Formaldehyde formation in large bore engines Part 2: Factors affecting measured CH2O

Current research shows that the only hazardous air pollutant of significanc e emitted from large bore natural gas engines is formaldehyde (CH2O). A lit erature review on formaldehyde formation is presented focusing on the inter pretation of published test data and its applicability to large bore natura l gas engines. The relationship of formaldehyde emissions to that of other pollutants is described Formaldehyde is seen to have a strong correlation t o total hydrocarbon (THC) level in the exhaust, Ir is observed that the rat io of formaldehyde to THC concentration is roughly 1.0-2.5 percent for a ve ry wide range of large bore engines and operating conditions. The impact of engine operating parameters, load, rpm, spark timing, and equivalence rati o, on formaldehyde emissions is also evaluated.