Alternative Vehicle Fuels Strategy in China: Well-to-Wheel Analysis on Energy Use and Greenhouse Gases Emission

Fuel-Cycle Energy and Emissions Impacts of Propulsion System/Fuel Alternatives for Tripled Fuel-Economy Vehicles

Life-cycle analysis on energy consumption and GHG emission intensities of alternative vehicle fuels in China

Fuel-cycle greenhouse gas emissions from alternative fuels in Australian heavy vehicles

<div>The United States Environmental Protection Agency (US EPA) Greenhouse Gas (GHG) Phase 3 regulation targets a substantial reduction in GHG emissions across model year (MY) 2027–2032 class 2b-8 vehicles. This article explores the implementation of alternative fuels, such as compressed natural gas (CNG) and liquefied petroleum gas (LPG), along with powertrain hybridization as viable pathways for achieving these stringent standards in a cost-effective manner. A detailed analysis is performed on a Class-7 medium–heavy-duty (MHD) truck configuration, featuring an inline 4-cylinder 5.2-L spark-ignited (SI) engine, modeled with both CNG and LPG fuels. The vehicle’s powertrain is simulated to evaluate GHG emissions and fuel efficiency. The study further examines the impact of low rolling resistance (LRR) tires and varying tire rolling resistance coefficients (C<sub>rr</sub>) on vehicle performance. For further lowering the GHG emissions, a hybrid powertrain sizing study was performed. The simulation results indicate that hybrid powertrain configurations, when combined with LRR tires, can achieve significant CO<sub>2</sub> emission reductions, meeting and exceeding the US EPA Phase 3 GHG targets. The powertrain with the CNG engine equipped with fuel-saving technologies such as neutral-idle, engine start–stop, and automatic engine shutdown can comply with MY 2032 standards while running 7.7 N/kN C<sub>rr</sub> tires. The hybrid powertrain with the LPG engine and 5.6 N/kN C<sub>rr</sub> tires reaches compliance with MY 2032 fleet average standards while maintaining minimal payload penalties. This research provides critical insights into the feasibility of leveraging alternative fuels and hybrid technologies to meet upcoming GHG regulations, presenting a viable pathway for manufacturers to reduce operational costs while achieving environmental compliance.</div>

This report documents the development and use of the most recent version (Version 1.5) of the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The model, developed in a spreadsheet format, estimates the full fuel-cycle emissions and energy associated with various transportation fuels and advanced vehicle technologies for light-duty vehicles. The model calculates fuel-cycle emissions of five criteria pollutants (volatile organic compounds, carbon monoxide, nitrogen oxides, particulate matter with diameters of 10 micrometers or less, and sulfur oxides) and three greenhouse gases (carbon dioxide, methane, and nitrous oxide). The model also calculates total energy consumption, fossil fuel consumption, and petroleum consumption when various transportation fuels are used. The GREET model includes the following cycles: petroleum to conventional gasoline, reformulated gasoline, conventional diesel, reformulated diesel, liquefied petroleum gas, and electricity via residual oil; natural gas to compressed natural gas, liquefied natural gas, liquefied petroleum gas, methanol, Fischer-Tropsch diesel, dimethyl ether, hydrogen, and electricity; coal to electricity; uranium to electricity; renewable energy (hydropower, solar energy, and wind) to electricity; corn, woody biomass, and herbaceous biomass to ethanol; soybeans to biodiesel; flared gas to methanol, dimethyl ether, and Fischer-Tropsch diesel; and landfill gases to methanol. This report also presents the results of the analysis of fuel-cycle energy use and emissions associated with alternative transportation fuels and advanced vehicle technologies to be applied to passenger cars and light-duty trucks.

