Is ethyl mercaptan's sulphur can add corrosive property of LPG?

Question

Ethyl mercaptan is added as odorant to LPG. Whether sulphur of Ethyl mercaptan can add corrosive property to LPG? Then why it is added?

Answer 1

Liquid mercaptans can be stored in metal drums for many years without any harm to the drum itself. While suphur is corrosive, the mercaptan is meant to be stored in metal structures.

Plastic will absorb the odorant and it will eventually cause the container to emit odors. This is why gas companies transport the liquid in metal containers, store it in metal containers, and ultimately have to dispose of the metal containers.

One property of the mercaptan is that it will adhere and invade any pore space on a near molecular level in the metallic container.

Answer 2

Mercaptan is used as an odourant because it can be detected in LPG and ng in very low quantities, typically 20 ppm. People have a very low odour threshold to mercaptan, so can smell it at very low concentrations.

While sulphur corrosion can a be problem at higher concentrations (say above 150 ppm elemental sulphur) the comercially available LPG and ng should have negligible amounts of water further reducing the corrosion risk.

Un odourised LPG and ng poses a greater risk for people inadvertently igniting an undetected gas cloud than the risk of corrosion induced equipment failure.

Answer 3

Mercaptan Sulphur