生命周期方法在天然气基汽车燃料评价中的运用

运用生命周期评价方法,对以天然气为原料生产压缩天然气、甲醇、二甲醚、柴油4种汽车代用燃料系统进行生命周期的能源、环境和经济评价,评价结果是：压缩天然气系统生命周期内的能耗相对少,总成本相对低,对生态环境更友好,压缩天然气是富含天然气地区一段时期内汽车代用燃料的优先选择．     

政府-企业-居民协同共治的道路交通碳交易机制

根据道路交通碳排放的影响机理,提出同时把上游燃料供应企业、中游汽车生产企业、下游汽车使用者同时作为道路交通碳交易的责任主体,设计了政府-企业-居民协同共治的道路交通碳交易机制,包括碳配额总量设定、初始碳配额分配、行业基准设定、履约考核、市场交易以及监测报告核查等制度.通过案例与情景分析揭示了道路交通碳交易的多主体协同作用机理：在政府对于碳配额总量和行业基准的调控下,燃料供应企业将通过改变燃料成分来降低燃料排放因子;汽车生产企业将通过提高汽车燃油经济性和新能源汽车比例来降低汽车能耗强度;汽车使用者将通过减少车辆行驶里程降低交通需求或者购买使用新能源汽车.本文所提出的政府-企业-居民协同共治的道路交通碳交易机制,可以分别从上游、中游、下游促进道路交通碳排放的3个关键影响因素——燃料排放因子、汽车能耗强度、交通活动需求协同优化,能够有效控制道路交通温室气体排放增长,进而加速“碳达峰”的实现和“碳中和”的转型.     

中国道路交通二氧化碳排放达峰路径研究

为研究我国道路交通行业CO₂排放未来控制路径,结合未来经济社会和货物运输发展状况、运输结构、能源结构和能效结构变化,采用行驶里程法分析了我国道路交通CO₂排放现状、未来变化趋势及主要驱动因素. 结果表明:①采用行驶里程法计算道路交通行业CO₂排放量相对合理,2019年全国汽车CO₂排放量为9.52×108 t,比油耗法所得结果高20%左右,二者存在差异的主要原因为交通油耗统计数据偏低. ②从车型看,重型货车和小型客车是汽车CO₂排放的主要来源,分别占39.7%、38.2%;从燃料种类看,汽油、柴油、其他燃料(天然气、醇类燃料等)CO₂排放量分别占42.8%、52.5%、4.7%. ③道路交通CO₂排放预计于“十五五”末达峰,峰值在12.2×108～13.9×108 t之间,达峰后有2～3年的平台期. ④推广新能源车是道路交通CO₂排放控制的主要驱动因素,其次为能效提升,运输结构调整在前期有一定的贡献,2025年上述措施对道路交通CO₂减排量占比分别为56%、34%和10%左右,2030年分别为55%、40%和5%左右. 研究显示,加大新能源汽车推广力度,持续降低新生产燃油车碳排放强度,推进运输结构调整,可有效降低道路交通CO₂排放.      

天然气-汽油双燃料车实际道路排放特性研究

为研究使用天然气对轻型汽车排放的影响,利用便携式排放测试系统（PEMS）,对25辆压缩天然气-汽油双燃料出租车在实际道路上分别使用汽油和天然气时的CO2、CO、NOx和THC排放进行了对比测试.研究结果表明：实际道路上,原装车使用天然气相比汽油时,CO2、CO的排放平均分别降低22%和24%,NOx和THC的排放平均分...     

