To measure the carbon emissions at each stage of buses throughout life cycle, this paper divided the life cycle of buses into process cycle and energy cycle. Considering the production, assembly, transportation, and recycling stages of each bus system, carried out research to obtain bus production data, combined the data provided by the company and GREET internal data, used Gabi to measure CO2 emissions of process cycle. Constructed a CO2 emissions measurement model that included the stages of energy extraction, production processing, transportation, and usage to estimate the energy cycle CO2 emissions of electric buses and diesel buses. The result shows that the CO2 emissions of electric buses are 39.2% higher than those of diesel buses during the process cycle. In the energy cycle, the CO2 emissions of electric buses are 14.2% lower than those of diesel buses. In a comprehensive life-cycle comparison, the CO2 emissions of electric buses are 9.73% lower than those of diesel buses.
工艺周期测算过程采用全生命周期评价法,根据本文的研究目标,测算步骤为:目标与范围的确定(系统边界)→清单分析→结果解释。借助全生命周期评价软件Gabi,结合调研获得的数据和GREET内部数据对公共汽车工艺周期各阶段的CO2排放量进行测算。对于能源周期,本文参考“井到轮”(Wells to wheels, WTW)评价原理,建立了公共汽车能源周期碳排放测算模型。WTW评价方法将能源周期划分为两个阶段:油井到油泵阶段(Wells-to-pump,WTP),油泵到车轮阶段(Pump-to-wheels,PTW)[11]。其中WTP阶段包括原材料的开采、运输以及燃料的生产、运输等;PTW为车辆运行过程的燃料消耗阶段[12]。
XiaoHong, DengZi-hao, RenYan-juan, et al. Urban transportation carbon emission prediction model strategies[J]. Journal of Chongqing Jiaotong University (Natural Science), 2023, 42(9): 85-92, 98.
[3]
BiekerG. A global comparison of the life-cycle greenhouse gas emissions of combustion engine and electric passenger cars[J]. Washington D.C.: Communications, 2021, 49(30): 847129-102.
[4]
WongE Y C, HoD C K, SoS, et al. Life cycle assessment of electric vehicles and hydrogen fuel cell vehicles using the greet model—a comparative study[J]. Sustainability, 2021, 13(9): 4872.
WangXue-ran, LiuWen-feng, ZhangLong-wen, et al. CO2 emission reduction effect of electric bus based on energy chain in life cycle[J]. Journal of Transportation Systems Engineering and Information Technology,2019(1): 19-25.
SongDa-feng, WuXi-tao, ZengXiao-hua, et al. Life cycle cost analysis of mild hybrid heavy truck based on theoretical fuel consumption mode[J]. Journal of Jilin University (Engineering and Technology Edition), 2018, 48(5): 1313-1323.
WangTong, DuYi-qun, ChenYi-song, et al. Life cycle assessment of city bus body based on structural lightweighting[J]. Automotive Engineering, 2022(5): 778-788.
TianCheng-shi, ZhangShi-ya. Source decomposition analysis of carbon footprint in China's industry supply chain: based on IO-LCA model[J]. Journal of Environmental Economics, 2019, 4(2): 58-75.
[13]
HarrisA, SobanD, SmythB M, et al. Assessing life cycle impacts and the risk and uncertainty of alternative bus technologies[J]. Renewable and Sustainable Energy Reviews, 2018, 97: 569-579.
[14]
ChangC C, LiaoY T, ChangY W. Life cycle assessment of alternative energy types-including hydrogen-for public city buses in Taiwan[J]. International Journal of Hydrogen Energy, 2019, 44(33): 18472-18482.
[15]
FerraoP, NhambiuJ. A comparison between conventional LCA and hybrid EIO-LCA: analyzing crystal giftware contribution to global warming potential[M]∥Handbook of Input-Output Economics in Industrial Ecology,Dordrecht: Springer Netherlands, 2009: 219-230.
Yu Da-li, Zhang Hong-shen, The life cycle analysis of energy consumption and emission of pure electric van and diesel van[J]. Acta Scientiae Circumstantiae, 2019(6): 2043-2052.
LiJuan, YangYan-ping, ChenYi-song. Comparative analysis on life cycle assessment between aluminum alloy and cast iron cylinder cover[J]. Chinese Journal of Environmental Engineering, 2015(11): 5642-5648.
ZhangLei, LiuZhi-feng, WangJin-jing. Comparative analysis of life cycle environmental impact between power system of electric and internal combustion engine vehicles[J]. Acta Scientiae Circumstantiae. 2013(3): 931-940.
[26]
程冬茹. 汽柴油全生命周期碳排放计算[D]. 北京: 中国石油大学化学工程与环境学院, 2016.
[27]
ChengDong-ru. Carbon emissions calculation of gasoline and diesel fuel based on life cycle assessment[D]. Beijing: College of Chemical Engineering and Environment, China University of Petroleum, 2016.
Xun-minOu, ZhangXi-liang. Fossil energy consumption and GHG emissions of final energy by LCA in China[J]. China Soft Science,2009(Sup.2): 208-214.
[30]
OuX M, YanX Y, ZhangX L. Life-cycle energy consumption and greenhouse gas emissions for electricity generation and supply in China[J]. Applied Energy, 2011, 88(1): 289-297.
JingXiao-yan. Research on energy consumption analysis and energy saving optimization of natural gas purification system[D]. Xi´an: College of Chemistry and Chemical Engineering, Xi´an Shiyou University,2019.