Gas scrubbing and gas scrubbers explained
Gas scrubbing – also called gas absorption – is a process that brings gas streams into contact with liquid and allows some of the gas components to pass through the liquid using a gas scrubber. The function of a gas scrubber – also referred to as a gas absorber – is to eliminate harmful particulates and liquid hydrocarbons from natural gas by neutralising them via absorption. This gas management process limits the negative impact gas emissions have on the environment and people in its surroundings.
Scrubbing is used to manage dust as well as gases, and there are primarily two types of industrial scrubbers – wet scrubber systems and dry scrubber systems. Wet scrubbers are extremely effective when used as air pollution control devices that remove gas or dust particles from industrial exhaust streams and those emitted from mining activities.
Wet and dry scrubbing – the difference
Dry scrubbers extract and clear pollutants from industrial exhaust gases using sorbent, a dry reaction material like alkaline slurry, for example. They remove acid from gas as it transfers through the sorbent, maximising binding. They are also used in dust management and control applications.
Wet scrubbers, on the other hand, transfer contaminated gas via a liquid that removes pollutants. They are not only used for gas scrubbing purposes, but perform excellently as dust scrubbers, simplifying and enhancing dust suppression and control. Through their versatility, most wet scrubbers can eliminate up to 99% of airborne particulate.
Gas scrubber composition and advantages
A gas scrubber consists of three main components – an absorption section where the gas is exchanged, a demister and a pump-driven recirculation tank. Gas scrubbers that remove gas from working environments offer several benefits:
- Collect dust & absorb gas in a single scrubber unit (dual functionality)
- Reduces risks of flammable & explosive dust
- Serves as refrigeration for warm gas flows
- Neutralises corrosive dusts & gases
- Consists of relatively elementary technology
- Caters to a broad range of applications
- Facilitates compact installations
- Relatively easy to maintain
In most countries that have industries where employees are exposed to harmful gases, gas scrubbers are a legal requirement. When used optimally, a high removal efficiency of gas particles is achieved so only non-contaminated fumes reach the environment.