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

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

doi:10.1016/j.biortech.2020.124130

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

Bioresour Technol. 2021 Jan:319:124130. doi: 10.1016/j.biortech.2020.124130. Epub 2020 Sep 18.

Authors

Yuying Hu¹, Xiaohuan Zheng², Shihao Zhang², Wenjie Ye², Jing Wu³, Souhila Poncin⁴, Huai Z Li⁵

Affiliations

¹ School of Civil Engineering and Architecture, East China Jiao Tong University, Nanchang 330013, China; State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China; Laboratory of Reactions and Process Engineering, Université de Lorraine, CNRS, 1, rue Grandville, BP 20451, 54001 Nancy cedex, France.
² School of Civil Engineering and Architecture, East China Jiao Tong University, Nanchang 330013, China.
³ State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
⁴ Laboratory of Reactions and Process Engineering, Université de Lorraine, CNRS, 1, rue Grandville, BP 20451, 54001 Nancy cedex, France.
⁵ Laboratory of Reactions and Process Engineering, Université de Lorraine, CNRS, 1, rue Grandville, BP 20451, 54001 Nancy cedex, France. Electronic address: Huai-Zhi.Li@univ-lorraine.fr.

PMID: 32977097
DOI: 10.1016/j.biortech.2020.124130

Abstract

High solid anaerobic digestion (HSAD) was a potential organic waste treatment. Compared with low solid anaerobic digestion, it had the advantages of small footprint, less digestate, and low heating energy. However, HSAD's methane production is poor, mainly due to the complex hydrodynamics. In this study, computational fluid dynamics were utilized for HSAD's hydrodynamics investigation at 14.3% solid content and compared to the particle image velocimetry measurement. Then, effects of mixing on hydrodynamics were investigated. The results indicated that the diameter of impeller was critical for the radial mixing, and the distance between the impellers dictated the axial mixing. Besides, rotating speed affected flow velocities significantly, but displayed less effect on expanding the mixing range. Furthermore, HSAD's treating capacity could be increased at large extent by optimizing mixing. The visualization of the hydrodynamics in this study could potentially offer conceptual basis for HSAD's design in practical engineering.

Keywords: Computational fluid dynamics; Dead zone; High solid anaerobic digestion; Hydrodynamic condition; Particle image velocimetry.

MeSH terms

Anaerobiosis
Hydrodynamics*
Rheology