H2S Gas – You May Know it as Swamp Gas
You have most likely come into contact with hydrogen sulfide gas if you work in the oil refining, wastewater, textile, or agriculture industries. Hydrogen sulfide (H2S), also known as swamp or sewer gas, appears colorless but is a highly toxic and hazardous gas. It occurs naturally in oil wells, sewers, and decaying fertilizer pits, giving it a strong and pungent odor similar to that of a rotten egg. It has a boiling point of -60.2 °C and a density slightly heavier than air.
Hydrogen sulfide is an important intermediate material with widespread commercial application, particularly in the manufacture of fuels and fuel additives. It is also produced as a byproduct of various industrial processes, such as petroleum production, wastewater treatment, textile manufacturing, and pulp and paper processing.
H2S Monitors & Gas Detectors are Often Used in These Applications
Petrochemical Refineries: H2S as a Passivation Agent in Reactor Walls
Hydrogen sulfide dissolves easily in chemicals found in the petrochemical refining sector, such as gasoline, kerosene, and crude oils. In the petroleum industry, where equipment or facilities are typically constructed of metallic materials, corrosion is one of the most serious operational issues. Passivation work is done specifically on the metallic reactor walls to address this issue. Hydrogen sulfide is essential in the superficial sulfurization of these internal metallic components, allowing reactors to overcome corrosion threats during the hydrodealkylation process and even during high-temperature steam cracking tasks.
Furthermore, hydrogen sulfide aids in the formation of sulfide layers in steel plate and wire finishing operations as a preparatory step prior to coating with plastic or paint. H2S helps improve the coating capacity of steel plates and wires in the same way that it is used as a passivation agent in metals to prevent corrosion. Incorporating hydrogen sulfide into the treatment process improves not only coating resistance but also primer adhesion.
Steel Production and Metal Purification Tasks: H2S as a Potent Catalyst
Catalysts are important substances that aid in accelerating chemical reactions. Some catalysts used in tasks involving metals need their metallic constituent to be in a sulfide form in order to function optimally. The same is true for using a catalyst in steel production, where it must be pretreated with H2S before it can fully catalyze.
In contrast with its pivotal role in absorbing atomic hydrogen in steel during sulfide stress cracking, H2S cuts down catalytic activity in certain processes to limit carbon-containing deposits. To facilitate such catalytic activity, reforming catalysts are sometimes “poisoned” with a significant amount of H2S. For example, selective flotation used in purifying manganese and nickel ores needs a catalyst that has first been treated with hydrogen sulfide.
H2S Gas is a Precursor in Producing Laboratory Substances
The solubility of hydrogen sulfide makes it an ideal intermediate reagent for producing a wide array of laboratory chemicals. Hydrogen sulfide easily dissociates in polar organic solvents, including acetone, methanol, and glycol ethers. Given this nature of H2S, several organosulfur-containing substances can be produced from it.
The most prominent use of H2S can be found in forming organic compounds containing the thiol function (hydrocarbon groups) or the thiol group with another function (alcohols and acids). Examples of these organic compounds include thioglycolic acid, ethanethiol, and methanethiol. In addition, H2S is essential in the production of elemental sulfur and sulfuric acid.
H2S is a Byproduct of Several Industrial Activities
While H2S is predominantly used in many applications, it is also an abundant byproduct of several industrial activities. It results from certain processes in food manufacturing and brewing, in kraft paper mills, textiles that include ryon, and chemical pulping. It is also encountered in metal mining, leather tanning, rubber vulcanizing, asphalt production, and coke ovens.
In the energy-harvesting sector, traces of H2S gas can be found in biodigesters, electric power and geothermal power waste products. The majority of H2S gas -as a by product can be linked to petroleum refineries and gas explorations. It is also emitted from solid waste landfills, sewage treatment units, and wastewater sludge facilities.
H2S Gas Exposure in the Workplace
Given its wide range of applications, this gas has a higher potential for causing adverse effects in humans. Many workers are exposed to it primarily through inhalation and direct skin or eye contact. The severity of the risks is determined by the concentration of the gas, the work being performed, and the length of time the worker has been exposed.
OSHA has approved a number of state plans and occupational safety programs that must be strictly followed in many workplaces to avoid unwanted exposure incidents. The various exposure limits, symptoms, and effects, as well as the necessary first aid measures to take in the event of an accidental gas release, are all listed on their website.
Since H2S gas is heavier than air, it can accumulate over time in confined spaces, making it even more dangerous for people working in poorly ventilated, low-lying, or enclosed areas. At concentrations ranging from 0.0005 to 0.3ppm, some people can detect a “rotten egg” odor of this gas. However, this is frequently insufficient to alert the workers of its pervasive presence in the workplace.
Continuous exposure to even low concentrations of H2S gas can result in olfactory desensitization. It can eventually dull our sense of smell, making it difficult to determine the amount of gas present in our workplace solely by smell. Many people view hydrogen sulfide gas as a silent threat because its presence in the workplace can be imperceptible to bodily senses.
Hydrogen Sulfide Gas Detectors are Vital
Because hydrogen sulfide is toxic when inhaled and acts as an irritant and asphyxiant, H2S gas monitors are commonly used to warn workers of its presence. Installing permanent H2S sensing devices and wearing portable H2S gas detectors can definitely spell the difference between safety and danger. Sturdy sulfide gas detection systems with quick response protocols must be strategically placed where H2S gas exposure may occur.
Hydrogen sulfide gas detectors are early warning devices that use special electrochemical sensor technology to detect H2S gas in pre-specified concentration levels. When triggered, the device generates an alarm, alerting users that the air in their vicinity is unsafe.
Calibration Gas for H2S Gas Detectors
Safety begins with regular bump testing and the accurate calibration of H2S gas detectors. Calibration tasks should be performed with regularity, according to OSHA guidelines, especially if these devices are frequently found in harsh conditions. Before each shift, a bump test of the H2S gas monitor is required. This is done for at least a minute while the monitoring device is exposed to a known level of the gas and its response is monitored to ensure that it functions right.
When the bump test fails, calibration of the device must be performed as directed by the manufacturer. This is a technical procedure that ensures that the reading from the H2S gas monitor is accurate and responsive to the acceptable gas concentration limits. Gas detectors that are commonly used in the workplace can be configured to meet the needs of the client. Calibrating them frequently requires the use of compatible kits and accessories, as well as H2S calibration gas mixtures, which are typically prepared by credible gas blending specialists like Spec Gas Inc.
Get Your H2S Gas Blends for Bump Tests and Calibration Needs Here
Specifying the right concentrations of H2S gas mixture is critical to the success of your gas monitoring tool calibration. SpecGas, Inc offers dependable H2S gas mixtures for your varying bump testing and tool calibration needs. Our calibration gas canisters contain concentration blends ranging from 300 ppb up to 10% of the total volume ordered, which are perfectly compatible with the calibration tasks of most hydrogen sulfide gas detectors on the market. We do encourage you to check with the manufacturer for the desired concentrations before ordering. Contact SpecGas, Inc. with any questions you may have or when you are ready to place an order.