Opinion ID: 771458
Heading Depth: 2
Heading Rank: 3

Heading: Chemical Composition of Synthesis Gas Burned in the Stationary Gas Turbines

Text: 61 Although our determination that Subpart J does not apply here frees us from having to determine whether the synthesis gas to be burned by the stationary gas turbines is a fuel gas regulated under Subpart J, we do note that the chemical composition of the synthesis gas is markedly different from the chemical composition of other fuel gases, the burning of which is subject to regulation under Subpart J. As the petitioners highlight in their brief, and as the regulatory history of Subpart J suggests, the exclusive focus and purpose of Subpart J is the reduction of sulfur emissions (specifically sulfur dioxide (SO2) emissions) by limiting the amount of hydrogen sulfide (H 2S) in combustible fuel gases combusted in petroleum refineries. According to Motiva, a not insignificant amount of the sulfur/SO2, emitted when the synthesis gas at issue is combusted in these turbines, comes not from H 2S in the synthesis gas but from COS in the synthesis gas. 62 Regardless of the exact source of the sulfur/SO2 emissions, it appears from the record that at least some of the sulfur/SO2 emitted when the synthesis gas at issue is combusted comes not from H2S in the gas but rather from COS in the gas. As mentioned above, compliance with Subpart J can be established either by measuring and monitoring the H2S level in the fuel gas prior to combustion or by measuring and monitoring the SO2 level in the emissions after combustion. See supra, note 4. If subject to regulation under Subpart J, Motiva is without a legally acceptable method for measuring the combined concentration of COS and H2S in the pre-combustion synthesis burned at the Repowering Project. Therefore, Motiva will be forced either to monitor and reduce the emission of SO2, or to monitor and control the level of H2S in the pre-combustion synthesis gas being combusted at the Repowering Project (rather than the level of H2S and COS in the pre-combustion synthesis gas), even though by itself, the level of H2S in the synthesis gas being combusted is an arguably poor and clearly inferior measure of Motiva's compliance with Subpart J. As the EPA points out, the unique chemical composition of the synthesis gas, in and of itself, does not and would not exempt the stationary gas turbines at issue here from regulation under Subpart J. This composition may suggest, however, that another regulation, for example, Subpart GG, 15 regulating stationary gas turbines, rather than Subpart J, may be the appropriate regulation under which to regulate emissions from these gas turbines. The discontinuity between the chemical composition of synthesis gas to be combusted at the Repowering Project and the chemical composition of other fuel gases, the combustion of which is subject to regulation under Subpart J, also suggests that the EPA's determination is inconsistent with the regulation at issue and should be set aside. 16 63