2010年中国机动车CH4和N2O排放清单

中国大部分机动车温室气体排放研究都集中于CO₂排放,对于CH₄和N₂O等排放的研究鲜见. 以中国机动车污染防治年报(2011年)、中国汽车工业年鉴(2011年)、中国统计年鉴(2011年)以及交通运输部发布的相关信息和数据(2011年)等为基础,结合文献调研和2008─2010年对北京、广州等国内10余座典型城市的实地调查结果,获得2010年我国机动车活动水平及排放特征. 基于上述基础信息,解析得到按不同车型、燃料和车龄分布的机动车保有量、年均行驶里程及排放因子,建立2010年中国机动车CH₄和N₂O排放清单. 结果表明:2010年中国机动车CH₄和N₂O排放量分别为23.90×104和6.01×104t,折算成CO₂分别为501.99×104和1862.51×104t. 不确定性分析则显示,中国CH₄排放量在18.21×104～27.52×104t之间,N₂O排放量在4.32×104～7.62×104t之间. 在机动车中,汽车CH₄和N₂O排放量最大,分担率(某车型污染物排放量占机动车排放总量的比例)分别为77.99%和94.22%,而摩托车和农用车排放分担率较小. 在各类汽车中,CH₄排放主要来源于轻型汽油车和天然气出租车,二者的排放分担率分别为47.98%和23.42%；N₂O排放则主要源于轻型汽油车,其分担率为73.09%. 因此,轻型汽油车是削减机动车CH₄和N₂O排放的重点车型,同时天然气出租车也应作为控制CH₄排放的主要车型. 

CH4and N2O Emission Inventory for Motor Vehicles in China in 2010

In China, most studies related to vehicular greenhouse gas (GHG) emissions have been focusing on CO_2emissions. In contrast, there are few studies on emission factors or total emissions of non-CO₂GHG such as CH_4and N₂O. To support the mitigation of non-CO₂GHG emissions, it is necessary to develop a reliable non-CO₂GHG emission inventory from motor vehicles in China based on solid investigation. The activity data and emission characteristics of motor vehicles in China in 2010were obtained from annual reports, yearbooks and information released by government, literature investigation and field survey of representative fleets over ten typical cities including Beijing, Guangzhou and Chongqing. Using the basic information, the vehicle population, annual mileage traveled and emission factors in the distribution of vehicle type, fuel and age were estimated to develop the CH_4and N₂O emission inventory for motor vehicles in 2010.The results showed that CH_4and N₂O emissions from motor vehicles were 23.90×10^4t (i.e., 501.99×10^4t CO₂) and 6.01×10^4t (i.e., 1862.51×10^4t CO₂), respectively, in 2010.Through the uncertainty analysis,CH_4and N₂O emissions ranged from 18.21×10⁴-27.52×10^4t and 4.32×10⁴-7.62×10^4t. Automobiles were the greatest contributor to the vehicular CH₄and N₂O emissions, by sharing 77.99% and 94.22% of the total emissions, respectively. In comparison, the contribution of emissions from motorcycles and agricultural vehicles were much smaller. Among automobiles, the light-duty gasoline vehicles and natural gas powered taxis were the major sources of CH_4emission, sharing 47.98% and 23.42% of the total amount; and N₂O emissions mainly originated from the light-duty gasoline vehicles, which shared 73.09% of the total emissions. Therefore, the light-duty gasoline vehicles were the key fleet to cut vehicular CH_4and N₂O emissions, and natural gas powered taxis were also the major fleet to control CH_4emissions.