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Emission Control Systems
Emission control systems are devices that monitor and diminish harmful byproducts of combustion and other processes that, without these systems in place, would be released into the atmosphere. Industrial processes, such as combustion, emit unburned hydrocarbons, carbon monoxide and oxides of nitrogen and sulfur among other harmful pollutants.
Emission control systems can convert these contaminants into water vapor and carbon dioxide which may be safely released into the environment or recirculated. Particulate and gaseous emissions pose a threat to cardiovascular and lung health in humans and animals. This pollution can also have serious environmental repercussions as they increase ozone depletion. Regulatory agencies, such as the EPA have placed strict limitations on acceptable emission levels or amount of pollutants that can be released into the environment. In order to comply, a wide range of industries are now using emission control systems. Automotive, pharmaceutical, medical, microelectronic, bio-safe labs and aerospace industries are just a few who employ these systems to decrease harmful byproducts. While the EPA sets a strict standard, state law dictating acceptable emissions varies. Many facilities employ continuous emissions monitoring systems to aid in the control and monitoring of harmful discharges for easy reporting to federal and state supervisory committees.
A variety of systems for managing emissions from different sources have been developed. VOC abatement systems are popular as are air filtration systems. Industrial emission control often entails the installation of large equipment, though it is not necessarily complex. Wet scrubbers and air scrubbers involve the installation of pools or streams which attract and remove particulates from the air as do many other air filtration systems. Both catalytic and thermal oxidizers are used to break down pollutants and purify the air by heating the materials to extreme temperatures. Those systems using incendiary temperatures often use heat recovery systems to help offset the cost of operations. Contaminants caught by mist collectors and other such devices may also be recycled for reuse. In this way the air pollution control industry benefits not only the environment and safety of workers, but often the company as well. The type and level of emission control system required in each setting depends largely on the quantity and specific composition of an air stream. Systems may be as small as an automotive catalytic converter or a massive scrubber atop a smoke stack. Early emissions control systems were simply add-on components that solved a particular emission need. While add-ons are still used today, products and factories often have built in emission control systems that have become a significant part of the combustion and manufacturing process.
Emission Control Systems - Anguil Environmental Systems
Emission Control Systems - B&W MEGTEC
Understanding the Use of Emission Control Systems
Ever since the EPS and other government agencies have reported on the adverse of effects of hazardous air pollutants (HAPs) on human health, the U.S. population has embraced stricter regulations and committed to broad-scale pollutant control. The toxic pollutants released by the stationary sources have proved to be oncogenic agents and mutagens, which can cause birth defects and can alter the environmental adversely. A long list of 187 toxic contaminants directly affects us, according to the EPA.
To combat the effects of contaminants, various types of air-pollution control measures have been adopted across a number of industries. These changes have resulted from the efforts of government agencies as well as citizens who seek out technologies to control air pollutants.
The main functionality of pollution control equipment is to protect outdoor air quality, which involves controlling particulate matter, sulfur dioxide, carbon monoxide, oxides of nitrogen, along with volatile organic compounds of carbon and hydrogen. Emission control equipment categories include scrubbers, electrostatic precipitators, specialized air filters, dust collectors, recycling equipment, and oxidizers. However, each equipment type is designed for controlling specific contaminants—there is not a single solution that can control all contaminants.
For controlling particulate matter and volatile organic compounds, basically, two types of techniques are used: absorption and oxidation.
Scrubbers are a group of air control devices that are administered when particulate matter and organic compounds need to be removed from an industrial exhaust airstream. The most common type of scrubbers is wet scrubbers that use liquids—mainly water, though for different application specialized solvents are used—to scrub the contaminants from an exhaust stream, with the help of a nozzle in a chamber. The most modern scrubber designs—dry scrubbers—use dry slurry to wash off the acid gases from an exhaust stream.
What determines the efficiency of scrubbers?
Two factors determine the removal efficiency of a scrubber:
- Residence time of the gas stream in the scrubber
- Area of contact between the contaminant and solvent
The oxidation process, in essence, is combustion of volatile organic compounds and related hazardous compounds into water and carbon dioxide. In the simplest of the thermal oxidizer, incompletely burned hydrocarbons and organic compounds fumes are incinerated with the help of an afterburner. Direct-flame oxidizers work similarly, however, they do not need auxiliary fuel for oxidation, as the air stream has enough concentration of volatile compounds that work as a fuel, making self-sustaining system. However, sophisticated oxidizers systems are available that not only oxidize the compounds but also reclaim heat for other purposes. Some oxidizers may need catalysts to increase the rate of reaction—this type of oxidizer is called a catalytic oxidizer.
