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 summary 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 dissolved methane recovery process. [Display omitted] •Dissolved CH4 recovery from anaerobic bioreactor effluents•Tuning anaerobic bioreactor and membrane contactor parameters for efficient CH4 recovery•Emerging membranes are being developed to enable self-sufficient membrane systems.•Mass-transfer resistances is a key parameter for detecting fouling and wetting.•Modeling of the fouling and wetting is a promising strategy to optimize membrane performance.