MacLean Heather L, Lave Lester B, Lankey Rebecca, Joshi Satish
a Department of Civil Engineering , University of Toronto , Toronto , Ontario , Canada.
b Graduate School of Industrial Administration , Carnegie Mellon University , Pittsburgh , Pennsylvania , USA.
J Air Waste Manag Assoc. 2000 Oct;50(10):1769-1779. doi: 10.1080/10473289.2000.10464209.
We examine the life cycles of gasoline, diesel, compressed natural gas (CNG), and ethanol (CHOH)-fueled internal combustion engine (ICE) automobiles. Port and direct injection and spark and compression ignition engines are examined. We investigate diesel fuel from both petroleum and biosources as well as CHOH from corn, herbaceous bio-mass, and woody biomass. The baseline vehicle is a gasoline-fueled 1998 Ford Taurus. We optimize the other fuel/powertrain combinations for each specific fuel as a part of making the vehicles comparable to the baseline in terms of range, emissions level, and vehicle lifetime. Life-cycle calculations are done using the economic input-output life-cycle analysis (EIO-LCA) software; fuel cycles and vehicle end-of-life stages are based on published model results. We find that recent advances in gasoline vehicles, the low petroleum price, and the extensive gasoline infrastructure make it difficult for any alternative fuel to become commercially viable. The most attractive alternative fuel is compressed natural gas because it is less expensive than gasoline, has lower regulated pollutant and toxics emissions, produces less greenhouse gas (GHG) emissions, and is available in North America in large quantities. However, the bulk and weight of gas storage cylinders required for the vehicle to attain a range comparable to that of gasoline vehicles necessitates a redesign of the engine and chassis. Additional natural gas transportation and distribution infrastructure is required for large-scale use of natural gas for transportation. Diesel engines are extremely attractive in terms of energy efficiency, but expert judgment is divided on whether these engines will be able to meet strict emissions standards, even with reformulated fuel. The attractiveness of direct injection engines depends on their being able to meet strict emissions standards without losing their greater efficiency. Biofuels offer lower GHG emissions, are sustainable, and reduce the demand for imported fuels. Fuels from food sources, such as biodiesel from soybeans and CHOH from corn, can be attractive only if the co-products are in high demand and if the fuel production does not diminish the food supply. CHOH from herbaceous or woody biomass could replace the gasoline burned in the light-duty fleet while supplying electricity as a co-product. While it costs more than gasoline, bioethanol would be attractive if the price of gasoline doubled, if significant reductions in GHG emissions were required, or if fuel economy regulations for gasoline vehicles were tightened.
我们研究了汽油、柴油、压缩天然气（CNG）和乙醇（CHOH）燃料的内燃机（ICE）汽车的生命周期。对进气道喷射和直接喷射以及火花点火和压缩点火发动机进行了研究。我们调查了来自石油和生物源的柴油以及来自玉米、草本生物质和木质生物质的CHOH。基准车辆是一辆1998年的汽油燃料福特金牛座。作为使车辆在续航里程、排放水平和车辆寿命方面与基准车辆具有可比性的一部分，我们针对每种特定燃料优化了其他燃料/动力总成组合。生命周期计算使用经济投入产出生命周期分析（EIO-LCA）软件完成；燃料循环和车辆报废阶段基于已发表的模型结果。我们发现，汽油车辆的最新进展、低油价以及广泛的汽油基础设施使得任何替代燃料都难以实现商业可行性。最具吸引力的替代燃料是压缩天然气，因为它比汽油便宜，受管制的污染物和有毒物质排放量更低，温室气体（GHG）排放量更少，并且在北美大量供应。然而，车辆要达到与汽油车辆相当的续航里程所需的储气罐的体积和重量需要对发动机和底盘进行重新设计。大规模使用天然气进行运输需要额外的天然气运输和配送基础设施。柴油发动机在能源效率方面极具吸引力，但对于这些发动机能否满足严格的排放标准，即使使用重新配方的燃料，专家们也存在分歧。直接喷射发动机的吸引力取决于它们能否在不损失更高效率的情况下满足严格的排放标准。生物燃料温室气体排放量更低，具有可持续性，并减少对进口燃料的需求。来自食物来源的燃料，如大豆生物柴油和玉米CHOH，只有在副产品需求旺盛且燃料生产不减少食物供应的情况下才具有吸引力。来自草本或木质生物质的CHOH可以替代轻型车队燃烧的汽油，同时作为副产品供电。虽然它的成本高于汽油，但如果汽油价格翻倍、需要大幅减少温室气体排放或收紧汽油车辆的燃油经济性法规，生物乙醇将具有吸引力。