The greenhouse gas (GHG) emissions reduction potentials of various near- and long-term transportation technologies were estimated. The estimated per-travel-distance GHG emissions results indicate that alternative transportation fuels and advanced vehicle technologies can help to significantly reduce transportation-related GHG emissions. Of the near-term technologies evaluated, electric vehicles, hybrid electric vehicles, compression-ignition, direct-injection vehicles, and E85 (85 percent ethanol and 15 percent gasoline) flexible-fuel vehicles can reduce fuelcycle GHG emissions by more than 25 percent on a fuel-cycle basis. Electric vehicles powered by electricity generated primarily from nuclear and renewable sources can reduce GHG emissions by 80 percent. Other alternative fuels (such as compressed natural gas and liquefied petroleum gas) offer limited, but positive, GHG emissions reduction benefits. Among the long-term technologies evaluated, conventional sparkignition and compression-ignition engines powered by alternative fuels and gasoline- and diesel-powered advanced vehicles can reduce GHG emissions by 10 to 30 percent. Dedicated ethanol vehicles, electric vehicles, hybrid electric vehicles, and fuel-cell vehicles can reduce GHG emissions by more than 40 percent. Spark-ignition engines and fuel-cell vehicles powered by cellulosic ethanol and solar hydrogen (for fuel-cell vehicles only) can reduce GHG emissions by over 80 percent. In conclusion, both near- and long-term alternative fuels and advanced transportation technologies can play a role in reducing GHG emissions from the transportation sector.

Evaluating automobile fuel/propulsion system technologies

Cropping system diversification can reduce the negative environmental impacts of agricultural production, including soil erosion and nutrient discharge. Less is known about how diversification affects energy use, climate change, and air quality, when considering farm operations and supply chain activities. We conducted a life cycle study using measurements from a nine-year Iowa field experiment to estimate fossil energy (FE) use, greenhouse gas (GHG) emissions, PM2.5-related emissions, human health impacts, and other agronomic and economic metrics of contrasting crop rotation systems and herbicide regimes. Rotation systems consisted of 2-year corn-soybean, 3-year corn-soybean-oat/clover, and 4-year corn-soybean-oat/alfalfa-alfalfa systems. Each was managed with conventional and low-herbicide treatments. FE consumption was 56% and 64% lower in the 3-year and 4-year rotations than in the 2-year rotation, and GHG emissions were 54% and 64% lower. Diversification reduced combined monetized damages from GHG and PM2.5-related emissions by 42% and 57%. Herbicide treatment had no significant impact on environmental outcomes, while corn and soybean yields and whole-rotation economic returns improved significantly under diversification. Results suggest that diversification via shifting from conventional corn-soybean rotations to longer rotations with small grain and forage crops substantially reduced FE use, GHG emissions, and air quality damages, without compromising economic or agronomic performance.

In December 2009, China government has officially announced, for the first time, a voluntary quantitative target of controlling its carbon dioxide emissions, which is to cut the carbon dioxide intensity (kg CO2 per GDP) by 40%~45% by the year 2020 (relative to the level of 2005). Transportation is one of the major sources of carbon dioxide emissions resulting from fossil fuel utilizations all over the world. In 2008 carbon dioxide emissions caused by transportation fuel combustion accounted for about 8% of the national total in China (Yang, 2011). This percentage is far behind some advanced economies, such as 33% in United States in 2004, 26% in Europe in 2004 (Wallington, 2008), and so forth. In either developing countries or developed countries road sector is responsible for approximate 80% of total carbon dioxide emissions resulting from transportation (Yang, 2011; Wallington, 2008), which indicates that road transportation has been playing a significant role in reducing transportation carbon dioxide emissions now and in the future. Compared with 824 vehicles per 1,000 people in United States in 2008 and 608 vehicles per 1,000 people in Japan in 2009, there were only about 68 vehicles per 1,000 people in China in 2010. It is clear that China’s vehicle population will be twice as many as present level when the vehicle ownership is doubled and meanwhile the national population is sustained. As an emerging economy, this situation will probably happen in next 5~10 years. Without revolutionary change of transportation system, the consequent carbon dioxide emissions from road transportation will possibly be doubled as well. It can be predicted that transportation sector would become one of the fastest growing sources of carbon dioxide emissions in China in next several decades. Thus, a low carbon transport system is expected to be proposed soon as a potential solution to addressing the conflict between the development of transportation and economy and the mitigation of climate change. In response to concerns over establishing the low carbon transport system and meeting the increasing domestic petroleum demand, interest in developing advanced vehicle technologies and alternative vehicle fuels has risen considerably in past ten years. Many research and demonstration programs of various technologies were supported by Chinese government, including light-duty vehicles (LDVs) using methanol (M85) and ethanol (E10), buses and taxies using liquefied petroleum gas (LPG), compressed natural gas (CNG), and liquefied natural gas (LNG), passenger cars and buses using dimethylether (DME), passenger cars using diesel, and so forth. Ethanol gasoline (E10) has been put into mandatory use since 2003 in five Chinese provinces (Jilin, Hei Longjiang, Henan, Anhui,

