Alternative fuels from forest residues for passenger cars - an assessment under German framework conditions

Chapter 13 - Substitute Natural Gas and Fischer-Tropsch Synthesis

Elastomer Compatibility of Blends of Biodiesel and Fischer-Tropsch Diesel

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.

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.

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.

The middle distillate fuel produced from natural gas (NG) via the Fischer-Tropsch (FT) process has been proposed as a motor fuel for compression-ignition (CI) engine vehicles. FT diesel could help reduce U.S. dependence on imported oil. The U.S. Department of Energy (DOE) is evaluating the designation of FT diesel as an alternative motor fuel under the 1992 Energy Policy Act (EPACT). As part of this evaluation, DOE has asked the Center for Transportation Research at Argonne National Laboratory to conduct an assessment of well-to-wheels (WTW) energy use and greenhouse gas (GHG) emissions of FT diesel compared with conventional motor fuels (i.e., petroleum diesel). For this assessment, we applied Argonne's Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) model to conduct WTW analysis of FT diesel and petroleum diesel. This report documents Argonne's assessment. The results are presented in Section 2. Appendix A describes the methodologies and assumptions used in the assessment.

Oil consumption and import of China increase very quickly in recent years. Because of vehicle population growing in a tremendous speed, nearly 40% of oil has already used in transportation sector in today's China. Many kinds of alternative fuel vehicles are introduced, demonstrated and used in cities to reduce the traditional gasoline and diesel not only to reduce the regulated emissions, but also to improve the oil security of China. When the Kyoto Protocol became effective in last year, Chinese government and experts began to focus on greenhouse gas (GHG) emissions of alternative vehicle fuels. In order to comprehensively evaluating energy and global warming impact lead by production and utilization of alternative vehicle fuels in China, Well-to-Wheel analysis is used in this paper to quantitatively calculate energy use and GHG emissions of recovery, production, transportation and distribution, and end-use of compressed natural gas (CNG), liquefied petroleum gas (LPG), ethanol, methanol, dimethyl ether (DME) and Fischer-Tropsch diesel (FTD). The feedstock of ethanol includes corn and wheat. The energy use and GHG emissions of alternative vehicle fuels are compared with traditional gasoline and diesel. The results show that CNG and LPG is good choice from energy saving and GHG reduction in China. NG-based and coal-based methanol, DME and F-T diesel have lower lifecycle petroleum consumption than traditional gasoline and diesel, so that they may be an answer to Chinese oil security. The lifecycle total energy use, fossil energy use and GHG emissions of NG-based synthesized fuels are lower than coal-based fuels, but obviously higher than traditional gasoline and diesel, so that utilization of them will lead to potential pressure to China GHG reduction responsibility. The GHG emissions performance of China ethanol fuel is not as good as U.S. ethanol. The main reason is abuse of agriculture chemical in corn farming, especial the nitrogenous fertilizer, which is caused great N20 emission

Effects of different agricultural organic wastes on soil GHG emissions: During a 4-year field measurement in the North China Plain

Global warming and fossil fuel depletion have necessitated alternative sources of energy. Biomass is a promising fuel source because it is renewable and can be carbon negative, even without carbon capture and storage. This study considers biomass as a clean, renewable source for transportation fuels. An Aspen Plus process simulation model was built of a biomass gasification biorefinery with Fischer-Tropsch (FT) synthesis of liquid fuels. A GaBi life cycle assessment model was also built to determine the environmental impacts using a cradle-to-grave approach. Three different product pathways were considered: Fischer-Tropsch synthetic diesel, hydrogen, and electricity. An offgas autothermal reformer with a recycle loop was used to increase FT product yield. Different configurations and combinations of biorefinery products are considered. The thermal efficiency and cost of production of the FT liquid fuels are analyzed using the Aspen Plus process model. The greenhouse gas emissions, profitability, and mileage per kg biomass were compared. The mileage traveled per kilogram biomass was calculated using modern (2019–2021) diesel, electric, and hydrogen fuel cell vehicles. The overall thermal efficiency was found to be between 20 and 41% for FT fuels production, between 58 and 61% for hydrogen production, and around 25–26% for electricity production for this biorefinery. The lowest production costs were found to be $3.171/gal of FT diesel ($24.304/GJ), $1.860/kg of H 2 ($15.779/GJ), and 13.332¢/kWh for electricity ($37.034/GJ). All configurations except one had net negative carbon emissions over the life cycle of the biomass. This is because carbon is absorbed in the trees initially, and some of the carbon is sequestered in ash and unconverted char from the gasification process, furthermore co-producing electricity while making transportation fuel offsets even more carbon emissions. Compared to current market rates for diesel, hydrogen, and electricity, the most profitable biorefinery product is shown to be hydrogen while also having net negative carbon emissions. FT diesel can also be profitable, but with a slimmer profit margin (not considering government credits) and still having net negative carbon emissions. However, our biorefinery could not compete with current commercial electricity prices in the US. As oil, hydrogen, and electricity prices continue to change, the economics of the biorefinery and the choice product will change as well. For our current biorefinery model, hydrogen seems to be the most promising product choice for profit while staying carbon negative, while FT diesel is the best choice for sequestering the most carbon and still being profitable.

Optical diagnosis on combustion characteristics and flame development process of Fischer-Tropsch diesel/biodiesel blends

The production of six regionally important cellulosic biomass feedstocks, including pine, eucalyptus, unmanaged hardwoods, forest residues, switchgrass, and sweet sorghum, was analyzed using consistent life cycle methodologies and system boundaries to identify feedstocks with the lowest cost and environmental impacts. Supply chain analysis models were created for each feedstock calculating costs and supply chain requirements for the production 453,592 dry tonnes of biomass per year. Cradle-to-gate environmental impacts from these supply systems were quantified for nine mid-point indicators using SimaPro 7.2 LCA software. Conversion of grassland to managed forest for bioenergy resulted in large reductions in GHG emissions, due to carbon sequestration associated with direct land use change. However, converting forests to energy cropland resulted in large increases in GHG emissions. Production of forest-based feedstocks for biofuels resulted in lower delivered cost, lower greenhouse gas (GHG) emissions and lower overall environmental impacts than the studied agricultural feedstocks. Forest residues had the lowest environmental impact and delivered cost per dry tonne. Using forest-based biomass feedstocks instead of agricultural feedstocks would result in lower cradle-to-gate environmental impacts and delivered biomass costs for biofuel production in the southern U.S.

The impact of uncertainties on predicted greenhouse gas emissions of dairy cow production systems

Characterisation of the Injection-Combustion Process in a Common Rail D.I. Diesel Engine Running with Sasol Fischer-Tropsch Fuel

Efficiency Potential of Solar Thermochemical Reactor Concepts with Ecological and Economical Performance Analysis of Solar Fuel Production

Energy and greenhouse gas balance of the use of forest residues for bioenergy production in the UK