobic digestion, [60]. During mechanical mixing, the size of the impeller and mixing properties affect significantly the, impeller, [61], [62]. Flow rates were affected by the speed and have not an important effect on the mixing rates.…”

Section: Why Heat Transfer Is Important?mentioning

confidence: 99%

See 1 more Smart Citation

Heat and Mass Limitations in an Anaerobic Digestion Process

Sponza,

Özteki̇n

2023

1790-5044

View full text Add to dashboard Cite

In this study, heat and mass limitations in an anaerobic reactor containing domestic solids were researched in batch reactors. The dynamic and static anaerobic data for 365 days showed that the methane production for the dynamic digestion reactor was measured as 176.86 m3 which is extremely high for static anaerobic one (102.78 m3). As the heat transfer data increased with elevated temperature the methane productions also were highlighted. The external mass transfer was observed for easily degradable solids. In the calculation of external mass transfer during the degradation of organics dissolved with difficulty some semiempirical regressions were used. In the calculation of internal mass transfer the microorganisms in the solids were taken into consideration and the diffusion was defined with Fick's law. The diffusion coefficient D, was found to be constant. Generally, the diffusion coefficient of solids in water (Dw) was < 1.0. The effect of the total solid (TS) concentration in anaerobic batch reactors (TS between 12% and 39%) was investigated. The methane gas production decreased minorly when the TS levels elevated to 30%. At a TS percentage of 39%, the methane generation decreased significantly. At high TS, the mass transfer was inhibited and ended with lowered methane generations while the hydrolysis process did not affect significantly at high TS concentrations.

show abstract

Section: Why Heat Transfer Is Important?mentioning

confidence: 99%

“…Flow rates were affected by the speed and have not an important effect on the mixing rates. No more studies were found researching the specific impacts of the mixing methods on the performance of anaerobic digesters with high solid content, [61], [62].…”

Section: Why Heat Transfer Is Important?mentioning

confidence: 99%

Heat and Mass Limitations in an Anaerobic Digestion Process

Sponza,

Özteki̇n

2023

1790-5044

View full text Add to dashboard Cite

show abstract

“…However, anaerobic digestion of food waste is worthwhile and growing interest [1, [89][90][91]. In addition, the impact of hydrodynamics on the performances of anaerobic digestion of high-solid waste is significant [62,92]. Solely, a review was carried out on the rheological properties of fruits and vegetables [93].…”

Section: Rheological Behavior Of Food Wastementioning

confidence: 99%

A Review on the Rheological Behavior of Organic Waste for CFD Modeling of Flows in Anaerobic Reactors

Caillet¹,

Adelard²

2022

Waste Biomass Valor

View full text Add to dashboard Cite

Anaerobic digestion is a widely used process for organic waste treatment and renewable energy production. This is a complex natural biodegradation of organic matter involving four main biochemical reactions through the action of four microbial groups. The performances of anaerobic digestion (biodegradation and biogas production) depend on the contact between the biodegradable materials and the micro-organisms. Consequently, hydrodynamics phenomena have a significant impact on the anaerobic digestion. Computational Fluid Dynamics (CFD) simulations allow to simulate the flow field within anaerobic digesters. In these models, the waste are characterized by their physical properties, specifically their rheological properties. Rheology consists in the study of the flow of liquids or viscous materials. In this respect, it involves the properties related to the flow behavior of liquids and the temporary and/or permanent deformation of materials. The knowledge on the rheological properties of the biowaste is crucial in order to describe the flows using CFD models. The aim of this review is to present the physical properties of different type of waste, as well as the rheological models. In conclusion, the rheological behaviors of wastewater, manure, and sludge are described in literature. However the rheological behaviors of a mix of biowaste and solid food waste are poorly known. Research should focus on the experimental measurements of these biowaste. These data are necessary for CFD modeling of flows in anaerobic reactors treating this type of waste.

show abstract

“…As for the substrates with high viscosity and solid content, like WAS, the efficient conversion of biodegradable waste into biogas requires biological, chemical, and physical uniformity within the digester, which can be only fulfilled by thoroughly mixing [15,16]. Proper mixing arrangements can contribute to the reduction in dead zones, the enhanced mass transfer between microbial populations, the reduction in the substrate size, and the separation of gas from the substrate [17,18]. Shaker and magnetic (or mechanical) stirring, located at the bottom of the reactor, are the most common mixing methods in current cases [11,19], which, unfortunately, make it difficult to achieve sufficient mixing of substrates, especially in large-scale devices [18].…”

Section: Introductionmentioning

confidence: 99%

“…Proper mixing arrangements can contribute to the reduction in dead zones, the enhanced mass transfer between microbial populations, the reduction in the substrate size, and the separation of gas from the substrate [17,18]. Shaker and magnetic (or mechanical) stirring, located at the bottom of the reactor, are the most common mixing methods in current cases [11,19], which, unfortunately, make it difficult to achieve sufficient mixing of substrates, especially in large-scale devices [18]. Notably, it was recently found that increasing the driving force by mixing improves the proton transfer rate between electrodes with a large distance, and thus reduces the internal resistance [20], which implies that sacrificing mixing for the purpose of shortening electrode spacing may not be inevitable.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Methanogenesis of Waste-Activated Sludge (WAS) in a Continuous Stirring Tank Reactor with Stealth Electrodes

He,

Zhang,

Zhang

et al. 2024

Fermentation

View full text Add to dashboard Cite

The integration of a microbial electrolysis cell (MEC) is an effective strategy for enhancing the efficiency and stability of an anaerobic digestion (AD) system for energy recovery from waste-activated sludge (WAS). Typically, electrodes are arranged as separate components, potentially disrupting mixing and complicating the reactor configuration, posing challenges for the scaling up of AD-MEC coupling systems. In this study, electrodes were introduced into a continuous stirring tank reactor (CSTR) in a “stealth” manner by integrating them with the inner wall and stirring paddle. This electrode arrangement approach was validated through a sequential batch digestion experiment, resulting in a remarkable 1.5-fold increase in cumulative methane production and a shortened lag period compared to the traditional CSTR with a nonconductive inner wall and stirring paddle. Both the conductive materials (CMs) employed in the electrodes and the electrochemical processes equally contributed to the observed enhancement effect of the electrodes by regulating the evolution of the microbial community within the electrode biofilms, with a specific emphasis on the enrichment of methanogens (primarily Methanobacterium). This research offers a potential avenue to solve the contradiction between the electrode introduction and the mixing operation in AD-MEC coupling systems and to contribute to its future commercial application.

show abstract

Investigation of hydrodynamics in high solid anaerobic digestion by particle image velocimetry and computational fluid dynamics: Role of mixing on flow field and dead zone reduction

Cited by 16 publications

References 22 publications

Heat and Mass Limitations in an Anaerobic Digestion Process

Heat and Mass Limitations in an Anaerobic Digestion Process

A Review on the Rheological Behavior of Organic Waste for CFD Modeling of Flows in Anaerobic Reactors

Enhanced Methanogenesis of Waste-Activated Sludge (WAS) in a Continuous Stirring Tank Reactor with Stealth Electrodes

Contact Info

Product

Resources

About