Folks;
I am looking for mercury specs adopted in the oil and gas industry. Does anybody know maximum values established for natural gas, LPG and naphtha, for example ?
Regards,
Luiz Silva
I've recently had cause to review a dozen different (mainline) pipeline tariffs from around the world and none of them set limits for mercury. I recall from the old old days when we had mercury manometers for dP measurement that gathering agreements sometimes had mercury specs, but those contracts have largely expired decades ago. I don't even remember the numbers, just that the contracts mentioned mercury. Sorry.
i recall that natural gas qualities contained in a FERC approved tariff is the one that is enforced. FERC approved tariffs are different for each company submitting the filing.
Typically, the spec is 10 ng/Nm3 (0.01 µg/Nm3) for natural gas upstream of cryogenic units.
For sales gas (pipeline), it can vary from 10 ng/Nm3 to 20-30 µg/Nm3, typically 1-5 µg/Nm3 but depends on the buyer.
For naphtha, LPG and ethane, the spec is typically around 1-5 wt ppb, depending on what the product is used for.
To reach this specification, solid adsorbents can be used. Metal sulphide on alumina last longer.