The dominant approach for methane emissions treatment is thermal oxidation, including flaring. These exothermic reactions are self-sustaining at sufficiently high concentrations, but significant heat is required to sustain them at atmospheric concentrations. Air temperatures of >700°C are necessary, while estimates for cost-effective and net climate-beneficial operation limit the heating budget for atmospheric methane removal to 1-10°C [1]. 

Significant effort has been directed toward developing thermal catalysts to lower the temperature for oxidation to occur. With state-of-the-art catalysts operating at ~300°C [2], it remains necessary to recover heat from the treated air before discharge using a heat exchanger, for the above budget to be satisfied. 

To first order, a heat exchanger can be made with arbitrarily high efficiency to achieve the heating budget, yet with exponentially increasing capital cost [3]. Thus, the trade-off between efficiency and cost of the heat exchanger is a dominant constraint on feasible atmospheric removal using thermal oxidation.

Existing studies deem thermal processes climate detrimental [1] by assuming low heat exchanger efficiencies, or cost-prohibitive [4] by extrapolating traditional heat exchanger costs to high efficiencies. The unexplored non-linear trade-off between efficiency and cost is governed by heat transfer surface area. Lowering the specific cost of this area could enable climate-beneficial and cost-effective systems. 

The primary goal is to reduce this specific cost - the figure of merit - below the current $100-150 per m2 for large units [5, 6]. Application-specific optimization of traditional heat exchangers may allow significant progress toward enabling catalytic oxidation. The development of novel heat recovery approaches with cost below $10 per m² would further enable non-catalytic thermal oxidation of methane at costs competitive with CO₂ direct air capture. 

Both approaches will require detailed design requirements to constrain and guide development. Thus, a secondary goal is to define the relationships between reaction temperature, energy source, climate effect, mitigation cost, and thermal efficiency. 

This project aims to explore and advance the feasibility of applying thermal oxidation to atmospheric methane reduction by: 

• Articulating heat recovery design requirements that optimize the tradeoff between capital cost and thermal efficiency to enable cost-effective removal. 
• Benchmarking the current cost and feasibility of thermal approaches by evaluating the performance of a traditional heat exchanger after application-specific optimization. 
• Developing and experimentally validating a novel heat recovery concept specifically tailored to this application.