The EPA has proposed approval of a new method for measuring total reduced sulfur (TRS) emissions from stationary sources. The EPA is making this method available for general use as requested by a number of source testing companies since it has been allowed for use in the past on a case-by-case basis for kraft pulp mills and refineries. According to the EPA, the proposed method would offer advantages over current methods in that real-time data are acquired and testers are allowed to use analyzers and procedures for measuring TRS that are commonly used to measure SO₂. The proposed method would offer an alternative to methods that are currently required.

The announcement is good news for petroleum refineries and some pulp & paper mills that typically measure TRS using older versions of Method 16 (normal, A and B).

Method 16C uses the sampling procedures of Method 16A and the analytical procedures of Method 6C to measure TRS. Total reduced sulfur is defined as hydrogen sulfide, methyl mercaptan, dimethyl sulfide, and dimethyl disulfide. As described in Method 16A, the sample is collected from the source through a heated probe and immediately conditioned in a citrate buffer scrubber. The conditioned sample is oxidized in a tube furnace to convert TRS to SO₂. The oxidized sample is then analyzed for SO₂ using a real-time SO₂ analyzer as prescribed in Method 6C.

Method 16C basically combines the = combustion process of Method 16A with the analytical techniques currently used for SO₂ to a new method for measuring TRS.

The method would become available as an option for use in connection with the New Source Performance Standards for kraft pulp mills and possibly petroleum refineries. The EPA allowed its use in approximately four tests over the past 10 years on a case-by-case basis and, based on those experiences, decided the method is a good alternative.

According to the agency, Method 16C "offers advantages over currently required methods by supplying real-time data in the field using analyzers and procedures that are currently used for other pollutants. Performance checks are contained in the method to ensure that bias and calibration precision are periodically checked and maintained."

The rule does not impact testing stringency; data are collected under the same conditions and time intervals as the current methods.

Comments must be received on or before Nov. 1, 2010. Read the notice in the Federal Register at: http://edocket.access.gpo.gov/2010/2010-21954.htm.

SOURCE: Federal Register