Fuel mobile

Figure 32-3. Schematic representation of fuel mobilization during fasting. Catabolism of muscle proteins provides alanine for gluconeogenesis and glutamine for utilization by the gut and kidney, while branched chain amino acids are primarily oxidized within the muscle. Breakdown of adipocyte triacylglycerols provides glycerol and free fatty acids (not shown) the free fatty acids provide fuel for liver, muscle and most other peripheral tissues. The liver utilizes both alanine and glycerol to synthesize glucose which is required for the brain and for red blood cells (not shown). Adapted from Besser and Thirner (2002).

A comparistxi of TPH removal values obtained by leaching columns with water alone and with surfactant solution (Table VIII) shows that the only substantial increase in amounts of TPH remove was observed in the 26.2-m column (S-13) a dramatic decrease was observed in the 23.2-m column, and only slight differences were observed in the 6.3-m and 17.1-m columns. These results indicate that the use of surfactants 15 and 18 did not yield an improvement over using water alone, but surfactant 13 was quite successful in enhancing the diesel fuel mobilization. The generally poor performance of these surfactants is in contrast to the screening results (Table IV) and the results of other studies (6-9). 

All cells continuously use adenosine triphosphate (ATP) and require a constant supply of fuels to provide energy for ATP generation. Insulin and glucagon are the two major hormones that regulate fuel mobilization and storage. Their function is to ensure that cells have a constant source of glucose, fatty acids, and amino acids for ATP generation and for cellular maintenance (Fig. 26.1). 

Insulin is the major anabolic hormone. It promotes the storage of nutrients as glycogen in liver and muscle, and as triacylglycerols in adipose tissue. It also stimulates the synthesis of proteins in tissues such as muscle. At the same time, insulin acts to inhibit fuel mobilization. 

Another characteristic similar to A/ 100 is the Distribution Octane Number (DON) proposed by Mobil Corporation and described in ASTM 2886. The idea is to measure the heaviest fractions of the fuel at the inlet manifold to the CFR engine. For this method the CFR has a cooled separation chamber placed between the carburetor and the inlet manifold. Some of the less volatile components are separated and collected in the chamber. This procedure is probably the most realistic but less discriminating than that of the AJ 100 likewise, it is now only of historical interest. 

Mobile Source POUisiosi, yilcohol-Fueled Uehicle Fleet Test, 9th Interim ARB/MS-89-09, California Air Resources Board, El Monte, Calif., Nov. 1989. 

By selection of appropriate operating conditions, the proportion of coproduced methanol and dimethyl ether can be varied over a wide range. The process is attractive as a method to enhance production of Hquid fuel from CO-rich synthesis gas. Dimethyl ether potentially can be used as a starting material for oxygenated hydrocarbons such as methyl acetate and higher ethers suitable for use in reformulated gasoline. Also, dimethyl ether is an intermediate in the Mobil MTG process for production of gasoline from methanol. 

Metha.nol-to-Ga.soline, The most significant development in synthetic fuels technology since the discovery of the Fischer-Tropsch process is the Mobil methanol-to-gasoline (MTG) process (47—49). Methanol is efftcientiy transformed into C2—C q hydrocarbons in a reaction catalyzed by the synthetic zeoHte ZSM-5 (50—52). The MTG reaction path is presented in Figure 5 (47). The reaction sequence can be summarized as... 

American Petroleum Institute, Task Force EF-18 of the Committee on Mobile Source Emissions, Alcohols—A Technical Assessment of Their Application as Fuels, Publication Mo. 4261, API, New York, July 1976. 

Direct fuel appHcations of methanol have not grown as anticipated (see Alcohol fuels). It is used in small quantities in California and other locations, primarily for fleet vehicle operation. Large-scale use of methanol as a direct fuel is not anticipated until after the year 2000. Methanol continues to be utilised in the production of gasoline by the Mobil methanol-to-gasoline (MTG) process in New Zealand. A variant of this process has also been proposed to produce olefins from methanol. 

There are four principal ways ia which biomass is used as a reaewable eaergy resource. The first, and most common, is as a fuel used directiy for space and process heat and for cooking. The second is as a fuel for electric power generation. The third is by gasification iato a fuel used oa the site. The fourth is by coaversioa iato a Hquid fuel that provides the portabiUty aeeded for transportatioa and other mobile appHcations of energy. Figure 7 shows the varied pathways which can be followed to convert biomass feedstocks to useful fuels or electricity. 

