ABSTRACT
Based on the typical city survey data and statistics of Guangdong Provinceï¼ a 2018-based 3 km×3 km gridded greenhouse gas emissions inventory was developed for Guangdong Province using the combination of top-down and bottom-up emission factor methods. The inventory covered the CO2ï¼ CH4ï¼ and N2O emissions from energyï¼ industrial processesï¼ agricultureï¼ land use change and forestï¼ waste managementï¼ and indirect sources. The results showed that estimates for CO2ï¼ CH4ï¼ and N2O in Guangdong Province for the year 2018 were 8.5×108ï¼ 1.9×106ï¼ and 1.1×105 tï¼ respectivelyï¼ and 8.5×108ï¼ 4.0×107ï¼ and 3.4×107 t by equivalent carbon dioxideï¼ totaling 9.2×108 t. CO2 was the main greenhouse gas in Guangdong Provinceï¼ accounting for 92.0% of the total emissions. Energy and indirect sources were the main emission sourcesï¼ accounting for 77.9% and 7.6%ï¼ respectivelyï¼ totaling 85.5%. Spatial distributions illustrated that most grids were greenhouse gas emissionsï¼ whereas some others were greenhouse gas sinksï¼ the greenhouse gas emissions were distributed mainly in the Pearl River Delta region and had certain characteristics of distribution along the road network and channels. The greenhouse gas grids of high emission were mainly the locations of high energy-consuming enterprises such as large power plantsï¼ steel millsï¼ and cement plants.
ABSTRACT
In this study, 127 light-duty gasoline cars and 10 light-duty gasoline trucks with different emission standards were selected to explore the influences of different conditions and vehicle parameters on the emission characteristics of carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (HC), and methane (CH4) using a portable emission measurement system based on a chassis dynamometer under acceleration simulation mode. The results showed that the gaseous pollutants of light-duty gasoline vehicles displayed a relatively lower emission rate under the idle condition, which accounted for only 22.9% and 25.8% of the emission rate at the accelerated condition and constant speed condition, respectively. The pollutant emission characteristics were closely related to the working conditions. The emission rates of CO2 and NOx in the accelerated condition were less than those at the constant speed condition, while the emission rates of CO, HC, and CH4 in the accelerated condition were higher than those at the constant speed condition. In the constant low-speed condition, the emission factors of CO2, CO, NOx, HC, and CH4 were 383.20, 2.98, 1.60, 0.14, and 0.03 g·km-1 for light-duty gasoline cars, respectively, and 360.66, 2.64, 1.61, 0.0055, and 0.0027 g·km-1 for light-duty gasoline trucks, respectively. Tighter emission standards have caused significant reductions in emissions. The emission factors of CO, NOx, HC, and CH4 could be decreased by 87.5%, 97.3%, 97.9%, and 86.4%, respectively, from China â to China â ¤. A non-linear relationship was found between the age, odometer, vehicle weight, and vehicular emissions. In addition, the engine displacement was positively correlated with vehicular emissions.
