NACE Requirement

The Jamesbury document here:

http://info2.jamesbury.com/requests/download/downloaddoc.aspx?docid=T101-4

goes through an example of determining the mol%H2S. Good reading!

Hi Carl E,

Thanks ... Informative document....

"NACE Requirement" is too vague.

As per NACE MR0103-2007:

1.3.5.1 Some environmental conditions known to cause SSC are those containing an aqueous phase and:

(a) >50 ppmw total sulfide content in the aqueous phase; or

(b) 1 ppmw total sulfide content in the aqueous phase and pH <4; or

(c) 1 ppmw total sulfide content and 20 ppmw free cyanide in the aqueous phase, and pH >7.6;

(d) > 0.3 kPa absolute (0.05 psia) partial pressure H2S in the gas phase associated with the aqueous phase of a process.

1.3.5.1.1 The high-pH sour environments differentiate refinery sour service from the oil and gas production sour environments covered by NACE MR0175/ISO 15156, because many wet sour streams in production also contain carbon dioxide and hence exhibit a lower pH. Another major difference is that chloride ion concentrations tend to be significantly lower in refinery sour services than in oil production sour services.