Odorierung

Odorierung is the deliberate addition of a distinctive odor to a gas or liquid to enable leak detection by smell. It is most commonly applied to natural gas and liquefied petroleum gas (LPG) to make leaks noticeable before they reach hazardous concentrations. The practice originated in the early 20th century and became widely adopted after gas-disaster events highlighted the dangers of odorless fuels.

In natural gas systems, odorants are sulfur-containing compounds with very low odor thresholds. The most common agents are tert-butyl mercaptan and ethyl mercaptan, often used in blends that may include dimethyl sulfide or related compounds. Odorants are chosen for stability, compatibility with materials, and a reliable, easily recognizable scent. They are added at trace concentrations, calibrated to produce a detectable but not overpowering odor under typical operating conditions.

The odorization process involves injecting odorant at controlled points in the supply chain, usually near gas distribution or processing facilities. Metering and monitoring equipment ensure a consistent odor strength throughout the network. Odorant performance can be affected by factors such as pressure, temperature, and gas composition, and some removal or masking can occur in filters, scrubbers, or certain end-use equipment.

Regulatory and standards framework governs odorization practices. Many jurisdictions require odorization of pipeline natural gas and set targets for odor strength, odorant purity, and testing methods. Dynamic olfactometry and related techniques are used to assess odor intensity. In addition to natural gas, odorization is applied to biogas and other fuel gases to maintain leak detectability when feedstocks are odorless.

Challenges include potential sensitivities among some individuals and the need to balance odor strength with nuisance or fatigue. Overall, odorization remains a key safety measure to prevent gas leaks from going undetected.