Transportable energy

Coa.1 Reserves. As indicated in Table 2, coal is more abundant than oil and gas worldwide. Moreover, the U.S. has more coal than other nations U.S. reserves amount to about 270 biUion metric tons, equivalent to about 11 x 10 MJ (1 x 10 ° BTU = 6600 quads), a large number compared to the total transportation energy use of about 3.5 x lO " MJ (21 quads) per year (11). Methanol produced from U.S. coal would obviously provide better energy security benefits than methanol produced from imported natural gas. At present however, the costs of producing methanol from coal are far higher than the costs of producing methanol from natural gas. 

S. C. Davis and P. S. Hu, Transportation Energy Data Book Edition 1 /, ORNL-6649, Oak Ridge National Laboratories for Office of Transportation Technologies, U.S. Dept, of Energy, Washington, D.C., 1991. 

This intermediate role of the Gd " ions in transporting energy from the sensitizer to the activator was first demonstrated in a number of stoichiometric Gd " compounds (22). 

The term e/(e — 1), which appears in equations 1 and 2, was first developed to account for the sensible heat transferred by the diffusing vapor (1). The quantity S represents the group ratio of total transported energy to convective heat transfer. Thus it may be thought of as the fractional... 

Euture large gasification plants, intended to produce ca 7 x 10 m standard (250 million SCE) of methane per day, are expected to be sited near a coal field having an adequate water supply. It is cheaper to transport energy in the form of gas through a pipeline than coal by either rail or pipeline. The process chosen is expected to utilize available coal in the most economical manner. 

U.S. Department of Energy. (1998). Transportation Energy Data Book Edition 18. ORNL-6941. Oak Ridge, TN. Oak Ridge National Laboratoiy... 

Movement of freight accounts for one-third of all U.S. transportation energy consumption. But if the U.S. share of the export/import cargo shipping market was included, the figure would be even higher. 

Davis, S. C. (1997). Transportation Energy Databook 17, ORNL-6919. Oak Ridge, TN Oak Ridge National Laboratory. 

In the United States in 1997, transit accounted for a small fraction of transportation energy consumption, largely because it played such a small role in the total travel market, representing only 1.8 percent of trips. Transit accounted for only 0.7 percent of transportation energy consumption (bus 0.4%, rail 0.2%, and suburban rail 0.1%). 

Surface friction is a source of rail s advantages in transport energy efficiency. Under similar conditions, steel wheels on steel rail generate only abont 20 to 30 percent of the rolling friction that rubber wheels on pavement generate, both because rails are much smoother than paT. cnicnt and because steel wheels arc much more rigid than rubber tires, so steel wheels deform much less at the point of contact with the gi ound. Each rail wheel has only about 0.3 sq in of surface in contact with the rail, whereas an automobile... 

Gordon, D. (1991). Steering a New Course Transportation, Energy and the Environment. Washington, DC Island Press. 

Even without congestion, from the perspective of capital utilization and energy consutnptioti, automobile and roadway use is inefficient. First, the majority of personal transportation energy is consumed in moving personal vehicles that contain only one occupant and drive one or two hours a day. Second, the transportation infrastructure usually operates below capacity. States expend tremendous resources building highways to accommodate peak period demands (7 A.M. to 9 A.M. and 3 P.M. to 6 P.M.). Most of these lanes are not needed for the rest of the day. Rush hour... 

It is likely that the reliable crude oil supply will not diminish any time soon. Petroleum-derived fuels will remain the primary source of transportation energy for well into the twenty-first century. Producers and refiners have been, and will be, environmentally responsible. The existing infrastructure of advanced product distribution systems can compete with alternative fuels readily. Future fuels will be competitive, both economically and environmentally. New global market conditions will dictate closure of inefficient facilities and investment in new technology. Larger and more efficient operations will survive and will focus on the niche market. ... 

Transport occurring in the absence of another source of transport energy is termed passive transport. 

With active transport, energy is expended to move a substance against its concentration gradient from an area of low concentration to an area of high concentration. This process is used to accumulate a substance on one side of the plasma membrane or the other. The most common example of active transport is the sodium-potassium pump that involves the activity of Na+-K+ ATPase, an intrinsic membrane protein. For each ATP molecule hydrolyzed by Na+-K+ ATPase, this pump moves three Na+ ions out of the cell and two K+ ions into it. As will be discussed further in the next chapter, the activity of this pump contributes to the difference in composition of the extracellular and intracellular fluids necessary for nerve and muscle cells to function. 

Chemists and chemical engineers will need to join with experts in other disciplines to invent new ways to generate and transport energy for human use and provide for the needs and aspirations of a growing population in a sustainable manner. New ways will also be needed to minimize the energy used for human activities, including manufacturing. 

Oak Ridge National Laboratory, Transportation Energy Data Book Edition 26, Table 1.13 Consumption of Petroleum by End-Use Sector, 1973-2006, pp. 1-17, http //cta.oml.gov/data/ tedb26/ Edition26 Chapter01. pdf (2007). 

Each year the U.S. consumes almost 200 billion gallons of gasoline, diesel fuel and other transportation fuels for road travel. This is about 20% of total U.S. energy consumption. When travel by air, water, and rail is added, including pipelines energy, total transportation energy rises to almost 30% of U.S. energy consumption. 

Two thirds of today s oil use of more than 81 million barrel per day is for transportation, of which land transport for people accounts for some 55%, land transport for freight for some 35% and air transport for people and freight for around 10%. Almost 97% of road transport is fuelled by oil. The three most important targets with respect to transportation energy use, which are also increasingly favoured by policy makers around the world, are reduction of local air pollution, greenhouse gas-emissions reduction and energy security.1 As a consequence, there is an enforced search for alternative transport fuels. 

The HyWays project has concluded that hydrogen can reduce the C02 emissions from road transport by over 50% much of the remaining emissions come from goods transport where no hydrogen fuel was assumed (HyWays, 2007). In contrast, biofuels can only supply a fraction of today s transportation energy demand (6% to 15% within the EU), if the competing use of biomass in the stationary sector is taken into account (JEC, 2007) (see also Chapter 7). 

A variety of alternative fuels, including LPG, CNG, ethanol, methanol, as well as electricity, have been implemented on a small scale in the USA, but with limited success - the total number of alternative fuelled vehicles remains less than 1 % of the total fleet (Davis and Diegel, 2007). The largest alternative fuel used in the USA is ethanol derived from corn, which is currently blended with gasoline up to 10% by volume in some regions, and accounts for 3% of US transportation energy use. 

---