Emissionsrening

Emissionsrening refers to processes and technologies designed to remove pollutants from exhaust streams to reduce environmental and health impacts of air emissions. It covers both stationary sources (power plants, industrial facilities) and mobile sources (vehicles). The aim is to lower emissions of sulfur oxides, nitrogen oxides, particulate matter, volatile organic compounds, and greenhouse gases, depending on regulatory requirements and technology options.

Key technologies include gas cleaning and scrubbing to remove acid gases (wet and dry scrubbers for SO2 and acid gases), selective catalytic reduction (SCR) and selective non-catalytic reduction (SNCR) for NOx; particulate control with electrostatic precipitators or fabric filters; VOC control with activated carbon adsorption and catalytic oxidation. For CO2 and other greenhouse gases, carbon capture and storage (CCS) or direct air capture is used, with post-combustion or pre-combustion approaches.

In vehicles, emissionsrening is achieved with catalytic converters and diesel particulate filters; in industry, scrubbers, precipitators and oxidizers are used to meet permit limits. The choice of technology depends on gas composition, flow rate, required removal efficiency, cost, and energy penalties.

Regulatory frameworks such as the EU Industrial Emissions Directive, the US Clean Air Act, and international accords drive deployment. Implementation challenges include capital cost, operating costs, energy use, and by-products management.

Ongoing trends include integration with energy efficiency, retrofit of existing plants, and combination with carbon capture for decarbonization, as well as monitoring, automation, and performance verification.