Since natural gas is naturally odorless and colorless, monitoring industrial processes that use natural gas can be difficult. Natural gas is both toxic and combustible, making potential gas leaks a major risk for any environment. This where natural gas odorization plays an important role in protecting your personal health and manufacturing equipment.
In 1937, the unauthorized use of non-odorized gas at a New London Texas school caused a tragic explosion and fire that killed 294 people, both students, and teachers. Following the accident, federal authorities came together and determined that injecting odorous chemicals would help prevent a similar event from happening in the future. These regulations currently require gas companies to inject sufficient odorant such that a person with a normal sense of smell can readily detect a natural gas leak.
Natural Gas Odorants
Before understanding the process behind gas odorization, it’s important to review the common types of natural gas odorants. Since natural gas is completely undetectable by the human nose, chemical compounds are added to gas streams to create an odor. The most common odor associated with natural gas is “rotten eggs”, which is often attributed to the chemical mercaptan.
In its organic state, mercaptan has chemical properties similar to natural gas, making it a versatile odorant. However, depending on the application and particular environment, gas companies may use odorant blends of various organic sulfur and non-sulfur compounds. These may include tertiary butyl mercaptan, tetrahydrothiophene, isopropyl mercaptan, dimethyl sulfide, and methyl ethyl sulfide.
Gas Odorization Technology
Natural gas distribution companies consider ambient temperatures, soil conditions, and pipeline age when selecting the best odorant blends for their area. Because they are extremely concentrated, and because even the slightest leaks can lead to a large number of gas leak reports, liquid odorants must be handled properly. Many odorant manufactures will deliver the chemicals by truck or transportable containers designed to eliminate any leakage.
Within the natural gas industry, there are three odorant injection technologies:
- Wick Style – Odorant is allowed to saturate a specially-designed wick suspended in a gas stream; odorant evaporates into the stream at a fixed rate. Wick-type odorizers are generally used in smaller applications where gas flow is relatively constant.
- Drip System – Odorant is gravity-fed through a needle valve and drips into the gas distribution pipe. The rate of flow is usually computer-controlled and varies by the amount of gas flowing in the pipe.
- Injection System – Odorant is injected into the gas pipe using an electrical pump or pneumatic pump. The injection rate is also computer-controlled and varies as the gas flow increases or decreases.
Pro Tip: Learn the correct terms! An odorant is the type of chemical being injected into the gas stream, and an odorizer is the type of equipment used for the process.
Monitoring Odorant Levels
To adhere to federal regulations, gas companies must maintain detectable gas odorization levels at one-fifth of the lower explosive limit. Proper monitoring of odorant levels is critical, as too little odorant provides insufficient protection, and too much can result in widespread gas leak calls by industrial and residential consumers. GDS Corp offers two families of odorant monitors to protect your gas pipelines:
- GDS-68SXP Advanced Natural Gas Odorant Monitor – Advanced remote odorant monitor designed for unattended, low-power operation. Supports automatic calibration, remote satellite monitoring and more.
- GDS-68XP Natural Gas Odorant Process Monitor– Process monitor designed to measure H2S. mercaptans and other gases in process flow applications. Uses low-cost electrochemical sensors and minimizes the amount of gas released into the environment.
Protect Your Employees and Equipment
Gas odorants play a critical role in protecting customers’ lives by ensuring that natural gas leaks are detected and repaired before hazardous conditions exist. Whether it’s injecting gas odorants, or monitoring gas odorant leaks around gas odorizing equipment, it’s crucial for your facility to have a reliable gas detection system.
Connect with our sales team to find a detection system customized for your specific environment.