ARCHIVED REPORTS LEC APPLICATION FOR CERTIFICATION

Home Browse Search

5AC:EVALUATION OF BEST AVAILABLE CONTROL TECHNOLOGY Published prohibitory rules from the BAAQMD,SMAQMD,SDCAPCD,SJVAPCD, and SCAQMD were reviewed to identify the CO standards that govern existing natural gas-fired simple cycle combustion gas turbines. Of the five prohibitory rules reviewed, the SJVAPCD prohibitory rule for combustion gas turbines is the only one that includes an emission limit for CO (200 ppmv @ 15% 02). The applicable NSPS (40 CFR 60 Subpart KKKK) does not include a CO limit. 5.1C.1.2.1.1 Conclusions BACT must be at least as stringent as the most stringent level achieved in practice,required in a federal NSPS or district prohibitory rule, or considered technologically feasible. The proposed CO emission limit of 3 ppmvd @ 15% 02 on a 3-hour average basis is more stringent than the level currently considered BACT,but is expected to be achievable in practice. 5.1C.1.3 VOC Emissions 5.1C.1.3.1 Achievable Controlled Levels and Available Control Options Most VOCs emitted from natural gas-fired turbines are the result of incomplete combustion of fuel. Therefore,most of the VOCs are methane and ethane,which are not effectively controlled by an oxidation catalyst. However, oxidation catalyst technology designed to control CO can also provide some degree of control of VOC emissions,especially the more complex compounds and toxic compounds formed in the combustion process. Therefore, use of an oxidation catalyst is generally considered BACT for VOC. The CARB's BACT guidance document for electric generating units rated at greater than 50 MW5 indicates that BACT for the control of POC emissions for combined-cycle and cogeneration power plants is 2 ppmvd @ 15% 02. The BAAQMD's BACT guidelines specify that,for natural gas-fired combined cycle combustion gas turbines larger than 40 MW, a VOC limit of 2 ppmvd @ 15% 02 has been "achieved in practice." The SJVAPCD's BACT guidelines contained a determination for gas turbines rated at larger than 50 MW with uniform load and with heat recovery. The SJVAPCD concluded that a VOC exhaust concentration of 2.0 ppmvd @ 15% 02 constituted BACT that had been achieved in practice,while 1.5 ppmvd @ 15% 02 is considered technologically feasible. The SCAQMD database contains BACT determinations for VOC emissions from two natural gas-fired combined cycle combustion gas turbines at 2.0 ppmvd @ 15% 02. Published prohibitory rules from the BAAQMD,SMAQMD,SDCAPCD,SJVAPCD, and SCAQMD were reviewed to identify the VOC standards that govern existing natural gas- fired simple cycle combustion gas turbines. None of the prohibitory rules for combustion gas turbines specify an emission limit for VOC. The applicable NSPS (40 CFR 60 Subpart KKKK) does not include a VOC limit. 5 Ibid,Table 1-1. 5.1C 8 SAC/371322/082330016(LEC_5.1C_APPENDIX.DOC)