Microbial Metabolic Pathways for Synergistic Biomethane Augmentation and CO₂ Sequestration in Coalbed Systems: A...

Area of Science:

• Environmental Science & Engineering
• Microbiology
• Geochemistry

Background:

• Natural gas, a transitional clean energy source, includes biogenic coalbed methane (CBM) found globally.
• Growing demand for CBM and carbon neutrality targets necessitate innovative bioengineering solutions.
• CBM bioengineering aims to boost methane generation, gas desorption, and reservoir permeability while sequestering CO2.

Purpose of the Study:

• To review recent advancements in microbially mediated CBM enhancement and CO2 sequestration.
• To focus on field-scale evidence and challenges for large-scale implementation of CBM bioengineering.
• To explore how coal properties and hydrogeological conditions influence biomethane generation.

Main Methods:

• Analysis of coal physicochemical characteristics (aromatic structures, macerals, pore-fracture architecture).
• Assessment of hydrogeological conditions (geothermal gradients, pH, redox potential) impacting microbial activity.
• Review of pretreatment strategies: enhancing coal bioconversion and optimizing microbial consortia (e.g., electric fields).

Main Results:

• Coal properties and hydrogeological conditions critically regulate microbial function and biomethane potential.
• Deep coalbed environments under CO2 pressure favor hydrogenotrophic methanogens, enhancing biomethane generation.
• Supercritical CO2 integrated with microbially acclimated fluids offers reservoir stimulation, carbon sequestration, and biomethane production.

Conclusions:

• CBM bioengineering presents a viable strategy for sustainable energy and carbon management.
• Future research should focus on coal matrix bioavailability, microbial consortia optimization, and carbon fixation.
• Overcoming challenges in modulating bioavailability, microbial synergy, and bioprocesses is crucial for large-scale CBM bioengineering.