Hydrogen sulfide gas
is a naturally occurring chemical compound that is created in nature with the decay of organic material. It is a chemical compound with a molecular formula comprised of (2) Hydrogen atoms and (1) one Sulfur atom. The formula is displayed as H2S. The gas is a colorless hydride gas and is often known as the “Rotten egg gas”. H2S is very dangerous as it is poisonous and toxic to all forms of life. It is also very corrosive and is flammable. The molar mass is 34.1 g/mol and it has a melting point of -76 F (-60 C) and a melting point of –115.6F or (-82C).
Hydrogen sulfide gas is also created more often from a byproduct of a manufacturing process or from the removal of water or waste water treatment systems.
In waste water as organic material decays H2S is released and must be captured and treated to protect both human lives, reduce corrosion, and reduce odor complaints. During the manufacturing operations at refineries, pulp mills, and mining hydrogen sulfide gas is produced. These higher levels of H2S are released during the manufacturing process and must be captured and neutralized to protect human life and prevent excessive corrosion. At higher concentration you cannot even smell the gas and it is not distinguishable as the “rotten egg” which makes it even more dangerous and drives the need for equipment known as Hydrogen Sulfide Scrubbers, Fume scrubbers, or Odor Control Scrubbers.
According to the “Agency for Toxic Substance & Disease Registry”
people who work within certain industries are exposed daily to higher levels of Hydrogen Sulfide gas than the normal public. Because the gas is also heavier than air it will settle into lower places like manholes, tanks, basements and it will travel across the ground filling in low level areas. To protect the public OSHA has set guidelines and rules known as “Permissible Exposure Limits” (PEL). A PEL is the legal limit a worker may be exposed to a chemical substance. The PEL limit for Hydrogen Sulfide is ten parts per million (10 ppm) over an eight-hour period.
Exposure to low levels of H2S can cause burning eyes, sore throat, coughing, and shortness of breath.
Longer exposure can cause more servere conditions like inflammation of the eyes, headaches, blurred vision, fatigue, insomnia, and even weight loss. The problem associated with understanding and calculating how much Hydrogen Sulfide is too much is that when measuring levels in a liquid like water you may record 4-5 0r 7 PPM and when degasification of the water occurs to remove the H2S you must calculate the “weighted average” of the amount of pounds per minute, per hour, and per day that will be removed during the degasification process because you will quickly see that in this example a person will exceed the PEL limit in less than an eight hour period even though the water quality sample was below the 10 PPM.
By using a Hydrogen Sulfide Scrubber, you can
neutralize the harmful gases well below the PEL levels. DeLoach Industries Inc. manufactures a wide range of Hydrogen Sulfide scrubbers which capture and treat the gas to neutralize it before venting it to the atmosphere. Often scrubbers are referred to as Odor Control Scrubbers or Fume Scrubbers. This is because it is very common for other types of gases like methane or other chemicals to also be present in the gas stream which are also treated and neutralized.
Hydrogen Sulfide scrubbers are comprised of a vertical tower or two towers in series. The towers are typically made from fiberglass because of its ability to withstand the corrosive conditions. However on higher temperature scrubber’s carbon steel and stainless steel can be utilized with special coatings and conditions. The DeLoach Industries Hydrogen Sulfide scrubbers are engineered for maximum removal efficiency and with operation and maintenance in mind. And with the use of AI "Artificial Intelligence" a much more cost effective design. They're 60 years of design and manufacturing experience has proven to produce reliable water treatment systems and hydrogen sulfide scrubbers. The dangerous H2S gas enters at the bottom of the vertical tower which contains water and often a neutralizing chemical agent like chlorine or caustic.
Higher concentrations often require two passes through two hydrogen sulfide scrubber towers in series.
The first hydrogen sulfide tower would be equipped with recirculation pumps that pump chlorinated water produced by injecting sodium hypochlorite into the stream or the base of the tower. This liquid is pumped up to the “distribution” system of the tower. The distribution system evenly sprays the liquid over a media bed located inside the tower and gravity allows the liquid to cascade down across the media bed as the toxic gases travel upward in a counter current fashion.
The chlorinated water reacts with the hydrogen sulfide forming elemental sulfur precipitates material that is later removed during a waste blow down process. To assure all removal of the Hydrogen sulfide gas a second tower is utilized with a similar recirculation system but instead of chlorine it will often utilize a caustic (NAOH) as a polishing method to ensure all hydrogen gas is removed from the air stream.
For more information of Hydrogen sulfide scrubbers and the treatment of hydrogen sulfide gases visit the professionals at www.DeLoachIndustries.com or call them at (941)371-4995.
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