轻型车NH_3排放实验研究

用傅里叶变换紫外光谱法对4辆不同里程、不同排量、不同排放标准的轻型车NH_3排放进行测量,试验车辆包括2辆双燃料出租车。实验结果表明:里程数越高的车辆,在同一个测试循环中产生的NH_3排放越多;在高速工况下,车辆产生的NH_3要高于在低速工况时;在循环中车辆加速过程产生的NH_3浓度较高;对于天然气燃料车辆,市区运转工况下基本上没有NH_3排放,在城郊运转工况下产生的NH_3要多于用汽油燃料时。     

基于LCA的新能源轿车节能减排效果分析与评价

新能源汽车在行驶过程中具有节能、环保等优点,在我国目前汽车保有量激增、能耗总量和温室气体排放量不断增大,城市交通对城市空气污染贡献日益增加的情况下,应用和推广新能源汽车被视为替代传统汽车、减缓环境危害的重要工具,但其生产阶段的能耗及污染问题同样不容忽视.因此,本研究运用生命周期评价(LCA)方法,选用美国阿贡国家实验室开发的GREET模型,对混合动力轿车、纯电动轿车、氢燃料电池轿车、E10乙醇汽油轿车4类新能源轿车在车辆制造、燃料及电力生产、行驶、拆解4个阶段的能耗及主要大气污染物排放进行了分析计算,并与传统汽油轿车进行比较.结果表明,同传统汽油轿车相比,4种新能源轿车的全生命周期能耗有不同程度的降低,其中,纯电动轿车在降低能耗方面最具优势.同时,4种新能源轿车全生命周期综合环境影响均低于传统汽油轿车,其中以氢燃料电池轿车的综合环境影响最小.     

汽油车技术发展对尾气排放影响研究进展

近年来,汽油车尾气排放已成为城市大气污染的主要来源之一.为减少油耗、温室气体和大气污染物的排放,汽油直喷技术(GDI)、醇类燃料替代以及混合动力系统等新兴技术被应用到汽车产品中,该研究对GDI发动机汽车、醇类燃料车和混合动力车的颗粒物(PM)、氮氧化物(NO_x)、总碳氢化合物(THC)的排放研究进行梳理和总结,综合评估先进动力技术和醇类燃料的环境影响.结果表明:GDI汽油车的PM排放因子为进气道喷射(PFI)汽油车的1.2~5倍,加装汽油颗粒物捕集器(GPF)后GDI汽油车的PM排放大幅下降,同时具备催化能力的GPF可减少NO_x和THC排放.与汽油车相比,乙醇燃料车PM排放量减少了35%~56%,尾气THC排放减少了10%~44%,但挥发性有机物(VOCs)蒸发排放增加了20%~41%,其主要来自于日呼吸损失.各类型车辆的NO_x排放差异较小,比较结果存在一定的不确定性.混合动力车相比传统内燃机汽车污染物减排优势明显,可积极推广其在公共交通和私家车队中的应用.建议今后研究应着重关注以下几个方面:①GDI和混合动力车在实际条件下排放污染物的环境影响;②醇类燃料车VOCs蒸发排放控制技术及相关法规标准的完善;③新兴技术汽油车排放污染物的生成机理及其影响因素.      

不同负荷CNG/汽油两用燃料电控发动机排放物对环境影响研究

CNG/汽油两用燃料发动机的开发是交通运输领域解决能源危机和环境污染的问题最为便捷和有效的途径.基于一台4RB2电控汽油机加装顺序喷射天然气系统,在完成动力性标定的基础上,开展了发动机在不同负荷CNG/汽油两种燃烧模式下,能量消耗和NOx、HC、CO等有害排放物对环境影响研究.结果发现,各测试负荷工况下,发动机燃用CNG的能耗比燃用汽油的低,NOx、HC、CO三种有害排放物亦优于汽油燃烧模式,说明了CNG作为点燃式发动机燃料对保护环境的优越性.     

On-board measurement of emissions from liquefied petroleum gas, gasoline and diesel powered passenger cars in Algeria