Evaluation of alternative fuels for light-duty vehicles in Iran using a multi-criteria approach

This study performed technoeconomic and life-cycle analyses to assess the economic feasibility and emission benefits and tradeoffs of various biofuel production pathways as an alternative to conventional marine fuels. We analyzed production pathways for (1) Fischer-Tropsch diesel from biomass and cofeeding biomass with natural gas or coal, (2) renewable diesel via hydroprocessed esters and fatty acids from yellow grease and cofeeding yellow grease with heavy oil, and (3) bio-oil via fast pyrolysis of low-ash woody feedstock. We also developed a new version of the Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) marine fuel module for the estimation of life-cycle greenhouse gas (GHG) and criteria air pollutant (CAP) emissions of conventional and biobased marine fuels. The alternative fuels considered have a minimum fuel selling price between 2.36 and 4.58 $/heavy fuel oil gallon equivalent (HFOGE), and all exhibit improved life-cycle GHG emissions compared to heavy fuel oil (HFO), with reductions ranging from 40 to 93%. The alternative fuels also exhibit reductions in sulfur oxides and particulate matter emissions. Additionally, when compared with marine gas oil and liquified natural gas, they perform favorably across most emission categories except for cases where carbon and sulfur emissions are increased by the cofed fossil feedstocks. The pyrolysis bio-oil offers the most promising marginal CO2 abatement cost at less than $100/tonne CO2e for HFO prices >$1.09/HFOGE followed by Fischer-Tropsch diesel from biomass and natural gas pathways, which fall below $100/tonne CO2e for HFO prices >$2.25/HFOGE. Pathways that cofeed fossil feedstocks with biomass do not perform as well for marginal CO2 abatement cost, particularly at low HFO prices. This study indicates that biofuels could be a cost-effective means of reducing GHG, sulfur oxide, and particulate matter emissions from the maritime shipping industry and that cofeeding biomass with natural gas could be a practical approach to smooth a transition to biofuels by reducing alternative fuel costs while still lowering GHG emissions, although marginal CO2 abatement costs are less favorable for the fossil cofeed pathways.

Contribution Feedstock and Fuel Transportation to Total Fuel-Cycle Energy Use and Emissions

This study expands and uses the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model to assess the effects of carbon capture and storage (CCS) technology and cellulosic biomass and coal cofeeding in Fischer-Tropsch (FT) plants on energy use and greenhouse gas (GHG) emissions of FT diesel (FTD). To demonstrate the influence of the coproduct credit methods on FTD life-cycle analysis (LCA) results, two allocation methods based on the energy value and the market revenue of different products and a hybrid method are employed. With the energy-based allocation method, fossil energy use of FTD is less than that of petroleum diesel, and GHG emissions of FTD could be close to zero or even less than zero with CCS when forest residue accounts for 55% or more of the total dry mass input to FTD plants. Without CCS, GHG emissions are reduced to a level equivalent to that from petroleum diesel plants when forest residue accounts for 61% of the total dry mass input. Moreover, we show that coproduct method selection is crucial for LCA results of FTD when a large amount of coproducts is produced.

Global Warming Impact of Gasoline vs. Alternative Transportation Fuels

Energy-related activities are a major contributor of greenhouse gas (GHG) emissions. A growing body of knowledge clearly depicts the links between human activities and climate change. Over the last century the burning of fossil fuels such as coal and oil and other human activities has released carbon dioxide (CO2) emissions and other heat-trapping GHG emissions into the atmosphere and thus increased the concentration of atmospheric CO2 emissions. The main human activities that emit CO2 emissions are (1) the combustion of fossil fuels to generate electricity, accounting for about 37% of total U.S. CO2 emissions and 31% of total U.S. GHG emissions in 2013, (2) the combustion of fossil fuels such as gasoline and diesel to transport people and goods, accounting for about 31% of total U.S. CO2 emissions and 26% of total U.S. GHG emissions in 2013, and (3) industrial processes such as the production and consumption of minerals and chemicals, accounting for about 15% of total U.S. CO2 emissions and 12% of total ...