Work

Mitigation of atmospheric and elevated methane by photochemical oxidation at ambient conditions

Year: 2025

Type: article

Abstract: Methane (CH 4 ) is a potent greenhouse gas and increased mitigation of anthropogenic sources will have immediate effects on global climate. Methane is an inherently inert gas and there is a need for methods capable of mitigating methane from point and non-point sources. Here we introduce a UV based methane oxidation system for mitigation of methane at atmospheric levels and above. Catalyst-free photochemical methane oxidation was achieved at ambient temperature and pressure using air and water vapor as sole reactants. Products included H 2 , H 2 O, CH 2 O and CO 2 that have lower radiative forcing potential than methane. The oxidation process rapidly removed ambient methane (2 ppm) to well below atmospheric levels within seconds. >90 % methane removal was obtained for both atmospheric and elevated methane (1–100,000 ppm). Rate coefficients increased with decreasing methane concentrations with half-life of <1 min to 10 min for concentrations ≤10,000 ppm. The environmental applicability of the process for mitigation of anthropogenic methane was demonstrated with thermogenic methane from a gas distribution hub and biogenic methane from a pig stable. The study introduces the fundamentals of a methane scrubber based on rainwater and UV irradiation that may contribute to future removal of methane from point and non-point sources. • New principles for efficient mitigation of methane sources are lacking • A UV based photochemical methane oxidation system is introduced (VUMOX) • VUMOX removed atmospheric methane and elevated methane concentrations • VUMOX proceeds at ambient conditions without catalysts or added oxidants • A Methane Scrubber may contribute to point and non-point source methane mitigation

Source: The Science of The Total Environment

DOI: 10.1016/j.scitotenv.2025.179338

Authors: Niels Iversen, Peter Roslev

Institution: Aalborg University

Language: English

Topic: Atmospheric and Environmental Gas Dynamics

Subfield: Global and Planetary Change

Field: Environmental Science

Domain: Physical Sciences

SDG: Climate action

Open Access status: hybrid

Estimated APC paid: $4,250