On-board measurements of unit emissions of CO,HC,NOx and CO2 were conducted on 17 private cars powered by different types of fuels including gasoline,dual gasoline–liquefied petroleum gas(LPG),gasoline,and diesel. The tests performed revealed the effect of LPG injection technology on unit emissions and made it possible to compare the measured emissions to the European Artemis emission model. A sequential multipoint injection LPG kit with no catalyst installed was found to be the most efficient pollutant reduction device for all of the pollutants,with the exception of the NOx. Specific test results for a sub-group of LPG vehicles revealed that LPG-fueled engines with no catalyst cannot compete with catalyzed gasoline and diesel engines. Vehicle age does not appear to be a determining parameter with regard to vehicle pollutant emissions. A fuel switch to LPG offers many advantages as far as pollutant emissions are concerned,due to LPG's intrinsic characteristics.However,these advantages are being rapidly offset by the strong development of both gasoline and diesel engine technologies and catalyst converters. The LPG's performance on a chassis dynamometer under real driving conditions was better than expected. The enforcement of pollutant emission standards in developing countries is an important step towards introducing clean technology and reducing vehicle emissions.     

Hydrogen and transportation: alternative scenarios

If hydrogen (H₂) is to significantly reduce greenhouse gas emissions and oil use, it needs to displace conventional transport fuels and be produced in ways that do not generate significant greenhouse gas emissions. This paper analyses alternative ways H₂ can be produced, transported and used to achieve these goals. Several H₂ scenarios are developed and compared to each other. In addition, other technology options to achieve these goals are analyzed. A full fuel cycle analysis is used to compare the energy use and carbon (C) emissions of different fuel and vehicle strategies. Fuel and vehicle costs are presented as well as cost-effectiveness estimates. Lowest hydrogen fuel costs are achieved using fossil fuels with carbon capture and storage. The fuel supply cost for a H₂ fuel cell car would be close to those for an advanced gasoline car, once a large-scale supply system has been established. Biomass, wind, nuclear and solar sources are estimated to be considerably more expensive. However fuel cells cost much more than combustion engines. When vehicle costs are considered, climate policy incentives are probably insufficient to achieve a switch to H₂. The carbon dioxide (CO₂) mitigation cost would amount to several hundred US$ per ton of CO₂. Energy security goals and the eventual need to stabilize greenhouse gas concentrations could be sufficient. Nonetheless, substantial development of related technologies, such as C capture and storage will be needed. Significant H₂ use will also require substantial market intervention during a transition period when there are too few vehicles to motivate widely available H₂ refueling.

氢燃料电池汽车动力系统生命周期评价及关键参数对比

发展氢燃料电池汽车被认为是解决能源安全和环境污染问题的理想解决方案之一,为量化探究氢燃料电池汽车动力系统的化石能源消耗和排放情况,运用GaBi软件建模,以新能源汽车相关技术路线为参考,构建我国氢燃料电池汽车动力系统的数据清单并对其全生命周期化石能源消耗和全球变暖潜值情况进行定量评价计算和预测分析,对不同类型的双极板、不同能量控制策略和不同制氢方式对环境的影响分别进行了对比研究,并对关键数据进行了不确定分析.结果表明,预计到2030年我国每台氢燃料电池汽车动力系统生命周期的化石能源消耗量（ADP_f）、全球变暖潜值（GWP,以CO₂ eq计）和酸化潜值（AP,以SO₂ eq计）分别为1.35×10⁵ MJ、9108 kg和15.79 kg.动力系统生产制造阶段的化石能源消耗和全球变暖潜值均高于使用阶段,主要原因是燃料电池堆栈和储氢罐的制造过程.金属双极板、石墨复合双极板和石墨双极板的制造工艺中石墨复合双极板的综合环境效益最好.能量控制策略的优化会使得氢能消耗降低,当氢能消耗降低22.8%时,动力系统的生命周期化石能源消耗和全球变暖潜值分别降低10.4%和8.3%.相比于甲烷蒸气重整制氢,基于混合电网电解水制氢的动力系统生命周期全球变暖潜值高出53.7%[KG-*6],而基于水电电解水制氢降低39.6%.降低动力系统生命周期化石能源消耗和全球变暖潜值的措施包括优化能量控制策略降低氢能消耗、规模化发展可再生能源发电电解水制氢产业和聚焦突破燃料电池堆栈关键技术实现性能提升.     

