Progress and challenges in recovering dissolved methane from anaerobic bioreactor permeate using membrane contactors: A comprehensive review

The recovery of a high amount of dissolved methane from the anaerobic bioreactor permeate requires efficient degassing technologies such as membrane contractors (MC). The review work presented here provides a sum-mary and analysis of the studies involving biomethane production by anaerobic treatments to distinguish the parameters affecting downstream MC, used for methane recovery. A general overview of MC principles and dissolved methane quantification is included. The paper then presents a discussion and analysis of diverse membrane characteristics, and liquid-and gas-phase hydrodynamics. The challenges and promises of the membrane contactor operations are also addressed. Currently, maximum recovery efficiencies obtained are close to 99 % for short-term experiments. However, additional resistances for the mass-transfer can be detected during long-term operation. It is therefore required to focus on membrane modifications and fine-tuning of the main parameters for reducing mass-transfer resistances; which may advance the development of a sustainable dis -solved methane recovery process.

Automated summary

This review summarizes and analyzes studies on biomethane production and the parameters affecting downstream membrane contactors. It provides an overview of membrane contactor principles, dissolved methane quantification, membrane characteristics, and liquid and gas phase hydrodynamics, as well as discusses the challenges and promises of membrane contactor operations.