Catalysis and related technologies and processes are essential in reducing greenhouse gas (GHGs) emissions and mitigating the related climate change effects. After a short introduction to catalysis and the general aspects of catalytic technologies for GHG abatement, the state of the art in reducing anthropogenic emissions of non-CO2 GHGs (N2O, CH4, fluorocarbons) is discussed. Although developments in this area regarding catalysts and catalytic technologies are still ongoing, this area fits within the general category of established and mature technologies. Catalytic technologies operate mainly as downstream cleaning technologies in stationary or mobile source emissions by converting the non-CO2 GHGs to not- or less-harmful chemicals: (i) N2 in the case of N2O; (ii) CO2 for methane, thus significantly reducing, but not eliminating, GHG impact; and (iii) chemicals without the strong C–F bonds present in fluorocarbons. For N2O, its reuse is also possible when large concentrations are present. The catalytic combustion for controlling methane emissions yields economic benefits due to the usually low methane concentration in its emissions. It avoids the formation of by-products in traces like formaldehyde, which may be more harmful than methane. Different relevant cases are discussed, particularly control of confined fugitive methane emissions (mines, waste treatment processes, natural gas processing) and elimination of unconverted methane in natural gas-fueled cars. The case of controlling unconfined methane emissions was also briefly discussed, along with the case of cattle emissions and the possibilities of methane capture from the air. The catalysts, their mechanism of action, and reactor options (regenerative catalytic combustion, reverse flow catalytic combustion, and catalytic combustion using a rotating concentrator) are discussed. The catalytic control of N2O emissions shows different specificities because different emission sources are present. The catalytic reduction or reuse of N2O from industrial emissions (particularly adipic and nitric acid production), the treatment of emissions from power plants or waste combustion, the alternatives of catalytic decomposition or reduction, and the role of the other gas components (O2, NOx, SOx) are discussed. In the case of the catalytic conversion of fluorocarbons (F-gases), catalysis plays a role in developing new paths to produce less-harmful chemicals, where the strong C–F bond is substituted by weaker bonds. There are also some studies on the catalytic conversion of fluorocarbons to inert chemicals.

Reduction of Non-CO2 Greenhouse Gas Emissions by Catalytic Processes

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发表日期：

2025年

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Gabriele Centi,
Siglinda Perathoner

摘要

Catalysis and related technologies and processes are essential in reducing greenhouse gas (GHGs) emissions and mitigating the related climate change effects. After a short introduction to catalysis and the general aspects of catalytic technologies for GHG abatement, the state of the art in reducing anthropogenic emissions of non-CO2 GHGs (N2O, CH4, fluorocarbons) is discussed. Although developments in this area regarding catalysts and catalytic technologies are still ongoing, this area fits within the general category of established and mature technologies. Catalytic technologies operate mainly as downstream cleaning technologies in stationary or mobile source emissions by converting the non-CO2 GHGs to not- or less-harmful chemicals: (i) N2 in the case of N2O; (ii) CO2 for methane, thus significantly reducing, but not eliminating, GHG impact; and (iii) chemicals without the strong C–F bonds present in fluorocarbons. For N2O, its reuse is also possible when large concentrations are present. The catalytic combustion for controlling methane emissions yields economic benefits due to the usually low methane concentration in its emissions. It avoids the formation of by-products in traces like formaldehyde, which may be more harmful than methane. Different relevant cases are discussed, particularly control of confined fugitive methane emissions (mines, waste treatment processes, natural gas processing) and elimination of unconverted methane in natural gas-fueled cars. The case of controlling unconfined methane emissions was also briefly discussed, along with the case of cattle emissions and the possibilities of methane capture from the air. The catalysts, their mechanism of action, and reactor options (regenerative catalytic combustion, reverse flow catalytic combustion, and catalytic combustion using a rotating concentrator) are discussed. The catalytic control of N2O emissions shows different specificities because different emission sources are present. The catalytic reduction or reuse of N2O from industrial emissions (particularly adipic and nitric acid production), the treatment of emissions from power plants or waste combustion, the alternatives of catalytic decomposition or reduction, and the role of the other gas components (O2, NOx, SOx) are discussed. In the case of the catalytic conversion of fluorocarbons (F-gases), catalysis plays a role in developing new paths to produce less-harmful chemicals, where the strong C–F bond is substituted by weaker bonds. There are also some studies on the catalytic conversion of fluorocarbons to inert chemicals.