Energy modeling on cleaner vehicles for reducing CO2 emissions in Japan

This study is to evaluate the impact of cleaner vehicles on energy systems and CO₂ emissions in the transportation sector in Japan. The transportation sector has the characteristic of spending petroleum. Even when the cost of petroleum rises, conventional vehicles cannot switch fuels to alternative energy right away. Cleaner vehicles, such as fuel cell vehicles, would be one of the alternative technologies in the transportation sector. It is supposed to have excellent performance in fuel efficiency and has strong possibility to reduce CO₂ drastically. This paper uses a multi-period market equilibrium model to explore the impacts of cleaner vehicles on the passenger transportation sector in Japanese energy system out to the year 2040. A Btu tax is tentatively imposed to evaluate the effect of fuel cost on energy consumption in the transportation sector. Financial parameters such as capital cost and operating cost are considered to summarize the profit in taxation case. The result of this study shows that fuel cell vehicles have a great effect on reducing CO₂ emissions especially when Btu taxes are imposed, which in turn has the advantage of encouraging a more diverse set of technologies and fuels. The analysis that petroleum consumption can be reduced using fuel cell vehicles will have effects on perspectives on energy systems in Japan.     

Influence of fuel quality on vehicular NOx emissions

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汽车代用燃料及应用前景

介绍了已经开发使用的代用燃料氢气，甲醇，乙醇，新配方汽油，天然气，液化石油气，电动汽车等，并对代用燃料车和汽油车的环境安全性，成本，能耗消耗等方面作了比较，指出天然气，液化石油气是当前最有前途的代用燃料。     

Attributional life cycle assessment of woodchips for bioethanol production

Besides the apparent need to reduce greenhouse gas emissions, other important factors contributing to the renewed interest in biofuels are energy security concerns and the need of sustainable transportation fuel. Nearly 30% of the annual CO₂ emissions in the U.S. come from the transportation sector and more than half of the fuel is imported. Biofuels appear to be a promising option to reduce carbon dioxide emissions, and the reliance on imported oil concomitantly. The interest on (ligno) cellulosic ethanol is gaining momentum as corn-based ethanol is criticized for using agricultural outputs for fuel production. Among many lignocellulosic feedstocks, woodchips is viewed as one of the most promising feedstocks for producing liquid transportation fuels. The renewable and carbon neutral nature of the feedstocks, similar chemical and physical properties to gasoline, and the low infrastructure cost due to the availability of fuel flex vehicles and transportation networks make (ligno) cellulosic bioethanol an attractive option. An in-depth LCA of woodchips shows that harvesting and woodchips processing stage and transportation to the facility stage emit large amount of environmental pollutants compared to other life cycle stages of ethanol production. Our analysis also found that fossil fuel consumption and respiratory inorganic effects are the two most critical environmental impact categories in woodchips production. We have used Eco-indicator 99 based cradle-to-gate LCA method with a functional unit of 4 m³ of dry hardwood chips production.     

城市汽车年检碳排放数据挖掘及其应用研究

基于城市汽车年检中CO₂的过程动态检测数据,对小型汽油客车CO₂的排放因子和排放水平信息进行了挖掘,并与文献研究结果进行了对比.结果表明,从城市汽车年检数据中挖掘的CO₂排放结果可以作为研究城市机动车碳排放的重要参考依据;合理有效地利用汽车年检数据可以为城市车辆尾气排放的精准分级管控、城市交通运输碳排放达峰的量化分析,以及城市交通源的污染物和CO₂协同减排提供重要的数据支撑;从国Ⅰ到国Ⅴ不同排放阶段汽油车的常规污染物CO、NO_x和HC的排放水平下降非常明显,而对应的CO₂排放水平差异不大;CO₂排放因子随累计行驶里程、车龄、基准质量和排量的变化关系反映出,如果需要削减城市汽车碳排放水平,应鼓励使用基准质量小或者排量小的车辆,淘汰高油耗高排放的老旧车辆,鼓励公共绿色出行而降低单车活动水平,增加纯电动车辆优化车队能源结构.     

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.      

