The transportable elemental sulfur reactor is used to convert the elemental sulfur in the side stream of a flowing gas stream into an easily detectable molecule. This is accomplished by sampling a representative portion of the natural gas stream and bubbling it through a chemical reaction of Triphenilphosphine (TPPS) in a solution of Dimethylformamide (DMF) that selectively reacts with crystals of elemental sulfur. Liquid samples extracted from the transportable elemental sulfur reactor are injected in to the elemental sulfur GC (HP 5890 w/ Sievers 350 SCD). All sulfur compounds are separated by means of a capillary column and directed in to a flameless burner to form sulfur oxide. The sulfur oxide will then react with ozone resulting in the formation of sulfur dioxide, oxygen, and an emission of light. The light emitted is detected by a photomultiplier tube and turned in to an electrical signal proportional to the concentration of sulfur in the sample. The concentration of TPPS is equivalent to the concentration of elemental sulfur found in the gas. Very low levels of S8 are being determined by this method (LDL ~-.1 mg S8/300 ml solution, 0.0001 lb/MMscf and potential 0.34 lb./MMscf). It is very important that any contamination with sulfur be strictly avoided.
Elemental sulfur impacts the quality of pipeline natural gas and deposits on pipeline flanges, fittings and valves, thereby, impacting their performance. Natural gas suppliers and distributers are in need of a standardized test method for measuring elemental sulfur. Some government regulators are also interested in development of this test method since it would provide a means for assessing the contribution of elemental sulfur in pipeline natural gas to the SOx emission inventory from burning of natural gas.
KeywordsPipeline, gaseous fuels
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Ballot Item Approved as D7800-2014 and Pending Publication