Development Of Test Technologies For Vehicle Gasoline Detergency And Evaluation Of Reduction Potential Of Vehicle Exhaust Emissions With Gasoline Detergency Improvement

Improving vehicle gasoline quality effectively reduces vehicle emissions. Detergency is a key environmental protection property of vehicle gasoline. Improving gasoline detergency can help reduce engine deposit formation and emissions. Knowledge of the use of gasoline detergent for a region and its quantitative impact on vehicle emissions are of great importance for fuel quality management and the accuracy of emission inventories and air quality simulation.Based on engine tests, simulation tests and test parameter optimization, this study develops a fast simulation test method, a lean oxygen gum simulation test and establishes a correlation between the M111 engine test standard and simulation tests such as the deposit plate test and lean oxygen gum simulation test. These tests provide important test technologies for large-scale regional investigation of gasoline detergency rapidly and with greatly reduced cost. Based on the quantitative relationship between the M111 test and the deposit plate test and its deposit pattern analysis, gasoline detergency in Beijing and 6 central cities including Shijiazhuang is tested and analyzed.50.7% of Beijing gasoline samples have effective detergency, 26.8% samples are inadequately additized with detergent and 22.5% samples contain no detergent additives.All of the samples from the 6 central cities are unadditized and of poor detergency.This study further investigates the impact of engine deposits on vehicle emissions using Chinese gasoline for in-use vehicles. With the removal of engine deposits from vehicles with heavy deposit accumulation, HC emissions drop 29.4% under hot running cycles; cold start CO emissions are reduced by23.0% and hot running CO emissions fall by 35.5%. This study establishes a quantitative relationship among the deposit plate test, M111 test, fleet deposit test and the amount of fleet emissions. Emission reduction in Beijing and nationwide is evaluated with 4 detergency scenarios. The highest reduction in Beijing of HC could be 9.4 thousand tons and of CO 100.0 thousand tons with top detergency. Nationwide reduction could be 518.0 thousand tons and 6.7million tons of HC and CO, respectively. Results show that improving gasoline detergency greatly reduces pollutant emissions of gasoline fueled vehicles.