What is natural gas odorization?
Odorization is the process of introducing an odorant into a gas stream to make the gas detectable through smell. This technique occurs for safety reasons.
While most people associate natural gas with a rotten egg smell, what causes the strong odor is natural gas odorant. Contrary to what most people believe, natural gas in its natural state is tough to detect, given that it is odorless. Being an extremely volatile hydrocarbon and not easy to recognize – it makes a dangerous combination.
Why do we Odorize Gas?
One of the processes in natural gas transmission and distribution is gas odorization, which adds an odorant to natural gas so people can smell it. The impetus behind odorizing natural gas goes back to one of the worst tragedies in U.S. history. In 1937, in London, Texas, natural gas ignited and blew up a school, killing nearly 300 children and teachers. Following the accident, Texas and other states adopted standards to regulate the odorization of natural gas. The natural gas industry goes through great efforts to safely deliver this fuel from the wellhead to the burner. Today, federal regulations mandate the odorization of natural gas.
Odorant Level in Natural Gas
When introducing trace amounts of organic sulfur compounds into portions of gas transmission and gas distribution lines, the gas smells. How much odorant is added to the gas? The regulations state that distribution lines of any combustible gas contain a natural odorant, “so that at a concentration in air of one-fifth of the lower explosive limit, the gas is readily detectable by a person with a normal sense of smell.” A combustible gas in Class 3 or Class 4 locations must meet odorization levels with some exceptions spelled out in the regulations for transmission lines.
Given that the lower explosive limit for natural gas is approximately 5%, the gas must be detected by smell when the gas reaches around 1% of gas in the air. According to experts in the field, combusting the odorized gas does not create any severe sulfur content or toxicity problems. Also, odorants are considered nontoxic at the minuscule concentrations that an end-user may encounter.
Odorant Injection Systems Distributor
Linc Energy Systems is a master distributor of GPL Odorizers, the manufacturer of odorant injection systems. The instrumentation accurately doses natural gas streams throughout various production phases, transmission, and distribution with odorants belonging to a group of organosulfur compounds. It is these compounds that give natural gas its distinct odor, as mandated in federal safety guidelines.
Smell Gas? Or not?
In my post “Natural gas leak detection and what to do,” I discussed methods of detecting, isolating, and what to do in the event of a gas leak. While in What is odor fade? we discuss the reasons why you may not smell gas.