that the majority are formaldehyde.
Table 4-33. Controlled refinery emissions in lb/1000 ft3 of gas
Fluid Catalytic Cracking
Moving-Bed Catalytic Crackers
Fluid Cooking Beds
Vapor Recovery Systems
Power Plant Emissions
Emission factors for the generation of electricity using large controlled gas turbines are also given in AP-42. It is assumed that all power plant gas turbines in the South Coast use selective catalytic reduction with water injection as the emission control device. Emission factors from AP-42 are given in Table 4-34.
Table 4-34. Emission Factors for Large Controlled Gas Turbines in lb/MMBtu Fuel Input
Natural Gas IC Engine Exhaust
Natural gas-fired internal combustion engines are used in the natural gas industry at pipeline compressor and storage stations. These engines provide power to drive the compressors. At pipeline compressor stations, the engine is used to move natural gas from station to station. It is assumed that all pipeline engines in the South Coast are controlled. While AP-42 gives emission factors for these type of engines, better speciated exhaust emissions for natural gas IC engines can be found from Phase 2 of the Auto/Oil Air Quality Improvement Research Program. In this program, three CNG vehicles were tested on four different natural gas fuels. Both engine out and tailpipe were measured. Since pipeline engines are controlled in the South Coast but not to the level found in CNG vehicles, the engine out and tailpipe emission levels from the Auto/Oil program were ratioed at 25 percent/75 percent respectively. This gave emission factors for benzene that were close the AP-42 values. Engine-out and tailpipe emission factors from the Auto/Oil program are given in Table 4-35.