The energy efficiencies of various fuel production pathways from well to pump. The efficiencies shown are defined as the energy in a given fuel (available at pumps in vehicle refueling stations) divided by total energy inputs during all Well-to-Pump activities, including the energy content of the fuel. One way to interpret the Well-to-Pump efficiencies in the figure is as the difference between 100% and the energy efficiencies, which roughly represent energy losses during Well-to-Pump stages for making a given fuel available at the pump. As stated in Section 3, Well-to-Pump activities include biomass feedstock production; feedstock transportation and storage; fuel production; and fuel transportation, storage, and distribution. (more…)
The combination of well-to-pump results and the energy use and emissions associated with vehicle operation (also called the pum ...
It shows Well-to-Wheels Greenhouse Gas emissions of the 23 vehicle/fuel systems. For each system, the bottom bar represents CO2 ...
Because different studies have different system boundaries and parametric assumptions, the studies described in Section 7 resulted ...
There are different types of vehicle propulsion systems and the transportation fuels that have been studied for their potential ...
At present, in the United States and worldwide, motor vehicles are fueled almost exclusively by petroleum based gasoline (or re ...
For processes that produce multiple products, energy and emission burdens have to be allocated to individual products. ISO 14040 advocates reducing the need to allocate by expanding the system boundary. That is, when comparing two systems, the system boundaries for both can be expanded so that all products from both systems are within a newly expanded single system. In transportation FCAs, the system boundary expansion is also called the displacement method. (more…)
ISO document 14040 identifies four areas for using life cycle analysis (LCA) results: (1) identifying opportunities to improve ...
Because different studies have different system boundaries and parametric assumptions, the studies described in Section 7 resulted ...
The spark-ignition and compression-ignition engine and internal combustion engines technologies that are currently employed in ...
All of today’s hydrogen conversion products, demonstration models, and prototypes possess some deficiencies; they cannot yet pr ...
The fuel cycle for a given transportation fuel includes the following processes: energy feedstock (or primary energy) product ...
The most widespread and practical process for capture solar radiation as organic fuels is the growth of virgin biomass. Extremely large quantities of carbon are fixed each year in the form of terrestrial and aquatic biomass. (more…)
Another large source of renewable carbon supplies is waste biomass. It consists of a wide range of materials and includes munic ...
Another large source of renewable carbon supplies is waste biomass. It consists of a wide range of materials and includes munic ...
The future development of energy crops, to the level at which they would replace residues as the major bioenergy fuel source, will ...
The hydrogen can come from various sources including fossil fuels, wind, solar, biomass, nuclear, solar thermo-chemical reactio ...
The accumulation of carbon within a forest growth cycle can be considered in four stages. The initial establishment stage involves ...