Optimal range of plug-in electric vehicles in Beijing and Shanghai

Both China’s national subsidy policies for plug-in electric vehicles (PEVs) purchasers and passenger cars corporate average fuel consumption and new vehicle credit regulation (dual-credit policy) favor long-range 300+ km battery electric vehicles (BEVs) and 80+ km plug-in hybrid electric vehicles (PHEVs). However, these electric vehicles tend to have lower energy efficiency and higher purchase and operation costs. Vehicle with larger batteries can also be less equitable because the subsidies are often provided to more expensive vehicles and wealthier owners. This study takes advantage of a novel dataset of daily driving data from 39,854 conventional gasoline vehicles in Beijing and 4999 PHEVs in Shanghai to determine the optimal range of BEVs and PHEVs within their respective cities. We simulate a model to explore ranges with which PEVs emit less GHGs than that of a baseline hybrid and conventional gasoline vehicle while ensuring that all daily travel demands are met. Our findings indicate that in both cities, the optimal ranges to balance cost and travel demand for BEVs are 350 km or less and for PHEVs are 60 km or less in Beijing and 80 km or less in Shanghai. We also find that to minimize carbon dioxide (CO₂) emissions, the ranges are even lower 10 km in Beijing and 30 km in Shanghai. Our study suggests that instead of encouraging long-range PEVs, governments should subsidize PEV models with shorter ranges. Parallel efforts should also be made to both increase renewable energy over fossil fuels and expand charging facilities. Although individual mobility demand varies, the government could reduce occasional long-distance driving by subsidizing alternative transportation choices. Providing week-long driving trials to consumers before their purchases may help decrease the demand of very long range PEVs by alleviating the range anxiety through a learning process.

     

含氧生物质燃料的生命周期评价

为公正评价汽车代用燃料的能耗与环境效益,运用生命周期评价方法,研究了在燃料中分别添加不同比例的乙醇和甲酯2种生物质,带来的生命周期能耗和污染物排放变化,并对含氧生物质燃料的未来情景进行了预测分析.结果表明:乙醇代用燃料未降低化石燃料消耗,甲酯代用燃料可降低约20%的化石燃料消耗;几种配比的代用燃料均可降低石油消耗,甲酯代用燃料降低的趋势更加明显;各种代用燃料的温室气体排放都比较严重;乙醇代用燃料增加了NO_x排放,而甲酯代用燃料可降低约50%的NO_x排放;乙醇和甲酯的加入均能降低车用阶段的PM₁₀排放;燃料生产阶段的SO₂排放在整个生命周期中约占80%,必须严格控制;甲酯代用燃料可降低VOC排放.     

低碳交通电动汽车碳减排潜力及其影响因素分析

交通运输是城市能源消耗和碳排放的重点行业,为通过节能减排实现低碳城市发展目标,传统汽油车向新能源汽车的转型是一项重要的举措,其中电动汽车因其节能减排的优势将在这次转型中发挥重要作用.在全面总结现有电动汽车节能减排研究成果的基础上,分析了影响电动汽车的减排因素,并应用燃料生命周期的理论,结合北京市的电动汽车推广计划,以纯电动汽车为例,采用改进的燃料碳排放模型,并设置6种情景分析了电动汽车的碳排放及其减排潜力,包括发电能源结构、车用燃料类型(单位燃料的CO2排放系数)、汽车类型(百公里能耗)、城市交通状况(时速)、煤电发电技术、电池类型(重量、能效)等因素对电动汽车减排潜力的影响.结果表明,改进后的模型能更科学测算燃料消耗碳排放;纯电动汽车具有明显的制约性碳减排潜力,在分析的6种影响因素中其波动幅度为57%～81.2%,其中,发电能源结构和煤电技术供电路线对电动汽车燃料生命周期碳减排空间起决定性作用,其减排空间分别可达78.1%及81.2%.最后从改善能源结构、提高煤电技术、推广节能技术、加快动力蓄电池研发、推广纯电动汽车等方面提出了推广电动汽车降低交通能耗和碳排放的优化措施,以期为低碳交通新能源汽车转型政策的制定提供科学依据和方法支撑.