Technology for Power Plant Emission and Pollution Control
June 22, 2020 Welcome
From its discovery to date, the large-scale production of electricity has significantly revolutionized how we live, work, and play. Production of significant quantities of electrical power is impossible without the invention of power plants.
Despite their vital role in electrical energy production, like most industrial facilities, power plants release waste gases and other environmental pollutants. This frequently poses health risks to workers within the facility and residents within range of the power generating station.
In the US, the Environmental Protection Agency (EPA) has established standards for the maximum levels of emissions allowed by a power generating plant. Fortunately, there are various power plant emission control technologies available to operators which will be discussed further in this article.
Biggest Sources of Air Pollution
The main substances causing power plant air pollution can be categorized into mercury metal compounds, non-mercury metals, toxic gases, and particulate air contaminants.
Types of Power Plant Air Pollution
The major types of air pollution due to thermal power plants are:
- Acid gases
- Sulfur dioxide (SO2)
- Nitrogen oxides (NOx)
Health Effects of Power Plants and Air Pollution
These chemical compounds pose significant long-term health risks to exposed persons.
Environmental exposure to even low levels of mercury can have serious effects on the health of affected individuals. Ingestion or inhalation of this toxic metal via contaminated air or water will cause damage to almost anyone’s organ system and increase the lifetime risk of developing certain cancers.
Although arsenic is only harmful if a significant amount is ingested, prolonged exposure to the metal, for example in long term power plant workers has been linked to chronic liver disease, cancer, and mental health deficits.
While short term exposure to chromium will cause skin ulcers, respiratory tract irritation, and acute breathing problems, persistent exposure to the compound will increase the overall lifetime risk of developing nasal and lung cancers.
Soot which is particulate carbon generated from incomplete combustion of various hydrocarbon compounds is a major pollutant generated by power stations. While airborne, soot is virtually invisible however it will settle as a black film on any exposed surface. Soot is associated with acute breathing difficulties, worsening of asthma in susceptible persons, and occupation-related cancers.
What Is MATS
MATS or Mercury and Air Toxic Standards refers to a set of standardized guidelines published by the EPA to regulate emissions released into the environment from all power plants across the US. These regulations were introduced following concerns over the absence of a limit on emissions released by power generating stations especially older plants without emission control technology.
The MATS set power plant emission control standards for all coal and oil power plants using the Minimum Achievable Control Technology (MACT) standard.
How to Meet MACT Standard
To meet the EPA’s thermal power plant emission standards, power generation facilities must meet the following criteria:
- MACT for new sources of key pollutants must perform as well as the emission reduction achieved by the best performing comparable source
- MACT for already existing sources of key pollutants must perform as well as the emission reduction achieved by the top 12 best performing comparable source
Achieving a MACT standard is a two-stage process where the “MACT floor” is determined by considering pollution control from pre-existing sources and EPA regulation while considering costs and other variables. The time frame for older facilities to achieve MACT standards is typically 3-4 years.
E-reporting Your MATS Progress
In April 2020, the EPA proposed a special electronic tool for reporting on compliance with its pollution standards that allows facilities to report their MATS progress conveniently. The Emission Collection and Monitoring Plan System (ECMPS) client tool give power plant operators the ability to submit their reports in portable document format PDF until December 2023.
Types of Technology for Cleaning Up Power Plant Emissions
To comply with environmental regulations on power plants, operators have a wide range of technologies to help with their power plant pollution control. These techniques will eliminate both gaseous and particulate pollutants generated during the plant operation.
SCR (Selective Catalytic Reduction)
This technology is mostly used to control the levels of mercury produced by electricity generation plants. SCR is performed within specialized chambers where mercury oxidation occurs thus limiting its emission into the environment. Learn more about SCR for NOx reduction in power plants today.
FGD (Flue Gas Desulfurization)
This technology is used to reduce sulfur dioxide emitted from plants run on fossil fuels. While there are various methods to achieve FGD, the most popular techniques use a two-stage process of fly ash removal and SO2 removal. In addition to sulfur elimination, nitrogen oxides and particulate impurities can also be eliminated during FGD.
ACI (Activated Carbon Injection)
The use of ACI is arguably the most efficient and cost-effective way to minimize mercury, dioxins, and furans emissions from power generation stations. Activated carbon in its powdered form, provides a large surface area which permits increased pollutant absorption with a subsequent reduction in emissions up to 90%.
FF (ACI with Fabric Filters)
This modification to ACI permits further purification of emitted gases as it eliminates particulate matter from discharged air. This technology involves the use of filters within a baghouse to collect particles generated within the power station.
ESP (Electrostatic Precipitators)
Another technology effective in eliminating soot, mercury, and acid gases is the electrostatic precipitator. This device works on the principle of induced electronic charges to separate particulate matter from a gas stream in an energy-efficient manner.
DSI (Dry Sorbent Injection)
The injection of a dry alkaline gas into a stream of flue gas is a cheap but effective method of eliminating acid gases. The most used sorbent gases are sodium bicarbonate, hydrated lime, and trona (sodium sesquicarbonate).
IFS Has Reliable SCR Solutions for Power Plant Emission Control
Integrated Flow Solutions, as one of the leading process skid manufacturers in the industry, is committed to delivering the best emission control technologies available. For power plant operators hoping to stay compliant with EPA emission regulations, IFS provides modular skids to facilitate ammonia injection for NOx control.
Contact us online today to learn more about the full range of oil and gas industry solutions we provide.