CFD simulation of anaerobic granular sludge reactors: A review

Area of Science:

• Environmental Engineering
• Biotechnology
• Chemical Engineering

Background:

• Anaerobic digestion (AD) generates biogas, a renewable energy source, while treating organic wastewater.
• Biogas production in AD systems is sensitive to internal mixing conditions.
• High-rate reactors like upflow anaerobic sludge blanket (UASB), expanded granular sludge bed (EGSB), and internal circulation (IC) reactors exhibit complex hydrodynamics influenced by wastewater, biogas, and biomass interactions.

Purpose of the Study:

• To provide a comprehensive review of computational fluid dynamics (CFD) applications in anaerobic granular sludge reactors (AGSRs).
• To critically discuss the state-of-the-art in CFD modeling for AGSRs, including modeling aspects, simulation approaches, and validation methods.
• To identify current challenges and future research perspectives in CFD modeling of AGSRs.

Main Methods:

• Literature review of research papers utilizing CFD for modeling AGSRs.
• Critical analysis of various CFD modeling approaches, including single-phase and multiphase simulations.
• Discussion of methods employed for validating CFD models in the context of AGSRs.

Main Results:

• CFD has been extensively used to investigate hydrodynamic behavior in various AGSRs.
• A critical analysis of different modeling strategies (e.g., single-phase vs. multiphase) and their suitability for AGSRs is presented.
• Various CFD model validation techniques are reviewed and discussed.

Conclusions:

• CFD is a powerful tool for understanding and optimizing AGSR performance.
• Gaps in current knowledge and future research directions for CFD modeling of AGSRs are identified.
• Further research is needed to refine CFD models for more accurate predictions of biogas generation and reactor efficiency.