Evaluation of the Effects of Carbon to Hydrogen Ratio and Sulfur Level in Fuel on Particulate Matters From Micro Gas Turbine Engine

The present work investigated the effects of fuel components on particulate matter (PM) from a natural gas-fueled micro gas turbine engine. A variety of fuel compositions were prepared considering atomic ratio of hydrogen to carbon (H/C ratio) and sulfur level. In the first test, controlled amounts of propane were injected into natural gas to establish H/C ratios between 3.23 and 3.99. In the second test, fuel-bound sulfur was scrubbed and controlled amounts of methyl mercaptan were injected into natural gas to establish sulfur levels between 0.0 ppm and 12.9 ppm. Sonic orifices were used for H/C ratio and fuel sulfur management. In each test, PM was collected from engine exhaust and analyzed. In the second test, total gaseous sulfur in the exhaust was also measured to establish the ratio of PM and gaseous sulfur formed from fuel sulfur. Test result showed no correlation between H/C ratio and PM, and strong correlation between fuel sulfur and PM. 82.4% of fuel sulfur contributed to form gaseous sulfur and 17.6% contributed to form PM in the exhaust. An increase of 1.0 ppm fuel sulfur produced an increase of approximately 4.7μg/m³ PM. By removing fuel-bound sulfur, PM levels from micro gas turbine engine exhaust are comparable to ambient levels of PM.