If the source fingerprints, for each of n sources are known and the number of sources is less than or equal to the number of measured species (n < m), an estimate for the solution to the system of equations (3) can be obtained. If m > n, then the set of equations is overdetermined, and least-squares or linear programming techniques are used to solve for L. This is the basis of the chemical mass balance (CMB) method (20,21). If each source emits a particular species unique to it, then a very simple tracer technique can be used (5). Examples of commonly used tracers are lead and bromine from mobile sources, nickel from fuel oil, and sodium from sea salt. The condition that each source have a unique tracer species is not often met in practice. 

Mobil Oil Corporation has developed a process on a pilot scale that can successfully convert methanol into 96 octane gasoline. Although methanol can be used directiy as a transportation fuel, conversion to gasoline would eliminate the need to modify engines and would also eliminate some of the problems encountered using gasoline—methanol blends (see Alcohol fuels Gasoline and other motor fuels). 

Mobile sources therefore consist of many different types of vehicles, powered by engines using different cycles, fueled by a variety of products, and emitting varying amounts of both simple and complex pollutants. Table 6-4 includes the more common mobile sources. 

Fuel cells, which rely on electrochemical generation of electric power, could be used for nonpolluting sources of power for motor vehicles. Since fuel cells are not heat engines, they offer the potential for extremely low emissions with a higher thermal effidency than internal combustion engines. Their lack of adoption by mobile systems has been due to their cost, large size, weight, lack of operational flexibility, and poor transient response. It has been stated that these problems could keep fuel cells from the mass-produced automobile market until after the year 2010 (5). 

In the United States, in particular, recent legislation has mandated sweeping improvements to urban air quality by limiting mobile source emissions and by promoting cleaner fuels. The new laws require commercial and government fleets to purchase a substantial number of vehicles powered by an alternative fuel, such as natural gas, propane, electricity, methanol or ethanol. However, natural gas is usually preferred because of its lower cost and lower emissions compared with the other available alternative gas or liquid fuels. Even when compared with electricity, it has been shown that the full fuel cycle emissions, including those from production, conversion, and transportation of the fuel, are lower for an NGV [2]. Natural gas vehicles offer other advantages as well. Where natural gas is abundantly available as a domestic resource, increased use... 

The United States generates about 20 million metric tons of nitrogen oxides per year, about 40% of which is emitted from mobile sources. Of the 11 million to 12 million metric tons of nitrogen oxides that originate from stationary sources, about 30% is the result of fuel combustion in large industrial furnaces and 70% is from electric utility furnaces. 

Alternatives to coal and hydrocarbon fuels as a source of power have been sought with increasing determination over the past three decades. One possibility is the Hydrogen Economy (p, 40), Another possibility, particularly for secondary, mobile sources of power, is the use of storage batteries. Indeed, electric vehicles were developed simultaneously with the first intemal-combustion-cngined vehicles, the first being made in 1888. In those days, over a century ago, electric vehicles were popular and sold well compared with the then noisy, inconvenient and rather unreliable peU ol-engined vehicles. In 1899 an electric car held the world land-speed record at 105 km per hour. In the early years of this century, taxis in New York, Boston and Berlin were mainly electric there were over 20000 electi ic vehicles in the USA and some 10000 cars and commercial vehicles in London. Even today (silent) battery-powered milk delivery vehicles are still operated in the UK. These use the traditional lead-sulfuric acid battery (p. 371), but this is extremely heavy and rather expensive. 

Figure 12.22 SFC-GC analysis of aromatic fraction of a gasoline fuel, (a) SFC trace (b) GC ttace of the aromatic cut. SFC conditions four columns (4.6 mm i.d.) in series (silica, silver-loaded silica, cation-exchange silica, amino-silica) 50 °C 2850 psi CO2 mobile phase at 2.5 niL/min FID detection. GC conditions methyl silicone column (50 m X 0.2 mm i.d.) injector split ratio, 80 1 injector temperature, 250 °C earner gas helium temperature programmed, — 50 °C (8 min) to 320 °C at a rate of 5 °C/min FID detection. Reprinted from Journal of Liquid Chromatography, 5, P. A. Peaden and M. L. Lee, Supercritical fluid chromatography methods and principles , pp. 179-221, 1987, by courtesy of Marcel Dekker Inc.

Research, development and entrepreneurial activities are peiwasive, fueled by ever-growing demands for lighter, smaller and more powerful batteries with even more reliability and extended shelf life for industrial, automotive, military, business, medical, and home uses. Mobile communications, coiuput-... 

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