Glossary
Standards and regulations
Mercury and Air Toxics Standards
Also known as MATS, Mercury and Air Toxics Standards.
MATS (Mercury and Air Toxics Standards) is the US EPA's rule setting national emission limits for mercury, acid gases and other hazardous air pollutants from coal-fired and oil-fired electric utility steam generators. Promulgated in 2012, MATS drove substantial retrofit investment in US power-plant pollution control through the 2010s.
Industrial implications
MATS compliance often requires retrofitting:
- Activated-carbon injection for mercury
- Dry sorbent injection or wet FGD for acid gases
- Higher-efficiency baghouses or upgraded ESPs for particulate-bound metals
- Continuous emissions monitoring upgrades
Sonic horns installed during MATS-driven retrofits help maintain the achieved compliance margin over the operating cycle — preserving ESP/baghouse performance against the fouling that would otherwise erode it.
Related terms
Related terms
- EPA New Source Performance StandardsEPA NSPS set emission limits for newly constructed and significantly modified industrial sources. Subpart D / Da / Db cover steam-generating units; many other subparts cover other sectors.
- Electrostatic precipitatorAn ESP removes particulate from flue gas by charging dust and collecting it on plate electrodes. Sonic horns are widely used to dislodge ash from plates and to keep hoppers from bridging.
- BaghouseA baghouse is the structural enclosure that holds the bags, cages, tubesheet, cleaning system and hoppers of a fabric-filter dust collector. Sized in compartments for online isolation.