What determines the efficiency of oxidizers?
- Resident time of the gas stream
- Airflow rates of the stream
To know if an oxidizer is working appropriately, these four factors are monitored by monitoring equipment.
Other than absorption and oxidation, a phenomenon called adsorption is also used for controlling emissions. It is commonly used in activated carbon systems.
How to Choose an Efficient Emission Control System
In today's industrial landscape where compliance standards are getting stringent, installing an efficient and effective system for air pollution control is necessary for a wide range of industries. However, given the overwhelming options of hardware for air pollution control, selecting an efficient system is proving to be a daunting task.
Installing a custom hardware for air pollution controlling depends on many variables and factors, including:
- The quantity of air pollutants
- The volume of the pollutants being exhausted
- Technology and design of an equipment
- Type of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs)
- Destruction requirements and energy demands
This is the primary information that you need while deciding which system will be suitable from a multitude of options available, such as thermal oxidizers and catalytic systems, including regenerative thermal oxidizer and conventional catalytic oxidizer, flares, and vapor combustors, etc.
The secondary factors that you have to consider for an efficient system are:
- The type of production process emitting the air pollutant to be controlled
- The geographical location and its effect on the system
- The number of hours a system will be operated
- The number of emission points to be controlled by the air pollution control system
- Temperatures and exhaust rates for individual emission points
These factors will give you a clear picture of your need, and will prove to be important factors for making a decision.
With modern equipment incorporating air filtration systems and vacuum cleaners etc., installation of a new system is worth the investment. However, retrofitting can also be considered a good option, such as installing a secondary recovery unit and other modern equipment. Relatively, all air pollution control technologies are expensive; you need to contemplate thoroughly before making the decision, plan well and invest time to get the best results.
Effective Ways for Industrial Pollution Control
Pollution is an outcome of almost all industrial processes, whether it is sourcing and sorting of raw materials, production of goods, or even management of wastes. Industries, despite the fact that they have played a key role in the progression of human kind, cast a serious threat to the environment that we live in. Industrial procedures can potentially contaminate soil, air, and water by releasing a variety of toxic elements. Practical steps and avant-garde technologies can help effectively reduce the rate of pollution.
The below descriptions talk about a number of up-to-the-minute appliances that industries can make use of to lower the emission of poisonous elements into the atmosphere. These are some of the best technologies for effective water, soil, and air pollution control –
Emission Control System – This mechanism can control the supply of poisonous gases into the environment. Commonly found built in automobiles and in commercial chimneys, this utility is a useful solution for industries. Affixing it with their exhaust stream can keep their carbon and sulfur emission under control. The term--emission control system—is broad in meaning and covers a great many devices and techniques.
Air Filters – Characteristically, air filters are a type of air pollution control device; however, it’s working mechanisms differ from other pollution control machines. When we talk about air filters, it is usually about the basic ones. The elementary air filters have a fabric furnace, through which the air or liquid stream is passed, and the contaminants are trapped or filtered by the furnace. Many other variations of air filtration systems are also deployed by manufacturing businesses to clean their exhaust stream.
Vacuum Cleaners – These are common household items; however, there are industrial vacuum cleaners too. The commercial machines, needless to say, are more powerful than their domestic counterparts are. These machines can perform more controlled and heavy cleaning of dust particles. To put it more simply, industrial vacuum cleaners can remove dust, particulate matters, and even some gaseous and solid elements that can contaminate industrial products.
Air Scrubbers – This apparatus cleans the dry and moist air stream by power scrubbing it. They can be labeled as a portable air filtration device. Scrubbers are an inexhaustible machine that continuously cleans the air supply being discharged by a manufacturing plant. The exhaust stream contains several contaminants that have a dreadful influence on the environment. Air scrubbers break those elements into micron-size particles or make them ineffective. The process promotes safety for all procedures.
Odor Control Systems – Chemical plants and mining sites experience a bad odor just about every day. The odor comes out from the exertion of chemicals and gases. At times, it is just a mixture of gases that can cause serious side effects to people working on the site if came into prolonged contact. Therefore, chemical plants and mining sites can install odor control systems to maintain a pleasant atmosphere on their work sites. This system requires the support of proper ventilation and air processing units.