Experimental investigation of influencing parameters on natural gas odor fading in gas distribution networks

Abstract

Natural gas is colorless-odorless which should be odorized to become detectable in the case of gas leakage. This odorizing step usually takes place in gas pressure regulation stations where proper amount of an odorant is injected directly into the high pressure gas stream. However in some cases, the concentration of odorant falls below the threshold level which cannot be detected using the sense of smelling mostly at the far end of distribution networks. In this research, different parameters affecting the odor fading of natural gas were investigated experimentally using a 10 in. Diameter steel pipe which is typically used in natural gas distribution networks. For this purpose, different scenarios comprising chemical reactions and physical adsorption of odorant molecules with iron oxide available on the inner surface of the steel pipe, probability of odorant settling down as liquid droplets within the pipe, and chemical reaction of odorant with solid particles collected by filter separators of the gas distribution network were explored experimentally. On the basis of obtained results, it was demonstrated that the chemical reaction of the odorant with iron oxide and exposure of natural gas to fine solid particles, would the main influencing factors on odor fading of natural gas.